A gearbox housing casting machine for construction machines

Abstract

The application relates to the technical field of shell die casting, and discloses an engineering machinery gearbox shell casting machine, which comprises a casting machine body, a fixed die and a movable die matched with the fixed die are slidably connected to the upper limit of the casting machine body, and a limiting plate is fixedly installed on the casting machine body. The demolding resistance during the demolding process of the workpiece is monitored through a pressure sensor, the speed of an operator in judging the cause of abnormal working conditions is improved through analysis of a pressure curve, the abnormal working conditions are accurately repaired in time, downtime is reduced, production efficiency is improved, and in the process of reciprocating sliding of the piston rod driven by the connecting plate, the gas discharge speed is accelerated through active suction, the probability of gas mixing with the aluminum liquid during the slow injection process of the aluminum liquid is reduced, and the flow of the gas flowing out of the gas outlet pipe is monitored through a flowmeter during the exhaust process, so that whether the top rod and the fixed die normally operate can be judged.

Description

Technical Field

[0001] This application relates to the field of housing die casting technology, and in particular to a gearbox housing casting machine for engineering machinery. Background Technology

[0002] A transmission, also known as a gearbox, is a mechanism used to change the speed and torque from an engine. It can change the transmission ratio between the output shaft and the input shaft in a fixed or progressively increasing manner. In order to ensure the fit of various components, the housing, as the skeleton of the entire transmission, must accommodate the high-speed rotating gear set and withstand the test of alternating loads and lubricating oil pressure. Therefore, its manufacturing precision directly determines the assembly consistency, smooth operation, and service life of the transmission.

[0003] When producing die-cast aluminum alloy shells, the molten aluminum liquid enters the mold cavity under the action of the injection punch. In order to ensure that the casting obtains a fine crystalline structure and shorten the production cycle, it needs to be rapidly cooled and solidified by the cooling system. This causes the mold to be subjected to severe thermal shock continuously during the working cycle. The surface is heated to near the temperature of the aluminum liquid at the moment of filling, and then rapidly cooled to the demolding temperature range by the action of the coolant. As the number of production cycles accumulates, when the thermal stress exceeds the fatigue limit of the mold material (usually hot work die steel, such as H13), fine thermal fatigue cracks will be generated on the inner wall of the mold cavity.

[0004] Thermal fatigue cracks not only affect the coaxiality of the bearing bore and the flatness of the mounting surface, but also disrupt the pressure field of aluminum solidification and feeding due to changes in local cross-sectional area. Especially in the subsequent pressure holding stage, the volume of the cracked area increases and the heat dissipation conditions change, resulting in the actual effective pressure on the aluminum liquid at that point being far lower than the set value. This easily leads to internal defects such as shrinkage porosity and shrinkage cavities. These quality hazards are difficult to detect with the naked eye or conventional inspection tools during the workpiece processing. They often only become apparent during the machining process or the final bench test. This lag and concealment of defects seriously restrict the stable improvement of yield. Summary of the Invention

[0005] This application proposes a gearbox housing casting machine for engineering machinery. It features a pressure sensor to monitor the demolding resistance during workpiece demolding, and analysis of the pressure curve to improve the operator's speed in identifying abnormal operating conditions, enabling timely and accurate maintenance, reducing downtime, and increasing production efficiency. Simultaneously, a connecting plate drives a piston rod to slide, drawing gas from the mold cavity through the air inlet pipe and air inlet hole. Compared to existing technologies where gas passively flows out from the vent hole under the influence of molten aluminum, this active suction accelerates gas discharge and reduces the probability of gas mixing with molten aluminum during slow injection. This addresses the problem in existing technologies where failure to promptly detect and maintain internal mold cracks leads to reduced workpiece yield.

