A sand shooting machine for forming a forklift accessory mold

Abstract

The present application relates to the technical fields of coated sand core making, in particular to a sand shooting machine for forklift accessory mold forming, comprising a sand shooting machine body, sand shooting heads, and a feeding table, wherein the sand shooting machine body is provided with the feeding table and a plurality of sand shooting heads, the sand shooting heads are provided with sand shooting nozzles, the feeding table can move in the vertical direction, the feeding table is provided with an upper mold at the bottom end, the sand shooting machine body is provided with a lower mold, the upper mold and the lower mold are matched to form a mold for forming coated sand, the sand shooting heads and the sand shooting nozzles are matched to spray coated sand into the mold, and the sand shooting heads and the feeding table are provided with a waste gas removal device. When the coated sand in the mold is heated to produce toxic waste gas during the working process of the sand shooting machine, the waste gas removal device can automatically remove the toxic waste gas.

Description

Technical Field

[0001] This invention relates to the field of coated sand core making technology, specifically a sand shooting machine for forming molds for forklift parts. Background Technology

[0002] Forklifts, as material handling vehicles, are widely used in factories, improving material transfer efficiency. In the vehicle manufacturing sector, the demand for castings is substantial; according to industry statistics from 2021, castings used in the vehicle industry accounted for more than 28% of the total annual production of castings.

[0003] Coated sand casting is a sand casting process that uses coated sand to manufacture sand cores and sand molds. Sand cores and molds made with coated sand have advantages such as high strength and high temperature resistance. Furthermore, by using a sand shot machine, this process can improve casting efficiency and reduce casting costs. Therefore, coated sand casting is favored by many foundry manufacturers. Sand shot machines can be divided into horizontal parting sand shot machines and vertical parting sand shot machines, depending on the parting method. For sand molds made with coated sand, considering the convenience of material unloading, a horizontal parting sand shot machine with side-firing is usually used. In this method, the sand shot head injects coated sand into the mold from the side, while the parting surface of the mold is parallel to the ground.

[0004] However, in the coated sand casting process, when the coated sand is used to form sand cores or sand molds using a sand-shooting machine, it needs to be heated to make the coated sand bond together. Under heating conditions, some components of the coated sand will decompose, thereby producing harmful substances such as ammonia, formaldehyde, and phenol. These harmful substances are directly emitted into the air in the factory, causing harm to the health of workers.

[0005] Therefore, a sand-shooting machine for forming molds of forklift parts is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a sand-shooting machine for forming molds of forklift parts. By using a waste gas removal device, when the coated sand inside the mold is heated and generates harmful gases, the waste gas removal device automatically removes the harmful gases, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A sand-shooting machine for forming molds for forklift parts, comprising:

[0009] Sand shooting machine body, sand shooting head, feed table;

[0010] The main body of the sand-shooting machine is equipped with a feed table and multiple sand-shooting heads. The sand-shooting heads are equipped with sand-blasting nozzles. The feed table can move vertically. An upper mold is installed at the bottom of the feed table. A lower mold is installed on the main body of the sand-shooting machine. The upper mold and the lower mold cooperate with each other to form a mold for molding coated sand. The sand-shooting head and the sand-blasting nozzle cooperate with each other to spray coated sand into the mold.

[0011] Also includes:

[0012] The exhaust gas removal device is provided on both the sand injection head and the feed table. When the coated sand in the mold is heated and generates toxic exhaust gas, the exhaust gas removal device automatically removes the toxic exhaust gas.

[0013] The exhaust gas removal device includes an exhaust pipe installed on the feed platform. An isolation cover is installed at the bottom of the feed platform. The isolation cover has multiple ventilation holes and multiple mating holes. Each of the multiple sand-shooting heads is provided with an annular plate that mates with the mating holes.

