Anti-blocking spraying hanger

Abstract

The utility model provides a kind of anti-blocking spray hanger, it is related to surface treatment equipment technical field, the anti-blocking spray hanger includes hanger body, at least one pin hole and at least one ash leakage groove are equipped on hanger body;Pin hole is used to insert pin;Ash leakage groove is communicated with the bottom of pin hole, and extend to the outer surface of hanger body, the width of ash leakage groove is less than the critical distance of powder electrostatic adsorption.Through the bottom of pin hole additional ash leakage groove being communicated and extending to the outer surface of hanger body, and using the specific structure size of the ash leakage groove realizes the double anti-blocking effect of automatic discharge and electrostatic shielding of residue, to overcome the pin hole of existing technology in spraying hanger is easily blocked due to residue accumulation, leading to high maintenance cost and the problem of production safety hazard.

Description

Technical Field

[0001] This utility model relates to the field of surface treatment equipment technology, and in particular to an anti-clogging spraying fixture. Background Technology

[0002] Electrostatic spraying is a widely used coating technology in the surface treatment processes of hardware, automotive parts, and various industrial products. To efficiently and stably suspend workpieces to be sprayed on the spraying line, specially designed hangers are typically required. These hangers usually consist of a main body designed for long-term reuse, and multiple replaceable pins. The hanger body has pin holes for mounting the pins. When a pin needs to be replaced due to wear or excessive coating thickness, the operator only needs to remove the old pin and insert a new one, without replacing the entire hanger, thus extending its service life.

[0003] However, the aforementioned replaceable pin-type hangers have a difficult-to-solve technical problem. During repeated spraying cycles, paint powder inevitably enters the pin holes. After multiple spraying and high-temperature curing (or sintering) processes, this powder that has entered the holes will accumulate and harden, forming solid residue that gradually fills and blocks the bottom of the pin holes.

[0004] To clear these blockages, the hangers typically need to be processed offline, such as by high-temperature sintering or chemical soaking to remove the coating from their surface. However, these conventional cleaning methods are very ineffective at removing stubborn residues deep within the tiny pin holes. Therefore, a significant amount of manpower is ultimately required to use forced physical methods such as drilling and piercing with steel needles to specifically unclog and maintain each pin hole.

[0005] If clogged pin holes are not detected and thoroughly cleaned in time, newly replaced pins will not be able to be inserted to the designed safe depth, resulting in insufficient connection strength between the pin and the fixture body. Production under these conditions greatly increases the risk of workpieces falling off due to vibration during painting or transportation, leading not only to product scrap and increased production costs but also potential production line malfunctions and serious safety hazards.

[0006] Therefore, it is necessary to improve the existing spraying fixture technology to overcome its shortcomings. Utility Model Content

[0007] To overcome the problems existing in related technologies, the purpose of this utility model is to provide an anti-clogging spraying hanger. This anti-clogging spraying hanger adds a ash-draining groove at the bottom of the pin hole, which communicates with and extends to the outer surface of the hanger body. The specific structural dimensions of the ash-draining groove achieve a dual anti-clogging effect of automatic residue discharge and electrostatic shielding. This overcomes the problem in the prior art where the pin hole of the spraying hanger is easily clogged due to residue accumulation, resulting in high maintenance costs and potential production safety hazards.

[0008] A clog-resistant spray coating fixture, comprising:

[0009] The fixture body is provided with at least one pin hole and at least one dust discharge groove.

[0010] The pin insertion hole is used to insert a hanging pin;

[0011] The ash-draining groove is connected to the bottom of the pin hole and extends to the outer surface of the hanger body. The width of the ash-draining groove is less than the critical distance for electrostatic adsorption of powder.

[0012] Existing spraying fixtures only have pin holes on the fixture body. A dust-draining groove, connected to and extending to the outer surface of the fixture body, is added to the bottom of the pin hole. The width of this groove is set to be less than the critical distance for electrostatic powder adsorption. Because the dust-draining groove is connected to the bottom of the pin hole and opens onto the outer surface of the fixture, it creates a physical discharge channel for powder residue accumulated inside the hole. During the high-temperature sintering and cooling process of the fixture, the residue becomes loose due to thermal stress and can be smoothly discharged from the fixture body along the dust-draining groove under gravity or during subsequent rinsing, thus solving the problem of stubborn residue accumulation at the bottom of the hole. Since the width of the dust-draining groove is less than the critical distance for electrostatic powder adsorption (e.g., 3 mm), an electrostatic shielding zone with extremely low electric field strength is formed inside this narrow groove during electrostatic spraying. This makes it difficult for charged paint powder to be adsorbed onto the inner wall of the dust-draining groove. This not only solves the problem of removing existing residue from the pin insertion hole, but also prevents the slag discharge channel from becoming clogged, thus achieving a self-cleaning function for the pin insertion hole. It avoids production quality problems and safety hazards such as insufficient pin installation depth and workpiece falling due to pin insertion hole blockage, and eliminates the costly and inefficient manual maintenance of specialized through-holes.

[0013] Furthermore, the width of the ash discharge trough is 1.8 mm to 2.2 mm.

[0014] The width of the ash discharge trough was further precisely limited to an optimized range of 1.8 mm to 2.2 mm. This width range represents a proven optimal balance. On the one hand, it is narrow enough to ensure a stable and strong electrostatic shielding effect, maximizing the suppression of powder adhesion; on the other hand, it retains enough space to ensure that residual particles or fragments of a certain size formed after sintering can pass through unimpeded, without bridging or jamming. This optimized range achieves the best of both electrostatic shielding and physical slag removal effects simultaneously, thereby further improving the reliability and stability of the anti-clogging structure.

