VVT chain wheel spring groove powder metallurgy forming die
Through the VVT sprocket spring groove powder metallurgy forming mold, VVT sprocket with complex structure is directly pressed into the mold, solving the problems of traditional long production cycle and high cost, and achieving efficient production and stable quality.
Patent Information
- Application Number
- CN202422710729.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-07
- Publication Date
- 2025-08-29
- Estimated Expiration
- 2034-11-07
AI Technical Summary
The traditional VVT sprocket combination design has a long production cycle, high cost and unstable quality, making it difficult to meet the rapid market demand.
The VVT sprocket spring groove powder metallurgy forming mold is used, combined with powder metallurgy technology and mold design, and the VVT sprocket with complex structure is directly pressed into the mold, and the mechanical processing process is omitted.
Improve production efficiency, reduce costs, ensure product quality stability, and meet fast market demand.
Smart Images
Figure CN223277189U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of metallurgical forming, and more specifically to a powder metallurgy forming die for a VVT sprocket spring groove. Background Art
[0002] As one of the key components of the engine, the design optimization of the VVT sprocket is particularly important for improving the performance of the entire vehicle and achieving the goal of lightweighting. In order to effectively reduce the complexity of the product structure and comply with the trend of lightweight design of the entire vehicle, the design concept of the VVT sprocket has gradually shifted to a more compact and efficient modular design mode. This design strategy cleverly integrates the originally scattered parts into a whole, which not only significantly reduces the number of assembly steps and interfaces between parts, but also greatly reduces the complexity and weight of the overall structure, thereby improving the response speed and fuel economy of the engine.
[0003] However, traditionally, achieving this combined design often relies on a dual combination of powder metallurgy and subsequent precision machining. Although this method can produce VVT sprockets that meet performance requirements, its production process faces many challenges: First, the combination of powder metallurgy and machining results in long production cycles, making it difficult to improve production efficiency and meet rapidly changing market demands; second, the superposition of two processes undoubtedly increases manufacturing costs, including material consumption, equipment investment, and labor costs, which puts pressure on cost control; third, multiple processes may introduce more quality variables, such as dimensional accuracy deviations and inconsistent surface roughness, which affect the final quality and stability of the product. Utility Model Content
[0004] To overcome the shortcomings of the prior art, the present invention provides a powder metallurgy forming die for a VVT sprocket spring groove. Leveraging the high precision, flexibility, and material utilization of powder metallurgy technology, a VVT sprocket with a complex structure and superior performance is directly pressed into the die.
[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:
[0006] A VVT sprocket spring groove powder metallurgy forming die includes an upper punch assembly and a lower punch assembly. The upper punch assembly is correspondingly arranged above the lower punch assembly, and the axes of the upper punch assembly and the lower punch assembly are located on the same vertical line. The upper punch assembly includes three upper punches, two upper punches and an upper punch part. The three upper punches, two upper punches and upper punch part are sequentially arranged from the inside to the outside, and the three upper punches, two upper punches and upper punch part are arranged with clearance fit.
[0007] The lower punch assembly includes a female mold, a lower punch, a second lower punch, a third lower punch, a pin and a core rod. The core rod is arranged at the center position of the female mold. The lower punch, the second lower punch and the third lower punch are sequentially arranged between the female mold and the core rod from the outside to the inside, and the lower punch, the second lower punch and the third lower punch are arranged with clearance fit.
[0008] The pin is inserted into the lower punch and the second lower punch, and the pin is clearance-fitted with the lower punch and the second lower punch.
[0009] The female mold is made of tungsten steel material.
[0010] The three upper punches are formed into a spring groove die.
[0011] Compared with the prior art, the present invention has the following beneficial effects:
[0012] The device, combined with a dedicated powder metallurgy C-shaped die and a pull-down demolding method, can mold parts with VVT sprocket spring grooves in a single step, eliminating the traditional CNC machining process for the spring grooves. This reduces production costs, improves production efficiency, and conserves materials. This overcomes the problem of complex structures and deep spring grooves on the end faces that cannot be mass-produced through machining or powder metallurgy processes alone, and instead uses a combination of powder metallurgy and machining to produce parts. VVT sprockets with complex structures and superior performance can be directly pressed into the mold. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is a schematic diagram of the assembly of the powder metallurgy forming die of the utility model;
[0014] Figure 2 This is a schematic diagram of powder loading in the present utility model;
[0015] Figure 3 This is a schematic diagram of the compression of the utility model
[0016] Figure 4 This is a schematic diagram of the demoulding of the utility model
[0017] Figure 5 This is a schematic diagram of the three-up punch of the utility model;
[0018] Figure 6 Schematic diagram of the second upper punch of the utility model
[0019] Figure 7 This is a schematic diagram of the upper punch of the utility model;
[0020] Figure 8 This is a schematic diagram of the female mold of the present utility model;
[0021] Figure 9This is a schematic diagram of the lower punch of the utility model;
[0022] Figure 10 This is a schematic diagram of the second lower punch of the utility model;
[0023] Figure 11 This is a schematic diagram of the three-down punch of the utility model;
[0024] Figure 12 This is a schematic diagram of the mandrel of the present utility model;
[0025] Figure 13 This is a schematic diagram of a pin of the present utility model;
[0026] Figure 14 This is a schematic diagram of the VVT sprocket of the present utility model;
[0027] In the figure: 1 is the third upper punch, 2 is the second upper punch, 3 is the upper punch, 4 is the female die, 5 is the lower punch, 6 is the second lower punch, 7 is the third lower punch, 8 is the pin, 9 is the core rod, 10 is the VVT sprocket, and 11 is the sprocket spring groove. DETAILED DESCRIPTION
[0028] In order to more clearly understand the above-mentioned purposes, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other without conflict.
