CN119098296A

CN119098296A - Spray nozzles for spraying target objects

Info

Publication number: CN119098296A
Application number: CN202411252109.4A
Authority: CN
Inventors: 王希; 冯建军; 徐琳菲; 周宇; 沈洁
Original assignee: Hangzhou Honghua Digital Technology Stock Co Ltd
Current assignee: Hangzhou Honghua Digital Technology Stock Co Ltd
Priority date: 2024-09-06
Filing date: 2024-09-06
Publication date: 2024-12-10
Anticipated expiration: 2044-09-06

Abstract

The present invention relates to a spray head for spraying a target object. The spray head comprises one or more spray head units, wherein each spray head unit comprises a liquid supply unit, a runner and one or more rows of capillary groups, the liquid supply unit is used for supplying liquid to the runner, the runner is communicated with a runner connecting port of each capillary in the capillary groups, each row of capillary groups comprises a plurality of capillaries, each capillary comprises a main body part, a runner connecting port and a liquid outlet, the runner connecting port and the liquid outlet are respectively arranged at two ends of the main body part, and the shape and the size of the liquid outlet are configured to enable the liquid to be sprayed to be continuously output from the liquid outlet. The invention has lower manufacturing cost, can avoid the discharge of flying liquid and improve the liquid spraying efficiency.

Description

Spray head for spraying target objects

Technical Field

The present invention relates generally to spray printing technology and, in particular, to spray heads for spraying of target objects.

Background

In existing spray heads, for example for coloring or spraying a target object (e.g. a fabric), a liquid to be sprayed (e.g. ink) is atomized for spraying on the target object, for example using ultrasonic atomization techniques. Since the atomization of the liquid to be sprayed requires additional energy consumption, and atomized droplets (e.g., ink droplets) that are not adhered to the target object require a coordinated absorbing means, the influence on the environment is reduced. The existing spray head based on the ultrasonic atomization technology has the technical advantages of saving a liquid to be sprayed, accurately and controllably spraying and printing patterns, and the like, but the existing spray head based on the ultrasonic atomization technology is high in manufacturing cost due to the fact that a transducer for realizing ultrasonic atomization and an absorption device for absorbing redundant atomized ink drops are required to be configured, and in addition, the efficiency of coloring or spraying the atomized liquid spray is poor.

In summary, the conventional spray head has the disadvantages of high manufacturing cost, and the problem of discharge of flying liquid (e.g., flying ink), and poor efficiency of spraying liquid (e.g., spraying ink).

Disclosure of Invention

The invention provides a spray head for spraying a target object, which has lower manufacturing cost, can avoid the discharge of flying liquid and improves the spraying efficiency.

According to a first aspect of the present invention, there is provided a spray head for spraying a target object, the spray head comprising one or more spray head units, each spray head unit comprising a liquid supply unit for supplying a liquid to be sprayed to a flow channel, the flow channel being in communication with a flow channel connection port of each capillary tube in the group of capillaries, and one or more rows of the groups of capillaries, each row of capillaries comprising a plurality of capillaries, each capillary tube comprising a body portion, a flow channel connection port and a liquid outlet, the flow channel connection ports and the liquid outlets being provided at respective two ends of the body portion, the liquid outlet being shaped and dimensioned such that the liquid to be sprayed is output from the liquid outlet in a continuous output manner.

In some embodiments, the continuous output mode is a liquid column output mode.

In some embodiments, the liquid supply unit includes a plurality of liquid inlets, and the flow channel is configured to make the flow rates of the liquid to be sprayed at the positions of the plurality of capillaries different from each other by adjusting the flow rates of the plurality of liquid inlets.

In some embodiments, the flow channel is configured as a longitudinal groove, the bottom surface of the longitudinal groove is an arc surface, an opening communicated with the flow channel connection port of the capillary is arranged on the arc surface, and the height of the longitudinal groove is smaller than or equal to a preset height threshold value.

In some embodiments, the two ends of the main body portion of the capillary tube are a flow channel connection end and a liquid outlet end, respectively, the outer diameter of the first end of the liquid outlet end is larger than the outer diameter of the second end of the liquid outlet end, the first end of the liquid outlet end is connected with the main body portion, and the second end of the liquid outlet end is provided with the liquid outlet.

In some embodiments, the included angle between the side wall of the liquid outlet end of the capillary tube and the radial cross-section of the capillary tube is greater than or equal to 10 degrees.

In some embodiments, the flow channel connection port is located at a first end of the flow channel connection end, and at least a portion of the outlet end is configured as a tapered tube.

In some embodiments, the ratio of the inner diameter and the outer diameter of the second end of the liquid outlet end is configured such that the difference from a transition ratio threshold value, which corresponds to a transition liquid outlet flow rate, is less than a predetermined range, the transition liquid outlet flow rate being a corresponding liquid outlet flow rate at which a transition of a manner in which a liquid body to be sprayed is outputted from the liquid outlet is made in a drop manner to a continuous spray manner.

In some embodiments, the liquid supply unit further comprises a liquid dispenser comprising a dispenser inlet and a plurality of dispenser outlets, a plurality of restrictor valves, each restrictor valve having an input in communication with a corresponding dispenser outlet of the plurality of dispenser outlets, and a plurality of sets of proportional valves, each restrictor valve having an output in communication with a corresponding set of proportional valves of the plurality of sets of proportional valves.

In some embodiments, each set of proportional valves in the plurality of sets of proportional valves includes a plurality of proportional valves in communication with a plurality of liquid inlets in the corresponding spray head unit, respectively.

In some embodiments, each head unit further includes a base plate having a plurality of mounting holes for mounting the capillary groups and defining a space between the capillaries, a flow channel plate having one or more of the flow channels disposed on a first surface thereof, and side walls forming a receiving space for the capillary groups with the base plate and a second surface of the flow channel plate.