[0014] Based on this scheme, the initial state of the present invention is that the upper mold and the lower mold are in a separated state, and the sand-shooting head is withdrawn to a position that does not contact the side wall of the mold. The working process of the present invention is as follows: First, the sand-shooting machine is started, and the feed table moves downward, so that the upper mold and the lower mold are closed. At this time, the bottom end of the isolation cover is pressed against the main body of the sand-shooting machine. Thus, the closed mold is completely covered inside the isolation cover. Afterward, multiple sand-shooting nozzles and their corresponding mounting tables, under the control of the PLC, pass through their corresponding mating holes and move towards the mold until the sand-shooting nozzles are mated and pressed against the corresponding positions on the mold. At this time, the annular plate covers the mating holes on the isolation cover, and then the sand-shooting head passes through the isolation cover, the feed table, and the main body of the sand-shooting machine. The mold body, multiple mounting platforms, and multiple annular plates together form a relatively enclosed space. Then, the sand-shooting head sprays coated sand into the mold cavity through the sand-blasting nozzle until the coated sand fills the cavity and is compacted. Next, the mold is heated, and the coated sand in the cavity is heated, bonded, and shaped, releasing irritating gases such as ammonia. At the same time, the air extraction pipe, under the action of an external air pump, begins to draw air from inside the isolation cover to remove the irritating gases generated by the heated coated sand. Subsequently, the sand-shooting head first retracts to its original position, and the feed platform then retracts to its original position, thus completing one working process.

[0015] It should be further explained that, since the sand-shooting machine is not used for a specific type of mold throughout its service life, and different molds have different design parameters, there may be differences in vertical height. However, for the isolation cover, since the size parameters of the same isolation cover are fixed, the same isolation cover obviously cannot be completely adapted to all molds. Otherwise, it is easy to cause two problems: on the one hand, if the isolation cover is too high, it may be squeezed and damaged during the feeding and mold closing process of the feeding table; on the other hand, if the isolation cover is too low, it will not be able to prevent the gas inside from escaping outward, thus affecting the working effect of the invention. For example, if the height of the isolation cover is 300mm, and the heights of the upper and lower molds are both 150mm, then when the upper and lower molds are closed, the isolation cover will perfectly enclose the closed molds and ensure the covering effect. However, if the height of the lower mold is 100mm, then the height of the closed mold is only 250mm, which is less than the height of the isolation cover. Therefore, when the upper and lower molds are closed, the isolation cover will be excessively squeezed by the feed table and damaged. Furthermore, if the height of the lower mold is 200mm, then the height of the closed mold is 350mm, which is higher than the height of the isolation cover. In this case, after the molds are closed, there will be a 50mm gap between the isolation cover and the main body of the sand shooting machine, making it impossible for the isolation cover to effectively prevent the internal gas from escaping.

[0016] For the reasons mentioned above, to ensure the effectiveness of the isolation cover in this invention, it should be installed on the bottom of the feed table in a detachable manner, such as by threaded connection or snap-fit ​​connection. This allows the isolation cover to be replaced according to the different dimensional parameters of different molds, ensuring that the height of the isolation cover matches the height of the mold behind it, thus guaranteeing the effectiveness of the isolation cover.

[0017] Furthermore, when the compacted coated sand inside the mold is heated, the harmful gases generated by the decomposition of the coated sand components mainly escape outward through the mating gaps of the mold parting surface. Therefore, based on the above technical solution, multiple ventilation holes should be located at the lower part of the isolation cover. More specifically, the height of the ventilation holes after the mold is closed should be lower than the height of the horizontal parting surface of the mold. With this setting, after the mold is closed, the external air entering the isolation cover from the ventilation holes will be blown into the isolation cover from below the horizontal parting surface of the mold. Therefore, the air flow direction inside the isolation cover is from the ventilation holes into the isolation cover, then from bottom to top across the mold parting surface, and finally to the exhaust pipe. Thus, the gas escaping from the mold parting surface can move smoothly along the airflow direction and be sucked out by the exhaust pipe, preventing the harmful gases escaping from the mold parting surface from accumulating at the bottom of the isolation cover without being discharged.

[0018] Furthermore, the ventilation holes should be arranged at an angle. The purpose of this is to ensure that the angle between the velocity direction of the external air flowing into the isolation hood through the ventilation holes and the outer wall of the mold is acute. This avoids the loss of kinetic energy caused by the sudden change in the velocity direction of the airflow, thereby reducing local pressure loss and ensuring the velocity of the airflow. This ensures that the airflow can quickly deliver the harmful gas to the extraction pipe, improving the efficiency of the extraction pipe's extraction work.

