Vehicle cover hinge forging die and vehicle cover hinge forging

Abstract

This invention relates to the field of metal forming technology, specifically to a forging die for a car hood hinge and a forged car hood hinge, comprising a sealing block assembly and a driving slider; the driving slider is slidably disposed within the ejector rod mounting hole and coaxially disposed with the ejector rod; the sealing block assembly has at least a first state and a second state, the state switching being driven by the sliding of the driving slider; when the sealing block assembly is in the first state, it fills the annular gap between the outer wall of the ejector rod tip and the inner wall of the ejector rod mounting hole inlet. Through an innovative sealing block assembly design, this invention can automatically and precisely fill the annular gap between the ejector rod and the mounting hole at the moment of die closing forging, forming a continuous and complete mold cavity sealing surface. This fundamentally prevents the possibility of high-temperature molten metal being squeezed into the gap, thereby completely eliminating defects such as flash and indentations on the bottom surface of the forging caused by gap squeezing.

Description

Technical Field

[0001] This invention relates to the field of metal forming technology, specifically to a hood hinge forging die, and a hood hinge forging forged using the hood hinge forging die. Background Technology

[0002] Forging, as an important metal forming process, is widely used in the automotive parts manufacturing industry. As a core load-bearing component connecting the car hood to the body, the hood hinge requires extremely high strength, precision, and reliability, and is typically manufactured using precision forging processes.

[0003] In traditional closed-die forging processes, an ejector device is typically installed at the bottom of the lower die to facilitate the removal of the forged part from the mold cavity. The core of this device is the ejector pin, which is installed in an ejector pin hole that runs through the bottom of the lower die cavity. During the forging stage, the ejector pin needs to retract until it is flush with the bottom surface of the cavity; during the demolding stage, the ejector pin extends under external drive, pushing the forging part away from the cavity.

[0004] However, this traditional structure has an inherent drawback: to ensure the ejector pin can extend and retract freely, a certain clearance must exist between the ejector pin and the ejector pin hole. During the high-temperature and high-pressure forging process, the metal material in a plastic flow state is easily squeezed into this tiny gap, forming difficult-to-remove "flash" or "burrs". This not only causes defects on the bottom surface of the forging, affecting dimensional accuracy and surface quality, but in severe cases, the squeezed metal can also cool and harden, causing the ejector pin to jam, move poorly, or even damage the die and forging. Summary of the Invention

[0005] This invention addresses the problems in the prior art by providing a forging die for a hood hinge and a forged hood hinge, the specific technical solution of which is as follows:

[0006] A hood hinge forging die includes an upper die base, a lower die base, a die cavity structure formed between the upper die base and the lower die base, and an ejector device disposed within the lower die base; the ejector device includes an ejector rod mounting hole communicating to the bottom of the die cavity structure, an ejector rod sleeve disposed within the ejector rod mounting hole, an ejector rod retractably disposed within the ejector rod sleeve, and a medium channel for driving the ejector rod to move.

[0007] It also includes a sealing valve block assembly and a drive slider;

[0008] The drive slider is slidably disposed in the top rod mounting hole and is coaxially disposed with the top rod;

[0009] The sealing flap block assembly has at least a first state and a second state, and the state switching is driven by the sliding of the driving slider.

[0010] When the sealing flap assembly is in the first state, it fills the annular gap between the outer wall of the top end of the push rod and the inner wall of the inlet of the push rod mounting hole; when the sealing flap assembly is in the second state, it releases the annular gap, allowing the push rod to extend.

[0011] As a further technical solution of the present invention, the sealing flap block group includes a plurality of sealing flap blocks that are evenly distributed around the top rod in the circumferential direction;

[0012] The outer side of the sealing valve has an outer guide surface, and the inner wall of the inlet of the top rod mounting hole has an inner guide surface that mates with the outer guide surface of the valve.

[0013] When the sealing valve block group is in the first state, all the sealing valve blocks converge towards each other and cooperate to form a closed ring that fills the annular gap; when the sealing valve block group is in the second state, all the sealing valve blocks disperse centrifugally.