In some embodiments, each spray head unit includes a plurality of sealing rings, each sealing ring of the plurality of sealing rings being disposed outside of the flow passage connection end of a corresponding capillary tube for sealing the capillary tube.

In some embodiments, the seal ring is disposed in a seal ring snap groove on the second side of the flow field plate, the flow field being disposed on the first surface of the flow field plate.

In some embodiments, the base plates of the head units have a splice-able structure for enabling splicing between base plates of adjacent head units.

In some embodiments, the shape, size, and distance between the liquid outlet and the target object are configured such that the liquid to be sprayed in a continuous liquid column section rather than a turbulent section of liquid column-to-liquid droplets is provided onto the target object.

The summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the invention, nor is it intended to be used to limit the scope of the invention.

Drawings

Fig. 1 illustrates a longitudinal cross-sectional view of a spray head for target object spraying in accordance with some embodiments of the invention.

Fig. 2 illustrates a side view of a receiving space of a capillary group according to some embodiments of the invention.

Fig. 3 illustrates a top view of a flow field plate according to some embodiments of the invention.

Fig. 4 illustrates a lateral cross-sectional view of a spray head unit according to some embodiments of the invention.

Fig. 5 illustrates a bottom view of a spray head unit according to some embodiments of the invention.

Fig. 6 illustrates a partial enlarged view of a capillary tube according to some embodiments of the invention.

Fig. 7 illustrates a partial cross-sectional view of a capillary tube according to some embodiments of the invention.

Fig. 8 illustrates a schematic of a capillary tube structure according to some embodiments of the invention.

Fig. 9 illustrates a fluid characteristic equivalent circuit schematic of a flow channel and a set of capillaries according to some embodiments of the invention.

Fig. 10 illustrates a schematic diagram of a continuous output and drip output mode according to some embodiments of the invention.

Fig. 11 illustrates a schematic diagram of a liquid supply unit according to some embodiments of the invention.

Fig. 12 illustrates a schematic diagram of a showerhead unit group according to some embodiments of the invention.

Like or corresponding reference characters indicate like or corresponding parts throughout the several views.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present invention are illustrated in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The term "comprising" and variations thereof as used herein means open ended, i.e., "including but not limited to. The term "or" means "and/or" unless specifically stated otherwise. The term "based on" means "based at least in part on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment. The term "another embodiment" means "at least one additional embodiment". The terms "first," "second," and the like, may refer to different or the same object.

As described above, the conventional spray head has disadvantages in that it has high manufacturing costs and has a problem of discharge of flying liquid.

To at least partially solve one or more of the above problems and other potential problems, an exemplary embodiment of the present invention proposes a spray head for spraying a target object by causing the spray head to include one or more spray head units each including a liquid supply unit for supplying a liquid to be sprayed to a flow path, a flow path communicating with a flow path connection port of each capillary tube in the capillary tube group, and one or more rows of capillary tube groups each including a plurality of capillaries, each capillary tube group including a main body portion, a flow path connection port, and a liquid outlet provided at both ends of the main body portion, respectively, the liquid outlet being shaped and sized such that the liquid to be sprayed is outputted from the liquid outlet in a continuous output manner. Because the liquid spraying mode based on the ultrasonic atomization transducer technology is replaced by the capillary group which outputs the liquid to be sprayed from the liquid outlet in a continuous output mode, the invention obviously reduces the manufacturing cost, has higher liquid spraying efficiency and does not generate flying liquid. Therefore, the invention has lower manufacturing cost and can avoid the discharge of flying liquid.

A spray head 100 for target object spraying is exemplarily described below with reference to fig. 1. Fig. 1 illustrates a longitudinal cross-sectional view of a spray head 100 for target object spraying in accordance with some embodiments of the invention.

The spray head 100 includes, for example, one or more spray head units. Fig. 1 illustrates a spray head including one spray head unit. As shown in fig. 1, each head unit includes a liquid supply unit, a flow channel 110, one or more rows of capillary groups 120 (two rows of capillary groups are illustrated in fig. 1).

With respect to the liquid supply unit, it is used for providing the liquid to be sprayed to the flow channel. The liquid supply unit supplies the liquid to be sprayed to the flow passage, for example, in the form of a constant current source. In some embodiments, the liquid supply unit includes a plurality of liquid inlets 150. As shown in fig. 1, each head unit includes, for example, 3 liquid inlets 150 (a first liquid inlet 150-1 located at the left side of the flow path, a second liquid inlet 150-2 located at the middle of the flow path, and a third liquid inlet 150-3 located at the right side of the flow path, respectively). In some embodiments, the liquid supply unit of each spray head unit includes, for example, two liquid inlets 150, as shown in fig. 11. It should be understood that the liquid supply unit may also comprise other numbers of liquid inlets.

Examples of the liquid to be sprayed include functional liquids such as ink, dye solution, medicinal liquid, and treatment solution. In some embodiments, the liquid to be sprayed is ink for coloring the target fabric.

Regarding the flow channel 110, it is used to supply the liquid to be sprayed from the liquid supply unit to the capillary group 120. The flow channel 110 communicates with a flow channel connection port of each capillary tube in the capillary group 120. Only the portion of the flow channel 110 exposed by the inlet 150 is illustrated in fig. 1.

As for the target object, it is, for example, a target fabric, a target base material, or the like.

Regarding the capillary group 120, it is used to output the liquid to be ejected from the flow path onto the target object. Each of the head units includes one or more rows of capillary groups 120. Each row of capillary groups 120 includes a plurality of capillaries. Each capillary tube comprises a main body part, a runner connecting port and a liquid outlet. The flow channel connection port and the liquid outlet are respectively arranged at two ends of the main body part, and the shape and the size of the liquid outlet are configured so that the liquid to be sprayed is output from the liquid outlet in a continuous output mode. With respect to the continuous output mode, it is, for example, a liquid column output mode, not a discontinuous mode like liquid droplets. It should be appreciated that the present invention can significantly improve the liquid ejecting efficiency because the liquid to be ejected is ejected from the liquid outlet in a continuous output manner.

