Forging forming device for commercial vehicle chassis base production

Abstract

The application discloses a forging forming device for commercial vehicle chassis base production, which comprises a rack, an upper die assembly and a lower die assembly. A plurality of radially slidable split blocks are arranged on the top surface of the lower die base in the circumferential direction. The bottom of the upper die body is fixed with a wedge driving rod, the lower end main push inclined surface of which is matched with the driven inclined surface of the split blocks to realize the closing of the mold, and the upper end reset inclined surface is matched with the return hook part to realize the opening of the mold. The center core block is arranged in the center of the lower die base in a lifting manner, the top boss of the center core block is butted with the center core rod of the upper die when the mold is closed to form a center through hole cavity. A delay cooling system is further arranged and is linked with the center core block, and after the delay liquid storage, the core rod and the core block are synchronously cooled to make the forging preferentially shrink to form a demolding gap. The integrated forming of the conical platform shape, the four-foot hollow and the center through hole is realized in a single stroke, and the problems of the foot filling difficulty and the demolding difficulty are solved.

Description

Technical Field

[0001] This invention relates to the field of forging technology, specifically to a forging forming apparatus for the production of commercial vehicle chassis bases. Background Technology

[0002] The commercial vehicle chassis base is a load-bearing integrated forging, with an overall composite three-dimensional structure of "frustum body + four outer legs". The upper part is a circular frustum body, with a dumbbell-shaped stepped through hole running axially through the center of the frustum. The lower part has four independent vertical cylindrical legs evenly distributed around the circumference of the bottom surface of the frustum, forming a hollow and suspended structure between adjacent legs. This type of forging has three complex features: a frustum shape, hollow four legs, and an irregularly shaped center hole, which places extremely high demands on the forging process.

[0003] In existing technologies, the forming of forgings with such complex structures mainly suffers from the following drawbacks: First, the multi-process step-by-step forging scheme requires four to five processes, including pre-forging, final forging, stamping of support legs, and machining of center holes. This results in large equipment investment, slow production cycle, material utilization rate of only about 70%, and high overall manufacturing cost.

[0004] Secondly, although the overall closed die forging scheme can reduce the number of processes, the metal must first fill the main body of the cone and then be diverted to the support cavity below the outer edge. The flow path is long and the direction changes sharply. The support cavity in the suspended area of ​​the outer edge is prone to underpressure and folding defects. The sharp change of the streamline in the transition rounded corner area can also lead to microcracks, making it difficult to guarantee the yield.

[0005] Third, in the scheme of using a fixed center core block in conjunction with an integral lower mold, after the forging is formed, the outer wall of the support leg is tightly held by the integral cavity, and the inner hole is supported by the fixed core block. When demolding, a huge ejection force is required, which can easily damage the root of the support leg, cause the forging to tilt and the ejector pin to leave indentations. At the same time, the mold is subjected to high thermal fatigue load, and the overall life is only about 8,000 to 10,000 pieces. Moreover, once the support leg cavity area fails locally, the entire part must be scrapped, resulting in high maintenance costs and long downtime. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a forging and forming device for the production of commercial vehicle chassis bases, which can simultaneously achieve the integrated near-net-shape forming of the frustum shape, the four-legged hollow structure and the dumbbell-shaped central through hole within a single press stroke, while solving the problems of difficult filling of the support cavities and difficult demolding.

[0007] To solve the above-mentioned technical problems, the present invention provides a forging forming device for the production of commercial vehicle chassis bases, including a frame, an upper die assembly vertically mounted on the frame, and a lower die assembly fixed to the frame and located below the upper die assembly. The upper die assembly includes an upper die body and an upper die center mandrel fixed to the upper die body. The lower die assembly includes a lower die base and a center core block. Multiple segmented blocks are circumferentially arranged on the top surface of the lower die base, and each segmented block is radially slidably mounted on the lower die base. Multiple inclined wedge drive rods are fixed to the outer edge of the bottom of the upper die body. The lower end of each inclined wedge drive rod has a main pushing inclined surface, and the upper end of each inclined wedge drive rod has a reset inclined surface. The outer side of each segmented block has a driven inclined surface that cooperates with the main pushing inclined surface. The system includes a return hook that mates with the reset inclined surface; the central core block is slidably disposed vertically at the center of the lower mold base, and the top of the central core block is provided with a small cylindrical boss, which axially connects with the lower end of the upper mold central core in the mold-closed state; it also includes a delayed cooling system, which includes a spiral cooling water channel disposed in the upper mold central core, a cooling water channel disposed in the central core block, and a delayed control unit disposed in the lower mold base. The delayed control unit includes a delayed cavity, a delayed piston slidably disposed in the delayed cavity, and a hydraulic trigger rod connected to the bottom of the central core block. The side wall of the delayed cavity is provided with a water inlet, and the bottom of the delayed cavity is provided with an upwardly angled water outlet channel communicating with the cooling water channel. The delay control unit is configured to supply cooling medium to the cooling water passage (334) of the center core block (330) only after a predetermined time has elapsed since the start of the mold closing and pressure holding stage. The predetermined time is determined by the time required for the cooling medium to fill the delay cavity (351).