[0014] As a further technical solution of the present invention, each of the sealing flaps is connected to the guide surface inside the mounting hole through a first sliding pair, and is connected to the driving slider through a second sliding pair;

[0015] When the drive slider slides toward the gap, it drives all the sealing petals to move synchronously through the second sliding pair, and under the constraint of the first sliding pair, all the sealing petals retract toward the top rod, switching to the first state;

[0016] When the drive slider slides away from the gap, it drives all the sealing blocks to move synchronously through the second sliding pair, and under the constraint of the first sliding pair, it causes all the sealing blocks to disperse away from the top rod, switching to the second state.

[0017] As a further technical solution of the present invention, the first sliding pair includes a first guide groove formed on the guide surface inside the mounting hole and a first slider slidably disposed in the first guide groove, wherein the first slider is fixedly connected to the sealing flap block.

[0018] The second sliding pair includes a second guide groove formed on the sealing flap block and a second slider slidably disposed in the second guide groove, the second slider being fixedly connected to the driving slider.

[0019] As a further technical solution of the present invention, a linkage drive mechanism is also included;

[0020] The linkage drive mechanism is configured to: drive the sealing flap block group to switch from the second state to the first state and maintain it during the mold closing process of the upper mold base and the lower mold base; and drive the sealing flap block group to switch from the first state to the second state and maintain it during the mold demolding process of the upper mold base and the lower mold base.

[0021] As a further technical solution of the present invention, the linkage drive mechanism includes:

[0022] The driving cavity is formed in the push rod mounting hole and is surrounded by the inner wall of the push rod mounting hole, the push rod sleeve, the push rod and the driving slider. Its volume changes as the driving slider slides.

[0023] A reset elastic element is disposed in the drive cavity and applies a tendency force to the drive slider to slide away from the gap.

[0024] The pressure chamber is formed on the mold closing end face of the lower mold base;

[0025] The pressure piston is slidably disposed in the pressure chamber, and part of its structure is exposed on the mold closing end face of the lower mold base, so as to be pressed in by the upper mold base when the mold is closed;

[0026] The connecting pipe connects the driving chamber and the pressurizing chamber, and together they form a closed volume filled with fluid medium.

[0027] As a further technical solution of the present invention, when the upper mold base and the lower mold base are closed, the pressure piston is pressed into the pressure chamber, and the fluid medium is pushed into the drive chamber through the connecting pipe, which pushes the drive slider to overcome the elastic force of the reset elastic element and slide towards the gap, thereby driving the sealing valve block group to switch to the first state.

[0028] As a further technical solution of the present invention, when the upper mold base and the lower mold base are demolded, the reset elastic element drives the driving slider to slide away from the gap, and the fluid medium in the driving cavity is pushed back to the pressure chamber through the connecting pipe, pushing the pressure piston part to be exposed, thereby driving the sealing valve block group to switch to the second state.

[0029] As a further technical solution of the present invention, the reset elastic element is a spring.

[0030] A hood hinge forging, wherein the hood hinge forging is forged using the hood hinge forging die described in any of the above technical solutions.

[0031] The beneficial effects of this invention are as follows:

[0032] Completely eliminates forging flash defects and significantly improves forging quality: This invention, through an innovative sealing flap assembly design, can automatically and precisely fill the annular gap between the ejector pin and the mounting hole at the moment of die closing forging, forming a continuous and complete die cavity sealing surface. This fundamentally prevents the possibility of high-temperature molten metal being squeezed into the gap, thereby completely eliminating defects such as flash and indentations on the bottom surface of the forging caused by gap squeezing, ensuring high dimensional accuracy and surface finish of the forging, and is particularly suitable for the production of automotive safety components such as hood hinges that have stringent requirements for strength and appearance.

[0033] This significantly extends the mold's service life and reduces maintenance costs: By eliminating metal intrusion, it effectively prevents ejector pin jamming, scoring, and the resulting mold surface damage. The sealing valve assembly and its drive mechanism share the friction and extrusion forces directly borne by the ejector pin hole in traditional structures, greatly reducing the wear of key moving parts such as ejector pins and ejector pin sleeves. This significantly extends the overall service life of the mold, reduces downtime and costs caused by mold repair and replacement, and improves production economy.