The continuous output method is, for example, a continuous liquid column output method. Fig. 10 illustrates a schematic diagram of a continuous output and drip output mode according to some embodiments of the invention. As shown in the left part of fig. 10, the liquid to be sprayed is outputted from the liquid outlet of the capillary in a continuous output manner. As shown in the left part of fig. 10, the liquid to be ejected continuously from the liquid outlet of the capillary includes, for example, a continuous liquid column section 111, a liquid column-droplet-changing turbulence section 113, and a droplet 117. As shown in the right part of fig. 10, the liquid to be ejected is ejected from the liquid outlet of the capillary in a discontinuous manner of the drop output. Examples of the liquid to be ejected, which is output from the liquid outlet of the capillary in a drop output manner, include a droplet generation region 119 and a droplet 117. It will be appreciated that the shape and size of the liquid outlet of the present invention is configured such that the liquid to be sprayed is output from the liquid outlet in a continuous output manner as shown in the left part of fig. 10. In some embodiments, the shape, size, and distance between the liquid outlet and the target object of the present invention are configured such that the liquid to be sprayed in the continuous liquid column section 111 instead of the disturbed section 113 of the liquid column-changed droplet is provided onto the target object, whereby the spray effect of the target object can be significantly improved.

It will be appreciated that the flow path and capillary will have a flow resistance as the liquid to be sprayed flows in the flow path and capillary. The magnitude of the flow resistance is generally determined by the viscosity of the fluid, the length of the flow path, and the radius. Fig. 9 illustrates a fluid characteristic equivalent circuit schematic of a flow channel and a set of capillaries according to some embodiments of the invention. As shown in fig. 9, includes N flow channel sections and N capillaries (N is, for example, a positive integer, and in some embodiments, N is an even number). In the flow channel, the flow channel section between each two openings has a certain flow resistance, as R _L1 in fig. 9 indicates the flow resistance of the first flow channel section (i.e., the flow channel before the first capillary), and R _LN indicates the flow resistance of the nth flow channel section. It should be appreciated that the flow resistance of the overall flow channel is similar to a plurality of flow channel sections "in series". Each flow channel section also has an "inductive reactance" (the inductive reactance indicates the flow channel's resistance to flow changes as evidenced by fluid flow changes, as indicated by L _L1 in fig. 9 for the inductive reactance of the first flow channel section; L _LN for the nth flow channel section). each capillary tube in communication with the opening of the flow channel also has a flow resistance (as indicated by R _Z1 in fig. 9 for the first capillary tube; R _ZN for the nth capillary tube), an inductive reactance (as indicated by L _Z1 in fig. 9 for the first capillary tube; L _ZN for the nth capillary tube), respectively. in addition, each set of flow channel sections and capillaries also has a "capacitive reactance" exhibited by the gas-liquid therein (the capacitive reactance indicates the reserve of fluid exhibited by the gas-liquid, as indicated by C _LZ1 in FIG. 9 for the first flow channel section and the first capillary, and C _LZN for the nth flow channel section and the nth capillary). in addition, I _L in fig. 9 indicates a constant current source that communicates with one end (e.g., the left end) of the flow path, I _M indicates a constant current source that communicates with the middle of the flow path (which communicates, for example, in the vicinity of the N/2 th capillary), and I _R indicates a constant current source that communicates with the other end (e.g., the right end) of the flow path. As shown in fig. 9, one ends of the three constant current sources are connected and "grounded" (as indicated by the inverted triangle in fig. 9). It should be understood that in a fluid characteristic equivalent circuit, "voltage" corresponds to fluid pressure and "current" corresponds to fluid flow. "grounded" corresponds to communication with atmospheric pressure. It will be appreciated that the outlet of each capillary is in communication with atmospheric pressure and thus corresponds to one end of the capillary being "grounded".

The following describes exemplary calculation methods of inductance, capacitance and flow resistance in combination with formulas (1) to (3), respectively.

In the above formula (1), L _LN represents the inductance of the nth flow channel section. ρ represents the density of the liquid to be sprayed. l _LN denotes the length of the nth flow channel section. A _R represents the cross-sectional area (for example, a circular cross-sectional area) of the nth flow channel section. It should be understood that the inductance of the capillary is calculated in a similar manner.

In the above formula (2), C _LZN represents the capacitive reactance of the nth flow path section and the nth capillary. V _LZN represents the volume of the nth flow channel section and the nth capillary. B represents the bulk modulus of the nth flow channel section and the nth capillary.

In the above formula (3), R _LN represents the flow resistance of the nth flow path section. Mu represents the viscosity of the liquid to be sprayed. l _LN denotes the length of the nth flow channel section. r _LN represents the radius of the cross-section (for example, a circular cross-section) of the nth flow channel section. As can be seen from the above formula (3), the radius of the cross section of the flow channel section has a relatively large influence on the flow resistance, and a small change in the radius brings about a significant change in the flow resistance. It should be understood that the flow resistance of the capillary is calculated in a similar manner. In addition, the flow channels and/or capillaries of circular cross section are exemplified by formulas (1) to (3). The cross-section of the flow channel and capillary tube may be other shapes.

