A gravity-type sand valve

Abstract

The present application relates to the field of rail transit braking technology, and particularly relates to a gravity type sanding valve. The gravity type sanding valve comprises a main valve body, wherein the main valve body is provided with a sand inlet, a sand channel assembly, a sand outlet head, an air inlet assembly, an air channel assembly and a sand blowing assembly. The air inlet assembly comprises an air inlet body, a total air inlet joint and a sand outlet air nozzle seat. The sand outlet air nozzle seat is detachably arranged on the air inlet body and is provided with the sand blowing assembly. The sand blowing assembly comprises a mounting seat, a needle rod, an elastic member and a sand outlet air nozzle. The sand blowing assembly is modularly designed, and the needle rod is inserted into the air channel of the sand outlet air nozzle by pressing, so as to dredge the air channel. The sanding efficiency is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of rail transit braking technology, specifically to a gravity-type sand-spreading valve. Background Technology

[0002] The sand-spraying valve is installed on the sand box of the rail vehicle. It uses compressed air inside the vehicle as a power source to spray sand particles between the wheel and rail to increase their adhesion, prevent wheel slippage and freewheeling, and ensure safe operation of the vehicle.

[0003] Existing sand-spreading valves all have two downward-facing nozzles, one in front and one behind, spraying air to lift and blow out sand particles. However, during use, these nozzles can become clogged by sand particles, leading to sand-spreading malfunctions. Furthermore, the airflow directly carrying sand particles causes abrasion to the internal sand-spreading chamber, risking damage to its surface. At the specified low pressure, existing sand-spreading valves eject sand particles in a weak, parabolic trajectory onto the rail surface instead of directly spraying them between the rail and wheelset wedges, resulting in low sand-spreading efficiency. Although sand-spreading technology has been continuously improved, these problems have not been fundamentally solved, leading to potential safety hazards for train operations.

[0004] In summary, there is an urgent need for a gravity-type sand-spreading valve that offers high sand-spreading efficiency, adjustable sand-spreading volume, and meets sand-spreading requirements to solve the problems existing in the current technology. Summary of the Invention

[0005] The purpose of this invention is to provide a gravity-type sand spreading valve with high sand spreading efficiency, adjustable sand spreading amount, and the ability to meet sand spreading requirements. The specific technical solution is as follows:

[0006] A gravity-type sand-spreading valve includes a main valve body, on which a sand inlet, a sand channel assembly, a sand outlet, an air inlet assembly, an air duct assembly, and a sand-blowing assembly are provided;

[0007] The sand channel assembly includes a first sand channel, a second sand channel, and a third sand channel connected in sequence. One end of the first sand channel is connected to the sand inlet, and the other end of the first sand channel is connected to the inlet of the third sand channel located in the sand outlet head through the second sand channel. The outlet of the third sand channel is connected to the sand outlet in the sand outlet head. A sand discharge port is provided at the bottom of the first sand channel.

[0008] The air inlet assembly includes an air inlet body, a main air inlet connector, and a sand outlet nozzle seat mounted on the air inlet body. The sand outlet nozzle seat is a columnar structure with a hollow channel and is detachably mounted on the air inlet body. A sand blowing assembly is provided on the sand outlet nozzle seat. The sand blowing assembly includes a needle rod, an elastic element, and a sand outlet nozzle. The sand outlet nozzle, mounted on the sand outlet nozzle seat, provides power for blowing out sand particles from the sand outlet head. The needle rod is inserted into the hollow channel and is movably mounted relative to the sand outlet nozzle via the elastic element. The air outlet on the sand outlet nozzle is cleaned by controlling the movement of the needle rod.

[0009] The air duct assembly includes a first air duct and a second air duct. The first air duct connects the main air inlet connector and the third sand channel in the sand outlet head, and is used to blow out the sand particles in the sand outlet head. The second air duct connects the main air inlet connector and the second sand channel, and is used to blow the sand particles in the second sand channel into the third sand channel.

[0010] Preferably, the air inlet body is provided with a tapered mounting hole that is wider at the top and narrower at the bottom, and the tapered mounting hole is provided with an internal thread; the sand outlet nozzle seat is a tapered body that matches the tapered mounting hole, and the outer wall of the tapered body is provided with an external thread that matches the internal thread.

