Flange-free leather cup single-cavity mold and vulcanization process

Abstract

The invention discloses a flash-free leather cup single-cavity mold, and belongs to the technical field of vulcanization molding of rubber products. Comprising a mold frame and a mold core system. The die frame is composed of an upper die plate, a middle die plate, a lower die plate and a base plate which are stacked from top to bottom. The mold core system comprises an upper mold core, a middle mold core and a lower mold core. The mold core is in clearance fit with the mold plate, so that the mold plate and the mold core are relatively independent, the matching precision of the mold core cannot be affected by deformation errors in the mold plate designing, machining and using processes, the requirement of the mold for the precision of the mold frame is reduced, and the mold manufacturing cost and the production vulcanization cost are reduced; the split type upper mold core is adopted, the upper mold inner core can slide up and down in the upper mold shell in a clearance mode, and the parting pressure-bearing glue sealing problem in a leather cup is solved; exhaust lines are added on a parting surface, so that the problem of vulcanization exhaust is solved. Through the improvement and innovation, no flash is generated during injection molding vulcanization of the leather cup, the subsequent trimming procedure is eliminated, and the labor intensity and the production and manufacturing cost are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of vulcanization molding of rubber products, and in particular to a single-cavity mold for a leather cup without flash and a vulcanization process. Background Art

[0002] The rimless rubber cup is a core seal in the braking system of new energy vehicles, directly affecting brake response speed and safety. Its flash-free design prevents brake fluid leakage and improves system stability. Global annual demand exceeds 300 million units.

[0003] Traditional molds have a rigid connection between the mold core and the template, and processing errors and vulcanization deformation lead to interference on the parting surface, resulting in flash and requiring additional trimming processes, resulting in a low yield rate. Summary of the Invention

[0004] The present invention provides a single-cavity mold for a leather cup without flash and a vulcanization process, which can solve the serious flash problem existing in traditional molds.

[0005] To achieve the above objectives, the technical solutions adopted by the present invention are as follows:

[0006] The present invention proposes a single-cavity mold for a leather cup without flash, comprising:

[0007] The mold frame is composed of an upper mold plate, a middle mold plate, a lower mold plate and a pad stacked from top to bottom;

[0008] A mold core system, comprising an upper mold core, a middle mold core, and a lower mold core;

[0009] The upper mold core includes an upper mold shell embedded in the upper mold plate, and an upper mold inner core with a clearance fit in the upper mold shell, and the upper mold inner core can slide axially along the upper mold shell; the middle mold core is embedded in the middle mold plate; the lower mold core is embedded in the lower mold plate, and a through-type exhaust hole is provided in the center of the lower mold core;

[0010] Parting surfaces of the middle mold core, the upper mold core and the lower mold core are all provided with radial exhaust grooves.

[0011] The present invention realizes the relative independence of the template and the core by adopting the clearance fit between the core and the template, so that the deformation error in the design, processing and use of the template will not affect the fitting accuracy of the core, reducing the mold's precision requirements on the mold frame and the precision requirements on the vulcanization equipment, thereby reducing the mold manufacturing cost and production vulcanization cost; the upper mold core adopts a separate upper mold shell and upper mold inner core structure, and the upper mold inner core can slide up and down in the upper mold shell in a clearance manner, solving the problem of parting pressure sealing in the leather cup; the parting surface adds exhaust lines to solve the problem of vulcanization exhaust. Through the above improvements and innovations, the leather cup can be injected and vulcanized without flash, eliminating the subsequent trimming process, and reducing labor intensity and production costs.

[0012] As a further solution of the present invention: the fitting clearance between the upper die inner core and the upper die outer shell is 0.1-0.3 mm.

[0013] As a further solution of the present invention: the upper mold shell is embedded in the upper mold plate through a dynamic retaining spring, and the fitting clearance between the upper mold shell and the upper mold plate is 0.02-0.2 mm.

[0014] As a further solution of the present invention: the middle mold core is embedded in the middle mold plate through a dynamic retaining spring, and the fitting clearance between the middle mold core and the middle mold plate is 0.2-0.5 mm.

[0015] As a further solution of the present invention: the lower mold core is fixed in the lower mold plate by a dynamic retaining spring, and the fitting clearance between the lower mold core and the lower mold plate is 0.2-0.5 mm.

[0016] As a further solution of the present invention: the dynamic retaining spring is an open elastic C-shaped ring with a compression rebound amount of ≥0.1mm.