In some embodiments, the flow resistance of the flow channel is configured such that the flow rates of the liquid to be sprayed at the positions of the plurality of capillaries are different from each other by adjusting the flow rates of the plurality of liquid inlets. For example, I _L in FIG. 9 indicates a constant current source in communication with one end (e.g., the left end) of the flow path, which is in communication with, for example, the first fluid inlet 150-1 located on the left side of the flow path. I _M in FIG. 9 indicates a constant current source in communication with the middle of the flow path, which is in communication with, for example, a second fluid inlet 150-2 located in the middle of the flow path. I _R in FIG. 9 indicates a constant flow source in communication with the other end (e.g., right end) of the flow path, which is in communication with, for example, a third fluid inlet 150-3 located on the right side of the flow path. In some embodiments, if the flow resistance of the flow channel is relatively large, in a steady state condition, a linear change in the flow rate at the capillary tube can be achieved by controlling the inlet flow rates of the first inlet 150-1 located at the left side of the flow channel, the second inlet 150-2 located at the middle of the flow channel, and the third inlet 150-3 located at the right side of the flow channel, respectively. For example, the flow rate at each capillary is made to gradually vary from left to right. For example, the inlet flow rate of the first inlet 150-1 positioned at the left side of the flow channel is 100% of the predetermined value, the inlet flow rate of the second inlet 150-2 positioned at the middle of the flow channel is-100% of the predetermined value, and the inlet flow rate of the third inlet 150-3 positioned at the right side of the flow channel is 100% of the predetermined value. At this time, the flow rate of the liquid inlet at the two ends of the flow channel is high, and the flow rate of the liquid inlet in the middle is low, so that the flow rates at different capillaries are different. For another example, the inlet flow rate of the first inlet 150-1 positioned at the left side of the flow channel is 100% of the predetermined value, the inlet flow rate of the second inlet 150-2 positioned at the middle of the flow channel is-50% of the predetermined value, and the inlet flow rate of the third inlet 150-3 positioned at the right side of the flow channel is 50% of the predetermined value. It will be appreciated that, for example, during the spray-dyeing of the fabric, the fabric may exhibit a non-uniform density across its width prior to entering the spray-printed area, as a result of the pretreatment process. If the dye liquor (i.e. the liquor to be sprayed) is applied in the same amount during the spray printing, uneven final coloration of the fabric may occur. According to the invention, by controlling the liquid inlet flow of the liquid inlets at different positions of the flow channel, different liquid outlet flow (for example, linear change) at different capillaries can be realized, so that the state of uneven density of the fabric on the whole width can be presented, and liquid to be sprayed with different flow is output at different capillaries, thereby realizing uniform coloring or spraying of the whole fabric.

With respect to the body portion of the capillary tube (as indicated by reference 126 in fig. 4), it is, for example, elongate, tubular in shape. The two ends at the ends of the main body portion are a flow passage connection end (indicated by reference numeral 124 in fig. 4) and a liquid outlet end 122, respectively.

The structure of the outlet end 122 of the capillary is described in detail below with reference to fig. 6-8. Fig. 6 illustrates a partial enlarged view of a capillary tube according to some embodiments of the invention. Fig. 7 illustrates a partial cross-sectional view of a capillary tube according to some embodiments of the invention. Fig. 8 illustrates a schematic of a capillary tube structure according to some embodiments of the invention. As shown in fig. 6, one end of the body portion 126 of the capillary tube is the liquid outlet end 122. The first end 127 of the liquid outlet 122 is connected to the main body 126, and the second end 128 of the liquid outlet 122 is a liquid outlet.

In some embodiments, the outer diameter of the first end 127 of the liquid outlet end 122 (e.g., indicated by "DN" in fig. 7 and 8) is greater than the outer diameter of the second end 128 of the liquid outlet end 122 (e.g., indicated by "D" in fig. 6-8). Therefore, the liquid outlet flow rate of the liquid outlet is favorably controlled. It should be appreciated that the outer diameter DN of the first end 127 of the outlet end 122, i.e. the outer diameter of the capillary tube. In some embodiments, the capillary tube has an outer diameter greater than or equal to 0.1mm.

Regarding the inner diameter of the liquid outlet end 122, in some embodiments, the inner diameter (dn) of the first end 127 of the liquid outlet end 122 is equal to the inner diameter (d) of the second end 128 of the liquid outlet end 122, as shown in FIG. 7. In some embodiments, the inner diameter (dn) of the first end 127 of the liquid out end 122 is greater than the inner diameter (d) of the second end 128 of the liquid out end 122, as shown in FIG. 8. In other embodiments, the inner diameter of the first end 127 of the liquid out end 122 is equal to the inner diameter of the second end 128 of the liquid out end 122, and the outer diameter of the first end 128 of the liquid out end 122 is equal to the outer diameter of the second end 128 of the liquid out end 122. In some embodiments, the inner diameter (D) of the second end 128 of the tapping end 122 is equal to the outer diameter (D) of the second end 128 of the tapping end 122. In some embodiments, the inner diameter (d) of the second end 128 of the discharge end 122 is greater than or equal to 0.02mm.

In some embodiments, the outer wall profile of the outlet end 122 is configured as an arc, a step, a segment, for example. In some embodiments, at least a portion of the outlet end 122 is configured as a conical tube, for example. As shown in fig. 7, the entire outlet end 122 is configured, for example, as a tapered tube, it being understood that the tapered tube may have a tapered outer diameter that is constant or tapered inner diameter. For example, as shown in FIG. 7, in the direction in which the first end 127 extends toward the second end 128 (D), the outer diameter of the liquid outlet end 122 gradually decreases from the outer Diameter (DN) at the first end 127 to the outer diameter (D) of the second end 128, while the inner diameter of the liquid outlet end 122 remains unchanged, i.e., is equal to the inner diameter of the second end 128. It should be appreciated that by configuring the outlet end as a tapered tube with a constant inside diameter, it is advantageous to control the outlet flow rate and facilitate processing.