[0019] As a preferred embodiment of the present invention, each of the shot-jetting heads is equipped with an mounting plate, and multiple guide sleeves are mounted on the mounting plate. Each guide sleeve is fitted with a spring, and the other end of each spring is connected to an annular plate. The annular plate is fitted on the mounting platform, and multiple guide posts that cooperate with the guide sleeves are mounted on the annular plate, with the guide posts passing through the guide sleeves.

[0020] A sealing gasket is installed on the annular plate.

[0021] A sealing film is installed on the side of the annular plate near the sand-shooting head. The sealing film is used to seal the mating gap between the annular plate and the mounting platform.

[0022] Based on this scheme, when the sand-shooting head is fed, the annular plate will gradually approach the isolation cover until the annular plate contacts the isolation cover and covers the mating hole. At this time, the sand-shooting nozzle does not contact the mold. So the sand-shooting head continues to feed until the sand-shooting nozzle is pressed against the mold that has been closed. During this process, multiple springs will be gradually compressed, and the annular plate will be pressed against the isolation cover by multiple springs to achieve the sealing of the mating hole.

[0023] The advantage of this design is that the elasticity of the spring allows the annular plate to slide a certain distance on the sandblasting nozzle. Thus, when the size parameters of the isolation cover change due to replacement, the annular plate can ensure its sealing effect on the mating hole without hindering the sandblasting head feed.

[0024] Furthermore, considering the relationship between the annular plate and the sandblasting nozzle, a clearance fit is required to ensure reliable sliding. However, this clearance fit leads to the spring bending downwards when the annular plate contacts the sandblasting head due to gravity. This means that when the spring is compressed, its elastic force is not parallel to the sliding direction of the annular plate. Therefore, the elastic force has a vertical component, which increases the compressive force at the contact surface between the annular plate and the sandblasting head, making it prone to wear. Moreover, since the annular plate is made of sheet metal with a small thickness, it is a component susceptible to damage. Specifically, the annular plate is prone to curling at its inner edge, which further increases the downward bending of the spring, creating a vicious cycle that shortens the lifespan of the invention and increases maintenance costs.

[0025] Therefore, each spring is equipped with a guide sleeve and a guide post. The weight of the annular plate is then borne by the guide post and guide sleeve, preventing the spring from bending downwards and thus avoiding the aforementioned problems, extending the equipment's service life. Simultaneously, since the inside of the isolation shroud is actually under negative pressure during the operation of the suction pipe, the annular plate is further pressed against the isolation shroud by external pressure. That is to say, the force pressing the annular plate against the isolation shroud during the operation of the suction pipe consists of the force caused by the pressure difference inside and outside the isolation shroud, and the force of the multiple springs. This means that when the pressing effect on the annular plate is the same, as the suction power provided by the suction pipe increases, the pressure difference inside and outside the isolation shroud increases, and therefore, the elastic force required from the springs decreases. Specifically, when using high suction power, a spring with a lower elastic modulus can be selected. In this case, the suction tube has a better effect and efficiency in removing harmful gases, but the corresponding power cost is higher. Conversely, when using low suction power, a spring with a higher elastic modulus should be selected to ensure that the annular plate is pressed tightly against the isolation cover during the operation of the suction tube. It is worth mentioning that the above description of "high" and "low" suction power of the suction tube is general. Therefore, the specific optimal parameters should be adjusted by the user before use, and targeted selection should be made to achieve the best trade-off between the effect of removing harmful gases and the power cost.

[0026] In addition, a sealing gasket should be installed at the fitting gap between the annular plate and the isolation cover to ensure the sealing of the fitting gap. In this way, when the exhaust pipe is performing the exhaust operation, the outside air will not enter the isolation cover from the gap, preventing the airflow from the vent to the exhaust pipe from being disturbed, and ensuring the effectiveness and efficiency of the present invention in removing harmful gases.

[0027] Furthermore, for the same sealing considerations, in order to prevent external air from entering through the gap between the annular plate and the sandblasting nozzle and thus causing interference with the airflow state inside the isolation cover, the present invention installs a sealing soft sheet on the side of the annular plate near the sandblasting head and arranges the sealing soft sheet around the inner edge of the annular plate.