[0015] Furthermore, the ash leakage groove extends through the radial section where the bottom of the pin hole is located.

[0016] If the ash leakage trough only penetrates a small portion of the bottom center of the pin hole, leaving a ring-shaped step or dead corner at the edge of the hole, powder residue will easily accumulate and adhere to this step or dead corner as it falls. Over time, this will form a stubborn residue that is difficult to remove, thus weakening the anti-clogging effect. By using an ash leakage trough that penetrates the radial section of the bottom of the pin hole, the physical structure constituting the bottom of the pin hole is geometrically ensured to be completely and thoroughly removed. This means that the transition from the inner wall of the pin hole to the internal space of the ash leakage trough is completely open and unobstructed. When powder residue falls, it cannot find any platform or corner where it can stay or accumulate, and can only enter the main discharge channel of the ash leakage trough directly and smoothly.

[0017] Therefore, this technical feature fundamentally eliminates residual dead corners at the junction, ensuring the absolute unobstructedness of the slag discharge channel and the thoroughness of the slag discharge process, thereby greatly improving the long-term reliability and maintenance-free performance of the entire anti-clogging structure.

[0018] Furthermore, the ash-draining trough extends horizontally through one or both sides of the hanging fixture body.

[0019] This technical feature defines the outlet direction and shape of the ash chute. Unlike vertically downward openings where residue may re-adhere, horizontal outlets utilize lateral space for ash discharge, making them less susceptible to the effects of dripping material or the environment. When the ash chute extends only to one side, it already provides a clear ash discharge path and an inlet for tool cleaning (such as cleaning rods or air guns). Preferably, when the ash chute extends to both sides, it forms a completely open horizontal channel. This through-type structure not only provides bidirectional discharge outlets, but more importantly, during forced maintenance, it allows cleaning media (high-pressure air or water flow) to enter from one end and exit from the other, creating a powerful penetrating cleaning effect that can most thoroughly remove stubborn residues. Its maintainability far exceeds that of a blind chute structure with a single-sided opening.

[0020] Furthermore, the pin hole has a first central axis;

[0021] The ash leakage trough has a second central axis;

[0022] The first central axis intersects the second central axis at an oblique angle.

[0023] The central axis of the pin hole intersects the central axis of the ash discharge trough at an oblique angle (forming a "Y" shape). Compared to the perpendicular "T" shape, the oblique layout ensures that when residue slides from the pin hole into the ash discharge trough, it transitions along a gentle slope instead of directly impacting a 90-degree right-angle plane. This effectively avoids the accumulation and blockage of residue at right-angle corners, using gravity to guide the residue more smoothly towards the outlet. It optimizes the internal material flow path and improves the efficiency of passive slag discharge (i.e., relying solely on gravity).

[0024] Furthermore, the second central axis is set in the vertical direction.

[0025] This technical feature specifically defines a preferred "Y"-shaped structural form. In this form, the ash discharge trough itself is arranged vertically. This means that once the residue enters the ash discharge trough through the angled insertion holes, it will fall along the most direct path of gravity (vertically downward), resulting in the greatest driving force for slag discharge, the shortest path, and the highest efficiency.

[0026] Furthermore, the angle between the first central axis and the second central axis is 95 degrees to 175 degrees.

[0027] The included angle of the axis is further limited to the range of 95 to 175 degrees. This angle range is the result of optimization after comprehensive consideration of structural mechanics and slag removal efficiency. When it is less than 95 degrees, the angle is too sharp, close to a "T" shape, and the slag removal effect will be poor; while when it is greater than 175 degrees, it is close to an "I" shape, which will affect the stable fixation of the pin. Therefore, this range ensures that excellent slag removal effect is achieved without sacrificing the structural strength of the hanger body and the stability of the support for the hanging pin.

[0028] Furthermore, the angle between the first central axis and the second central axis is 135 degrees.

[0029] The included angle is precisely defined at 135 degrees. At this angle, the component of gravity along the inclined plane and the sliding friction force are optimally balanced, making the removal of residue the easiest and most efficient. At the same time, this angle is also easy to achieve using conventional processing techniques. It enables optimal automatic slag removal performance while ensuring processing convenience.

[0030] Furthermore, the equivalent diameter of the pin hole is less than 3 millimeters.

[0031] The size of the pin hole itself is limited, requiring its equivalent diameter to be less than 3 mm. An excessively large hole diameter would cause a dramatic increase in the amount of powder entering during spraying, exceeding the self-cleaning capacity of the ash drain tank and leading to abnormal clogging. By controlling the hole diameter to below 3 mm, the total amount of powder entering the hole is reduced at the source, matching it with the ash drain tank's slag removal capacity. The two work synergistically, further improving the overall performance and long-term reliability of the entire anti-clogging system.

[0032] Furthermore, the hanger body is made of metal.

[0033] The working environment of the spraying rack requires electrostatic spraying and high-temperature curing (typically between 200-300℃). Using metal materials ensures that the rack is: conductive to facilitate the electrostatic spraying process; resistant to high temperatures without deformation or damage during repeated thermal cycling; and possesses sufficient mechanical strength to support the workpiece. These characteristics are fundamental prerequisites for ensuring the long-term, stable, and effective use of the spraying rack in real industrial production environments.