The sectional view of the upper right corner in fig. 8 is an enlarged view of the area surrounded by the circle indicated by the mark 121. As shown in fig. 8, a portion of the discharge end 122 is configured as a tapered tube, e.g., the discharge end 122 is configured as a combination of a tapered tube and a cylindrical tube. The axial height n of the conical tube is less than or equal to the axial height of the discharge end 122. The difference between the outer Diameter (DN) at the first end 127 and the inner Diameter (DN) of the first end 127 may or may not be equal to the difference between the outer diameter (D) of the second end 128 and the inner diameter (D) of the second end 128. The outer diameter of the liquid outlet end 122 gradually decreases from the outer diameter of the end of the cylindrical tube to the outer diameter (D) of the second end 128 in the direction in which the first end 127 extends toward the second end 128 (D), and at the same time, the inner diameter of the liquid outlet end 122 gradually decreases from the inner diameter (dn) of the first end 127 to the inner diameter (D) of the second end 128. It should be appreciated that by configuring at least a portion of the outlet end as a tapered tube with both reduced inner and outer diameters, more effective control of the outlet flow rate is facilitated. Regarding the sidewall of the liquid-out end of the capillary tube, in some embodiments, as shown in fig. 7, the included angle θ between the sidewall 810 of the liquid-out end of the capillary tube relative to the radial cross-section 812 of the capillary tube is greater than or equal to 10 degrees. In some embodiments, the included angle θ is any value greater than or equal to 10 degrees, less than 90 degrees. In some embodiments, the included angle θ is any value greater than or equal to 80 degrees, less than 90 degrees. By setting the included angle θ within the above-described angle range, it is possible to prevent the liquid output from the liquid outlet from wetting to the side face of the liquid outlet end, so as to promote formation of a continuous liquid column. It will be appreciated that if the liquid output from the liquid outlet wets to the side of the liquid outlet end, asymmetric wetting conditions tend to form, thereby negatively affecting the output of a continuous liquid column from the liquid outlet.

As shown in FIG. 6, arrow 123, for example, indicates the inner diameter of second end 128 of discharge end 122, which is represented, for example, by the letter "d". Arrow 125, for example, indicates the outer diameter of second end 128 of discharge end 122, which is represented, for example, by the letter "D".

The following equations (4) to (6) are used to describe the inner diameter D and the outer diameter D of the liquid outlet and the critical Weber numberIs a relationship of (3).

B₀＝[ρgD²/(2σ)]^1/2 (5)

In the above-mentioned formula (4),Representing the critical weber number. B ₀ Representing the bond number based on the inner and outer diameters of the outlet, respectively. K represents a constant. B ₀ andIs related to the ratio of the inner diameter to the outer diameter. In the above formulas (5) and (6), ρ represents the density of the liquid to be sprayed by the flow. σ represents the surface tension of the liquid to be sprayed. g represents the gravitational acceleration. v ₀ represents the flow rate of the liquid to be sprayed. D represents the inner diameter (diameter) of the capillary of the liquid outlet. It will be appreciated that weber number is a characteristic number applied in fluid mechanics that characterizes the ratio of the deformation inertial force and the stable cohesive force of a liquid (e.g., a liquid to be sprayed) as it flows through a fluid medium (e.g., a capillary). Cohesion is related to surface tension or interfacial tension, which resists the increase in surface area and thus deformation. The droplets of the liquid to be sprayed are brought together by surface tension or interfacial tension. Critical weber numberThe weber number of the liquid to be ejected, which indicates the density ρ, the surface tension σ, is output from the liquid outlet in a droplet manner to a continuous ejection manner (or "continuous output manner", for example, a liquid column) when the flow velocity v ₀ passes through the liquid outlet of the inner diameter D. It should be appreciated that the critical Weber numberAssociated with a transition flow rate that causes a transition from a drop-wise manner to a continuous-jet manner in which the liquid to be sprayed is output from the liquid outlet.

As for the transitional flow rate, it is, for example, a corresponding flow rate at the time of transition from a manner in which the liquid to be ejected is caused to be ejected from the liquid outlet, in a droplet discharge manner (or "droplet discharge manner") shown in the right part of fig. 10, to a continuous ejection manner (or "continuous discharge manner" or "liquid column manner") shown in the left part of fig. 10.

Studies have shown that when the inner diameter of the capillary (e.g., the inner diameter of the liquid outlet end is equal to the inner diameter of the capillary) is sufficiently small, the interface of the liquid to be sprayed can stabilize to Rayleigh-Taylor instability (RT instability for short), in which state the inertia of the liquid to be sprayed, the capillary action, and the gravitational action of the liquid to be sprayed are dominant as compared with the viscosity of the liquid to be sprayed. When the inner diameter D of the liquid outlet is unchanged, the closer the outer diameter D is to the inner diameter D (i.e., the smaller the outer diameter D is), the smaller the transition flow rate at which the liquid to be ejected outputted from the liquid outlet is caused to transit from the droplet-down mode to the continuous ejection mode. In some embodiments, the ratio of the inner diameter and the outer diameter of the second end of the liquid outlet end is configured such that the difference from a transition ratio threshold value, which corresponds to a transition liquid outlet flow rate, is less than a predetermined range, the transition liquid outlet flow rate being a corresponding liquid outlet flow rate at which a transition of a manner in which a liquid body to be sprayed is outputted from the liquid outlet is made in a drop manner to a continuous spray manner.

As shown in fig. 1 and 2, in some embodiments, each showerhead unit further includes a bottom plate 130, side walls 132, a flow field plate 134, and a plurality of sealing rings 140.

Regarding the base plate 130, it has a plurality of mounting holes for mounting the capillary group 120, and defining the interval between capillaries.

Regarding the flow field plate 134, a first surface thereof (e.g., an upper surface of the flow field plate 134 in fig. 1) is configured with one or more flow channels 110. In some embodiments, a second surface of the flow field plate 134 (e.g., a lower surface of the flow field plate 134 in fig. 1) is provided with a seal ring snap groove for snapping the seal ring 140.