[0028] It should be noted that during the molding of coated sand, the temperature inside the mold is typically below 300℃. Due to the obstruction of the isolation cover, there is a certain distance between the sealing sheet and the high-temperature mold. Simultaneously, the airflow within the isolation cover also plays a role in heat dissipation due to the exhaust pipe. Therefore, the heat resistance requirements for the sealing sheet are relatively low, and materials such as engineering plastics can be used, resulting in a wide range of material selection. Specific material selection can be determined by measuring the ambient temperature on-site to ascertain the required long-term heat resistance temperature of the sealing sheet, thus determining the appropriate material. More specifically, for example, if the highest temperature inside the heat insulation cover reaches 220℃, PPS sheet (heat distortion temperature 240℃) can be used; if the highest temperature inside the heat insulation cover reaches 300℃, PBI material (heat distortion temperature 435℃) can be used.

[0029] Regarding the installation of the sealing strip, it is important to note that a portion of the sealing strip near the center of the annular plate should extend beyond the inner edge of the annular plate. This extended portion of the sealing strip serves as the actual working part for sealing the mating gap between the annular plate and the sandblasting nozzle. For example, if both the annular plate and the sealing strip are circular, and the inner edge of the sealing strip mates with the annular plate, then the sealing strip and the annular plate are arranged concentrically and connected by adhesive bonding. In this case, a portion of the sealing strip near its center extends beyond the inner edge of the annular plate. Based on this design, the working principle of the sealing strip is as follows: when the exhaust pipe is not pumping air, the sealing strip adheres to the side wall of the sandblasting nozzle due to its own elasticity; when the exhaust pipe is pumping air, a pressure difference is created inside and outside the isolation cover. This pressure difference acts on the sealing strip, pressing it tightly against the sandblasting nozzle, thus sealing the mating gap between the annular plate and the sandblasting nozzle.

[0030] It is worth noting that using sealing sheets as seals has particular advantages, which will be explained in detail below.

[0031] For common sealing components, more specifically, taking sealing rings as an example, in order to achieve a sealing effect, it is usually necessary to ensure that there is a certain compressive force between the sealing component and the sealed part. However, regarding the fitting gap between the annular plate and the sandblasting nozzle in this invention, if the sealing ring maintains compressive force within the fitting gap for a long time, it means that when the annular plate moves on the sandblasting nozzle, there is also a large frictional force between the sealing ring and the sandblasting nozzle. This can easily lead to the sealing ring wearing out during operation.

[0032] However, for the sealing sheet in this invention, since the main driving force for the sealing effect of the sealing sheet is the pressure difference generated inside and outside the isolation cover due to the air extraction pipe, when the air extraction pipe is extracting air, the sealing sheet can be tightly pressed onto the sandblasting nozzle under the pressure difference to achieve a seal. When the air extraction pipe is not extracting air, the mutual squeezing force between the sealing sheet and the sandblasting nozzle is small, and only the elasticity of the sealing sheet itself is present. Therefore, the friction between the sandblasting nozzle and the sealing sheet is small at this time, reducing the wear of the sealing sheet.

[0033] As a preferred embodiment of the present invention, a plurality of springs are installed on the sandblasting nozzle, and the other end of the plurality of springs is connected to a collection box for collecting excess coated sand, and the collection box has a collection cavity for holding the coated sand.

[0034] A support is installed at the bottom of the collection chamber, and a baffle is installed on the support. The baffle is made of steel. A discharge hole that cooperates with the baffle is opened at the bottom of the collection chamber. A torsion spring is installed on the baffle, and the other end of the torsion spring is installed on the side wall of the collection chamber. A collection groove that cooperates with the collection box is opened on the main body of the sand shooting machine. An electromagnet that cooperates with the baffle is installed on the main body of the sand shooting machine.

[0035] A filter screen is installed at the inlet of the extraction pipe.