[0011] Preferably, the sand discharge assembly further includes an elastic element mounting base and a pressing base. The sand discharge nozzle is installed at the bottom of the sand discharge nozzle base. The needle rod is inserted into the hollow channel in the sand discharge nozzle base until it reaches the end face of the sand discharge nozzle. The front end of the needle rod near the sand discharge nozzle is needle-shaped, and its outer diameter is smaller than the air outlet on the sand discharge nozzle. The elastic element mounting base is installed at the top of the sand discharge nozzle base. One end of the elastic element is installed on the elastic element mounting base, and the other end is connected to the pressing base installed at the top of the needle rod. By operating the pressing base, the needle rod is driven to move, thereby cleaning the air outlet on the sand discharge nozzle. The pressing base is located on the outside of the main valve body.

[0012] Preferably, the sand channel assembly further includes a fourth sand channel and a fifth sand channel. The central axis of the first sand channel is arranged vertically. The bottom end of the first sand channel is connected to the second sand channel through the fourth sand channel. The outlet of the second sand channel is connected to the third sand channel, which is inclined downwards along the centerline axis, through the fifth sand channel, which is arranged vertically along the central axis. The offset distance Y between the centerline axis of the first sand channel and the centerline axis of the second sand channel in the horizontal plane is 10-20mm. The offset distance X between the top surface of the connection between the second and fifth sand channels and the bottom surface of the connection between the third and fifth sand channels in the vertical plane is 10-15mm.

[0013] Preferably, the two ends of the second sand channel are enclosed by a sand-pushing cap seat, an airflow cap, and a baffle cleaning seat;

[0014] The baffle cleaning seat is used to open the second sand channel laterally to clean the impurities mixed in the second sand channel; the distance between the baffle cleaning seat and the central axis of the second sand channel is 30-40mm.

[0015] The airflow cap is installed on the second sand channel via a sand-pushing cap seat. The airflow through the second air channel blows out compressed air after passing through the airflow cap, which is used to drive the sand particles flowing into the second sand channel forward into the third sand channel.

[0016] Preferably, the airflow cap includes a hollow column and a core structure disposed within the column, wherein the core structure is a sheet-like or plate-like structure with micropores.

[0017] Preferably, the main valve body is further provided with a sand-spraying amount adjustment mechanism, which includes an adjustment column for adjusting the airflow size passing through the airflow cap.

[0018] Preferably, the air inlet assembly further includes a filter assembly, which includes a filter mounting base and a filter. The filter is mounted in the air inlet body through the filter mounting base. The filter is a hollow columnar structure with a cavity. The main air inlet connector communicates with the cavity of the filter, so that the air entering through the main air inlet connector passes through the filter and flows smoothly into the airflow cap and out.

[0019] Preferably, the sand discharge port is detachably provided with a sand-blocking plug and a sand-blocking cover, and a portion of the sand-blocking plug can be inserted into the sand discharge port; the sand-blocking cover is located on the outside of the sand-blocking plug and is used to completely seal the sand discharge port.

[0020] The application of the technical solution of the present invention has the following beneficial effects:

[0021] (1) The gravity-type sand-spreading valve of the present invention includes a main valve body, on which a sand inlet, a sand channel assembly, a sand outlet, an air inlet assembly, an air duct assembly, and a sand-blowing assembly are provided. The air inlet assembly includes an air inlet body, a main air inlet connector, and a sand outlet nozzle seat. The sand outlet nozzle seat is detachably mounted on the air inlet body, and the sand outlet nozzle seat is provided with a sand-blowing assembly. The sand-blowing assembly includes a mounting base, a needle rod, an elastic element, and a sand outlet nozzle. In the prior art, the sand outlet nozzle on the sand-spreading valve blows out the stirred-up sand particles. Although blockage rarely occurs in actual use, if the air duct of the nozzle is blocked by sand particles, the conventional method is to disassemble the sand outlet nozzle, then use a wire or other needle-like object to clear the air duct, and finally reassemble it. This process is time-consuming and labor-intensive. However, the present invention, through the modular design of the sand-blowing assembly and by pressing the needle rod to insert it into the air duct of the sand outlet nozzle to clear it, can achieve a fast and effective cleaning effect, which can greatly improve the sand-spreading efficiency.

[0022] (2) The air inlet body of this invention is provided with a tapered mounting hole that is wider at the top and narrower at the bottom, and the tapered mounting hole is provided with an internal thread; the lower end of the sand outlet nozzle seat is a tapered body that matches the tapered mounting hole, and the outer wall of the tapered body is provided with an external thread that matches the internal thread. This invention adopts an external structure for the sand blowing assembly, which is convenient for disassembly and maintenance; when the sand blowing assembly needs to be removed as a whole for maintenance, sand particles or dust will inevitably be brought out. This invention adopts a tapered face contact form, which on the one hand ensures that sand particles or dust will not easily fall into the countersunk hole on the end face, and on the other hand ensures that the sand particles or dust that fall in will flow out by themselves with the inclined surface, avoiding contamination.