[0006] To achieve the above objectives, this application adopts the following technical solution: a casting machine for a gearbox housing of engineering machinery, comprising a casting machine body, a fixed mold and a movable mold adapted to the fixed mold being slidably connected to the upper limit of the casting machine body, and a limiting plate fixedly installed on the casting machine body, the limiting plate being placed on the side of the fixed mold away from the movable mold, a plurality of push rods being slidably connected to the limiting plate, the ends of the plurality of push rods away from the fixed mold being fixedly connected, and the ends of the plurality of push rods near the fixed mold being movably inserted through the limiting plate and the fixed mold and adapted to or separated from the mold cavity of the fixed mold, a plurality of guide rails being fixedly installed on the top of the casting machine body, and each guide rail being slidably connected to the bottom limit of the fixed mold, a pressure sensor being fixedly installed inside the guide rail, the pressure sensor being electrically connected to the PLC control system, and the pressure sensor being placed on the side of the fixed mold near the movable mold, so that during the process of the push rods extruding the workpiece to assist in demolding, abnormal working conditions are fed back by the value changes monitored by the pressure sensor.

[0007] Furthermore, a cylinder is fixedly installed on the side of the limiting plate away from the fixed mold. A piston rod is airtightly slidably connected to the end of the cylinder away from the limiting plate. An air inlet is opened on the side of one of the push rods near the fixed mold. The air inlet penetrates the interior of the push rod to the end of the push rod near the limiting plate. The end of the cylinder near the limiting plate is fixedly connected to the air inlet through an air inlet pipe. When the piston rod moves away from the limiting plate, the gas inside the mold cavity formed by the fixed mold and the moving mold is drawn into the cylinder through the air inlet and the air inlet pipe.

[0008] Furthermore, a connecting plate is fixedly connected to the end of the piston rod away from the cylinder body, and the connecting plate is connected to the injection assembly in a transmission manner. A slip ring is fixedly installed on the connecting plate, and the slip ring is slidably fitted on the outside of the corresponding push rod.

[0009] Furthermore, the interior of the fixed mold is provided with a groove that matches the air inlet.

[0010] Furthermore, an exhaust pipe is fixedly connected to the outer side of one end of the cylinder near the limiting plate, and a spring-loaded one-way valve is fixedly installed inside the exhaust pipe to restrict gas from flowing out of the cylinder only through the exhaust pipe.

[0011] Furthermore, a flow meter is fixedly connected to the end of the exhaust pipe away from the cylinder body to monitor the flow rate of the gas flowing out through the exhaust pipe, and the flow meter is electrically connected to the PLC control system.

[0012] Furthermore, a disc spring is fixedly installed between the fixed mold and the inner wall of the guide rail to support and limit the fixed mold.

[0013] The beneficial effects of this invention are as follows:

[0014] This application provides a gearbox housing casting machine for engineering machinery. During the demolding process of the ejector rod reciprocating to demold the workpiece, a pressure sensor monitors the demolding resistance of the workpiece. By analyzing the pressure curve, the operator can improve the speed at which to judge the cause of abnormal working conditions, and repair abnormal working conditions in a timely and accurate manner, thereby reducing downtime and improving production efficiency. At the same time, during the reciprocating sliding of the piston rod driven by the connecting plate, the active suction accelerates the gas discharge speed, reducing the probability of gas mixing with aluminum liquid during slow injection of aluminum liquid. During the exhaust process, a flow meter monitors the flow rate of gas flowing out through the exhaust pipe to determine whether the ejector rod and the fixed mold are operating normally. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort:

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0017] Figure 2 This is a side cross-sectional view of the limiting plate of the present invention;

[0018] Figure 3 This is a schematic diagram of the push rod, cylinder body, and exhaust pipe of the present invention;

[0019] Figure 4 This is a side view cross-sectional structural diagram of the guide rail of the present invention.