[0036] Before introducing this technical solution, it should be noted that during the operation of the horizontal parting sand-shooting machine used in this invention, after the sand-shooting nozzle sprays coated sand into the mold, some coated sand remains inside the nozzle. This coated sand falls outwards from the nozzle outlet due to gravity and inertia as the nozzle retracts with the sand-shooting head, landing on the main body of the sand-shooting machine inside the isolation hood. More specifically, it lands on the main body of the sand-shooting machine near the mold. Furthermore, as the sand-shooting machine operates repeatedly, this coated sand accumulates. Since the mold temperature is around 280°C during operation, this accumulated coated sand is heated for extended periods, leading to an increasing amount of harmful gases generated inside the isolation hood. This increases the difficulty of removing harmful gases through the extraction pipe and increases its workload. Simultaneously, this coated sand will adhere after being heated, potentially sticking to the main body of the sand-shooting machine, further increasing the difficulty of cleaning.

[0037] Based on the above problems, this technical solution was designed. First, by setting up a collection box and a second spring, when the sandblasting nozzle is fed along with the sand-shooting head, the side of the collection box closest to the mold first contacts the mold. Then, the second spring is compressed, and relative sliding occurs between the sandblasting nozzle and the collection box. The sandblasting nozzle passes over the collection cavity of the collection box until it is pressed against the mold. At this time, the collection box is pressed against the side wall of the mold by the second spring. When the sandblasting nozzle retracts with the sand-shooting head, during the initial retraction of the sandblasting nozzle by the sand-shooting head, relative sliding occurs again between the sandblasting nozzle and the collection box because the collection box is pressed against the mold by the compressed second spring. This causes the sandblasting outlet of the sandblasting nozzle to pass over the collection box. During this process, the coated sand falling from the sandblasting nozzle will fall into the collection cavity and be collected by the collection box, preventing the coated sand from falling onto the main body of the sand-shooting machine. It is worth noting that the end of the sandblasting nozzle furthest from the sandblasting head, i.e., the sandblasting outlet, should always be located inside the collection box to ensure that the coated sand falling from the sandblasting nozzle does not spill outside the collection box.

[0038] Furthermore, by incorporating an electromagnet, a collection trough, and a baffle, the coated sand collected in the collection chamber can be automatically emptied during each processing cycle. This allows the invention to operate continuously for extended periods without the need for frequent manual cleaning of the collected sand. Specifically, after the sand-shooting machine completes the heating and shaping of the coated sand, the sand-shooting head moves the blasting nozzle back to its initial position. Under PLC control, the electromagnet activates and generates magnetic force, which overcomes the spring force of the torsion spring, attracting the steel baffle downwards. This opens the baffle, opening the bottom of the collection chamber. The collected coated sand then falls out and slides along the baffle into the collection trough. The collection trough guides this coated sand into a final collection container, such as a collection bag or collection box. The connection between the collection trough and the collection container can be achieved through various methods, including pipe connections.

[0039] Additionally, it should be noted that due to the wide variety of coated sand available on the market, with a rich selection of mesh sizes ranging from as small as 20 mesh to as large as 140 mesh, the small weight and volume of individual coated sand particles make them prone to being scattered within the isolation hood during the air extraction process. Specifically, although in the design of this invention, the coated sand falling from the sandblasting nozzle is intended to enter the collection chamber of the collection box, the thickness of the sidewalls forming the collection chamber means that a small amount of coated sand may not fall into the collection chamber but instead remain on the sidewalls. This small portion of coated sand, under the influence of the airflow within the isolation hood, may be drawn into the air extraction pipe, increasing the load on the filter of the air pump connected to the extraction pipe. This is particularly problematic for the equipment of this invention, which is already located in a dusty production environment within a foundry, as it can negatively impact the reliability and stability of the equipment. Therefore, a filter screen is installed at the inlet of the air extraction pipe to prevent the coated sand from entering the air extraction pipe, thereby reducing the workload of the air pump's filter.

[0040] In summary, the beneficial effects of the present invention are as follows:

[0041] 1. During the heating process of the coated sand inside the mold by the sand-shooting machine, a relatively enclosed space is formed by the isolation hood, feed table, main body of the sand-shooting machine, and multiple annular plates. Under the action of an external air pump, air is drawn from inside the isolation hood through the extraction pipe to remove the irritating gases generated by the heated coated sand. Furthermore, by arranging the ventilation holes at an angle, the kinetic energy loss caused by sudden changes in airflow direction is avoided, ensuring the airflow speed. This ensures that the airflow can quickly deliver harmful gases to the extraction pipe, improving the efficiency of the extraction pipe's work.