Regarding the side wall 132, it forms an accommodation space of the capillary group 120 with the bottom plate 130, and the second surface of the flow channel plate 134. In some embodiments, the sidewalls 132 include at least a first sidewall 132-1 and a second sidewall 132-2 (as shown in FIG. 2), for example.

With respect to the sealing ring 140, it is used to seal the capillary tube. In some embodiments, the number of sealing rings is equal to the number of capillaries. As shown in fig. 1, each sealing ring is disposed outside the flow path connection end of the corresponding capillary tube for sealing the capillary tube. An enlarged view of a portion of the virtual line indicated by reference numeral 102 in the dashed box in the upper left corner of fig. 1 indicates that each seal 140 is fitted over the outside of the flow path connection end of the corresponding capillary tube. And the seal is disposed in a seal snap groove on the second side of the flow field plate 134.

In some embodiments, each showerhead unit also includes, for example, a top plate 138, a sealing plate 136, and a mounting plate 142.

Regarding the top plate 138, it is configured to be located on the upper surface of the head unit, for example. In some embodiments, the top plate 138 is used to mount one or more fluid inlets 150.

Regarding the sealing plate 136, it is disposed between the top plate 138 and the flow channel plate 134 for sealing the communication space of the flow channel and the liquid inlet 150. In some embodiments, both the seal plate 136 and the top plate 138 are provided with through holes (e.g., top plate through hole 139 and seal plate through hole 137 shown in fig. 2) that communicate with the liquid inlet 150 in order to direct the liquid to be sprayed from the liquid inlet 150 to the flow channel 110.

As for the mounting plate 142, it is provided, for example, between the flow path plate 134 and the side wall 132 for achieving relative fixation between the flow path plate 134 and the side wall 132.

A schematic view of the accommodation space of the capillary group is exemplarily described below with reference to fig. 2. Fig. 2 illustrates a side view of a receiving space of a capillary group according to some embodiments of the invention.

Regarding the accommodation space 135 of the capillary group, in some embodiments, it is defined, for example, by at least the side wall 132 (the side wall 132 specifically includes, for example, the first side wall 132-1, the second side wall 132-2), the upper surface of the bottom plate 130, and the second surface (i.e., the lower surface) of the flow path plate 134, as shown in fig. 2. It should be appreciated that each head unit includes, for example, a capillary group of accommodation spaces 135. Each of the capillary group accommodation spaces 135 accommodates, for example, one or more rows of the capillary groups. As shown in fig. 2, the accommodation space 135 of the capillary group accommodates two rows of the capillary groups.

A schematic diagram of the flow field plate 134 is exemplarily described below in conjunction with fig. 3. Fig. 3 illustrates a top view of a flow field plate according to some embodiments of the invention.

As shown in fig. 3, the flow field plate 134 has a first surface (i.e., an upper surface of the flow field plate 134) and a second surface (i.e., a lower surface of the flow field plate 134).

The first surface of the flow field plate 134 is provided with a plurality of flow channels 110, for example. The first surface of the flow channel plate 134 is schematically shown in fig. 3 to include 2 flow channels. It should be understood that the number of flow channels 110 configured by the flow channel plate 134 of each head unit is equal to the number of rows of capillary tubes, and each flow channel 110 is configured to provide liquid to be ejected to a corresponding row of capillary tubes 120. Each flow channel 110 includes, for example, a plurality of openings through which the flow channels communicate with flow channel connection ports of corresponding capillaries in the capillary group. In some embodiments, the flow field plate 134 is also provided with a plurality of mounting holes 114 for achieving relative fixation between the flow field plate 134 and the seal plate 136, mounting plate 142, and/or side wall 132.

Regarding the flow channel 110, in some embodiments, the flow resistance of the flow channel is configured such that the flow rates of the liquid to be sprayed at the positions of the plurality of capillaries are different from each other by adjusting the flow rates of the plurality of liquid inlets. As shown in FIG. 3, the indicia 112-M indicates the Mth opening, and the Mth opening 112-M corresponds to the position of the Mth capillary, for example. The N-th opening is indicated by reference numeral 112-N. The nth opening corresponds to, for example, the position of the nth capillary. It should be understood that the flow resistance of the flow channel 110 is configured such that the liquid discharge flows of the liquid to be discharged at the positions of the plurality of capillaries at the M-th capillary and at the N-th capillary are different from each other by adjusting the flow rates of the plurality of liquid inlets, for example.

In some embodiments, the flow channel 110 is configured, for example, as a flow channel configured as a longitudinal groove, the bottom surface of which is a cambered surface, and an open hole communicating with the flow channel connection port of the capillary tube is arranged on the cambered surface. It should be appreciated that by setting the bottom surface of the flow channel 110 to be a cambered surface, the flow channel of the present invention can reduce the residue of the liquid to be sprayed in the flow channel.

As for the longitudinal grooves, for example, elongated shallow grooves extending in the X direction in fig. 3 are mentioned. In some embodiments, the longitudinal slot is semi-circular in cross-section. In some embodiments, the height of the longitudinal slot is less than or equal to a predetermined height threshold. As regards the predetermined height threshold, it is for example, but not limited to, 1 mm. For example, in some embodiments, the height of the longitudinal slot is configured to be 0.5 millimeters. By making the height of the longitudinal grooves low, i.e. by making the longitudinal grooves to be provided as elongated shallow grooves, it is easy to control the flow resistance of the flow channel. In some embodiments, the width of the longitudinal groove is, for example, 1 millimeter.

It will be appreciated that at low flow resistances, slight changes in the flow resistance in the line will significantly affect the stability of the flow rate of the liquid to be sprayed. The stability of the flow rate of the liquid to be ejected from the ejection head can be improved by making the flow resistance of the flow passage larger (e.g., making the flow resistance of the flow passage exceed a predetermined flow resistance threshold).