[0020] In the diagram: 1. Casting machine body; 2. Fixed mold; 3. Moving mold; 4. Limiting plate; 5. Push rod; 6. Guide rail; 7. Cylinder body; 8. Piston rod; 9. Connecting plate; 10. Slip ring; 11. Air inlet pipe; 12. Air outlet pipe; 13. Air inlet hole; 14. Hydraulic cylinder; 15. Oil supply pipe; 16. Disc spring. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] See Figures 1 to 4 A casting machine for a gearbox housing of engineering machinery includes a casting machine body 1. A limiting plate 4 is fixedly installed on the casting machine body 1. A fixed mold 2 is slidably installed on one side of the limiting plate 4. A movable mold 3 is also slidably connected to the casting machine body 1, and the movable mold 3 is located on the side of the fixed mold 2 away from the limiting plate 4. The fixed mold 2 and the movable mold 3 together form a mold cavity. An injection assembly is provided on the side of the movable mold 3 away from the fixed mold 2. The injection assembly includes a pressure chamber and an injection punch. Two ejector rods 5 are slidably installed on the limiting plate 4. The ends of the two ejector rods 5 away from the fixed mold 2 are fixedly connected. The ends of the ejector rods 5 near the fixed mold 2 movably pass through the limiting plate 4 and the fixed mold 2. The ends of the ejector rods 5 near the fixed mold 2 are inside the mold cavity of the fixed mold 2. When the casting machine body 1 is running, the moving mold 3 is first driven by the drive source to move towards the fixed mold 2. When the fixed mold 2 and the moving mold 3 are in contact, the mold is closed and the fixed mold 2 is pressed on the limit plate 4. Then, the aluminum liquid is added into the pressure chamber and the aluminum liquid is pushed into the mold cavity by the injection punch. The cooling system inside the fixed mold 2 and the moving mold 3, including spot cooling and circulating water channels, is used to force and quickly cool the aluminum liquid so that it can quickly solidify and form. After the workpiece is solidified and formed, the moving mold 3 is first moved away from the fixed mold 2 by the drive source to reset. Then, the ejector rod 5 is driven by the drive source to move towards the fixed mold 2 to push the workpiece out slightly. The robotic arm then takes the workpiece away and transports it to the next process.

[0023] Two guide rails 6 are symmetrically fixedly installed on the casting machine body 1. The guide rails 6 are slidably connected to the bottom limit of the fixed mold 2. Disc springs 16 are fixedly installed between the fixed mold 2 and the inner wall of the guide rails 6. The disc springs 16 provide certain support and limit for the fixed mold 2 to ensure its stability. A pressure sensor is fixedly installed inside the guide rails 6. The pressure sensor is located on the side of the fixed mold 2 away from the limit plate 4. The detection end of the pressure sensor is in contact with the limit plate 4. The pressure sensor is electrically connected to the PLC control system. When the casting machine body 1 is run for the first time or after maintenance, the fixed mold 2 is in contact with the limit plate 4. The molds of the fixed mold 2 and the moving mold 3 are in contact. The inner wall of the cavity is also in a normal and intact state. Therefore, during this stage, when the ejector rod 5 moves towards the fixed mold 2 under the action of the drive source to eject the workpiece, since there are no cracks in the inner wall of the mold cavity or the number and degree of cracks are within the normal range, the proportion of aluminum liquid solidifying in the cracks and producing undercuts is also within the normal range. Therefore, the resistance between the workpiece and the mold cavity that the workpiece experiences during demolding is also within the normal range. The workpiece is demolded normally under the action of the ejector rod 5. Therefore, the increased resistance between the workpiece and the mold cavity of the fixed mold 2 will not cause the workpiece to exert a pulling force towards the moving mold 3 on the fixed mold 2. The pressure sensor inside the guide rail 6 towards the fixed mold 2 will not detect abnormal pressure changes.

[0024] When there are many cracks in the inner wall of the mold cavity, the probability of the molten aluminum solidifying in the cracks and causing undercut increases significantly. At this time, when the workpiece is pushed out towards the moving mold 3 by the ejector rod 5, the workpiece will cause the fixed mold 2 to slide towards the moving mold 3 due to the demolding resistance between it and the fixed mold 2. The greater the demolding resistance, the more obvious the movement trend, and the larger the value monitored by the pressure sensor. When the value exceeds the upper limit of the threshold, it indicates that the demolding of the workpiece is abnormal, and the mold cavities of the fixed mold 2 and the moving mold 3 need to be inspected and maintained.