[0008] Furthermore, the top surface of the lower mold base is provided with a dovetail guide rail extending radially, the bottom of the segmented block is provided with a dovetail boss that slides with the dovetail guide rail, and a return spring is provided between the segmented block and the lower mold base.

[0009] Furthermore, the return hook is an inwardly opening groove located on the outside of the segmented block, and the inner inclined surface of the groove is in the same direction as the inclination of the reset inclined surface.

[0010] Furthermore, it also includes a hydraulic linkage lifting system, which includes a hydraulic drive cavity disposed at the bottom of the lower mold base, a hydraulic drive rod connected to the bottom of the central core block and extending into the hydraulic drive cavity, a lateral control cavity disposed on the side of the lower mold base, a control piston slidably disposed in the lateral control cavity, a hydraulic pipeline connecting the hydraulic drive cavity and the lateral control cavity, and a trigger push rod fixed to the bottom of the upper mold body, wherein the trigger push rod corresponds vertically to the control piston.

[0011] Furthermore, a reset spring is provided between the bottom of the central core block and the lower mold base.

[0012] Furthermore, the delay control unit also includes a hydraulic control cavity disposed on the upper part of the delay cavity and a hydraulic linkage cavity disposed in the lower mold base. The hydraulic linkage cavity cooperates with the hydraulic trigger rod, and the hydraulic linkage cavity and the hydraulic control cavity are connected through a hydraulic pipeline.

[0013] Furthermore, there are four segments, which are distributed at 90° intervals along the circumference, and each segment has a quarter-leg cavity on its top surface.

[0014] Furthermore, it also includes an ejection mechanism, which includes an ejector rod and an ejection hydraulic cylinder. The ejector rod passes through the lower mold base and is located below the area enclosed by the plurality of segmented blocks and the central core block.

[0015] Furthermore, the delay control unit also includes an adjustable throttle valve located at the front end of the third water inlet of the delay cavity, and an accumulator is also provided between the third water inlet of the delay cavity and the circulating water pump.

[0016] Furthermore, the angle of the main pushing slope is 15°, and the angle of the reset slope is 10°~15°.

[0017] The beneficial effects of this invention are: This invention features multiple radially slidable segmented blocks on the lower mold base and a wedge drive rod with a main pushing slope and a reset slope fixed at the bottom of the upper mold body. When the upper mold descends, the wedge drive rod pushes the segmented blocks radially inward through the main pushing slope to form a complete support cavity. This transforms the traditional method of active metal outflow filling into a method of active cavity closure and metal encapsulation, significantly improving the fullness of the support cavity and avoiding folding and underpressure defects. Simultaneously, the central core block is vertically and vertically positioned at the center of the lower mold base. When the mold closes, its small cylindrical boss on top axially aligns with the central core rod of the upper mold to form a dumbbell-shaped central hole cavity. When the mold opens, the central core block sinks to release the inner hole support, and in conjunction with the radial outward retraction of the segmented blocks, it releases the lateral constraints of the support legs. This achieves a demolding strategy of releasing constraints first and then ejecting under light load, significantly reducing ejection force and preventing forging damage and deformation. Furthermore, this invention employs a purely mechanical delayed cooling scheme linked to the central core block, which has significant advantages over the control methods of electronic timers and solenoid valves used in existing technologies. First, the forging environment is harsh, characterized by high temperatures, strong vibrations, and electromagnetic interference. Electronic components operating in such environments suffer from poor reliability, high failure rates, and high maintenance costs over extended periods. The mechanical-hydraulic solution of this invention avoids the use of electronic components, resulting in a robust and durable structure capable of withstanding the extreme conditions of forging. Second, this solution initiates the delay by physically linking the hydraulic trigger rod with the central core block. Its response is completely synchronized with the mold's movement, ensuring precise control without electrical delay and guaranteeing absolute reliability of the cooling timing. The delayed cooling system, linked to the central core block via the hydraulic trigger rod, synchronously cools the mold after delayed liquid accumulation during the mold closing and pressure holding stage. This causes the forging to preferentially shrink, forming a radial demolding gap, further reducing demolding difficulty. The entire device can simultaneously complete the near-net-shape forming of the truncated cone shape, four-legged hollow, and dumbbell-shaped central hole within a single press stroke, significantly reducing processes and substantially improving material utilization and production efficiency. Attached Figure Description

[0018] Figure 1 This is an isometric view of the entire invention; Figure 2 This is a cross-sectional view of the present invention; Figure 3 for Figure 2 A magnified view of a portion of point A in the middle; Figure 4 This is a sectional view of the present invention; Figure 5 for Figure 4 A magnified view of a portion of point B in the middle; Figure 6 This is a schematic diagram of the product to be produced according to the present invention.