[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.
[0030] like Figures 1 to 14 As shown, a VVT sprocket spring groove powder metallurgy forming die includes an upper punch assembly and a lower punch assembly. The upper punch assembly is correspondingly arranged above the lower punch assembly. The axes of the upper punch assembly and the lower punch assembly are located on the same vertical line. The upper punch assembly includes three upper punches 1, two upper punches 2 and an upper punch part 3. The three upper punches 1, the two upper punches 2 and the upper punch part 3 are sequentially arranged from the inside to the outside, and the three upper punches 1, the two upper punches 2 and the upper punch part 3 are clearance-fitted.
[0031] Preferably, the lower punch assembly includes a female mold 4, a lower punch 5, a second lower punch 6, a third lower punch 7, a pin 8 and a core rod 9. The core rod 9 is arranged at the center of the female mold 4. The lower punch 5, the second lower punch 6 and the third lower punch 7 are sequentially arranged from the outside to the inside between the female mold 4 and the core rod 9. The lower punch 5, the second lower punch 6 and the third lower punch 7 are arranged with clearance fit. The lower punch 5 is used to form the tooth end face of the part, the second lower punch 6 is used to form the lower end face, and the third lower punch 7 is used as a spring groove forming powder transfer punch; the core rod 9 and the pin 8 are used to form the various through-holes of the part.
[0032] Preferably, the pin 8 is inserted into the lower punch 5 and the second lower punch 6 , and the pin 8 is provided with clearance fit with the lower punch 5 and the second lower punch 6 .
[0033] Preferably, the female mold 4 is made of tungsten steel.
[0034] Preferably, the three upper punches 1 are formed spring slot molds.
[0035] During use, the molding process consists of three stages: powder filling, compaction, and demolding. During powder filling, the powder filling height at each stage is calculated based on the part height and compression ratio. The powder feed shoe vibrates 3-5 times at the top of the die cavity according to a pre-set program to ensure the powder is densely packed. During compaction, after the press is activated, the third upper punch 1, the second upper punch 2, and the upper punch 3 move downward. Just as they come into contact with the powder, the center core rod 9 and the pin 8 move upward 1-4 mm according to the press's pre-set program. Friction between the core rod 9 and the iron powder causes some of the powder to be moved to the flat surface of the die cavity. Then, the third upper punch 1, the second upper punch 2, and the upper punch 3 begin applying pressure. The female die 4 moves downward under the friction of the iron powder, and the lower punch 5 and the second lower punch 6 each move downward onto the slider, compacting the iron powder. The third lower punch 7 independently transfers the powder to the powder filling position. The third upper punch 1 begins pressing downward, and the third lower punch 1 moves down onto the slider, forming the spring groove in the product. During demolding, the female die 4 is pulled down, and a protective demolding method is used. The upper punch 3 maintains contact with the upper end surface of the part, preventing hidden cracks from occurring where the part's cross-section changes due to elastic aftereffects. Once the female die 4, lower punch 5, second lower punch 6, mandrel 9, and pin 7 are completely demolded, the upper punch 3 is retracted and the mandrel 9 is pulled down, completing the demolding. The VVT sprocket 10 with sprocket spring groove 11 can be produced using powder metallurgy. Experimental verification has shown that it fully meets practical requirements and can replace existing sprockets manufactured using machining techniques.
[0036] The above only describes in detail the preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by ordinary technicians in this field, various changes can be made without departing from the purpose of the present invention, and various changes should be included in the scope of protection of the present invention.
Claims
1. A powder metallurgy forming die for a VVT sprocket spring groove, characterized by: The invention comprises an upper punch assembly and a lower punch assembly, wherein the upper punch assembly is correspondingly arranged above the lower punch assembly, and the axes of the upper punch assembly and the lower punch assembly are arranged on the same vertical line, and the upper punch assembly comprises three upper punches (1), two upper punches (2) and an upper punch part (3), and the three upper punches (1), the two upper punches (2) and the upper punch part (3) are sequentially sleeved from the inside to the outside, and the three upper punches (1), the two upper punches (2) and the upper punch part (3) are arranged with clearance fit.
2. The powder metallurgy forming die for a VVT sprocket spring groove according to claim 1, characterized in that: The lower punch assembly comprises a female die (4), a lower punch (5), a second lower punch (6), a third lower punch (7), a pin (8) and a core rod (9); the core rod (9) is arranged at a central position in the female die (4); the lower punch (5), the second lower punch (6) and the third lower punch (7) are sequentially sleeved from the outside to the inside between the female die (4) and the core rod (9); and the lower punch (5), the second lower punch (6) and the third lower punch (7) are arranged with clearance fit.
3. The powder metallurgy forming die for a VVT sprocket spring groove according to claim 2, characterized in that: The pin (8) is inserted into the lower punch (5) and the second lower punch (6), and the pin (8) and the lower punch (5) and the second lower punch (6) are all provided with clearance fit.
4. The powder metallurgy forming die for a VVT sprocket spring groove according to claim 2, characterized in that: The female mold (4) is made of tungsten steel material.
5. The powder metallurgy forming die for a VVT sprocket spring groove according to claim 1, characterized in that: The three upper punches (1) are formed into a spring groove die.