[0025] Before the fixed mold 2 and the moving mold 3 are closed, the spraying of the release agent is also related to the demolding resistance between the workpiece and the mold cavity. If the release agent is sprayed abnormally due to abnormal blockage of the spraying device, the demolding resistance between the workpiece and the mold cavity in the area not covered by the release agent will also increase. Therefore, when the pressure value is abnormal, the pressure change curve is processed and analyzed by the PLC control system. When too many cracks are generated inside the mold cavity of the fixed mold 2, because the cracks are irreversible after they are generated, their interference with the demolding resistance is also irreversible. Therefore, the pressure value monitored by the pressure sensor is continuously abnormal and the abnormal values ​​are similar. When the release agent spraying device is abnormal, such as the release agent delivery pipeline is twisted and folded, or the relevant valves in the liquid pump are intermittently blocked, the area of ​​abnormal release agent before each die casting will be different. The spraying abnormality is intermittent. Therefore, the pressure value monitored by the pressure sensor is intermittently and continuously abnormal and the difference between the abnormal values ​​is large, which indicates that the release agent spraying is abnormal. Therefore, by analyzing the pressure curve, the operator can improve the speed of judging the cause of abnormal working conditions and repair abnormal working conditions in a timely and accurate manner.

[0026] A cylinder 7 is fixedly installed on the side of the limiting plate 4 away from the fixed mold 2. A piston rod 8 is airtightly slidably connected to the end of the cylinder 7 away from the limiting plate 4. An air inlet 13 is opened on the side of one of the ejector rods 5 near the fixed mold 2. The air inlet 13 penetrates the interior of the ejector rod 5 to the end of the ejector rod 5 near the limiting plate 4. The end of the cylinder 7 near the limiting plate 4 is fixedly connected to the air inlet 13 through the air inlet pipe 11. The end of the piston rod 8 away from the cylinder 7 is connected to the injection punch. After the current workpiece is ejected and demolded by the ejector rod 5, the fixed mold 2 and the moving mold 3 are closed to prepare for the production of the next workpiece. The end of the ejector rod 5 near the fixed mold 2 is still placed inside the mold cavity of the fixed mold 2. Therefore, at this time, the mold cavity is connected to the cylinder 7 through the air inlet 13 and the air inlet pipe 11. After adding aluminum liquid into the pressure chamber, the aluminum liquid is slowly injected through the injection punch. The injection punch drives the piston rod 8 to move synchronously through the transmission connection, so as to extract the gas inside the mold cavity through the air inlet pipe 11 and the air inlet 13. Compared with the prior art, where the gas only passively flows out from the exhaust hole under the action of the aluminum liquid, the active suction speed of the gas discharge is accelerated, and the probability of gas mixing with aluminum liquid during the slow injection of aluminum liquid is reduced.

[0027] A connecting plate 9 is fixedly installed at the end of the piston rod 8 away from the limiting plate 4. The connecting plate 9 is connected to the injection punch via hydraulic transmission. When the moving mold 3 drives the injection assembly to move synchronously, the hydraulic oil flow pipe involved in the hydraulic transmission connection between the connecting plate 9 and the injection punch is a flexible hose with a margin of variation. Therefore, when the moving mold 3 drives the injection assembly to move synchronously, the connecting plate 9 will not move synchronously. Only when the injection punch moves alone will the connecting plate 9 be driven to move synchronously via hydraulic transmission. A slip ring 10 is fixedly installed at the end of the connecting plate 9 away from the air inlet pipe 11. The slip ring 10 is slidably fitted on the outside of the corresponding ejector rod 5. During the slow injection stage of the injection punch, the injection punch drives the connecting plate 9 and the slip ring 10 to slide away from the moving mold 3 via the transmission connection. The connecting plate 9 then drives the piston rod 8 to slide through the air inlet pipe 11 to draw gas from the mold cavity through the air inlet pipe 11 and the air inlet hole 13.