[0019] Reference numerals: 100, Frame; 110, Top plate; 120, Bottom plate; 130, Support column; 140, Main hydraulic cylinder; 141, Main hydraulic rod; 150, Guide column; 200, Upper mold assembly; 210, Upper mold body; 211, Inverted frustum-shaped cavity; 220, Upper mold center mandrel; 221, Spiral cooling water channel; 240, Wedge drive rod; 241, Main push slope; 242, Reset slope; 250, Trigger push rod; 300, Lower mold assembly; 310, Lower mold base; 311, Core block guide hole; 312, Disc sliding cavity; 313, Hydraulic drive cavity; 314, Lateral control. 320. Cavity; 321. Split block; 322. Return hook; 323. Driven inclined surface; 330. Center core block; 331. Forming section; 332. Small cylindrical boss; 333. Disc section; 334. Cooling water passage; 341. Hydraulic drive rod; 342. Control piston; 351. Delay chamber; 352. Delay piston; 353. Hydraulic control chamber; 354. Hydraulic trigger rod; 355. Hydraulic linkage chamber; 356. Third water inlet; 357. Sloping upward water outlet channel; 360. Ejection mechanism; 361. Ejector rod; 362. Ejection hydraulic cylinder; 400. Circulating water pump 400. Detailed Implementation

[0020] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0021] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "clockwise" and "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0022] See also Figure 1 The present invention provides a forging and forming device for the production of commercial vehicle chassis bases, which includes three main parts: frame 100, upper mold assembly 200 and lower mold assembly 300.

[0023] The frame 100 includes a top plate 110 horizontally arranged at the top, a bottom plate 120 horizontally arranged at the bottom, and four support columns 130 connecting the four corners of the top plate 110 and the four corners of the bottom plate 120. The four support columns 130 are fixed to the top plate 110 and the bottom plate 120 by bolts, forming a rectangular rigid frame. A main hydraulic cylinder 140 is fixedly installed at the center of the top plate 110. The main hydraulic cylinder 140 is connected to the top plate 110 by flange bolts, and its main hydraulic rod 141 passes through the top plate 110 and extends downward into the frame, serving as the drive source for the upper mold assembly 200. Four guide columns 150 are also vertically arranged on the inner sides of the four corners of the frame 100. The guide columns 150 cooperate with the guide sleeves on the upper mold assembly 200, constraining the upper mold assembly 200 to move vertically only.

[0024] The upper die assembly 200 includes an upper die body 210 and an upper die center mandrel 220. The upper die body 210 is a rectangular block structure with an inverted frustum-shaped cavity 211 machined at its bottom. The inner wall shape of the inverted frustum-shaped cavity 211 corresponds to the outer cone surface and upper end face contour of the target forging, and is used to form the frustum shape of the forging. A stepped hole is opened at the center of the top of the upper die body 210, and the hole diameter decreases from top to bottom. The upper die center mandrel 220 is a stepped cylindrical structure, including an upper large-diameter section and a middle small-diameter section. The outer diameter of the middle small-diameter section corresponds to the upper large hole and the middle necked section of the dumbbell-shaped central through hole of the forging. The top of the upper die center mandrel 220 is a stepped enlarged section, which is inserted from top to bottom into the stepped hole at the top of the upper die body 210 for axial positioning. The top of the upper die body 210 is pressed against the stepped surface of the upper die center mandrel 220 by bolts through a pressure plate to prevent axial movement of the mandrel during forging. The upper die center mandrel 220 has a spiral cooling water channel 221 machined inside, which extends spirally along the mandrel's axis. The top side wall of the upper die center mandrel has a first water inlet and a first water outlet, and the water pipes extend along the side wall of the upper die to the outside and connect to the circulating water pump 400. The four corners of the upper die body 210 and the four corners of the top pressure plate are equipped with guide sleeves that cooperate with the guide posts 150. The lower end of the main hydraulic rod 141 is fixed to the top pressure plate of the upper die body 210 by threads and a locking nut, driving the upper die assembly 200 to rise and fall as a whole.