[0023] (3) The sand channel assembly in this invention also includes a fourth sand channel and a fifth sand channel. The central axis of the first sand channel is set in the vertical direction. The bottom end of the first sand channel is connected to the second sand channel through the fourth sand channel. The outlet of the second sand channel is connected to the third sand channel, which is set at an incline downwards, through the fifth sand channel, which is set in the vertical direction of the central axis. The offset distance Z between the central axis of the first sand channel and the central axis of the second sand channel in the horizontal plane is 10-20mm. The offset distance X between the central axis of the second sand channel and the central axis of the third sand channel in the vertical plane is 10-15mm. This invention employs a five-channel sand distribution design. Since sand particles flow directly downwards through the first channel, the weight of the accumulated sand particles is concentrated at the bottom of the first channel. At this point, the airflow lifts the sand particles flowing in. If the second channel were perpendicular to the first, the compressed air might not be able to lift the sand particles or might experience stagnation, leading to unstable sand distribution. Therefore, the second channel is offset so that the weight of the sand particles acts on the bottom of the first channel, allowing them to flow through the fourth channel to the second channel by their own weight. In this case, the airflow only needs to lift a portion of the sand particles flowing into the second channel, improving the stability of sand distribution. The vertical offset distance X between the top surface of the connection between the second and fifth channels and the bottom surface of the connection between the third and fifth channels is 10-15mm. This difference prevents sand particles flowing from the first channel into the second channel from overflowing from the third channel due to vibration during rail vehicle operation.

[0024] (4) In this invention, the two ends of the second sand channel are sealed by a sand-pushing cap seat, an airflow cap, and a baffle cleaning seat. The original sand-spreading valve's agitator nozzles were all installed downwards, their function being to agitate the sand particles in the sand chamber. Because they directly contacted the raised sand particles, blockages frequently occurred, leading to poor sand spreading, requiring disassembly and maintenance. Furthermore, the high-speed airflow vertically spraying onto the sand chamber surface would cause significant impact and wear. Therefore, this invention adopts an airflow cap design. The airflow cap only allows gas to pass through, while retaining sand particles on the outer surface of the permeation plate. With the input of compressed air through the main air inlet, even dust adhering to the outer surface of the sintering plate will be discharged with the compressed air, equivalent to a self-cleaning process, preventing blockage. Moreover, after the gas passes through the airflow cap, the pressure is reduced while the compressed air is dispersed, resulting in a very low spray force, avoiding direct impact and wear on the components.

[0025] (5) The main valve body of the present invention is also provided with a sand-spreading amount adjustment mechanism, which includes an adjustment column for adjusting the airflow through the airflow cap. Existing sand-spreading valves adjust the sand-spreading amount by changing the total air intake. The sand-spreading nozzle and the sand-stirring nozzle in the sand-spreading valve have the same air duct input. When the required sand-spreading amount is small, the air volume will also be reduced accordingly. At this time, due to the limited air volume blown out, the sand particles it carries will be weakly ejected onto the rail surface in a parabolic shape, instead of being directly sprayed between the wedge angle of the rail and the wheelset, resulting in low sand-spreading efficiency. The present invention designs the sand-spreading amount adjustment mechanism at the air duct leading to the airflow cap. When the total air intake is at the rated value, the high-pressure air directly to the sand outlet nozzle ensures the sand blowing force. By adjusting the air volume at the sand outlet nozzle, the amount of sand blown up can be controlled, thereby adjusting the sand-spreading amount. Finally, the airflow blown out by the sand outlet nozzle will spray the sand particles at high speed between the wedge angle of the rail and the wheelset, improving the sand-spreading efficiency.

[0026] (6) The air inlet assembly of this invention also includes a filter assembly, which includes a filter mounting base and a filter. The filter assembly is designed to ensure that sufficient compressed air enters the airflow cap while blocking impurities in the air to prevent contamination of the air duct. The sand discharge port is detachably equipped with a sand plug and a sand cover. When the sand plug and sand cover are opened, large particles of impurities can be cleaned and flow out along the first sand channel. When the sand plug and sand cover are closed, sand particles can be prevented from continuing to flow out.