[0028] Meanwhile, during the slow injection stage of the injection punch, the push rod 5 is driven by the drive source to move away from the fixed mold 2, so as to achieve the purpose of the push rod 5 finally matching the mold cavity of the fixed mold 2. The fixed mold 2 has a groove (not shown in the figure) that matches the air inlet 13. When the push rod 5 moves to the position that matches the fixed mold 2, the air inlet 13 is connected to the groove. When the air inlet 13 moves from being connected to the mold cavity to being connected to the groove, the injection punch enters the fast injection stage, that is, it performs high-pressure injection on the aluminum liquid in the pressure chamber. During this stage, when the injection punch drives the connecting plate 9 and the piston rod 8 to move synchronously, the gas inside the groove enters the cylinder 7 through the air inlet 13 and the air inlet pipe 11 to ensure the normal operation of the injection punch.

[0029] The cylinder body 7 is fixedly connected to the end near the limiting plate 4 with an exhaust pipe 12, and a spring-type check valve is fixedly installed inside the exhaust pipe 12 to restrict the gas to flow out of the cylinder body 7 in only one direction, so that the gas inside the cylinder body 7 can be discharged when the piston rod 8 is reset. A flow meter (not shown in the figure) is fixedly installed at the end of the exhaust pipe 12 away from the cylinder body 7. The flow meter is an instrument used to measure the flow rate of fluid in pipes or open channels.

[0030] A hydraulic cylinder 14 is fixedly installed on the side wall of the limiting plate 4 near the slip ring 10. The telescopic end of the hydraulic cylinder 14 is fixedly connected to the connecting plate 9. The rodless chamber of the hydraulic cylinder 14 is fixedly connected to an oil supply pipe 15. The oil supply pipe 15 is made of a telescopic material. The end of the oil supply pipe 15 away from the hydraulic cylinder 14 is fixedly connected to the rod chamber in the hydraulic system that controls the movement of the injection punch. When the hydraulic oil in the injection punch hydraulic system enters the rodless chamber to push the piston and the telescopic end to move the injection punch, the hydraulic oil in the rod chamber flows through the oil supply pipe 15 to the rodless chamber of the hydraulic cylinder 14, thereby synchronously driving the telescopic end of the hydraulic cylinder 14 to move. The telescopic end of the hydraulic cylinder 14 drives the connecting plate to move synchronously. When the injection punch needs to be reset, the hydraulic oil enters the rod chamber of the hydraulic cylinder 14, thereby driving the telescopic end of the hydraulic cylinder 14 to move in the opposite direction. The hydraulic oil in the rodless chamber of the hydraulic cylinder 14 is then transported through the oil supply pipe 15 to the rod chamber in the injection punch hydraulic system to synchronously drive the injection punch to move in the opposite direction and reset.

[0031] Working principle:

[0032] When the casting machine body 1 is running, the driving source first drives the moving mold 3 to move towards the fixed mold 2. When the fixed mold 2 and the moving mold 3 are in contact, the mold is closed and the fixed mold 2 is pressed on the limit plate 4. Then, the aluminum liquid is added into the pressure chamber and the aluminum liquid is pushed into the mold cavity by the injection punch. The cooling system inside the fixed mold 2 and the moving mold 3 is used to force and quickly cool it so that the aluminum liquid can quickly solidify and form. After the workpiece is solidified and formed, the driving source first controls the moving mold 3 to move away from the fixed mold 2 to reset. Then, the driving source drives the ejector rod 5 to move towards the fixed mold 2 to push the workpiece out slightly. The robotic arm then takes the workpiece away and transports it to the next process.