[0025] See Figure 2 and Figure 5Four wedge drive rods 240 are evenly distributed and fixed along the circumferential direction on the bottom outer edge of the upper mold body 210. The wedge drive rods 240 are vertical strip structures, fixed to the mounting base on the bottom outer edge of the upper mold body 210 by welding or bolts, and rise and fall together with the upper mold assembly 200. The lower end of each wedge drive rod 240 is provided with a main pushing slope 241, the slope angle of the main pushing slope 241 is about 15°, and the slope direction is wider at the top and narrower at the bottom, converging inward, that is, gradually approaching the center of the device from top to bottom. The upper end of each wedge drive rod 240 is provided with a reset slope 242, the slope angle of the reset slope 242 is about 10° to 15°, and the slope direction is narrower at the top and wider at the bottom, opening outward. The bottom of the upper mold body 210 is also fixed with a trigger push rod 250. The trigger push rod 250 is located on the bottom surface of the upper mold body 210 near the side and extends vertically downward. Its lower end corresponds vertically to the control piston 342 of the hydraulic linkage lifting system in the lower mold assembly 300.

[0026] See Figure 3 and Figure 5 The lower mold assembly 300 includes a lower mold base 310, four segmented blocks 320, a central core block 330, a hydraulic linkage lifting system, a delayed cooling system, and an ejection mechanism 360.

[0027] The lower mold base 310 is bolted to the center of the base plate 120, serving as the supporting base for the lower mold assembly 300. The central area of ​​the lower mold base 310 has, from top to bottom, a core block guide hole 311, a disc sliding cavity 312, and a hydraulic drive cavity 313, all coaxially connected. These are used for guiding the upper forming section 331 of the central core block 330, axially sliding and positioning the disc section 333, and installing the hydraulic drive rod 341, respectively. A lateral control cavity 314 is provided on the side of the lower mold base 310. The lateral control cavity 314 has a stepped hole structure, within which a control piston 342 is installed. A connecting through hole is also provided on the side wall of the lower mold base 310. The position of this connecting through hole is precisely aligned with the second inlet and second outlet on the side wall of the disc section 333 when the central core block 330 is lifted into position. The top surface of the lower mold base 310 is provided with four dovetail guide rails that extend radially at 90° intervals along the circumference. The radial length of each dovetail guide rail is 3 to 5 mm, which limits the radial sliding stroke of the segment block 320.

[0028] See Figure 5The four segmented blocks 320 are independent metal block units, distributed at 90° intervals along the circumference on four dovetail guide rails on the top surface of the lower die base 310. Each segmented block 320 has a quarter-leg cavity machined on its inner side. When the four segmented blocks 320 are closed, the four quarter-leg cavities are combined to form a complete four-legged forming cavity. The inner wall contour of the cavity corresponds to the shape of the four cylindrical legs of the forging. Each segmented block 320 has a dovetail boss at its bottom, which engages with the corresponding dovetail guide rail to form a radial sliding fit, allowing the segmented block 320 to move only radially without dislodging. Each segmented block 320 has a driven inclined surface 322 on its outer side, which has the same inclination angle as and fits snugly against the main pushing inclined surface 241 at the lower end of the wedge drive rod 240. Each segment block 320 is also provided with a return hook 321 on its outer side. The return hook 321 has a groove structure, and the inner inclined surface of the groove is in the same direction as the inclination of the upper end reset inclined surface 242 of the wedge drive rod 240. The hook inclined surface and the reset inclined surface 242 form a hook-groove fit. A first reset spring is installed between the outer side of each segment block 320 and the lower mold base 310. The first reset spring applies a radially outward elastic force to the segment block 320, so that the segment block 320 remains radially open when no external force is applied.

[0029] During mold closing, the upper mold assembly 200 moves downward, and the main pushing inclined surface 241 at the lower end of the wedge drive rod 240 contacts the driven inclined surface 322 on the outer side of the segment block 320. The wedge-shaped structure of the inclined surface decomposes the vertical driving force into a radially inward component and a vertical component. The radially inward component overcomes the elastic force of the first return spring and pushes the four segment blocks 320 synchronously towards the center along the dovetail guide rail to the closed position. The four support cavities are assembled to form a complete cavity. During mold opening, the upper mold assembly 200 moves upward, and the return inclined surface 242 at the upper end of the wedge drive rod 240 slides upward along the inclined surface inside the groove of the return hook 321, generating a normal force obliquely outward and upward on the upper lip of the hook. Its radially outward component hooks the segment block 320 radially outward and retracts it to the open position. The first return spring assists in the reset, releasing the constraint of the support side wall.