[0042] 2. By incorporating multiple springs and sealing gaskets, the annular plate ensures the sealing of the mating holes even when the dimensional parameters of the isolation cover change due to replacement, without hindering the feed of the sandblasting head. Furthermore, the sealing soft plate, when the extraction pipe is evacuating, is pressed tightly against the sandblasting nozzle by the pressure difference inside and outside the isolation cover, achieving a seal. When the extraction pipe is not evacuating, the mutual pressure between the sealing soft plate and the sandblasting nozzle is small. This avoids prolonged and high friction between the sandblasting nozzle and the sealing soft plate, reducing wear on the sealing soft plate and extending the equipment's service life while ensuring a good seal.

[0043] 3. By setting up a collection box, electromagnet, collection trough, and baffle, the coated sand falling from the sandblasting nozzle can be automatically collected during each processing. This avoids the increase in the generation of harmful gases in the isolation hood caused by the accumulation of coated sand on the sandblasting machine body near the mold and prolonged heating. At the same time, after the coated sand is collected in the collection box, the present invention can also automatically empty the coated sand collected in the collection chamber, so that the equipment of the present invention can work continuously for a long time without the need for frequent manual cleaning of the coated sand collected in the collection box. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0045] Figure 2 for Figure 1 A sectional view;

[0046] Figure 3 for Figure 2 Enlarged view of section A;

[0047] Figure 4 This is a planar front view of the present invention;

[0048] Figure 5 for Figure 4 Enlarged sectional view of section B;

[0049] Figure 6 This is a schematic diagram of the isolation enclosure.

[0050] Figure 7 This is a sectional view of the isolation enclosure;

[0051] Figure 8 for Figure 7 Enlarged view of section C.

[0052] In the diagram: 1. Main body of the sand-shooting machine; 2. Sand-shooting head; 3. Feeding platform; 4. Air extraction pipe; 11. Collection tank; 12. Electromagnet; 21. Mounting plate; 22. Annular plate; 23. Sand-blasting nozzle; 24. Collection box; 31. Isolation cover; 211. Guide sleeve; 221. Guide post; 222. Spring 1; 223. Sealing gasket; 224. Sealing soft sheet; 231. Spring 2; 232. Mounting platform; 241. Collection chamber; 242. Baffle; 311. Vent hole; 312. Mating hole. Detailed Implementation

[0053] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0054] like Figures 1 to 8As shown, a first specific embodiment of the present invention is illustrated, wherein the coated sand used is 70 mesh, the air pump power is 4kW, the elastic modulus of spring 222 is 125N / m, and the elastic modulus of spring 231 is 60N / m.

[0055] Before introducing the installation method of this invention, several points need to be explained in advance: First, unless otherwise specified, all connection methods used for fixed installation in the following description are threaded connections; Second, the equipment of this invention is modified from an existing horizontal parting side sandblasting machine, so the connection methods of the sandblasting machine body 1, sandblasting head 2, sandblasting nozzle 23, feed table 3, and mold will not be described in detail; Third, the feed table 3 is provided with mounting holes for installing the suction pipe 4, so that after the suction pipe 4 is installed on the feed table 3, it can smoothly draw air from the mold. The air inside the hood 31; fourth, the sealing gasket 223 is pre-installed on the annular plate 22; fourth, the baffle 242 is pre-installed on the collection box 24 via a support pre-set at the lower part of the collection chamber 241, and the two ends of the torsion spring are respectively fixed to the side wall of the collection chamber 241 and the baffle 242 by buckles; fifth, the main body 1 of the sand shooting machine is provided with a space for accommodating the collection bag, in which a collection bag for collecting coated sand is placed, and the collection bag is connected to the collection trough 11 by a guide pipe; sixth, the electrical control not specifically described below is implemented by PLC.