[0027] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 This is a schematic diagram of the gravity sand-spreading valve in a preferred embodiment of the present invention;

[0030] Figure 2 yes Figure 1 AA section view;

[0031] Figure 3 yes Figure 2 A magnified view of a portion of the image;

[0032] Figure 4 yes Figure 1 CC section view;

[0033] Figure 5 yes Figure 1A structural diagram from another perspective;

[0034] Figure 6 yes Figure 5 BB cross-sectional view;

[0035] Figure 7 yes Figure 1 The D-direction view;

[0036] The components include: 1. Main valve body; 2. Sand inlet; 3. Sand channel assembly, including 3.1 First sand channel, 3.2 Second sand channel, 3.3 Third sand channel, 3.4 Fourth sand channel, and 3.5 Fifth sand channel; 4. Sand outlet head; 5. Air inlet assembly, including 5.1 Air inlet body, 5.2 Main air inlet connector, 5.3 Sand outlet nozzle seat, 5.4 Filter assembly, including 5.4.1 Filter mounting seat, and 5.4.2 Filter; 6. Duct assembly, including 6.1 First duct, 6.2 Second duct, 6.3 Third duct, 6.4 Fourth duct, 6.5 Fifth duct, and 6.6 Fifth duct. 6. Air ducts: 6.7, 7. Air ducts: 6.8, 8. Air ducts: 6.9, 9. Air ducts: 6.10, 10. Air ducts: 6.11, 11. Air ducts: 6.12, 12. Air ducts: 6.13, 13. Air ducts: 6.14, 14. Air ducts: 6.15, 15. Air ducts: 7. Sand blowing assembly: 7.1, Pressing seat: 7.2, Needle rod: 7.3, Elastic element: 7.4, Sand discharge nozzle: 7.5, Elastic element mounting seat: 8. Sand pushing cap seat: 9. Airflow cap: 10. Baffle cleaning seat: 11. Adjusting column: 12. Sand plug: 13. Sand plug cover: 14. Plug: Detailed Implementation

[0037] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0038] Example:

[0039] A gravity-type sand-spreading valve is installed at the outlet of the lower part of a sand box, which can be any type of sand box in the prior art.

[0040] The gravity-type sand-spreading valve of this embodiment includes a main valve body 1, which is provided with a sand inlet 2, a sand channel assembly 3, a sand outlet 4, an air inlet assembly 5, an air duct assembly 6, and a sand-blowing assembly 7. See [reference needed] Figures 1-7 The detailed structure is as follows:

[0041] The main valve body 1 has a sand channel assembly 3 internally machined with channels for sand particle flow, see [link / reference]. Figure 2 , Figure 4 , Figure 6 and Figure 7The sand channel assembly 3 includes a first sand channel 3.1, a second sand channel 3.2, a third sand channel 3.3, a fourth sand channel 3.4, and a fifth sand channel 3.5. One end of the first sand channel 3.1 is connected to the sand inlet 2, and the other end of the first sand channel 3.1 is connected to the inlet of the third sand channel 3.3 in the sand outlet head 4 through the fourth sand channel 3.4, the second sand channel 3.2, and the fifth sand channel 3.5. The outlet of the third sand channel 3.3 is connected to the sand outlet in the sand outlet head 4. The bottom of the first sand channel 3.1 is provided with a sand discharge port. Preferably, the central axis of the first sand channel 3.1 is vertically oriented; the bottom end of the first sand channel 3.1 is connected to the second sand channel 3.2 via the fourth sand channel 3.4; the outlet of the second sand channel 3.2 is connected to the third sand channel 3.3, which is inclined downwards along its central axis, via the fifth sand channel 3.5, which is vertically oriented along its central axis; the horizontal offset distance Z between the central axis of the first sand channel 3.1 and the central axis of the second sand channel 3.2 is 10-20 mm; the vertical offset distance X between the top surface of the connection between the second sand channel 3.2 and the fifth sand channel and the bottom surface of the connection between the third sand channel 3.3 and the fifth sand channel is 10-15 mm. This drop prevents sand particles flowing from the first sand channel into the second sand channel from overflowing from the third sand channel due to vibration during the operation of the rail vehicle. More preferably, the central axes of the second and fourth sand channels are inclined downwards along the direction of the sand particles.