[0030] See Figure 3The central core block 330 is located in the central region of the lower die base 310, radially inner to the four segmented blocks 320. The upper part of the central core block 330 is the forming section 331, whose shape corresponds to the spatial shape enclosed by the four legs, used to form the inner surface shape between the bottom surface of the forging cone and the legs. A small cylindrical boss 332 protrudes upwards from the top center of the forming section 331, its outer diameter and height corresponding to the inner diameter and depth of the large hole below the dumbbell-shaped central through hole in the forging. The lower part of the central core block 330 is the disc section 333, whose diameter is larger than the circumscribed circle diameter of the forming section 331. The disc section 333 is inserted into the disc sliding cavity 312 of the lower die base 310 to form an axial sliding fit. A second return spring is installed between the upper surface of the disc segment 333 and the lower mold base 310. The second return spring applies a downward elastic force to the central core block 330, causing it to be in a sunken position when there is no external force. Cooling water channels 334 are machined inside the central core block 330. The cooling water channels 334 meander and extend inside the core block to ensure sufficient heat exchange. A second water inlet and a second water outlet are provided on the side wall of the disc segment 333. When the central core block 330 is raised to its final position, the second water inlet and the second water outlet are precisely aligned and connected with the connecting holes on the side wall of the lower mold base 310, allowing the cooling medium to flow into the internal water channels of the core block for circulation and heat dissipation.

[0031] In the mold-closed state, the central core block 330 is lifted to the lifting position, and the upper end face of the small cylindrical boss 332 is axially aligned with the lower end face of the upper mold central core bar 220. The middle section of the small diameter section of the upper mold central core bar 220 forms the upper large hole and the necking section of the dumbbell-shaped through hole, and the small cylindrical boss 332 forms the lower large hole of the dumbbell-shaped through hole. Together with the four closed segmented blocks 320 and the inverted frustum-shaped cavity 211 of the upper mold body 210, they form a complete integrated forging cavity.

[0032] See Figure 3 The hydraulic linkage lifting system enables the passive lifting of the center core block 330 at the end of mold closing and automatic reset during mold opening. The hydraulic linkage lifting system includes a hydraulic drive cavity 313, a hydraulic drive rod 341, a lateral control cavity 314, a control piston 342, and hydraulic pipelines. The upper end of the hydraulic drive rod 341 is fixedly connected to the center of the bottom surface of the disc section 333 of the center core block 330, and the lower end of the hydraulic drive rod 341 extends into the hydraulic drive cavity 313, which is filled with hydraulic oil. The control piston 342 is slidably installed in the lateral control cavity 314. A cover plate is provided at the outer end of the lateral control cavity 314 to limit the control piston 342 from dislodging. The upper end of the control piston 342 extends out of the top surface of the lower mold base 310 and corresponds vertically to the trigger push rod 250 at the bottom of the upper mold body 210. The hydraulic pipelines connect the inner cavities of the hydraulic drive cavity 313 and the lateral control cavity 314, forming a closed hydraulic circuit.

[0033] At the end of the mold closing stage, when the upper mold assembly 200 descends to near the end position, the lower end of the trigger push rod 250 contacts and presses down the control piston 342. The control piston 342 slides inward in the lateral control cavity 314, compressing the hydraulic oil in the lateral control cavity 314 and flowing into the hydraulic drive cavity 313 through the hydraulic pipeline. The oil pressure in the hydraulic drive cavity 313 increases, pushing the hydraulic drive rod 341 to move upward. The hydraulic drive rod 341 drives the central core block 330 to rise upward along the core block guide hole 311 to the predetermined lifting position. When the mold opens, the upper mold assembly 200 moves upward, triggering the push rod 250 to disengage from the control piston 342, depressurizing the lateral control chamber 314. Under the downward force of the second reset spring, the central core block 330 drives the hydraulic drive rod 341 downward. The hydraulic oil in the hydraulic drive chamber 313 flows back to the lateral control chamber 314, and the central core block 330 sinks and resets to the sinking position. The small cylindrical boss 332 retracts below the surface of the lower mold base 310, and the inner hole support is released.

[0034] See Figure 3 The delayed cooling system enables synchronous delayed cooling of the upper mold center core rod 220 and center core block 330 during the mold closing and pressure holding stage. The delayed cooling system's delayed control unit is located inside the lower mold base 310 and includes a delayed cavity 351, a delayed piston 352, a hydraulic control cavity 353, a hydraulic trigger rod 354, a hydraulic linkage cavity 355, a third water inlet 356, an upwardly angled water outlet channel 357, and hydraulic pipelines.

[0035] The delay cavity 351 is a cavity formed inside the lower mold base 310. Its lower part is a large-diameter water storage cavity, and its upper part is a small-diameter hydraulic control cavity 353. The delay piston 352 has a stepped piston structure. Its upper small-diameter section cooperates with the hydraulic control cavity 353, and its lower large-diameter section cooperates with the lower large-diameter cavity of the delay cavity 351. The delay piston 352 can slide vertically within the delay cavity 351. A third water inlet 356 is provided on the side wall of the delay cavity 351. The third water inlet 356 is connected to the external circulating water pump 400 through a pipeline. The bottom of the delay cavity 351 is provided with an upwardly angled water outlet channel 357. The upwardly angled water outlet channel 357 extends obliquely upward from the lower left corner of the bottom of the delay cavity 351 to the position of the second water inlet on the side wall of the disc section 333 of the central core block 330. When the central core block 330 is lifted into place, the upwardly angled water outlet channel 357 connects with the second water inlet.