[0017] As a further solution of the present invention: the exhaust hole in the center of the lower mold core is coaxially connected to the vertical exhaust channel of the pad, and the diameter of the exhaust channel is 8 mm.

[0018] As a further solution of the present invention: the radial exhaust grooves are radiated from the center of the cavity as the origin, with a groove depth of 0.002-0.008 mm and a groove width of 0.02-0.08 mm.

[0019] The present invention also proposes a flashless leather cup vulcanization process, which is performed using any of the flashless leather cup single-cavity molds, and includes the following steps:

[0020] S1, mold closing and glue injection:

[0021] Inject the rubber into the cavity formed by the upper mold core, the middle mold core and the lower mold core, with a mold closing pressure of 10-25MPa;

[0022] S2, independent sealing and pressure:

[0023] The inner core of the upper mold slides downward along the outer shell of the upper mold under the hydraulic pressure of the rubber material, independently compacting the inner parting surface;

[0024] The middle mold core elastically compensates for the position deviation of the middle mold plate through the dynamic matching retaining spring to ensure the fit of the outer parting surface;

[0025] S3, sulfide exhaust:

[0026] Vulcanization temperature 160-190℃, pressure 15-22MPa;

[0027] The gas flows radially through the radial exhaust grooves and is discharged to the central exhaust hole of the lower mold core;

[0028] S4, mold opening and parts removal:

[0029] The leather cup is ejected without flash and no trimming process is required.

[0030] As a further solution of the present invention: in step S2, the sliding stroke of the inner core of the upper mold is 0.05-0.15 mm, and the downward pressure is ≥8 MPa;

[0031] In step S3, the gas flow rate of the radial exhaust groove is ≥0.5 m / s, and the vulcanization time is 360-480 seconds.

[0032] Beneficial effects of the present invention:

[0033] (1) The mold frame of the present invention is composed of an upper mold plate, a middle mold plate, a lower mold plate and a pad stacked from top to bottom. The mold core system includes an upper mold core, a middle mold core and a lower mold core. The upper mold core, the middle mold core and the lower mold core together form a leather cup cavity. The upper mold core adopts a separate upper mold shell and upper mold inner core structure. The upper mold shell and the upper mold inner core are combined into the upper mold core by vulcanization injection. At the same time, the upper mold inner core still has the ability to move freely up and down, so that the inner and outer partings of the upper mold core can independently withstand pressure and seal, avoiding the mutual interference caused by the mold processing precision error to produce flash, and solving the problem of flash between the inner parting and the outer lip parting of the product;

[0034] (2) The present invention realizes the relative independence of the mold core and the mold template by adopting the clearance fit between the mold core and the mold template, so that the deformation error during the design, processing and use of the mold template will not affect the matching accuracy of the mold core, thereby reducing the mold's precision requirements on the mold frame and the precision requirements on the vulcanization equipment, thereby reducing the mold manufacturing cost and production vulcanization cost;

[0035] (3) After the rubber material of the present invention is injected into the mold cavity, the inner core of the upper mold slides downward along the upper mold shell under the reaction force of the rubber material, independently compacting the inner parting surface. At the same time, the middle mold core elastically compensates for the position deviation of the middle mold plate through the dynamic matching retaining spring to ensure the fit of the outer parting surface. The rubber material hydraulic pressure is used to drive the inner core of the upper mold to slide, replacing the traditional rigid pressing;

[0036] (4) The present invention provides radial exhaust grooves on the parting surfaces of the middle mold core, the upper mold core and the lower mold core. The radial exhaust grooves are radiated with the center of the cavity as the origin. The sulfide gas radially converges through the radial exhaust grooves to the exhaust hole in the center of the lower mold core for discharge; the gas is discharged through the exhaust hole in the lower mold core, eliminating the air trap defect. Compared with the traditional straight groove exhaust efficiency, the air trap defect rate is improved by at least 40%, and the air trap defect rate is reduced from more than 18% to less than 1%. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be further described below with reference to the accompanying drawings.

[0038] Figure 1 This is a schematic diagram of the overall structure of a single-cavity mold for a leather cup without flash in the present invention;

[0039] Figure 2 It is a front cross-sectional schematic diagram of a single-cavity mold for a leather cup without flash according to the present invention;

[0040] Figure 3 It is a front cross-sectional schematic diagram of the lower mold core structure of the present invention;

[0041] Figure 4 It is a top view schematic diagram of the lower mold core structure of the present invention.