[0042] The air inlet assembly 5 includes an air inlet body 5.1, a main air inlet connector 5.2, and a sand outlet nozzle seat 5.3, as detailed below. Figure 2 and Figure 3The sand outlet nozzle seat 5.3 is detachably mounted on the air inlet body 5.1, and the sand outlet nozzle seat 5.3 is equipped with a sand blowing assembly. The sand blowing assembly 7 includes a pressing seat 7.1, a needle rod 7.2, an elastic element 7.3 (preferably a spring), a sand outlet nozzle 7.4, and an elastic element mounting seat 7.5 (preferably a positioning spring seat). The sand outlet nozzle 7.4 is fixedly mounted at the front end of the sand outlet nozzle seat 5.3 and provides power for blowing out sand particles from the sand outlet head 4. The needle rod 7.2 is movably mounted relative to the sand outlet nozzle 7.4 through the elastic element 7.3, and the movement of the needle rod is controlled to clean the air outlet on the sand outlet nozzle 7.4. The needle rod 7.2 passes through the hole in the sand outlet nozzle seat 5.3 to the end face of the sand outlet nozzle 7.4, and the needle rod 7.2 is close to the sand outlet nozzle 7. The front end of the needle 7.4 is needle-shaped, and its outer diameter is smaller than the air outlet on the sand outlet nozzle 7.4. The elastic element mounting seat 7.5 is installed on the top of the sand outlet nozzle seat 5.3. One end of the elastic element 7.3 is installed on the elastic element mounting seat 7.5, and the other end is installed on the pressing seat 7.1 at the top of the needle rod 7.2. The spring forms a tension through the sealing ring fixing step at the middle and rear of the needle rod and the limiting of the pressing seat, so that the sealing ring fixing step at the middle and rear of the needle rod is pressed tightly against the bottom of the positioning spring seat, sealing the sealing ring installed there. The sealing ring fixing step at the middle and rear of the needle rod can also play a limiting role, positioning it at the bottom of the spring seat. By operating the pressing seat 7.1, the needle rod is driven to clean the air outlet on the sand outlet nozzle 7.4. After releasing the pressing seat, the needle rod returns to its original position under the action of the spring. The pressing seat 7.1 is located on the outside of the main valve body 1. In this preferred embodiment, the air inlet 5.1 is provided with a tapered mounting hole that is wider at the top and narrower at the bottom, and the tapered mounting hole has an internal thread; the lower end of the sand outlet nozzle seat 5.3 is a tapered body that matches the tapered mounting hole, and the outer wall of the tapered body has an external thread that matches the internal thread. The sand outlet nozzle, sand outlet head, and third sand channel have a coaxial inclined straight-through structure. Since there are no pipe bends, it can efficiently transmit airflow and avoid wear on the pipe wall.

[0043] In this preferred embodiment, the air inlet assembly further includes a filter assembly 5.4, which includes a filter mounting base 5.4.1 and a filter 5.4.2, as detailed below. Figure 2 and Figure 3The filter 5.4.2 is installed inside the air inlet body 5.1 via the filter mounting base 5.4.1; the filter 5.4.2 is a hollow columnar structure with a cavity, and the main air inlet connector 5.2 is connected to the cavity of the filter 5.4.2, so that the air entering through the main air inlet connector 5.2 passes through the filter 5.4.2 and smoothly enters the airflow cap 9 and flows out. More preferably, the filter tip is made of plastic and has a groove at its front end. The inner diameter of the filter tip is smaller than the outer diameter of the cylindrical boss of the filter tip seat into which it is inserted. Because the filter tip has a groove, it can be inserted into the cylindrical boss of the filter tip seat and tightly wrapped when the groove is opened. Due to the flexibility of plastic, it can ensure that the filter tip can fit tightly against the filter tip seat and prevent it from tearing. The filter tip seat has a filter screen with a length of 10-15mm and a pore size of 0.1×0.1 on both sides of the middle part. This ensures that enough compressed air can enter while blocking impurities and preventing contamination of the air duct. The rear end of the filter tip is a closed structure and has a protruding flat opening. Tools can be used to clamp this part to insert or remove the filter tip.

[0044] In this preferred embodiment, the two ends of the second sand channel 3.2 are enclosed by a sand-pushing cap seat 8, an airflow cap 9, and a baffle cleaning seat 10, as detailed below. Figure 6 The baffle cleaning seat 10 is used to laterally open the second sand channel 3.2 to clean impurities mixed in the second sand channel. The distance between the baffle cleaning seat 10 and the central axis of the second sand channel 3.2 is 30-40mm. This distance ensures that the sand particles stored in the third sand channel will not automatically flow out due to their own accumulation angle when the baffle cleaning seat is opened, facilitating cleaning. The airflow cap 9 is installed on the second sand channel 3.2 through the sand pusher cap seat 8. After the airflow passes through the airflow cap 9, compressed air is blown out to drive the sand particles flowing into the second sand channel 3.2 forward into the third sand channel 3.3. Further preferably, the airflow cap 9 includes a hollow column and a core structure disposed within the column. The core structure is a sheet-like or plate-like structure with micropores. The airflow cap is placed horizontally and coaxially with the second sand channel. The compressed air blown out by the airflow cap drives the sand particles flowing into the second sand channel to flow forward. At this time, the sand outlet nozzle blows out a high-speed airflow, resulting in low pressure inside the airflow and high pressure outside due to slow flow speed. The pressure difference causes the airflow to "suck up" the sand particles blown by the airflow cap in the second sand channel and blow them out from the third sand channel, thus achieving the purpose of sand spreading.