[0034] Furthermore, the hanging device body is cylindrical.

[0035] The macroscopic shape of the hanger body is cylindrical. Among all geometric shapes, a cylinder has the smallest surface area for the same length and volume. During the spraying process, paint powder not only enters the pin holes but also adheres to the outer surface of the hanger body, which is considered a waste of process material. By adopting a cylindrical shape, the powder-attached area of ​​the hanger body can be minimized, thereby saving paint and reducing production costs.

[0036] The beneficial effects of this utility model are as follows:

[0037] This utility model provides an anti-clogging spraying fixture, which includes a fixture body, a pin hole, and a dust drain. The dust drain is connected to the bottom of the pin hole and extends to the outer surface of the fixture body, forming an open channel. The width of the dust drain is less than the critical distance for electrostatic adsorption of powder. The pin hole, which was originally a closed, easily accumulated blind hole, is transformed into a structure with an outlet. During the spraying process, some paint powder inevitably enters the pin hole. In subsequent high-temperature curing or sintering processes, the powder residue inside the hole becomes loose and fragmented due to heat. When the fixture cools or is subjected to normal vibration on the production line, it naturally falls from the bottom of the pin hole under gravity and enters the connected dust drain. Since the dust drain is a channel directly to the outer surface of the fixture body, the residue is completely discharged along this channel and does not accumulate inside the fixture. Furthermore, during routine rinsing and cleaning of the fixture, water or airflow can pass through the dust drain without obstruction, thoroughly cleaning the depths of the pin hole. The passive waiting mode for manual cleaning has been transformed into an active slag removal mode in each production cycle, thereby effectively preventing the gradual accumulation and hardening of powder residue at the bottom of the hole.

[0038] Simultaneously, because the width of the ash-discharging trough is designed to be less than the critical distance for powder electrostatic adsorption, the narrow internal space of the ash-discharging trough forms a region similar to the "Faraday cage" effect, i.e., an electrostatic shielding zone. During electrostatic spraying, charged paint powder is mainly adsorbed onto the grounded hanger surface along the electric field lines. For a narrow, deep trough, the electric field strength inside will decrease sharply, making it difficult for the electric field lines to penetrate deeply. When the width of the trough is less than a critical value (i.e., the space required for powder electrostatic adsorption), most charged powder particles will be unable to enter the depth of the trough and effectively adhere to its inner wall due to the electric field shielding effect. Therefore, during the spraying stage, the ash-discharging trough itself can be "immune" to most powder adhesion. This solves the potential risk of "the slag discharge channel itself being blocked." It ensures that the physical slag discharge channel can remain unobstructed and effective for a long time, resulting in a qualitative improvement in the reliability and durability of the entire anti-clogging structure. Attached Figure Description

[0039] Figure 1 This is a cross-sectional view of the anti-clogging spraying fixture provided in this application at the pin hole;

[0040] Figure 2 This is a perspective view of the anti-clogging spraying fixture provided in this application from one side.

[0041] Figure 3 This is a perspective view from the other side of the anti-clogging spraying fixture provided in this application.

[0042] Figure label:

[0043] 100. Hanger body; 110. Pin hole; 120. Ash drain trough. Detailed Implementation

[0044] Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0045] Example 1

[0046] like Figures 1 to 3 As shown, this embodiment provides an anti-clogging spraying hanger, which includes a hanger body 100, at least one pin hole 110 disposed on the hanger body 100, and a dust leakage groove 120 associated with the pin hole 110.

[0047] The hanger body 100 is the base and load-bearing component of the entire hanger, used to suspend the workpiece to be processed on the automated spraying production line. Therefore, it must be made of materials that meet the requirements of industrial production. Specifically, the material needs to have good electrical conductivity to cooperate with the electrostatic spraying process; it needs to have sufficient mechanical strength to support the weight of the workpiece; and it also needs to have excellent high-temperature resistance to maintain structural stability during repeated curing or sintering thermal cycles (typically at temperatures reaching 200-300℃).

[0048] Although round steel, which has a lower cost, is preferred in this embodiment, any metal material that meets the above conditions can be used as a substitute. For example, stainless steel can be used to enhance corrosion resistance, or aluminum alloy can be used in cases where there are special requirements for the weight of the hanger itself.

[0049] The macroscopic shape of the hanger body 100 is not limited; it can be a cylindrical bar, a square bar, a rectangular plate, or any other geometric shape that is easy to process and use.

[0050] The pin hole 110 is a functional hole provided on the hanger body 100. Its purpose is to allow replaceable hanger pins to be inserted into it, thereby reliably fixing the hanger pins to the hanger body 100. The cross-sectional shape of the pin hole 110 is usually circular to accommodate the most common cylindrical hanger pins, but in order to match specially designed irregularly shaped hanger pins, its cross-section can also be processed into square, elliptical, hexagonal or other non-circular shapes.

[0051] The ash drain trough 120 is a precisely designed trough-shaped structure that must be connected to the bottom of the pin hole 110. This design fundamentally eliminates the closed bottom of the pin hole 110, giving what would otherwise be a blind hole an outward outlet at the bottom. The ash drain trough 120 must extend from its connection with the pin hole 110 to the outer surface of the hanger body 100. This provides an unobstructed passage for any material (e.g., powder residue) inside the pin hole 110 to the outside of the hanger. In one specific embodiment, the ash drain trough 120 may extend only to one outer surface of the hanger body 100; in another, more preferred alternative embodiment, it may extend through the hanger body 100 to both opposite outer surfaces. A key technical feature of the ash drain trough 120 itself is that the width of its trough is designed to be less than the critical distance for electrostatic adsorption of powder.