[0056] When installing this invention, connect the suction pipe 4 to the external air pump, and then connect the suction pipe 4 to the feed table 3 via a threaded connection. Next, fix the isolation cover 31 to the bottom of the feed table 3. Then, fit the mounting platform 232 onto the sandblasting nozzle 23 and fix the mounting platform 232 onto the sandblasting head 2. Fit the mounting plate 21 onto the sandblasting nozzle 23 and fix the mounting plate 21 onto the sandblasting head 2. Next, remove the annular plate 22, and glue the sealing film 224 onto the annular plate 22. Then, fit springs 222 onto each of the multiple guide posts 221 and fix each spring 222. The spring 22 is fixedly installed on the annular plate 22, and then the annular plate 22 is fitted onto the sandblasting nozzle 23, so that the multiple guide posts 221 and multiple guide sleeves 211 are matched one by one. Then, the unfixed end of each spring 222 is fixedly installed on the mounting plate 21. Subsequently, the multiple springs 231 are fixedly connected to the mounting platform 232. Then, the collection box 24 is fitted onto the sandblasting nozzle 23, and the unfixed end of each spring 231 is fixedly installed on the collection box 24. Finally, the electromagnet 12 is fixedly installed next to the collection groove 11, and it is ensured that the electromagnet 12 can correctly attract the baffle 242 when working. At this point, the installation of the present invention is completed.

[0057] When this invention is in operation, firstly, the feed table 3 feeds downwards until the upper and lower molds are closed. At this time, the isolation cover 31 is in contact with the main body 1 of the sand-shooting machine, and then the sand-shooting head 2 feeds in. As the sand-shooting head 2 feeds in, the collection box 24 and the sand-shooting nozzle 23 pass through the corresponding mating holes 312 and enter the interior of the isolation cover 31 in sequence. Then, the annular plate 22 contacts the isolation cover 31, and then the spring 222 is compressed. When the spring 222 is compressed to two-thirds of its original length, the collection box 24 contacts the mold. After that, the sand-shooting head 2 continues to feed, and both the spring 222 and the spring 231 are compressed until the sand-shooting nozzle 23 is pressed against the mold. At this time, the length of the spring 222 is compressed to one-third of its original length. Then, the sand-shooting head 2 injects coated sand into the cavity of the mold through the sand-shooting nozzle 23 and compacts it. Next, the mold continues to heat the coated sand to form it, generating harmful gases. At the same time, the air pump connected to the extraction pipe 4 starts, and the extraction pipe 4 sucks out the harmful gases from the isolation cover 31. After the outermost layer of the coated sand is bonded and formed, the sand-shooting head 2 drives the sand-blasting nozzle 23 to retract. As the sand-shooting head 2 retracts, during the process of the spring 222 returning to two-thirds of its original length, the outlet of the sand-blasting nozzle 23 passes above the collection chamber 241. As a result, the coated sand remaining in the sand-blasting nozzle 23 falls into the collection chamber 241 and is blocked by the baffle 242. When the spring 222 returns to two-thirds of its original length, the mold is kept warm to ensure that the coated sand is completely bonded and formed. The equipment of the present invention remains in its current state, that is, the sand-shooting head 2 stops retracting, the spring 222 maintains its current length, and the extraction pipe 4 continues to suck out the harmful gases from the isolation cover 31.

[0058] Next, the coated sand is kept at a constant temperature in the mold for 45 seconds until it is fully bonded and formed. At this time, the air pump stops pumping air, and the sand-shooting head 2 begins to retract. As the spring 222 returns from two-thirds of its original length to its original length, the sand-blasting nozzle 23 and the collection box 24 pass through the corresponding mating holes 312 and exit the isolation cover 31. When the sand-shooting head 2 retracts to its initial position, the feed table 3 drives the isolation cover 31 to return to its initial position. At the same time, the electromagnet 12 is activated, attracting the baffle 242 to open downwards, causing the coated sand in the collection chamber 241 to fall into the collection trough 11 and be collected in the collection bag. The electromagnet 12 is activated for 5 seconds and then deactivated. At this time, the baffle 242 returns to its original position under the action of the torsion spring, and the entire equipment returns to its initial state, ready for the next production.

[0059] During the actual production process, the harmful gases generated by the thermal decomposition of the coated sand components did not leak out of the isolation cover 31. When the invention finished working, no coated sand remained on the main body 1 of the sand shooting machine, and the coated sand in the collection chamber 241 fell smoothly into the collection bag through the collection trough 11.