[0042] In the figure: 1. Upper mold plate; 101. Upper mold core; 1011. Upper mold shell; 1012. Upper mold inner core; 2. Middle mold plate; 201. Middle mold core; 3. Lower mold plate; 301. Lower mold core; 302. Exhaust hole; 4. Pad; 5. Radial exhaust groove; 6. Annular groove. DETAILED DESCRIPTION

[0043] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0044] In the description of the present invention, it should be understood that the terms "up", "down", "left", "right", "front", "back", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, and a specific direction structure and operation. Therefore, they cannot be understood as limiting the present invention.

[0045] In addition, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0046] Rimless cups are primarily used in brakes for new energy vehicles. They primarily transmit pressure and seal, ensuring stable flow of brake fluid through the system and preventing leakage. They are core sealing components in the braking system. With the development of new energy vehicles, global automotive demand for rimless cups is increasing annually. By 2024, global demand will reach nearly 300 million units, with domestically produced rimless cups accounting for 35% of the market share, leaving ample room for growth. Single-mold rimless cups are used for customer development of new products, with an annual demand of nearly 200 sets. Domestically, there is no rimless single-mold manufacturing technology, and all molds are imported. With significant tariff fluctuations in recent years, the cost of imported molds has continued to rise, making it increasingly unacceptable for the company and its customers. With the development of new energy vehicles, market demand for rimless cups has increased significantly. Relying on imported molds is no longer sufficient to meet the needs of domestic new energy vehicle development, making the development of domestically produced rimless cup single-molds imperative.

[0047] Based on this, see Figure 1-4 As shown, an embodiment of the present invention provides a single-cavity mold for a leather cup without flash, including a mold frame and a mold core system.

[0048] See also Figure 1 As shown, in one embodiment of the present invention, the mold frame is composed of an upper mold plate 1, a middle mold plate 2, a lower mold plate 3, and a backing plate 4 stacked from top to bottom. The upper mold plate 1, the middle mold plate 2, the lower mold plate 3, and the backing plate 4 are preferably made of P20 pre-hardened mold steel with a hardness of 28-34HRC to ensure the rigidity of the mold frame.

[0049] See also Figure 2 As shown, the core system includes an upper mold core 101, a middle mold core 201, and a lower mold core 301, which together form the cup cavity. The upper, middle, and lower mold cores 101, 201, and 301 are preferably made of H13 hot-working die steel with a hardness of 48-52 HRC to enhance the core system's heat and wear resistance.

[0050] Among them, in one embodiment of the present invention, the upper mold core 101 includes an upper mold outer shell 1011 and an upper mold inner core 1012. The upper mold outer shell 1011 is embedded in the upper mold plate 1, and the upper mold inner core 1012 is gap-fitted in the upper mold outer shell 1011. The upper mold inner core 1012 can slide axially along the upper mold outer shell 1011, and the fitting clearance between the upper mold inner core 1012 and the upper mold outer shell 1011 is 0.1-0.3mm.

[0051] Specifically, in one embodiment of the present invention, the upper mold shell 1011 can be embedded in the upper mold plate 1 through a dynamic retaining spring, and the dynamic retaining spring is installed in the annular groove 6 opened in the upper mold plate 1. The dynamic retaining spring locks the upper mold shell 1011 so that the fitting clearance between the upper mold shell 1011 and the upper mold plate 1 is 0.02-0.2mm. The dynamic retaining spring can be an open elastic C-shaped ring with a compression rebound amount ≥0.1mm.

[0052] The upper mold core 101 of the present application adopts a separate upper mold outer shell 1011 and upper mold inner core 1012 structure, and the upper mold outer shell 1011 and the upper mold inner core 1012 are combined into the upper mold core 101 through vulcanization injection. At the same time, the upper mold inner core 1012 still has the ability to move freely up and down, so that the inner and outer partings of the upper mold core 101 can independently bear pressure and seal, avoiding the mutual interference caused by the mold processing precision error to produce flash, and solving the problem of flash on the inner parting and the outer lip parting of the product.

[0053] See also Figure 2 As shown, in one embodiment of the present invention, the middle mold core 201 is embedded in the middle mold plate 2. Specifically, the middle mold core 201 can be embedded in the middle mold plate 2 by a dynamic retaining spring. The dynamic retaining spring is installed in an annular groove 6 provided in the middle mold plate 2. The dynamic retaining spring locks the middle mold core 201 so that the clearance between the middle mold core 201 and the middle mold plate 2 is 0.2-0.5mm. The dynamic retaining spring can be an open elastic C-shaped ring with a compression rebound of ≥0.1mm.