[0045] In this preferred embodiment, the main valve body 1 is further provided with a sand-spraying amount adjustment mechanism, which includes an adjustment column 11, and the adjustment column 11 is used to adjust the airflow size passing through the airflow cap 9.

[0046] The main valve body has an internally machined air duct assembly 6 with a compressed air flow channel, see details. Figure 1 , Figure 2 , Figure 3 , Figure 5 and Figure 6 The air duct assembly 6 includes a first air duct 6.1, a second air duct 6.2, a third air duct 6.3, a fourth air duct 6.4, a fifth air duct 6.5, a sixth air duct 6.6, a seventh air duct 6.7, an eighth air duct 6.8, a ninth air duct 6.9, a tenth air duct 6.10, an eleventh air duct 6.11, a twelfth air duct 6.12, a thirteenth air duct 6.13, a fourteenth air duct 6.14, and a fifteenth air duct 6.15. The first air duct 6.1 connects the main air inlet connector 5.2 and the third sand channel 3.3 in the sand outlet head 4, and is used to blow sand particles out of the sand outlet head. The second air duct 6.2 connects the main air inlet connector 5.2 and the second sand channel 3.2, and is used to blow sand particles in the second sand channel 3.2 into the third sand channel 3.3. The specific structure is as follows:

[0047] The portion of the first channel 5.1.1 connected to the main air inlet connector 5.2 is provided with a first air duct 6.1; the cavity located on the outer periphery of the filter forms a second air duct 6.2, and the cavity of the filter forms a third air duct 6.3; the sand outlet nozzle seat 5.3 is T-shaped, with a conical surface in the middle, and the cone angle Y is between 15° and 25°, see details. Figure 3 A sealing groove is designed on the conical surface to hold a sealing ring, which seals by fitting against the conical inner hole of the air inlet 5.1. An annular groove is opened at the rear end of the conical surface of the sand outlet nozzle seat 5.3 to form the fifth air duct 6.5. A through hole is machined at the center of the groove to form the sixth air duct 6.6. The middle round rod of the needle rod 7.2 connects with the countersunk hole and inner hole in the middle of the sand outlet nozzle seat 5.3 to form the seventh air duct 6.7 and the eighth air duct 6.8 in sequence. The eighth air duct 6.8 is connected to the sand outlet nozzle 7.4. The second air duct 6.2 is connected to the seventh air duct 6.7 through the fourth air duct 6.4, the fifth air duct 6.5, and the sixth air duct 6.6 in sequence. The third air duct 6.3 delivers airflow to the second sand channel 3.2 through the ninth air duct 6.9 and the tenth air duct 6.10 in sequence.

[0048] The adjusting column 11 has a cylindrical structure with an internal hexagonal groove on its outer end face and a blind hole coaxial with the tenth air duct 6.10 on the other end face to form the eleventh air duct 6.11. The depth of the blind hole is exactly at the intersection with the thirteenth air duct 6.13. A through circular hole coaxial with the thirteenth air duct 6.13 is opened at the bottom of the above-mentioned circular hole to form the twelfth air duct 6.12. At this time, the ninth air duct 6.9 is connected to the thirteenth air duct 6.13 through the eleventh air duct 6.11 and the twelfth air duct 6.12 on the adjusting column 11. By rotating the internal hexagonal groove on the adjusting column 11, the twelfth air duct 6.12 on the adjusting column 11 can be rotated, and the air volume can be adjusted by changing the cross-sectional area of ​​the twelfth air duct 6.12. The twelfth air duct 6.12 is connected to the airflow cap 9 through the thirteenth air duct 6.13, the fourteenth air duct 6.14 and the fifteenth air duct 6.15 connected in sequence. The fourteenth air duct is formed by the sand pusher cap seat 8 and the plug 14.