[0034] This invention achieves intelligent linkage between sealing and ejection states, ensuring high-efficiency and reliable production. It innovatively designs a linkage drive mechanism directly driven by the mold closing action. The sealing and release actions are completely synchronized with the mold opening and closing, and are performed automatically, without the need for an additional independent control system or manual intervention. This ensures both absolute accuracy in sealing timing and sufficient sealing force, as well as reliable release of the pre-ejection gap. The entire process is smooth, fast, and reliable, achieving excellent sealing performance without affecting the original production cycle, making it particularly suitable for automated, high-volume assembly line production. Attached Figure Description

[0035] Figure 1 A schematic diagram of the forging die for the hood hinge is shown.

[0036] Figure 2 This diagram shows the structure of the sealing flap assembly engaging with the drive slider in the first state.

[0037] Figure 3 A schematic diagram of the sealing flap assembly engaging with the drive slider in the second state is shown.

[0038] Figure 4 A schematic diagram of the linkage drive mechanism for the sealing valve block assembly in the first state is shown.

[0039] Figure 5 A schematic diagram of the linkage drive mechanism for the sealing flap block assembly in the second state is shown.

[0040] Figure Descriptions: 1. Upper mold base; 11. Central column; 2. Lower mold base; 21. Lower mold cavity; 3. Ejection device; 31. Ejector rod mounting hole; 32. Ejector rod sleeve; 33. Ejector rod; 34. Medium channel; 4. Sealing valve block assembly; 41. Sealing valve block; 411. Outer guide surface of valve block; 311. Inner guide surface of mounting hole; 42. First sliding pair; 421. First guide groove; 422. First slider; 43. Second sliding pair; 431. Second guide groove; 432. Second slider; 5. Drive slider; 6. Linkage drive mechanism; 61. Drive cavity; 611. Reset elastic element; 62. Pressure cavity; 621. Pressure piston; 63. Connecting pipeline. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0042] Example

[0043] The hood hinge forging die of this embodiment is used to form hood hinge forgings and includes at least an upper die base 1, a lower die base 2, a die cavity structure, and an ejection device 3.

[0044] In this embodiment, the mold cavity structure refers to a cavity precisely machined according to the three-dimensional shape of the hood hinge product, which is used to complete the forming of the main structure of the hinge in one forging process. During the mold closing period, the mold cavity structure ensures that the outline of the forging is complete and the dimensions are accurate. After the mold is opened, the formed forging will be smoothly removed from the mold cavity by the ejection device 3, thereby ensuring the surface quality and forming efficiency of the forging. It is suitable for the mass precision forging production of automotive hood hinges.

[0045] Figure 1 A schematic diagram of the forging die for the hood hinge is shown. Figure 1 In this process, the hood hinge forging die includes an upper die base 1 and a lower die base 2. Normally, the lower die base 2 is fixed on a machine tool, while the upper die base 1 is movable and controlled by a drive device to perform reciprocating up and down movements. The closing end of the upper die base 1 has a protruding upper die core 11, and the closing end of the lower die base 2 has an inwardly recessed lower die cavity 21. When the upper die base 1 moves toward the lower die base 2 and closes the die, the upper die core 11 and the lower die cavity 21 cooperate to form the die cavity structure. Correspondingly, the raw material pre-placed in the lower die cavity 21 is also forged into a hood hinge forging.