[0054] See also Figure 2 As shown, in one embodiment of the present invention, the lower mold core 301 is embedded in the lower mold plate 3. Specifically, the lower mold core 301 can be embedded in the lower mold plate 3 through a dynamic retaining spring. The dynamic retaining spring is installed in an annular groove 6 opened in the lower mold plate 3. The dynamic retaining spring locks the lower mold core 301 so that the fitting clearance between the lower mold core 301 and the lower mold plate 3 is 0.2-0.5mm. The dynamic retaining spring can be an open elastic C-shaped ring with a compression rebound amount ≥0.1mm.

[0055] It should be noted that, in one embodiment of the present invention, a through exhaust hole 302 is provided in the center of the lower mold core 301, and the exhaust hole 302 in the center of the lower mold core 301 is coaxially connected to the vertical exhaust channel in the center of the pad 4, and the diameter of the exhaust hole 302 in the center of the lower mold core 301 and the exhaust channel in the center of the pad 4 is set to 8 mm.

[0056] It is worth noting that, in one embodiment of the present invention, radial exhaust grooves 5 are provided on the parting surfaces of the middle mold core 201, the upper mold core 101, and the lower mold core 301. The radial exhaust grooves 5 are radiated from the center of the cavity as the origin, with a groove depth of 0.002-0.008 mm and a groove width of 0.02-0.08 mm. The spacing between adjacent grooves decreases from the outside to the inside, with the spacing between the outer edges of adjacent grooves being 1.2-1.8 mm and the spacing between the central confluence areas being 0.1-0.3 mm. The radial exhaust grooves 5 can be processed by a fiber laser. After the mold core system is assembled, the entire mold is closed to lock the parting surface; the laser beam scans perpendicular to the parting surface and ablates the material along a preset radiation path; nitrogen assists in blowing out the slag to avoid burrs on the groove edges. The sulfide gas flows along the radial exhaust grooves 5 to the exhaust hole 302 in the center of the lower mold core 301.

[0057] The embodiment of the present invention further provides a flashless leather cup vulcanization process, which is performed using the flashless leather cup single-cavity mold described above, and specifically includes the following steps:

[0058] S1, mold closing and glue injection:

[0059] The rubber material is injected into the cavity formed by the upper mold core 101, the middle mold core 201 and the lower mold core 301, and the mold closing pressure is 10-25 MPa.

[0060] S2, independent sealing and pressure:

[0061] After the rubber material is injected into the cavity, the hydraulic system drives the upper mold plate 1 to press down. The upper mold core 1012 slides downward 0.05mm along the upper mold shell 1011 under the reaction force of the rubber material, independently compacting the inner parting surface. At the same time, the middle mold core 201 elastically compensates for the position deviation of the middle mold plate 2 through the dynamic matching retaining spring to ensure the fit of the outer parting surface.

[0062] S3, sulfide exhaust:

[0063] Vulcanization temperature 160-190℃, pressure 15-22MPa;

[0064] The vulcanized gas is radially converged through the radial exhaust grooves 5 to the central exhaust hole 302 of the lower mold core 301 and discharged through the Φ4mm exhaust hole 302 of the lower mold core 301, eliminating the gas pocket defect.

[0065] S4, mold opening and parts removal:

[0066] The leather cup is ejected without flash and no trimming process is required.

[0067] Furthermore, in step S2, the sliding stroke of the upper mold inner core 1012 is 0.05-0.15 mm, and the downward pressure is ≥8 MPa.

[0068] In step S3, the gas flow rate of the radial exhaust grooves 5 is ≥0.5 m / s, and the vulcanization time is 360-480 seconds.

[0069] In summary, the present invention realizes the relative independence of the template and the core by adopting the clearance fit between the core and the template, so that the deformation error in the design, processing and use of the template will not affect the fitting accuracy of the core, reducing the mold's precision requirements on the mold frame and the precision requirements on the vulcanization equipment, thereby reducing the mold manufacturing cost and production vulcanization cost; the upper mold core 101 adopts a separate upper mold shell 1011 and upper mold inner core 1012 structure, and the upper mold inner core 1012 can slide up and down in the upper mold shell 1011 in a clearance manner, solving the problem of parting pressure sealing in the leather cup; the parting surface adds exhaust lines to solve the problem of vulcanization exhaust. Through the above improvements and innovations, the leather cup injection vulcanization is achieved without flash, the subsequent trimming process is eliminated, and the labor intensity and production manufacturing costs are reduced.