[0036] The upper end of the hydraulic trigger rod 354 is fixedly connected to the side of the bottom surface of the disc segment 333 of the central core block 330, and the lower end of the hydraulic trigger rod 354 extends into the hydraulic linkage cavity 355. The hydraulic linkage cavity 355 is a sealed cavity formed inside the lower mold base 310, which is filled with hydraulic oil. The hydraulic linkage cavity 355 is connected to the hydraulic control cavity 353 above the delay cavity 351 through a hydraulic pipeline.

[0037] The working process of the delayed cooling system is as follows: In the early stage of the mold closing and pressure holding stage, the central core block 330 is lifted, which drives the hydraulic trigger rod 354 to move upward. The lower end of the hydraulic trigger rod 354 is pulled out from the hydraulic linkage cavity 355, and the oil pressure in the hydraulic linkage cavity 355 decreases. The hydraulic oil in the hydraulic control cavity 353 flows to the hydraulic linkage cavity 355 through the hydraulic pipeline to replenish it. The oil pressure in the hydraulic control cavity 353 decreases accordingly. The delayed piston 352 is lifted upward under the action of the upper and lower pressure difference. The third water inlet 356, which was originally blocked in the lower large diameter section of the delayed piston 352, is exposed. The cooling water provided by the external circulating water pump 400 begins to enter the water storage cavity in the lower part of the delayed cavity 351 through the third water inlet 356 for water storage. Since the outlet of the upward-sloping water outlet channel 357 is located at the bottom of the delay chamber 351 and the channel extends upwards, an adjustable throttle valve is installed on the water inlet pipe at the front end of the third water inlet 356. By adjusting the opening of the throttle valve, the flow rate of cooling water entering the delay chamber 351 can be precisely controlled, thereby obtaining a stable and adjustable delay time. An accumulator is installed at the outlet of the circulating water pump 400 to ensure that the inlet water pressure is constant and to avoid delay time drift caused by water pump pressure fluctuations. The cooling water needs to fill the water storage chamber to form sufficient water pressure to overcome the height difference of the liquid column in the channel. This water storage process constitutes the delay effect. By adjusting the throttle valve, any stable delay time within 3 to 10 seconds can be obtained. In this embodiment, it is preferably set to 5 seconds.

[0038] In the later stage of the pressure holding phase, after the delay cavity 351 is filled with cooling water, the water pressure pushes the cooling water through the upward-sloping outlet channel 357 into the second inlet of the central core block 330. After flowing through the internal cooling water channel 334 of the core block, it flows out from the second outlet through the connecting hole of the lower mold base 310. At the same time, the cooling water enters the first inlet of the upper mold central core rod 220 through the pipeline, flows through the spiral cooling water channel 221, flows out from the first outlet, and returns to the external circulating water pump 400, forming a closed-loop cooling circuit. The upper mold central core rod 220 and the central core block 330 are cooled rapidly and synchronously. Due to the difference in thermal expansion coefficient between the forging and the mold material, the forging shrinks preferentially, forming a radial demolding gap of about 0.1 to 0.2 mm between the outer surface of the forging and the inner wall of the cavity.

[0039] During the mold opening stage, the central core block 330 sinks and resets, and the hydraulic trigger rod 354 moves down and re-inserts into the hydraulic linkage cavity 355. The oil pressure in the hydraulic linkage cavity 355 increases and back pressures the hydraulic control cavity 353 through the hydraulic pipeline. The delay piston 352 is pushed back to its lower position, and its large-diameter section re-seals the third water inlet 356, interrupting the cooling water supply. During the downward movement of the delay piston 352, the remaining small amount of cooling water in the delay cavity 351 is squeezed out through the upward-sloping water outlet channel 357. The discharged small amount of water flows out from the fitting gap between the ejector rod 361 and the lower mold base 310, and the cooling circuit is automatically shut off.

[0040] See Figure 1The ejection mechanism 360 includes an ejector rod 361 and an ejection hydraulic cylinder 362. The ejector rod 361 is vertically positioned, passing through a pre-drilled hole at the bottom of the lower mold base 310, with its top end located directly below the area enclosed by the four segmented blocks 320 and the central core block 330, i.e., below the bottom surface of the forging. The ejection hydraulic cylinder 362 is mounted below the base plate 120, and its piston rod is fixedly connected to the lower end of the ejector rod 361. After the mold is opened, the forging no longer has lateral clamping force or internal hole support force. The ejection hydraulic cylinder 362 drives the ejector rod 361 upward, allowing the forging to be smoothly ejected with a relatively small ejection force.