[0046] Figure 1The hood hinge forging mold also includes an ejector device 3, which is mounted on the lower mold base 2 and is used to help demold the hood hinge forging. The ejector device 3 includes an ejector rod mounting hole 31, an ejector rod sleeve 32, an ejector rod 33, and a medium channel 34. The ejector rod mounting hole 31 is connected to the bottom surface of the lower mold cavity 21. The ejector rod sleeve 32 is installed in the ejector rod mounting hole 31. The ejector rod 33 is telescopically mounted in the ejector rod sleeve 32. The input end of the medium channel 34 is connected to a medium source, and the output end of the medium channel 34 is connected to the ejector rod sleeve 32. The ejector rod 33 can extend and lift the workpiece for demolding when driven by the medium. After the workpiece has been formed and the upper mold base 1 and the lower mold base 2 are separated, the medium flows into the ejector rod sleeve 32, and the corresponding ejector rod 33 is pushed out and extends into the lower mold cavity 21, thereby lifting the workpiece in the lower mold cavity 21 and completing the demolding.

[0047] Figure 2 This shows a schematic diagram of the structure of the sealing valve block assembly 4 cooperating with the drive slider 5 in the first state; Figure 3 This shows a schematic diagram of the structure of the sealing valve block assembly 4 cooperating with the drive slider 5 in the second state; Figure 2 and Figure 3In the process, there is a gap between the push rod mounting hole 31 and the push rod 33 that allows the push rod 33 to extend and retract. The sealing valve block assembly 4 has at least a first state and a second state. The driving slider 5 is slidably disposed in the push rod mounting hole 31. The sealing valve block assembly 4 is switched between the first state and the second state by the sliding of the driving slider 5. In the first state, the sealing valve block assembly 4 fills the gap and restricts the extension and retraction of the push rod 33. In the second state, the sealing valve block assembly 4 releases the gap and allows the push rod 33 to extend and retract. Further, the sealing valve block assembly 4 includes multiple sets of sealing valve blocks 41 evenly distributed around the push rod 33. The sealing valve blocks 41 have an outer guide surface 411. The push rod mounting hole 31 has an inner guide surface 311 that matches the outer guide surface 411. In the first state, all the sealing valve blocks 41 converge towards each other and cooperate to form a ring that fills the gap. In the second state, all the sealing valve blocks 41 disperse centrifugally to release the gap. Furthermore, each sealing valve block 41 also has a corresponding first sliding... The moving pair 42 and the second sliding pair 43 are slidably connected between the sealing flap 41 and the guide surface 311 in the mounting hole via the first sliding pair 42, and between the sealing flap 41 and the driving slider 5 via the second sliding pair 43. When the second sliding pair 43 slides toward the gap, the sealing flap group 4 is in the first state, and all the sealing flaps 41 retract toward the push rod 33 while sliding with the driving slider 5. When the second sliding pair 43 slides away from the gap, the sealing flap group 4 is in the second state, and all the sealing flaps 41 disperse away from the push rod 33 while sliding with the driving slider 5. Furthermore, the first sliding pair 42 includes a first guide groove 421 formed on the guide surface 311 in the mounting hole and a first slider 422 sliding in the first guide groove 421. The first slider 422 is connected to the sealing flap 41. The second sliding pair 43 includes a second guide groove 431 formed on the sealing flap 41 and a second slider 432 sliding in the second guide groove 431. The second slider 432 is connected to the driving slider 5.

[0048] The working principle of the sealing petal block assembly 4 and the driving slider 5 is as follows: Before mold closing, the ejector pin 33 retracts to be flush with the bottom wall of the lower mold cavity 21. There is a gap between the end of the ejector pin 33 and the connection between the ejector pin mounting hole 31 and the lower mold cavity 21, driving the driving slider 5 to slide towards the end of the ejector pin 33. At this time, the sealing petal block 41 moves synchronously under the drive of the driving slider 5. Due to the cooperation of the guide surface 311 inside the mounting hole and the guide surface 411 outside the petal block, the sealing petal block 41 moves towards the end of the ejector pin 33 while also approaching the ejector pin 33. When the sealing petal block 41 moves to the end of the ejector pin 33, all the sealing petal blocks 41 are circumferentially connected to form a seal. The inner ring of the closed ring body matches the outer diameter of the ejector rod 33, that is, the sealing petal block 41 fits against the surface of the ejector rod 33, thereby filling the gap and ensuring the integrity and sealing of the cavity structure during molding. After the workpiece is formed, the driving slider 5 is driven to slide towards the root of the ejector rod 33 (i.e. away from the gap), while the sealing petal block 41 moves synchronously with the driving slider 5 through the action of the second sliding pair 43. At the same time, due to the restriction of the sealing petal block 41 sliding along the trajectory of the first guide groove 421, the sealing petal block 41 moves away from the gap and also moves away from the ejector rod 33, thereby releasing the gap. The ejector rod 33 can then extend and lift the formed workpiece.