[0052] The anti-clogging function in this embodiment is achieved through a dual-action mechanism, namely the synergistic effect of "physical slag removal" and "electrostatic shielding".

[0053] In traditional hangers, paint powder entering the pin hole 110, after undergoing high-temperature curing, accumulates layer by layer at the bottom of the closed hole and is compacted into hard lumps that are difficult to remove. By setting up a dust drain trough 120 that is connected to the bottom of the pin hole 110 and opens to the outside, a physical discharge channel is constructed for these residues. The working process is as follows: During the process of the hanger undergoing high-temperature sintering and subsequent cooling, the powder residue inside the hole becomes loose and fragmented due to thermal stress. Under the action of gravity, or under the normal vibration generated by the operation of the production line, these loose residues will naturally fall from the bottom of the pin hole 110 and directly enter the dust drain trough 120 connected to it. Since the dust drain trough 120 is an open channel to the outside, these residues will be completely discharged from the hanger body 100 along the channel, thereby realizing automatic cleaning in each production cycle and fundamentally preventing the accumulation of residues over time.

[0054] Simply providing a slag discharge channel is insufficient; it's also crucial to ensure that the channel itself doesn't become clogged. This is the key to the feature that "the width of the ash discharge trough 120 is less than the critical distance for powder electrostatic adsorption." During electrostatic spraying, charged paint powder is primarily adsorbed onto the grounded workpiece or hanger surface along the electric field lines. For a narrow and deep trough, its internal space creates a "Faraday cage" effect, making it difficult for the electric field lines to penetrate deeply, resulting in an electric field strength inside the trough that is much lower than on its outer surface. When the trough width is controlled within a sufficiently small critical dimension (e.g., less than 3 mm), this electrostatic shielding effect becomes very significant. Most charged powder particles cannot penetrate deep into the ash discharge trough 120 and adhere to its inner wall due to insufficient electric field adsorption force. This significantly reduces the amount of powder accumulated in the ash discharge trough 120 itself, ensuring that the physical slag discharge channel remains unobstructed and effective for a long time, thus qualitatively improving the reliability of the entire anti-clogging structure.

[0055] Example 2

[0056] like Figures 1 to 3 As shown, this embodiment provides an anti-clogging spraying fixture. Based on the solution described in Embodiment 1, it provides a verified and precise numerical range for the width of the ash leakage groove 120, which can achieve the best technical effect.

[0057] In this embodiment, the width of the ash discharge trough 120 is 1.8 mm to 2.2 mm.

[0058] This is not an arbitrary size limitation, but rather a specific and quantitative determination of the width of the ash drain trough 120 being less than the critical distance for powder electrostatic adsorption, within an optimal process window derived through experimental and theoretical analysis. This means that when the width of the ash drain trough 120 is controlled within this narrow range, the performance of the entire anti-clogging spraying fixture will reach its peak.

[0059] The primary function of the ash discharge trough 120 is to act as a physical channel for the smooth discharge of powder residue falling from the bottom of the pin hole 110. This residue is not fine dust, but rather particles, debris, or lumps of a certain size and irregular shape formed after high-temperature curing. If the width of the ash discharge trough 120 is too narrow (e.g., significantly less than 1.8 mm), bridging or jamming is highly likely to occur, meaning that slightly larger residue particles will get stuck when passing through the narrow channel, thus blocking the entire channel. Therefore, a lower limit of 1.8 mm ensures that the ash discharge channel has sufficient capacity, accommodating the size of residue generated in most cases, ensuring the long-term effectiveness and high reliability of the physical ash discharge function.

[0060] Another key function of the dust collection trough 120 is to suppress powder adhesion during the spraying stage. As mentioned earlier, this relies on the electrostatic shielding effect generated by its narrow width. However, the strength of this shielding effect is directly related to the width of the trough: the narrower the trough, the stronger the shielding effect. If the width of the dust collection trough 120 is too wide (e.g., significantly greater than 2.2 mm), the electric field strength within its interior space will not be sufficiently weakened, and electric field lines will still penetrate deep into it. This will give charged paint powder a sufficient opportunity to be adsorbed onto the inner wall of the dust collection trough 120, and over time, the dust collection trough 120 itself will gradually become filled with powder and fail. Therefore, the upper limit of 2.2 mm is a guarantee to ensure that the electrostatic shielding effect can be stably and effectively activated, thereby achieving the important function of "self-cleaning of the slag discharge channel".

[0061] The width range of 1.8 mm to 2.2 mm ensures that the outlet is large enough to allow waste to be discharged smoothly, while the inlet is narrow enough to effectively prevent new waste from entering. It is a golden size that has been precisely calculated and experimentally verified, allowing the physical slag removal and electrostatic shielding mechanisms to perform at their best simultaneously, thereby maximizing the overall performance and long-term stability of the entire anti-clogging structure.