[0060] like Figures 1 to 8As shown, a second specific embodiment of the present invention is illustrated, which differs from the first specific embodiment in that the coated sand used is a low-odor 140-mesh coated sand.

[0061] Considering that the coated sand has a large mesh size and the sand particles are relatively light, it is easy for them to fly around inside the isolation cover 31 when the air extraction pipe 4 is working. Therefore, a filter screen is fixedly installed at the inlet of the air extraction pipe 4 to completely cover the inlet of the air extraction pipe 4.

[0062] Considering that this type of coated sand produces a small amount of harmful gases and requires less suction power, a low-power air pump with a specific power of 0.25kW is used. Additionally, using a low-power air pump also reduces the amount of coated sand flying around inside the isolation hood 31, lowering the possibility of flying coated sand intruding into the extraction pipe 4.

[0063] When the device of the present invention is operated under the above settings, the harmful gases generated by the thermal decomposition of the coated sand components during the working process do not leak out of the outside of the isolation cover 31. When the present invention is finished, there is no coated sand left on the main body 1 of the sand shooting machine, and the coated sand in the collection chamber 241 falls smoothly into the collection bag through the collection trough 11.

Claims

1. A sand-shooting machine for forming molds for forklift parts, comprising: Sand shooting machine body, sand shooting head, feed table; The main body of the sand shooting machine is equipped with a feed table and multiple sand shooting heads. The sand shooting heads are equipped with sand spray nozzles. The feed table can move vertically. An upper mold is installed at the bottom of the feed table. A lower mold is installed on the main body of the sand shooting machine. The upper mold and the lower mold cooperate with each other to form a mold for molding coated sand. The sand shooting head and the sand spray nozzle cooperate with each other to spray coated sand into the mold. Its characteristic is that it further includes: The exhaust gas removal device is installed on the sand injection head and the feed table. When the coated sand in the mold is heated and generates toxic exhaust gas, the exhaust gas removal device will automatically remove the toxic exhaust gas. The exhaust gas removal device includes an exhaust pipe installed on the feed platform, which is connected to an external air pump. The sand-shooting head is equipped with a mounting platform that cooperates with the sand-shooting nozzle. An isolation cover is installed at the bottom of the feed platform. The isolation cover has multiple ventilation holes and multiple mating holes. The mating holes cooperate with the mounting platform. Each of the multiple sand-shooting heads is equipped with an annular plate that cooperates with the mating holes. Multiple vents are located at the bottom of the isolation cover, and all vents are arranged at an angle. Multiple springs are installed on the mounting platform. The other end of the multiple springs is connected to a collection box for collecting excess coated sand. The collection box has a collection cavity for holding the coated sand. Each shot head is equipped with an installation plate, and multiple guide sleeves are installed on the installation plate. Each guide sleeve is fitted with a spring, and the other end of each spring is connected to an annular plate. The annular plate is fitted on the installation platform, and multiple guide posts that cooperate with the guide sleeves are installed on the annular plate, with the guide posts passing through the guide sleeves. A sealing gasket is installed on the annular plate to seal the gap between the annular plate and the isolation cover; The end of the sandblasting nozzle furthest from the sandblasting head is located inside the collection box; A support is installed at the bottom of the collection chamber, and a baffle is installed on the support. The baffle is made of steel. A discharge hole that cooperates with the baffle is opened at the bottom of the collection chamber. A torsion spring is installed on the baffle, and the other end of the torsion spring is installed on the side wall of the collection chamber. A collection groove that cooperates with the collection box is opened on the main body of the sand shooting machine. An electromagnet that cooperates with the baffle is installed on the main body of the sand shooting machine.

2. A sand-shooting machine for forming molds of forklift parts according to claim 1, characterized in that: A sealing strip is installed on the side of the annular plate near the sand-shooting head. The sealing strip is used to seal the mating gap between the annular plate and the mounting platform.

3. A sand-shooting machine for forming molds for forklift parts according to claim 1, characterized in that: A filter screen is installed at the inlet of the exhaust pipe.

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