[0049] Figure 4 A schematic diagram of the linkage drive mechanism 6 when the sealing valve block assembly 4 is in the first state is shown. Figure 5 A schematic diagram of the linkage drive mechanism 6 of the sealing valve block assembly 4 in the second state is shown; Figure 4 and Figure 5The forging mold for the hood hinge also includes a linkage drive mechanism 6. This mechanism is configured to drive the sealing flap assembly 4 to a first state during the mold closing process of the upper mold base 1 and lower mold base 2, and maintain this first state after mold closing. Simultaneously, it drives the sealing flap assembly 4 to a second state during the demolding process of the upper mold base 1 and lower mold base 2, and maintains this second state after demolding. Specifically, the linkage drive mechanism 6 includes a drive cavity 61, a pressure chamber 62, and a connecting pipe 63. The drive cavity 61 is formed within the ejector mounting hole 31 through the peripheral wall of the ejector mounting hole 31, the ejector sleeve 32, the ejector 33, and the drive slider 5. The drive cavity 61 changes volume as the drive slider 5 slides. A reset elastic element 611 is provided within the drive cavity 61. The reset elastic element 611 acts on the drive slider 5 and applies a tendency force to slide away from the gap. The pressure chamber 62... A pressure piston 621 is slidably provided in the pressure chamber 62 formed at the mold closing end of the lower mold base 2, and part of the pressure piston 621 is exposed outside the pressure chamber 62. The connecting pipe 63 connects the drive chamber 61 and the pressure chamber 62 and forms a closed fluid volume. The closed fluid volume is filled with fluid medium. When the upper mold base 1 and the lower mold base 2 are closed, the pressure piston 621 is compressed into the pressure chamber 62 and the medium pushes the drive slider 5 to slide in the gap direction. The sealing valve block group 4 switches from the second state to the first state. When the upper mold base 1 and the lower mold base 2 are demolded, the drive slider 5 slides away from the gap direction under the elastic restoring force of the reset elastic element 611. The sealing valve block group 4 switches from the first state to the second state, and part of the pressure piston 621 is exposed outside the pressure chamber 62 by the medium. In this embodiment, the reset elastic element 611 is a spring.

[0050] The working principle of the drive slider 5 and the linkage drive mechanism 6 is as follows:

[0051] When the upper mold base 1 and the lower mold base 2 approach each other and close the mold, the exposed pressure piston 621 is pressed into the pressure chamber 62 by the upper mold base 1. The medium in the pressure chamber 62 is pushed into the drive chamber 61 through the connecting pipe 63. At this time, the drive slider 5 is pushed by the medium to slide in the gap direction. The reset elastic element 611 is stretched and deformed, forcing the sealing valve block group 4 to switch from the second state to the first state and fill the gap, forming a gap that is automatically filled as the upper mold base 1 and the lower mold base 2 close the mold.