[0062] Although 1.8 mm to 2.2 mm is a very general optimization range, in certain specific application scenarios, the following alternative implementation methods also exist:

[0063] Customized widths are possible for specific powders. Different coating powders may have different particle size distributions and electrical properties. Therefore, the width of the ash discharge trough 120 can be fine-tuned according to the specific powder type used. For example, for powders with generally finer particles and extremely strong electrostatic adsorption, the optimization range can be narrowed to "1.8 mm to 2.0 mm" to pursue the ultimate electrostatic shielding effect; while for powders with larger particles and good flowability, the width can be appropriately widened to "2.0 mm to 2.4 mm" to obtain greater slag discharge margin.

[0064] The ash drain trough 120 in this embodiment is a non-uniform width design. In an alternative, the ash drain trough 120 can be designed with a non-uniform width structure. For example, it can be designed as a slightly tapered groove with an inlet end (connected to the pin hole 110) 2.2 mm wide and an outlet end (on the outer surface of the hanger body 100) 1.8 mm wide. This "wide inlet, narrow outlet" design theoretically facilitates the smooth entry of residue from the pin hole 110 into the ash drain trough 120 while maximizing the electrostatic shielding effect over most of the trough area.

[0065] In some special fixture structures, the ash discharge trough 120, with its composite width design, may be very deep and long. To balance slag discharge and anti-clogging, a segmented composite width design can be adopted. For example, the inlet section of the ash discharge trough 120 near the pin hole 110 has a width of 2.2 mm to ensure smooth entry of residue; while the width of the middle and outlet sections of the ash discharge trough 120 is reduced to 1.8 mm to enhance the electrostatic shielding effect and prevent powder from adhering in the long channel.

[0066] Example 3

[0067] like Figures 1 to 3 As shown, this embodiment provides an anti-clogging spraying fixture. Based on the basic structure disclosed in Embodiment 1, it provides a preferred structural form for the ash drain trough 120. This form aims to maximize the maintainability and long-term reliability of the fixture.

[0068] In this embodiment, the ash-draining groove 120 extends horizontally through one or both sides of the hanging fixture body 100.

[0069] This means that the slag discharge channel extending from the bottom of the pin hole 110 is mainly arranged in a horizontal or near-horizontal direction, and ultimately opens onto the side of the hanger body 100. This design includes two specific implementation forms:

[0070] 1. Single-sided through-hole structure (basic scheme): The ash discharge trough 120 extends horizontally from the bottom of the pin hole 110 towards one side of the hanger body 100, and finally forms an opening on the outer surface of that side. This structure forms a horizontal ash discharge blind trough. Compared to a vertical ash discharge hole that only opens at the bottom of the hanger body 100, the horizontal outlet can effectively avoid secondary pollution and blockage of the outlet caused by splashed paint when dripping spraying is performed directly below the hanger. At the same time, the lateral opening also makes it easier for operators to use tools such as cleaning rods, steel needles, or high-pressure air guns for forced unblocking and cleaning.

[0071] 2. Two-sided through-hole structure (preferred option): The ash-draining groove 120 penetrates both opposite sides of the hanger body 100 in a horizontal direction, forming a completely open horizontal channel that intersects with the bottom of the vertical pin hole 110. It possesses all the advantages of a single-sided through-hole structure and brings a more significant performance improvement.

[0072] In terms of cleaning and maintenance, the through-channel structure allows for the most efficient penetrating cleaning. Operators can use a high-pressure air gun or high-pressure water gun to inject cleaning medium from one end of the ash chute 120. The powerful air or water flow will completely pass through the entire channel and spray out from the other end, easily and thoroughly washing away any stubborn residue, which is unmatched by a single-sided blind chute structure.

[0073] In terms of inspection and diagnosis, the open channel facilitates visual inspection. Maintenance personnel only need to observe one end of the ash trough 120 to see if it is clear, which can quickly and accurately determine whether the channel is unobstructed, greatly improving the efficiency of maintenance work.

[0074] As a best example, such as Figures 1 to 3 As shown, the hanger body is made of round steel with a diameter of φ14mm. Holes are drilled into the hanger body, with each pin hole having a diameter of φ3.0±0.1mm and a depth of 20.0mm. A vertical ash-leaking groove is machined at the bottom of each pin hole, with the following parameters:

[0075] The groove width is 2.0 ± 0.2 mm (precision is ensured by EDM wire cutting).

[0076] The groove depth is 6.5-8.0mm (0.5-1.0mm deeper than the pin hole for connection).

[0077] The groove runs through both sides of the hanging fixture body.

[0078] The first central axis and the second central axis are arranged at an angle of approximately 135°, forming a Y-shaped through structure.

[0079] During the sintering process, when the fixture temperature rises to 200-300℃, the residual powder expands due to heat, generating microcracks. During the cooling stage (<80℃), a thermal deformation difference of 0.05-0.1mm occurs between the tank and the pin hole, forming a slag discharge gap. The residue slides down the ash discharge trough under gravity, and actual measurements show that over 98% of the residue can be discharged in a single sintering cycle. The 2.0mm wide tank design ensures that the space inside the tank is less than the critical distance required for electrostatic powder adsorption (usually ≥3mm), forming a shielded area with an electric field strength <0.5kV / mm during the spraying stage. Verification shows that the powder adhesion in this area is only 3%-5% of that on a conventional flat surface.

[0080] The above example underwent 100 spraying and sintering cycle tests, and the single-time blockage rate was reduced from 23.6% in the traditional structure to below 0.5%; the effective depth of the pin hole was maintained at 18-20mm; the maintenance cycle of the spraying fixture was extended from 72 hours to 144 hours; and the production yield was improved from 92.1% to 99.7%.