[0041] The complete working process of the present invention will be described below with reference to the accompanying drawings.

[0042] Step 1: Mold Opening and Material Waiting State. Under the elastic force of their respective first return springs, the four segmented blocks 320 open radially outward along the dovetail guide rail to their travel limit positions, forming a cross-shaped open distribution. The central core block 330 is in a sunken position under the action of the second return spring, and the small cylindrical boss 332 is lower than the top surface of the lower mold base 310. The upper mold assembly 200 is at its top dead center. The operator places the cylindrical blank heated to forging temperature in the central area of ​​the lower mold base 310.

[0043] Step Two: Mold Closure and Forming. The main hydraulic cylinder 140 drives the upper mold assembly 200 to move downward along the guide post 150. The inverted frustum-shaped cavity 211 at the bottom of the upper mold body 210 first contacts the upper end face of the blank, applying vertical downward pressure to the blank. The metal flows radially and downward to begin filling the frustum-shaped body. As the upper mold assembly 200 continues to descend, the main push slope 241 at the lower end of the wedge drive rod 240 contacts the driven slope 322 on the outer side of the segmented block 320. The radially inward component force pushes the four segmented blocks 320 to close synchronously towards the center. The segmented blocks 320 push the outer edge metal radially in the opposite direction into the support leg cavity, realizing the filling of the support leg. At the same time, the push rod 250 is triggered to press down the control piston 342, the hydraulic linkage lifting system is activated, the central core block 330 is lifted upward to the lifting position, and the small cylindrical boss 332 axially connects with the lower end of the upper mold central core rod 220 to jointly form a dumbbell-shaped central through hole. After the upper and lower dies are fully closed, the upper end reset slope 242 of the wedge drive rod 240 has been inserted into the groove of the return hook 321 of the split block 320, and the forging cavity is completely sealed.

[0044] Step 3: Pressure Holding and Delayed Cooling. The upper die assembly 200 maintains the forging pressure at the lower dead center position for approximately 10 seconds. The first 5 seconds are the water filling stage: the central core block 330 is in the lifted position, the hydraulic trigger rod 354 has moved upward to trigger the delayed piston 352 to lift, the third water inlet 356 is exposed, and cooling water enters the delayed chamber 351 to fill. The next 5 seconds are the cooling stage: after the delayed chamber 351 is full, the water pressure forces the cooling water through the upward-sloping water outlet channel 357 into the cooling water channel 334 of the central core block 330 and the spiral cooling water channel 221 of the upper die central core rod 220 for closed-loop cooling. The forging shrinks preferentially over the die, forming a radial demolding gap of 0.1 to 0.2 mm.

[0045] Step Four: Mold Opening and Three-Step Active Demolding. Step One, Central Support Release: The main hydraulic cylinder 140 drives the upper mold assembly 200 upwards, triggering the push rod 250 to disengage from the control piston 342. The central core block 330 sinks and resets under the action of the second return spring, releasing the internal support of the large hole under the dumbbell-shaped through hole. Simultaneously, the hydraulic trigger rod 354 moves downwards, and the delay piston 352 resets and seals the third water inlet 356, closing the cooling circuit. Step Two, Lateral Constraint Release: The upper mold assembly 200 continues to move upwards. The upper end of the wedge drive rod 240 slides upwards along the inclined surface inside the groove of the return hook 321. The radially outward force pulls the four segmented blocks 320 back to their open positions along the dovetail guide rail. The first return spring assists in reset, completely releasing the constraint between the outer wall of the support leg and the cavity. The third step is light-load ejection: After the upper die assembly 200 is completely separated from the forging, the ejection hydraulic cylinder 362 drives the ejector rod 361 to move upward, smoothly ejecting the forging that has no lateral clamping, no internal hole support, and has formed a radial demolding gap.

[0046] Step 5: Removal and Reset. The operator removes the forging, and the ejector rod 361 retracts under the return drive of the ejector hydraulic cylinder 362. Under the action of gravity and the return springs, all moving parts of the device return to the initial state of Step 1, and the process begins the next production cycle.

[0047] The above description provides examples of the preferred embodiments of the present invention. Parts not detailed herein are common knowledge to those skilled in the art. The scope of protection of the present invention is determined by the claims. Any equivalent modifications based on the technical teachings of the present invention are also within the scope of protection of the present invention.