[0049] In this preferred embodiment, a sand-blocking plug 12 and a sand-blocking cover 13 are detachably provided at the sand discharge port. A portion of the sand-blocking plug 12 can be inserted into the sand discharge port. The sand-blocking cover 13 is located on the outside of the sand-blocking plug 12 and is used to completely seal the sand discharge port. Specifically, the sand-blocking plug is designed with a cylindrical head at one end and a flat structure at the other end. When the sand-blocking plug and the sand-blocking cover are opened, large particles of impurities can be cleaned and flow out along the first sand channel. After cleaning, the cylindrical head of the sand-blocking plug can be inserted upward into the first sand channel. Since the outer diameter of the top cylindrical head of the sand-blocking plug is slightly smaller than the inner diameter of the first sand channel, it is beneficial for the sand particles to flow down into the gap and form friction force during the upward insertion process. This can seal the sand-blocking plug tightly on the first sand channel and prevent sand particles from continuing to flow out. Then, the sand-blocking cover is installed to seal it.

[0050] The specific solution for applying this embodiment is as follows:

[0051] The flow path of the sand particles is as follows:

[0052] The sand particles are stored in the sand box; the sand particles in the sand box enter the sand inlet 2 in the main valve body 1 of the gravity sand spreading valve through the outlet at the bottom of the sand box; the sand particles falling through the sand inlet 2 fall into the first sand channel 3.1, and under the weight of their own, the sand particles enter the fourth sand channel 3.4 and fall into the second sand channel 3.2; under the action of the airflow ejected by the airflow cap 9, the sand particles in the second sand channel 3.2 are blown into the inclined third sand channel 3.3 through the fifth sand channel 3.5, and then ejected at high speed from the sand outlet head 4 under the action of the airflow of the sand outlet nozzle 7.4.

[0053] The airflow path is as follows:

[0054] The airflow entering through the main air inlet connector 5.2 in the air inlet assembly 5 enters the first air duct 6.1 and then splits into two paths, as follows:

[0055] First airflow path: After the airflow enters the second airflow path 6.2 through the first airflow path 6.1, it passes through the fourth airflow path 6.4, the fifth airflow path 6.5, the sixth airflow path 6.6, the seventh airflow path 6.7 and the eighth airflow path 6.8 in sequence before connecting with the sand discharge nozzle 7.4, providing power for the high-speed ejection of sand particles from the sand discharge head 4.

[0056] The second airflow path: After passing through the first air duct 6.1, the gas enters the third air duct 6.3 through the filter nozzle. The airflow passes through the third air duct 6.3, the ninth air duct 6.9, the tenth air duct 6.10, the eleventh air duct 6.11, the twelfth air duct 6.12, the thirteenth air duct 6.13, the fourteenth air duct 6.14, and the fifteenth air duct 6.15 in sequence before connecting with the airflow cap, providing power for the sand particles in the second sand duct 3.2 to be blown into the inclined third sand duct 3.3 through the fifth sand duct 3.5.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A gravity-type sand-spreading valve, characterized in that, It includes a main valve body (1), which is provided with a sand inlet (2), a sand channel assembly (3), a sand outlet (4), an air inlet assembly (5), an air duct assembly (6), and a sand blowing assembly (7); The sand channel assembly (3) includes a first sand channel (3.1), a second sand channel (3.2), and a third sand channel (3.3) connected in sequence. One end of the first sand channel (3.1) is connected to the sand inlet (2), and the other end of the first sand channel (3.1) is connected to the inlet of the third sand channel (3.3) in the sand outlet (4) through the second sand channel (3.2). The outlet of the third sand channel (3.3) is connected to the sand outlet in the sand outlet (4). The bottom of the first sand channel (3.1) is provided with a sand discharge port. The air intake assembly (5) includes an air intake body (5.1) and a main air intake connector (5.2) and a sand outlet nozzle seat (5.3) disposed on the air intake body (5.1); the sand outlet nozzle seat (5.3) is a columnar structure with a hollow channel and is detachably disposed on the air intake body (5.1); the sand outlet nozzle seat (5.3) is provided with a sand blowing assembly (7), the sand blowing assembly (7) includes a needle rod (7.2), an elastic element (7.3) and a sand outlet nozzle (7.4), the sand outlet nozzle (7.4) is disposed on the sand outlet nozzle seat (5.3) and can provide power for blowing out sand particles in the sand outlet head (4); the needle rod (7.2) is inserted into the hollow channel and is movably disposed relative to the sand outlet nozzle (7.4) by the elastic element (7.3), and the air outlet on the sand outlet nozzle (7.4) is cleaned by controlling the movement of the needle rod; The air duct assembly (6) includes a first air duct (6.1) and a second air duct (6.2). The first air duct (6.1) connects the main air inlet connector (5.2) and the third sand channel (3.3) in the sand outlet head (4) for blowing out sand particles from the sand outlet head. The second air duct (6.2) connects the main air inlet connector (5.2) and the second sand channel (3.2) for blowing sand particles in the second sand channel (3.2) into the third sand channel (3.3).