In some embodiments, the cross-sectional area of the flow channel is configured to be less than a predetermined cross-sectional area threshold, for example. In some embodiments, the cross-sectional area of the flow channel is, for example and without limitation, 0.5 square millimeters. In some embodiments, the cross-sectional area of the flow channel is determined based on the sensitivity requirements of the spray head for flow control of the liquid to be sprayed. It should be understood that the flow resistance in a microfluidic is mainly caused by the pressure drop and energy loss caused by friction between the liquid and the channel walls. Experimental data show that when the liquid to be sprayed with viscosity is in a laminar flow state, the flow resistance of the liquid to be sprayed is larger as the liquid to be sprayed is closer to the wall of the flow channel, the corresponding flow velocity is smaller, and the flow resistance is larger as the inner diameter size of the flow channel is smaller under the same pressure, the flow velocity is lower. Therefore, the flow passage is configured as the long and narrow shallow groove, and the cross section size of the flow passage is made to be small enough, so that the flow resistance in the flow passage is increased, the flow speed is reduced, and the sensitivity of flow control of the liquid to be sprayed by the spray head is improved.

As shown in fig. 3 and 4, the base plate 130 is provided with mounting holes. Mounting plate 142 is provided with mounting holes. The side wall 132 is also provided with mounting holes. The first mounting means 144 sequentially passes through the mounting holes of the base plate 130, the side walls 132 and the mounting plate 142, thereby achieving the fixation between the base plate 130, the side walls 132 and the mounting plate 142.

As shown in fig. 4, the relative fixation between the top plate 138, the sealing plate 136, the flow field plate 134 and the mounting plate 142 is achieved by coupling the second mounting device 146 with mounting holes on the top plate 138, the sealing plate 136, the flow field plate 134 and the mounting plate 142, respectively.

In some embodiments, the first mounting device 144 and the second mounting device 146 are configured, for example, as bolts. In some embodiments, coupling and decoupling may be achieved between the first mounting device 144 and the second mounting device 146.

It should be appreciated that by way of the above-described installation, the present invention facilitates localized maintenance and installation. For example, the disassembly of the bottom plate 130 and the side walls 132 may be conveniently accomplished by decoupling the first mounting means 144 from the mounting holes on the bottom plate 130, the side walls 132 and the mounting plate 142, thereby facilitating the installation and maintenance of the capillaries without affecting the relative fixation between the top plate 138, the sealing plate 136, the flow channel plate 134 and the mounting plate 142. Similarly, disassembly of the top plate 138, the sealing plate 136, and the flow field plate 134 may be conveniently accomplished by decoupling the second mounting device 146 from mounting holes in the top plate 138, the sealing plate 136, the flow field plate 134, and mounting holes in the mounting plate 142, thereby facilitating installation and maintenance of the flow field or fluid inlet without affecting the relative fixation between the bottom plate 130, the side walls 132, and the capillary group.

The dotted box in the upper right hand corner of fig. 4 is an enlarged view of the partial structure within the dotted box indicated by reference numeral 148. The indicia 112 indicate the opening of the flow passage. The opening 112 is located, for example, at the bottom surface of the flow channel of the first surface 115 of the flow field plate 134. The opening 112 is in communication with the flow path connection end of the capillary tube for providing the liquid to be sprayed in the flow path to the capillary tube via the opening 112. The liquid to be sprayed supplied into the capillary tube flows through the flow path connecting end of the capillary tube, the main body portion 126, and finally is discharged from the liquid outlet of the second end (i.e., the tip) of the liquid outlet end 122.

Fig. 4 also shows that the second surface 118 of the flow field plate 134 is provided with a gasket catch groove 116. The seal ring fastening groove 116 is used for fastening the seal ring 140, so that the seal ring 140 is fixed on the outer side of the runner connection end of the capillary tube, and is used for sealing the runner connection end of the capillary tube. Fig. 5 illustrates a bottom view of a spray head unit according to some embodiments of the invention.

The structure of the liquid supply unit of the plurality of head units will be specifically described below with reference to fig. 11. Fig. 11 illustrates a schematic diagram of a liquid supply unit of a plurality of spray head units according to some embodiments of the present invention. As shown in fig. 11, the liquid supply unit 170 is configured to supply a liquid to be sprayed to the head unit group 172. The nozzle unit group 172 is formed by splicing a plurality of nozzle units, for example. The liquid supply unit 170 includes a liquid dispenser 180, a plurality of restrictor valves 190, a plurality of sets of proportional valves 192, and connecting lines. The liquid dispenser is for dispensing liquid to be sprayed supplied via the dispenser inlet 182 to the respective restrictor valves 192 via the plurality of dispenser outlets 184. The liquid dispenser 180 includes a dispenser inlet 182 and a plurality of dispenser outlets 184. The dispenser inlet 182 is, for example, in communication with a constant current source for receiving a constant current of liquid to be sprayed. The plurality of dispenser outlets 184 are in communication with a plurality of restrictor valves 190, respectively. The restrictor valve 190 is configured to regulate the flow provided to the corresponding set of proportional valves 192 in accordance with control instructions, such as generated based on density profile data of a target object (e.g., fabric), such as provided by a supplier of the target object or generated based on sensed data for the target object. Each restrictor valve 190 is in communication with a set of proportional valves 192, respectively. The set of proportional valves 192 includes, for example, a plurality of proportional valves. As shown in fig. 11, each of the restrictor valves 190 communicates with a set of proportional valves 192 consisting of a first proportional valve 192-1 and a second proportional valve 192-2, respectively. Different proportional valves in the same group of proportional valves are respectively communicated with different liquid inlets 150 in the corresponding same nozzle unit. For example, the first proportional valve 192-1 is in communication with the first fluid inlet 150-1 for regulating the fluid inlet flow to the first fluid inlet 150-1. The second proportional valve 192-2 is in communication with the second fluid inlet 150-2 for regulating the fluid inlet flow of the second fluid inlet 150-2. By adopting the scheme, the invention not only can conveniently supply liquid (for example, ink) for the nozzle unit group, but also can independently control the flow of the capillaries in different nozzle units, thereby overcoming the problem of uneven coloring or spraying caused by uneven density in the width direction of the fabric.