Claims

1. A forging and forming apparatus for producing a commercial vehicle chassis base, comprising a frame (100), an upper die assembly (200) vertically mounted on the frame (100), and a lower die assembly (300) fixed to the frame (100) and located below the upper die assembly (200), wherein the upper die assembly (200) includes an upper die body (210) and an upper die center mandrel (220) fixed to the upper die body (210), and the lower die assembly (300) includes a lower die base (310) and a center core block (330); characterized in that, The top surface of the lower mold base (310) is provided with a plurality of segmented blocks (320) along the circumferential direction, and each segmented block (320) is slidably mounted on the lower mold base (310) in the radial direction; the bottom outer edge of the upper mold body (210) is fixed with a plurality of inclined wedge drive rods (240), the lower end of the inclined wedge drive rod (240) is provided with a main push inclined surface (241), the upper end of the inclined wedge drive rod (240) is provided with a reset inclined surface (242), and the outer side of the segmented block (320) is provided with a driven inclined surface (322) that cooperates with the main push inclined surface (241) and a return hook (321) that cooperates with the reset inclined surface (242); The central core block (330) is slidably disposed at the center of the lower mold base (310) in the vertical direction. The top of the central core block (330) is provided with a small cylindrical boss (332). In the mold closing state, the small cylindrical boss (332) is axially connected to the lower end of the upper mold central core rod (220). It also includes a delayed cooling system, which includes a spiral cooling water channel (221) disposed in the upper mold center core rod (220), a cooling water channel (334) disposed in the center core block (330), and a delayed control unit disposed in the lower mold base (310). The delayed control unit includes a delayed cavity (351), a delayed piston (352) slidably disposed in the delayed cavity (351), and a hydraulic trigger rod (354) connected to the bottom of the center core block (330). The side wall of the delayed cavity (351) is provided with a third water inlet (356), and the bottom of the delayed cavity (351) is provided with an upwardly inclined water outlet channel (357) communicating with the cooling water channel (334). The delay control unit is configured to supply cooling medium to the cooling water passage (334) of the center core block (330) only after a predetermined time has elapsed since the start of the mold closing and pressure holding stage. The predetermined time is determined by the time required for the cooling medium to fill the delay cavity (351).

2. The forging apparatus according to claim 1, characterized in that, The top surface of the lower mold base (310) is provided with a dovetail guide rail extending radially, and the bottom of the segment block (320) is provided with a dovetail boss that slides with the dovetail guide rail. A first return spring is provided between the segment block (320) and the lower mold base (310).

3. The forging apparatus according to claim 1, characterized in that, The return hook (321) is an inwardly opening groove located on the outside of the split block (320), and the inner inclined surface of the groove is in the same direction as the inclination of the reset inclined surface (242).

4. The forging apparatus according to claim 1, characterized in that, It also includes a hydraulic linkage lifting system, which includes a hydraulic drive cavity (313) disposed at the bottom of the lower mold base (310), a hydraulic drive rod (341) connected to the bottom of the central core block (330) and extending into the hydraulic drive cavity (313), a lateral control cavity (314) disposed on the side of the lower mold base (310), a control piston (342) slidably disposed in the lateral control cavity (314), a hydraulic pipeline connecting the hydraulic drive cavity (313) and the lateral control cavity (314), and a trigger push rod (250) fixed to the bottom of the upper mold body (210), wherein the trigger push rod (250) corresponds vertically to the control piston (342).

5. The forging apparatus according to claim 4, characterized in that, A second reset spring is provided between the bottom of the central core block (330) and the lower mold base (310).

6. The forging apparatus according to claim 1, characterized in that, The delay control unit further includes a hydraulic control cavity (353) disposed on the upper part of the delay cavity (351) and a hydraulic linkage cavity (355) disposed in the lower mold base (310). The hydraulic linkage cavity (355) cooperates with the hydraulic trigger rod (354), and the hydraulic linkage cavity (355) and the hydraulic control cavity (353) are connected through a hydraulic pipeline.

7. The forging apparatus according to claim 1, characterized in that, The plurality of segmented blocks (320) are four in number, distributed at equal intervals of 90° along the circumference, and each segmented block (320) has a quarter-leg cavity on its inner side.

8. The forging apparatus according to any one of claims 1-7, characterized in that, It also includes an ejection mechanism (360), which includes an ejector rod (361) and an ejection hydraulic cylinder (362). The ejector rod (361) passes through the lower mold base (310) and is located below the area enclosed by the plurality of segmented blocks (320) and the central core block (330).

9. The forging apparatus according to claim 1, characterized in that, The delay control unit also includes an adjustable throttle valve located at the front end of the third inlet (356) of the delay cavity (351), and an accumulator is also provided between the third inlet (356) of the delay cavity (351) and the circulating water pump (400).

10. The forging apparatus according to claim 3, characterized in that, The angle of the main pushing slope (241) is 15°, and the angle of the reset slope (242) is 10°~15°.

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