[0033] After the current workpiece is ejected and demolded by ejector pin 5, when the fixed mold 2 and the moving mold 3 are closed to prepare for the production of the next workpiece, the end of ejector pin 5 near the fixed mold 2 is still placed inside the mold cavity of the fixed mold 2. Therefore, at this time, the mold cavity is connected to the cylinder 7 through the air inlet 13 and the air inlet pipe 11. After adding aluminum liquid into the pressure chamber, during the slow injection stage of the injection punch, the injection punch drives the connecting plate 9 and the slip ring 10 to slide away from the moving mold 3 through the transmission connection. The connecting plate 9 then drives the piston rod 8 to slide to draw gas from the mold cavity through the air inlet pipe 11 and the air inlet 13. Compared with the prior art where the gas only passively flows out from the exhaust hole under the action of the aluminum liquid, the active suction speed of gas discharge is accelerated, and the probability of gas mixing with aluminum liquid during the slow injection of aluminum liquid is reduced.

[0034] Meanwhile, during the slow injection stage of the injection punch, the drive source drives the ejector rod 5 to move away from the fixed mold 2, so as to achieve the purpose of the ejector rod 5 matching the mold cavity of the fixed mold 2. When the ejector rod 5 moves to the position matching the fixed mold 2, the ejector rod 5 stops moving, and the air inlet 13 is connected to the groove. When the air inlet 13 moves from being connected to the mold cavity to being connected to the groove, the injection punch enters the fast injection stage, that is, it performs high-pressure injection on the aluminum liquid in the pressure chamber. During this stage, when the injection punch drives the connecting plate 9 and the piston rod 8 to move synchronously, the gas inside the groove enters the cylinder 7 through the air inlet 13 and the air inlet pipe 11 to ensure the normal operation of the injection punch.

[0035] After the current workpiece is shaped, the driving source drives the moving mold 3 to move in the opposite direction to demold. Then, the driving source drives the injection punch to move in the opposite direction. The injection punch drives the connecting plate 9 and the piston rod 8 to move in the opposite direction to reset through the transmission connection between the injection punch and the connecting plate 9. The piston rod 8 drives the piston rod through the air inlet pipe 11 to discharge the gas inside the cylinder 7 through the air inlet pipe 11 and the air outlet pipe 12. During the process of the gas being discharged through the air inlet pipe 11 and the air outlet pipe 12, some gas will return to the groove through the air inlet pipe 11. Under the action of the spring-type one-way valve inside the air outlet pipe 12, the groove is filled with gas and the remaining gas will be discharged through the air outlet pipe 12. The flow rate of the gas discharged through the air outlet pipe 12 is monitored by the flow meter. Finally, the driving source drives the ejector rod 5 to move towards the fixed mold 2 to assist in demolding the workpiece.

[0036] When too many cracks are generated inside the mold cavity of mold 2, because the cracks are irreversible after they are generated, their interference with the demolding resistance is also irreversible. Therefore, the pressure values ​​monitored by the pressure sensor are continuously abnormal and the abnormal values ​​are similar. When the mold release agent spraying device is abnormal, such as the mold release agent delivery pipeline is twisted and folded, or the relevant valves in the liquid pump are intermittently blocked, the area of ​​abnormal mold release agent before each die casting will be different. The spraying abnormality is intermittent. Therefore, the pressure values ​​monitored by the pressure sensor are intermittently continuous abnormal and the difference between abnormal values ​​is large, which indicates that the mold release agent spraying is abnormal. Therefore, by analyzing the pressure curve, the operator can improve the speed of judging the cause of abnormal working conditions and repair abnormal working conditions in a timely and accurate manner.