The manner of splicing the plurality of head units is specifically described below with reference to fig. 12. Fig. 12 illustrates a schematic diagram of a showerhead unit group according to some embodiments of the invention. As shown in fig. 12, the head unit group 170 includes, for example, a plurality of head units (e.g., the head unit group 170 includes a first head unit 170-1, a second head unit 170-2, and a third head unit 170-3). The base plate 130 of each head unit has, for example, a splice-able structure 129 thereon for splicing with the base plate of an adjacent head unit. In some embodiments, the splice 129 is, for example, one or more sets of dovetail mechanisms. In other embodiments, the splice 129 is, for example, one or more sets of latch mechanisms.

By adopting the mode, the invention can conveniently construct spray printing equipment with various widths, thereby meeting the coloring or spraying requirements of fabrics with different widths. It should be appreciated that the side walls, bottom plates of any of the head units (e.g., the second head unit 170-2) of fig. 12 may be independently installed and removed, whereby the present invention may be readily used for independent maintenance and repair of the head unit capillaries (e.g., damage to the outlet of the capillaries or clogging of the capillaries) without the need for removal of the entire head unit.

The foregoing description of embodiments of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described.

The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the technical improvements in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

The above embodiments do not limit the scope of the present application. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors.

Claims

1. A spray head for spraying a target object, comprising one or more spray head units, each spray head unit comprising:

A liquid supply unit for supplying a liquid to be sprayed to the flow passage;

a flow channel communicating with a flow channel connection port of each capillary tube in the capillary group, and

One or more rows of capillary groups, each row of capillary group comprising a plurality of capillaries, each capillary group comprising a main body portion, a flow channel connection port and a liquid outlet, the flow channel connection port and the liquid outlet being provided at both ends of the main body portion, respectively, the liquid outlet being shaped and dimensioned such that a liquid to be sprayed is outputted from the liquid outlet in a continuous output manner.

2. The spray head of claim 1, wherein the continuous output mode is a liquid column output mode.

3. The spray head according to claim 1, wherein the liquid supply unit includes a plurality of liquid inlets, and the flow passage is configured such that the flow rates of the liquid to be sprayed at the positions of the plurality of capillaries are different from each other by adjusting the flow rates of the plurality of liquid inlets.

4. The spray head according to claim 1, wherein the flow channel is configured as a longitudinal groove, the bottom surface of the longitudinal groove is an arc surface, an opening communicated with the flow channel connection port of the capillary tube is arranged on the arc surface, and the height of the longitudinal groove is smaller than or equal to a preset height threshold value.

5. The spray head according to claim 1, wherein the two ends of the body portion of the capillary tube are a flow passage connection end and a liquid outlet end, respectively, the outer diameter of the first end of the liquid outlet end is larger than the outer diameter of the second end of the liquid outlet end, the first end of the liquid outlet end is connected with the body portion, and the second end of the liquid outlet end is provided with the liquid outlet.

6. The spray head of claim 5 wherein the angle between the side wall of the liquid outlet end of the capillary tube and the radial cross-section of the capillary tube is greater than or equal to 10 degrees.

7. The spray head of claim 5 wherein the flow channel connection port is located at a first end of the flow channel connection end and at least a portion of the outlet end is configured as a conical tube.

8. The spray head according to any one of claims 5 to 7, wherein the ratio of the inner diameter and the outer diameter of the second end of the liquid outlet end is configured such that the difference from a transition ratio threshold value, which corresponds to a transition liquid outlet flow rate, is smaller than a predetermined range, the transition liquid outlet flow rate being a corresponding liquid outlet flow rate at the transition from a drop-wise manner to a continuous-jet manner of a liquid to be sprayed output from the liquid outlet.

9. The spray head of claim 1, wherein the liquid supply unit further comprises:

a liquid dispenser comprising a dispenser inlet and a plurality of dispenser outlets;

a plurality of restrictor valves, each restrictor valve having an input in communication with a corresponding one of the plurality of dispenser outlets, and

The output end of each flow limiting valve is communicated with the corresponding group of proportional valves in the plurality of groups of proportional valves.

10. The spray head of claim 9, wherein each set of proportional valves of the plurality of sets of proportional valves includes a plurality of proportional valves that are in communication with a plurality of fluid inlets of a corresponding spray head unit, respectively.

11. The spray head of claim 1, wherein each spray head unit further comprises:

a base plate having a plurality of mounting holes for mounting the capillary groups and defining a space between the capillaries;

a flow channel plate having one or more of the flow channels disposed on a first surface thereof, and

And the side wall forms an accommodating space of the capillary group with the bottom plate and the second surface of the runner plate.

12. The spray head of claim 5, wherein each spray head unit comprises:

and each sealing ring is arranged at the outer side of the flow passage connecting end of the corresponding capillary tube and used for sealing the capillary tube.

13. The spray head of claim 12 wherein the seal is disposed in a seal snap groove on the second side of the flow field plate, the flow field being disposed on the first surface of the flow field plate.

14. The spray head according to claim 11, wherein the bottom plates of spray head units have a splice-able structure for enabling splicing between bottom plates of adjacent spray head units.

15. The spray head of claim 11, wherein the shape, size, and distance between the outlet and the target object are configured such that the body to be sprayed in a continuous column section rather than in a turbulent section of liquid column-changing droplets is provided onto the target object.