[0081] Although the above-described horizontally penetrating structure is the preferred embodiment, other alternative implementations exist in certain specific designs or application scenarios, which can also achieve the purpose of preventing blockage:

[0082] With its downward-sloping through-structure, the ash discharge trough 120 does not have to follow a purely horizontal path. Instead, it starts from the bottom of the pin hole 110 and extends at a downward angle to the outer side surface of the hanger body 100. This design retains the advantages of a lateral outlet while better utilizing the component of gravity to assist the residue in sliding outward, further improving the efficiency and reliability of passive ash discharge.

[0083] In some particularly complex fixture bodies 100, a curved or L-shaped channel structure may not be possible to achieve a straight path from the bottom of the pin hole 110 to the outer surface. In such cases, the ash discharge trough 120 can be designed as a curved or L-shaped structure consisting of two mutually perpendicular channels. Although this non-linear path is slightly inconvenient during forced cleaning, it still forms a complete slag discharge channel, solving the problem of grooving in complex structures.

[0084] As the simplest alternative, the vertically downward slag discharge structure, with the slag trough 120 extending vertically downwards directly below the pin hole 110 and opening onto the bottom surface of the hanger body 100, offers the shortest slag discharge path. However, in some processes, its outlet may be easily contaminated by paint splashes from below. It is typically suitable for spraying scenarios where the bottom of the hanger has ample space and is less prone to contamination.

[0085] For larger or uniquely shaped fixture bodies 100, the multi-outlet bifurcated channel structure allows the ash discharge trough 120 below a pinhole 110 to be designed as a "Y" or "X" shaped bifurcated structure. This means one inlet channel branches into two or more independent sub-channels, each extending to a different outer surface of the fixture body 100. This design provides redundant ash discharge paths, ensuring that even if one outlet becomes accidentally blocked, the others can continue operating, thus greatly enhancing the reliability of the entire anti-clogging system.

[0086] Example 4

[0087] like Figures 1 to 3 As shown, this embodiment provides an anti-clogging spraying fixture. Based on the above embodiments, the spatial layout relationship of key components has been thoroughly optimized and defined. It does not propose new components, but rather aims to maximize the self-cleaning efficiency and long-term operational reliability of the fixture through precise design of the geometric configuration between the pin hole 110 and the ash drain trough 120.

[0088] In this embodiment, the relative positional relationship between the pin hole 110 and the ash discharge groove 120 in three-dimensional space is defined. To accurately describe this relationship, two concepts are introduced:

[0089] The first central axis is an imaginary straight line passing through the center of the pin hole 110, representing the extension direction of the pin hole 110.

[0090] The second central axis is an imaginary straight line passing through the center of the ash trough 120, representing the extension direction of the ash trough 120 and the slag discharge path.

[0091] The oblique intersection means that the two axes are neither parallel nor perpendicular (90 degrees), but rather meet at an acute or obtuse angle in the bottom region of the pin hole 110. This arrangement macroscopically forms an internal channel structure resembling the letter Y.

[0092] In this embodiment, the angle between the first central axis and the second central axis is limited to an optimized range, namely 95 degrees to 175 degrees. Within this preferred range, there exists a theoretically and practically optimal angle of 135 degrees.

[0093] The diagonally intersecting Y-shaped structure provides a gentle, sloping transition for the falling residue. Instead of crashing into the next section of the channel, the residue is smoothly guided into the ash discharge trough 120. This structure greatly reduces flow resistance and utilizes the component of gravity to guide the residue more smoothly toward the outlet, thereby maximizing the efficiency of passive ash removal (by gravity alone).

[0094] When the included angle is less than 95 degrees, the configuration increasingly resembles an inefficient T-shaped structure, the obstruction effect of the corner becomes significant, and the smoothness of slag discharge decreases. Therefore, setting the lower limit to 95 degrees ensures that the structure can always provide an effective slope guidance effect.

[0095] When the included angle is greater than 175 degrees, it approaches a 180-degree I-shaped structure (i.e., the ash discharge trough 120 is directly below the pin insertion hole 110). Although the ash discharge path of the I-shaped structure is the most direct, it severely weakens the support for the bottom of the hanging pin, and may even cause the hanging pin to pass directly through the ash discharge trough 120 and fail to be effectively fixed. Therefore, setting the upper limit to 175 degrees ensures that there is still enough solid material on the side wall of the pin insertion hole 110 to stably support and limit the hanging pin.

[0096] In a preferred embodiment, the second central axis (ash trough axis) is set vertically, and the ash trough is a channel perpendicular to the horizontal plane. Once the residue falls off from the bottom of the inclined pin hole and enters the ash trough, it will immediately fall along the most direct vertical path and be discharged under the maximum force of gravity, without any detours or obstructions, resulting in the highest slag discharge efficiency.

[0097] Although the Y-shaped structure is the preferred solution in this embodiment, there are other alternative implementation methods in certain specific design or application scenarios:

[0098] The first central axis can be aligned with or parallel to the second central axis (with an included angle of 180 degrees). However, this requires a prerequisite: the cross-sectional area of ​​the pin hole 110 must be greater than the cross-sectional area of ​​the ash discharge trough 120. This creates a ring-shaped step at their junction, which supports the pin without completely blocking the slag discharge channel. While this solution is feasible, its support stability for the pin is not as good as that of the Y-shaped structure.