[0037] Similarly, the injection punch moves the same distance each time it injects, and the volume of gas entering the cylinder 7 is also the same. Therefore, when the gas is discharged, if the ejector rod 5 and the fixed mold 2 are in a normal airtight sliding connection, the remaining gas inside the cylinder 7 after the groove is filled with gas will flow out through the exhaust pipe 12, and the value monitored by the flow meter will be normal. If the ejector rod 5 and the fixed mold 2 are worn, causing gas to flow out, the value monitored by the flow meter will fluctuate. When the value is not within the threshold range, it indicates that the gap between the ejector rod 5 and the fixed mold 2 caused by wear is large, and there is a possibility that the aluminum liquid may seep in, which will affect the shaping of the workpiece. Timely maintenance is required to improve the yield of the workpiece.

[0038] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A casting machine for a gearbox housing of engineering machinery, comprising a casting machine body (1), wherein a fixed mold (2) and a movable mold (3) adapted to the fixed mold (2) are slidably connected to the upper limit of the casting machine body (1), characterized in that, It also includes a limiting plate (4) fixedly installed on the casting machine body (1), and the limiting plate (4) is placed on the side of the fixed mold (2) away from the moving mold (3). Multiple push rods (5) are slidably connected on the limiting plate (4). The ends of the multiple push rods (5) away from the fixed mold (2) are fixedly connected. The ends of the multiple push rods (5) close to the fixed mold (2) move through the limiting plate (4) and the fixed mold (2) and are adapted to or separated from the mold cavity of the fixed mold (2). Multiple guide rails (6) are fixedly installed on the top of the casting machine body (1), and each guide rail (6) is slidably connected to the bottom of the fixed mold (2). A pressure sensor is fixedly installed inside the guide rail (6). The pressure sensor is electrically connected to the PLC control system, and the pressure sensor is placed on the side of the fixed mold (2) close to the moving mold (3). During the process of the push rod (5) extruding the workpiece to assist in demolding, the abnormal working condition is fed back by the value change monitored by the pressure sensor.

2. A casting machine for a gearbox housing for engineering machinery according to claim 1, characterized in that, A cylinder (7) is fixedly installed on the side of the limiting plate (4) away from the fixed mold (2). A piston rod (8) is airtightly slidably connected to the end of the cylinder (7) away from the limiting plate (4). An air inlet (13) is opened on the side of one of the push rods (5) near the fixed mold (2). The air inlet (13) penetrates the interior of the push rod (5) to the end of the push rod (5) near the limiting plate (4). The end of the cylinder (7) near the limiting plate (4) is fixedly connected to the air inlet (13) through the air inlet pipe (11). When the piston rod (8) moves away from the limiting plate (4), the gas inside the cavity formed by the fixed mold (2) and the moving mold (3) is drawn into the cylinder (7) through the air inlet (13) and the air inlet pipe (11).

3. A gearbox housing casting machine for engineering machinery according to claim 2, characterized in that, The piston rod (8) is fixedly connected to a connecting plate (9) at one end away from the cylinder (7), and the connecting plate (9) is connected to the injection assembly in a transmission manner. A slip ring (10) is fixedly installed on the connecting plate (9), and the slip ring (10) is slidably fitted on the outside of the corresponding push rod (5).

4. A gearbox housing casting machine for engineering machinery according to claim 3, characterized in that, The mold (2) has a groove inside that matches the air inlet (13).

5. A casting machine for a gearbox housing for engineering machinery according to claim 4, characterized in that, The cylinder (7) is fixedly connected to an exhaust pipe (12) on the outer side of one end near the limiting plate (4), and a spring-type one-way valve is fixedly installed inside the exhaust pipe (12) to restrict gas from flowing out of the cylinder (7) through the exhaust pipe (12).

6. A gearbox housing casting machine for engineering machinery according to claim 5, characterized in that, A flow meter is fixedly connected to one end of the outlet pipe (12) away from the cylinder (7) for monitoring the flow rate of the gas flowing out through the outlet pipe (12), and the flow meter is electrically connected to the PLC control system.

7. A casting machine for a gearbox housing for engineering machinery according to claim 1, characterized in that, A disc spring (16) is fixedly installed between the inner wall of the fixed mold (2) and the guide rail (6) to support and limit the fixed mold (2).

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