2. The gravity-type sand-spreading valve according to claim 1, characterized in that, The air inlet body (5.1) is provided with a tapered mounting hole that is wider at the top and narrower at the bottom, and the tapered mounting hole is provided with an internal thread; the sand outlet nozzle seat (5.3) is a tapered body that matches the tapered mounting hole, and the outer wall of the tapered body is provided with an external thread that matches the internal thread.

3. The gravity-type sand-spreading valve according to claim 1, characterized in that, The sand blowing assembly also includes a pressing seat (7.1) and an elastic element mounting seat (7.5). The sand outlet nozzle (7.4) is installed at the bottom of the sand outlet nozzle seat (5.3). The needle rod (7.2) is inserted into the hollow channel in the sand outlet nozzle seat (5.3) until the end face of the sand outlet nozzle (7.4). The front end of the needle rod (7.2) near the sand outlet nozzle (7.4) is needle-shaped, and its outer diameter is smaller than the air outlet on the sand outlet nozzle (7.4). The elastic element mounting base (7.5) is installed on the top of the sand outlet nozzle seat (5.3); one end of the elastic element (7.3) is installed on the elastic element mounting base (7.5), and the other end is connected to the pressing seat (7.1) installed on the top of the needle rod (7.2). By operating the pressing seat (7.1), the needle rod is driven to move to clean the air outlet on the sand outlet nozzle (7.4); the pressing seat (7.1) is located on the outside of the main valve body (1).

4. The gravity-type sand-spreading valve according to claim 1, characterized in that, The sand channel assembly (3) further includes a fourth sand channel (3.4) and a fifth sand channel (3.5). The central axis of the first sand channel (3.1) is set vertically. The bottom end of the first sand channel (3.1) is connected to the second sand channel (3.2) through the fourth sand channel (3.4). The outlet of the second sand channel (3.2) is connected to the third sand channel (3.3) with its central axis inclined downward through the fifth sand channel (3.5) set vertically along its central axis. The offset distance Z between the central axis of the first sand channel (3.1) and the central axis of the second sand channel (3.2) in the horizontal plane is 10-20 mm. The offset distance X between the top surface of the connection between the second sand channel (3.2) and the fifth sand channel (3.5) and the bottom surface of the connection between the third sand channel (3.3) and the fifth sand channel (3.5) in the vertical plane is 10-15 mm.

5. The gravity-type sand-spreading valve according to claim 1, characterized in that, The two ends of the second sand channel (3.2) are enclosed by a sand pusher cap seat (8), an airflow cap (9), and a baffle cleaning seat (10); The baffle cleaning seat (10) is used to open the second sand channel (3.2) laterally and to clean the impurities mixed in the second sand channel; the distance between the baffle cleaning seat (10) and the central axis of the second sand channel (3.2) is 30-40mm; The airflow cap (9) is installed on the second sand channel (3.2) via the sand pusher cap seat (8). The airflow through the second air channel (6.2) blows out compressed air after passing through the airflow cap (9), which is used to drive the sand particles flowing into the second sand channel (3.2) to flow forward into the third sand channel (3.3).

6. The gravity-type sand-spreading valve according to claim 5, characterized in that, The airflow cap (9) includes a hollow column and a core structure disposed within the column. The core structure is a sheet-like or plate-like structure with micropores.

7. The gravity-type sand-spreading valve according to claim 5, characterized in that, The main valve body (1) is also provided with a sand-spraying amount adjustment mechanism, which includes an adjustment column (11) for adjusting the airflow size passing through the airflow cap (9).

8. The gravity-type sand-spreading valve according to claim 5, characterized in that, The air intake assembly (5) further includes a filter assembly (5.4), which includes a filter mounting base (5.4.1) and a filter (5.4.2). The filter (5.4.2) is installed in the air intake body (5.1) through the filter mounting base (5.4.1). The filter (5.4.2) is a hollow columnar structure with a cavity. The main air intake connector (5.2) is connected to the cavity of the filter (5.4.2), so that the air entering through the main air intake connector (5.2) passes through the filter (5.4.2) and flows smoothly into the airflow cap (9) and out.

9. The gravity-type sand-spreading valve according to any one of claims 1-8, characterized in that, The sand discharge port is detachably provided with a sand plug (12) and a sand plug cover (13). A portion of the sand plug (12) can be inserted into the sand discharge port. The sand plug cover (13) is located on the outside of the sand plug (12) and is used to completely seal the sand discharge port.

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