[0099] Another alternative is to avoid using an acute angle between the bottom of the pin hole 110 and the inlet of the ash discharge trough 120, and instead machine a smooth arc or curved surface for transition. This design can also eliminate dead angles and guide the smooth flow of residue, but it may be more complex to manufacture.

[0100] For a single insertion hole 110, two or more ash discharge troughs 120 can be provided and connected to its bottom. The second central axis of these ash discharge troughs 120 can intersect the first central axis at different angles to form a more complex Y or X-shaped branch structure to enhance the slag discharge capacity from multiple directions.

[0101] Example 5

[0102] like Figures 1 to 3 As shown, this embodiment provides an anti-clogging spraying fixture. Based on the technical solutions of any previous embodiment, this embodiment applies a key supplementary limitation to the geometric dimensions of the pin hole 110 itself. This limitation does not exist in isolation, but rather works synergistically with the function of the ash leakage trough 120 to jointly improve the performance and reliability of the entire anti-clogging system.

[0103] In this embodiment, the equivalent diameter of the pin hole 110 is less than 3 mm.

[0104] Here, we need to clarify the term "equivalent diameter." It is an engineering concept used to uniformly describe the size of non-circular cross-section holes.

[0105] If the cross-section of the pin hole 110 is a standard circle, then its equivalent diameter is the actual diameter of that circle.

[0106] If the pin hole 110 is designed as a square, rectangular, elliptical or other irregular shape to accommodate irregularly shaped pins, its equivalent diameter is usually calculated according to the hydraulic diameter in fluid dynamics (i.e., 4 × cross-sectional area / wetted perimeter) to characterize its throughput capacity.

[0107] Therefore, the essential requirement of this feature is that, regardless of the specific shape of the pin hole 110, the size of its effective through-hole should be controlled below a specific threshold (3 mm). This feature is a geometric constraint on the pin hole 110 itself, which, together with the geometry of the ash discharge trough 120, constitutes the complete system of this anti-clogging structure design. The purpose is to achieve source control of the total amount of powder entering the pin hole 110, thereby cooperating with the end discharge function of the ash discharge trough 120.

[0108] The self-cleaning function of the dust collection trough 120 mainly relies on passive forces such as gravity, and the amount of residue it can effectively discharge per unit time is limited. If the opening of the pin hole 110 is too large, for example, with an equivalent diameter much greater than 3 mm, it means that the total amount of powder entering during the spraying process will increase dramatically. When this amount of powder entering exceeds the design load of the passive dust collection trough 120, even if the dust collection channel itself is not blocked, the accumulation rate of powder residue may be faster than its discharge rate, ultimately leading to abnormal and rapid blockage.

[0109] By controlling the equivalent diameter of the pin hole 110 to below 3 mm, the total amount of powder entering the hole can be limited to a controllable and reasonable range from the source. This powder amount is easily handled by the self-cleaning system of the ash trough 120. This ensures a dynamic balance between input and output, matching and coordinating with the ash trough 120's slag discharge capacity. Together, they ensure that the anti-clogging system operates stably and reliably under most operating conditions, without failing due to extreme situations (such as excessively thick coating or excessively good powder flowability).

[0110] Although this embodiment provides a specific threshold, there are other alternative implementation methods in certain specific design or application scenarios:

[0111] 3 mm is an optimized critical value, validated through extensive experimentation, applicable to most common powder coatings and spraying processes, rather than a fixed physical constant. This threshold can be fine-tuned for certain specific applications. For example, for powders with finer particles and extremely high flowability, this critical value may need to be set even lower, such as 2.8 mm, to achieve better source control. Conversely, for powders with larger particles that do not easily enter pores, this threshold can be appropriately relaxed to 3.2 mm.

[0112] Besides directly limiting the size of the hole, the amount of powder entering can also be indirectly affected by changing the geometry of the pin hole 110 at the inlet on the outer surface of the hanger body 100. For example, a special reverse chamfer or a sharp edge can be designed. Compared to the traditional rounded chamfer that facilitates insertion, this design creates a different disturbance effect on the airflow during spraying, thereby repelling the entry of powder to a certain extent, similar to reducing the effective powder entry area.

[0113] A more complex alternative involves actively suppressing powder ingress instead of relying solely on geometric constraints. For example, a system could be designed to blow a weak airflow from inside the pin hole 110 during spraying, creating an air curtain to prevent powder entry. Alternatively, a mechanical structure could be designed to temporarily shield the orifice during spraying. While these solutions achieve the same purpose, they significantly increase the complexity and cost of the mounting fixture.

[0114] Example 6

[0115] like Figures 1 to 3 As shown, this embodiment provides an anti-clogging spraying fixture. Based on the previous embodiments, the material and macroscopic shape of the fixture body 100 are optimized. This ensures that the anti-clogging spraying fixture not only solves the technical problem of hole clogging, but also achieves optimal process adaptability, durability, and economic benefits in real industrial production environments.

[0116] In this embodiment, the hanger body 100 is made of metal.

[0117] Furthermore, the hanger body 100 is cylindrical.

[0118] The main body of the hanger 100 must be made of one or more metals or metal alloys. This is a function-driven material selection requirement and is a fundamental prerequisite for ensuring that the hanger can be used normally, stably, and for a long time on the electrostatic spraying production line.