[0070] This invention utilizes a gap-fitting mold core and mold base, creating an independent pressure-bearing structure. This simplifies demolding and eliminates the need for post-processing punching and trimming, enabling the domestic production of single-mold molds for rimless leather cups. The single-mold manufacturing cycle is 45 days, half the 90-day production time compared to purchasing from abroad. The manufacturing cost is 25,000 yuan, a 75% reduction compared to the 100,000 yuan per set imported from abroad.

[0071] The above detailed description of the preferred embodiments of the present invention should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent of the present invention.

Claims

1. A single-cavity mold for a leather cup without flash, characterized in that: include: A mold frame, wherein the mold frame is composed of an upper mold plate (1), a middle mold plate (2), a lower mold plate (3) and a pad (4) stacked from top to bottom; A mold core system, the mold core system comprising an upper mold core (101), a middle mold core (201) and a lower mold core (301); The upper mold core (101) comprises an upper mold shell (1011) embedded in the upper mold plate (1), and an upper mold inner core (1012) loosely fitted in the upper mold shell (1011), wherein the upper mold inner core (1012) can slide axially along the upper mold shell (1011); the middle mold core (201) is embedded in the middle mold plate (2); the lower mold core (301) is embedded in the lower mold plate (3), and a through-type exhaust hole (302) is provided at the center of the lower mold core (301); The parting surfaces of the middle mold core (201), the upper mold core (101) and the lower mold core (301) are all provided with radial exhaust grooves (5).

2. The single-cavity mold for a flashless leather cup according to claim 1, characterized in that: The fitting clearance between the upper mold inner core (1012) and the upper mold outer shell (1011) is 0.1-0.3 mm.

3. The single-cavity mold for a flashless leather cup according to claim 1, characterized in that: The upper die shell (1011) is embedded in the upper die plate (1) via a dynamic retaining spring, and the matching clearance between the upper die shell (1011) and the upper die plate (1) is 0.02-0.2 mm.

4. The single-cavity mold for a flashless leather cup according to claim 3, characterized in that: The middle mold core (201) is embedded in the middle mold plate (2) via a dynamic retaining spring, and the matching clearance between the middle mold core (201) and the middle mold plate (2) is 0.2-0.5 mm.

5. The single-cavity mold for a leather cup without flash according to claim 4, characterized in that: The lower die core (301) is fixed in the lower die plate (3) via a movable retaining spring, and the matching clearance between the lower die core (301) and the lower die plate (3) is 0.2-0.5 mm.

6. The single-cavity mold for a flashless leather cup according to claim 5, characterized in that: The dynamic retaining spring is an open elastic C-shaped ring with a compression rebound amount of ≥0.1mm.

7. The single-cavity mold for a leather cup without flash according to claim 1, characterized in that: The exhaust hole (302) at the center of the lower mold core (301) is coaxially connected to the vertical exhaust channel of the pad (4), and the diameter of the exhaust channel is 8 mm.

8. The single-cavity mold for a leather cup without flash according to claim 1, characterized in that: The radial exhaust grooves (5) are radiated with the center of the cavity as the origin, with a groove depth of 0.002-0.008 mm and a groove width of 0.02-0.08 mm.

9. A flashless leather cup vulcanization process, performed using a flashless leather cup single-cavity mold according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, mold closing and glue injection: Injecting the rubber material into the cavity formed by the upper mold core (101), the middle mold core (201), and the lower mold core (301), with a mold closing pressure of 10-25 MPa; S2, independent sealing and pressure: The upper mold inner core (1012) slides downward along the upper mold outer shell (1011) under the hydraulic pressure of the rubber material, and independently compacts the inner parting surface; The middle mold core (201) elastically compensates for the position deviation of the middle mold plate (2) through the dynamic matching retaining spring, ensuring that the outer parting surface fits; S3, sulfide exhaust: Vulcanization temperature 160-190℃, pressure 15-22MPa; The gas is radially converged through the radial exhaust grooves (5) to the central exhaust hole (302) of the lower mold core (301) and discharged; S4, mold opening and parts removal: The leather cup is ejected without flash and no trimming process is required.

10. The flashless cup vulcanization process according to claim 9, characterized in that: In step S2, the sliding stroke of the upper mold inner core (1012) is 0.05-0.15 mm, and the downward pressure is ≥8 MPa; In step S3, the gas flow rate of the radial exhaust groove (5) is ≥0.5m / s, and the vulcanization time is 360-480 seconds.

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