[0052] When the upper mold base 1 and the lower mold base 2 move away from each other during demolding, they are pulled by the elastic force of the reset elastic element 611. At this time, the drive slider 5 slides away from the gap, the sealing valve block group 4 switches from the first state to the second state and releases the gap, and the medium in the drive cavity 61 is pushed into the pressure cavity 62 through the connecting pipe 63. The pressure piston 621 is pushed by the medium and partially exposed in the pressure cavity 62, so that it can be automatically released when the gap is formed during the next mold closing.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. A forging die for a car hood hinge, comprising an upper die base, a lower die base, a die cavity structure formed between the upper die base and the lower die base, and an ejector device disposed within the lower die base; the ejector device includes an ejector rod mounting hole communicating to the bottom of the die cavity structure, an ejector rod sleeve disposed within the ejector rod mounting hole, an ejector rod retractably disposed within the ejector rod sleeve, and a medium channel for driving the ejector rod to move; characterized in that It also includes a sealing valve block assembly, a drive slider, and a linkage drive mechanism; The drive slider is slidably disposed in the top rod mounting hole and is coaxially disposed with the top rod; The sealing flap assembly includes multiple sealing flaps that are evenly distributed around the top rod in the circumferential direction. The outer side of the sealing valve has an outer guide surface, and the inner wall of the inlet of the top rod mounting hole has an inner guide surface that mates with the outer guide surface of the valve. Each of the sealing flaps is connected to the guide surface inside the mounting hole via a first sliding pair and to the drive slider via a second sliding pair; The sealing flap block assembly has at least a first state and a second state, and the state switching is driven by the sliding of the driving slider. When the sealing flap assembly is in the first state, it fills the annular gap between the outer wall of the top end of the push rod and the inner wall of the inlet of the push rod mounting hole. When the sealing valve block assembly is in the second state, it releases the annular gap, allowing the push rod to extend; The linkage drive mechanism includes: The driving cavity is formed in the push rod mounting hole and is surrounded by the inner wall of the push rod mounting hole, the push rod sleeve, the push rod and the driving slider. Its volume changes as the driving slider slides. A reset elastic element is disposed in the drive cavity and applies a tendency force to the drive slider to slide away from the annular gap. A pressure chamber is formed on the mold closing end face of the lower mold base; A pressure piston is slidably disposed in the pressure chamber, with part of its structure exposed on the mold closing end face of the lower mold base, for being pressed in by the upper mold base during mold closing; A connecting pipe connects the driving chamber and the pressurizing chamber, and together they form a closed volume filled with a fluid medium.

2. The hatch hinge forging die of claim 1, wherein When the sealing valve block group is in the first state, all the sealing valve blocks converge towards each other and cooperate to form a closed ring that fills the annular gap; when the sealing valve block group is in the second state, all the sealing valve blocks disperse centrifugally.

3. The hatch hinge forging die of claim 2, wherein: When the drive slider slides toward the annular gap, it drives all the sealing petals to move synchronously through the second sliding pair, and under the constraint of the first sliding pair, all the sealing petals retract toward the top rod, switching to the first state; When the drive slider slides away from the annular gap, it drives all the sealing petals to move synchronously through the second sliding pair, and under the constraint of the first sliding pair, it causes all the sealing petals to disperse away from the top rod, switching to the second state.

4. The hatch hinge forging die of claim 3, wherein: The first sliding pair includes a first guide groove formed on the guide surface inside the mounting hole and a first slider slidably disposed in the first guide groove, the first slider being fixedly connected to the sealing flap block; The second sliding pair includes a second guide groove formed on the sealing flap block and a second slider slidably disposed in the second guide groove, the second slider being fixedly connected to the driving slider.

5. The hatch hinge forging die of claim 3, wherein: The linkage drive mechanism is configured to: drive the sealing flap block group to switch from the second state to the first state and maintain it during the mold closing process of the upper mold base and the lower mold base; and drive the sealing flap block group to switch from the first state to the second state and maintain it during the mold demolding process of the upper mold base and the lower mold base.

6. The hatch hinge forging die of claim 5, wherein: When the upper mold base and the lower mold base are closed, the pressure piston is pressed into the pressure chamber, and the fluid medium is pushed into the drive chamber through the connecting pipe, which pushes the drive slider to overcome the elastic force of the reset elastic element and slide towards the annular gap, thereby driving the sealing valve block group to switch to the first state.

7. The hatch hinge forging die of claim 5, wherein: When the upper mold base and the lower mold base are demolded, the reset elastic element drives the drive slider to slide away from the annular gap. The fluid medium in the drive cavity is pushed back to the pressure chamber through the connecting pipe, pushing the pressure piston part to be exposed, thereby driving the sealing valve block group to switch to the second state.

8. The hatch hinge forging die of claim 5, wherein: The reset elastic element is a spring.

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