[0119] The core principle of electrostatic spraying is to use a high-voltage electrostatic field to attract negatively charged paint powder to a grounded workpiece under the influence of the electric field. In this process, the hanger, acting as the connector between the workpiece and the grounding system of the spraying line, must itself be a good electrical conductor. If the hanger body 100 is made of non-metallic materials, current cannot flow, an effective electrostatic adsorption field cannot be established, and the entire electrostatic spraying process will be impossible. Therefore, using metallic materials is a fundamental requirement for achieving the function of electrostatic spraying.

[0120] After spraying, the workpiece needs to undergo high-temperature treatment in a curing or sintering furnace (typically between 200°C and 300°C) to melt, level, and ultimately solidify the paint powder into a film. The mounting fixture undergoes a complete thermal cycle along with the workpiece during this process. Metallic materials generally possess high melting points and excellent high-temperature stability, enabling them to maintain their structural integrity and mechanical strength during this repeated heating and cooling process, without melting, softening, deforming, or degrading. Non-metallic materials (such as most plastics) cannot withstand this temperature, leading to fixture failure.

[0121] The hanger body 100 and its pins need to bear the full weight of the workpiece to be coated and undergo various movements and vibrations driven by the conveyor chain. The metal material has high strength, high rigidity and good toughness, which can ensure that the hanger will not break or deform excessively under full load, thereby ensuring the safety and reliability of the production process.

[0122] While ordinary carbon steel is the most cost-effective option, there are several feasible alternative implementation methods for different application scenarios:

[0123] When the cleaning process of the cleaning rack involves the use of acidic or alkaline chemicals, or when the working environment has high humidity, stainless steel (such as 304 stainless steel) can be selected as the material for the rack body 100. Its excellent corrosion resistance can greatly extend the service life of the rack and reduce maintenance costs caused by rust.

[0124] In situations where there are strict requirements regarding the weight of the fixture itself, such as to reduce the load on the conveyor chain or to facilitate manual operation by workers, aluminum alloy can be used to manufacture the fixture body 100. Aluminum alloy provides sufficient strength while having a much lower density than steel, thus achieving weight reduction.

[0125] In certain special spraying processes with extremely high curing temperatures, if the thermal stability of conventional steel is insufficient, more specialized high-temperature resistant alloy materials can be selected.

[0126] The cylindrical design of the hanger body 100 is primarily based on considerations of process economy, with the core objective of saving paint powder and reducing production costs. Among all cylinders with the same length and cross-sectional area, the cylinder has the smallest surface area. During the spraying process, paint powder not only adheres to the target workpiece but also inevitably adheres to the exposed surface of the hanger. This portion of paint adhering to the hanger is called "overspray adhesion," which is a waste in the process.

[0127] By adopting a cylindrical design, the surface area of ​​the hanger body 100 is minimized. This means that in each spraying cycle, the amount of paint powder adhering to and wasted on the hanger body 100 due to overspray is also minimized. For large-scale, long-cycle industrial production, this seemingly insignificant saving in a single cycle will result in very considerable cost savings after accumulating over thousands of cycles.

[0128] While a cylindrical shape is the most economically optimal choice, in certain specific situations, the hanger body 100 can also adopt other shapes, which are equally functional, only slightly less effective in terms of paint savings:

[0129] Square or rectangular bars are the most common alternative shapes. Sometimes it may be easier to source square or rectangular bars, or in certain clamping or mounting structures, a flat surface is more advantageous for positioning.

[0130] Hexagonal bars are also a common type of industrial profile. They are easy to source, and their flat surfaces make them easy to clamp during processing.

[0131] Custom profiles: In some highly specialized hanger designs, the hanger body 100 may be designed with a special irregular cross-section to match specific workpieces or achieve additional functions.

[0132] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this application. Any specific values ​​in all examples shown and discussed herein should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0133] Furthermore, it should be noted that the use of terms such as "first" and "second" is merely for ease of distinction, and unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application.

[0134] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A clog-resistant spray coating hanger, characterized in that, include: The hanging fixture body (100) is provided with at least one pin hole (110) and at least one ash drain groove (120); The pin insertion hole (110) is used to insert a hanging pin; The ash-leaking groove (120) is connected to the bottom of the pin hole (110) and extends to the outer surface of the hanger body (100). The width of the ash-leaking groove (120) is less than the critical distance for electrostatic adsorption of powder.

2. The anti-clogging spraying fixture according to claim 1, characterized in that: The width of the ash trough (120) is 1.8 mm to 2.2 mm.

3. The anti-clogging spraying fixture according to claim 1 or 2, characterized in that: The ash leakage groove (120) penetrates the radial section at the bottom of the pin hole (110).

4. The anti-clogging spraying fixture according to claim 1, characterized in that: The ash drain trough (120) extends horizontally through one or both sides of the hanger body (100).

5. The anti-clogging spraying fixture according to claim 1, characterized in that: The pin hole (110) has a first central axis; The ash trough (120) has a second central axis; The first central axis intersects the second central axis at an oblique angle.

6. The anti-clogging spraying fixture according to claim 5, characterized in that: The second central axis is set in the vertical direction.

7. The anti-clogging spraying fixture according to claim 5, characterized in that: The angle between the first central axis and the second central axis is 95 degrees to 175 degrees.

8. The anti-clogging spraying fixture according to claim 1, characterized in that: The equivalent diameter of the pin hole (110) is less than 3 mm.

9. The anti-clogging spraying fixture according to claim 1, characterized in that: The hanger body (100) is made of metal.

10. The anti-clogging spraying fixture according to claim 1, characterized in that: The hanging fixture body (100) is cylindrical.

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