阅读说明：本技术 发动机燃烧室零件胀形成形方法 (Bulging forming method for engine combustion chamber part ) 是由 姜男 徐晶 孙健通 于 2019-11-25 设计创作，主要内容包括：本发明涉及一种发动机燃烧室零件胀形成形方法,其包括下述步骤：将胀形模具安装在液压机上,将胀形模具上、下模座打开至适合高度,将圆柱空心坯料内孔润滑后套在胀形凹模外,成形时胀形凸模缓慢下行至计算的距离,稳定后胀形凸模上行,设备卸载后取下成型零件,更换不同直径的胀形凸凹模,成型另外规格的燃烧室零件。采用本发明进行产品加工,加工出的零件尺寸精度高、效率高,选择不同尺寸的胀形凸凹模,可成形多种不同直径尺寸的燃烧室零件。(The invention relates to a bulging forming method for engine combustion chamber parts, which comprises the following steps: installing the bulging die on a hydraulic press, opening the upper die seat and the lower die seat of the bulging die to proper heights, lubricating the inner hole of the cylindrical hollow blank, then sleeving the inner hole of the cylindrical hollow blank outside the bulging female die, slowly descending the bulging male die to a calculated distance during forming, ascending the bulging male die after stabilization, taking down the formed part after unloading the equipment, replacing the bulging male die and the bulging female die with different diameters, and forming the combustion chamber part with other specifications. The invention is adopted to process products, the processed parts have high dimensional precision and high efficiency, and the expanding convex-concave dies with different sizes are selected to form combustion chamber parts with different diameters.)

1. The bulging forming method for the engine combustion chamber is characterized by comprising the following steps: installing an expanding die on a hydraulic machine, opening an upper die seat and a lower die seat of the expanding die to a proper height, lubricating an inner hole of a cylindrical hollow blank, then sleeving the inner hole outside an expanding female die, slowly descending an expanding male die to a calculated distance during forming, ascending the expanding male die after stabilization, taking down a formed part after unloading equipment, replacing expanding male and female dies with different diameters, and forming a combustion chamber part with another specification;

the bulging die structure comprises an upper die base, a lower die base, a bulging female die and a bulging male die, wherein the bottom end of the bulging female die is mounted on the lower die base, the top end of the bulging male die is mounted on the upper die base, and the bulging male die is inserted into the bulging female die.

2. The method of claim 1, wherein the billet diameter D is a diameter of a billet₀Calculated from the following formula:

D₀＝D_max/K

in the formula: d_maxMaximum diameter of the expanded part

K-ultimate bulging coefficient

Wherein the ultimate bulging coefficient of the material is related to the allowable elongation of the material.

3. The engine combustion chamber expander forming method of claim 1, wherein said blank length L is set to be longer than said blank length L₀Calculated from the following formula:

L₀＝L[1+(0.3～0.4)δ]+Δl

in the formula: l-length of the bus of the workpiece

δ——δ＝(D_max-D₀)/D₀

Delta l is trimming allowance and is 10-20 mm.

4. The method of bulge forming for an engine combustion chamber according to claim 1, wherein the bulging force at the time of bulge forming is calculated as follows:

F＝P*A

in the formula: f-bulging force (N)

P-bulging Unit pressure (MPa)

A-area of bulging (mm)²)

The bulging specific pressure P is related to the tensile strength of the part material, the maximum bulging diameter, and the original thickness of the part.

5. The bulging forming method for the engine combustion chamber according to claim 1, characterized in that the bulging female die is a split female die, the split female die is a circular inner cavity formed by 8 die pieces, and the gaps between the 8 die pieces and the bulging male die are consistent.

6. The method of claim 1, wherein the profile roughness of the bulging male die and the bulging female die is required to be 0.4 μm.

Technical Field

The invention relates to a bulging process, in particular to a bulging forming method for an engine combustion chamber.

Background

The bulging process is characterized in that the bulging medium is utilized to enable the thin-walled tubular part to bear load to generate plastic deformation, so that the forming and high-precision realization are achieved. The bulging die can complete the working procedures of thinning the thickness and increasing the surface area of a blank in one stroke of a hydraulic press, is usually combined with other stamping modes to form military parts with complex shapes, and is a simple, mature and reliable stamping forming method.

However, the existing bulging process cannot meet the forming requirements of combustion chamber parts which are relatively complex in shape, high in dimensional accuracy requirement and capable of being produced in batches.

Disclosure of Invention

The invention provides a bulging forming method for an engine combustion chamber, aiming at the problems in the prior art, and the bulging forming requirement of combustion chamber parts is met.

The technical scheme of the invention comprises the following steps:

installing an expanding die on a hydraulic machine, opening an upper die seat and a lower die seat of the expanding die to a proper height, lubricating an inner hole of a cylindrical hollow blank, then sleeving the inner hole outside an expanding female die, slowly descending an expanding male die to a calculated distance during forming, ascending the expanding male die after stabilization, taking down a formed part after unloading equipment, replacing expanding male and female dies with different diameters, and forming a combustion chamber part with another specification;

the bulging die structure comprises an upper die base, a lower die base, a bulging female die and a bulging male die, wherein the bottom end of the bulging female die is mounted on the lower die base, the top end of the bulging male die is mounted on the upper die base, and the bulging male die is inserted into the bulging female die.

The diameter D of the blank₀Calculated from the following formula:

D₀＝D_max/K

in the formula: d_maxMaximum diameter of the expanded part

K-ultimate bulging coefficient

Wherein the ultimate bulging coefficient of the material is related to the allowable elongation of the material.

The length L of the blank₀Calculated from the following formula:

L₀＝L[1+(0.3～0.4)δ]+Δl

in the formula: l-length of the bus of the workpiece

δ——δ＝(D_max-D₀)/D₀

Delta l is trimming allowance and is 10-20 mm.

During bulging, the bulging force is calculated according to the following formula:

F＝P*A

in the formula: f-bulging force (N)

P-bulging Unit pressure (MPa)

A-area of bulging (mm)²)

The bulging specific pressure P is related to the tensile strength of the part material, the maximum bulging diameter, and the original thickness of the part.

The bulging female die is a split female die, the split female die is a circular inner cavity formed by 8 die pieces, and the gaps between the 8 die pieces and the bulging male die are consistent.

The roughness of the molded surfaces of the bulging male die and the bulging female die is required to be 0.4 mu m.

The invention has the following positive effects:

the invention has the advantages that the product processing is carried out, the processed parts have high dimensional accuracy and high efficiency, and the expansion convex-concave dies with different sizes are selected, so that various combustion chamber parts with different diameters can be formed, the requirements of the technology and the batch production of enterprises are met, and meanwhile, the production cost is reduced. The die has the advantages of reliable production, convenient maintenance, short processing period and high efficiency, and meets the requirements of the engine on the precision, the efficiency, the service life and the repair of parts.

Drawings

FIG. 1 is a schematic structural diagram of a combustion chamber component being processed according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a blank according to an embodiment of the present invention.

Fig. 3 is a schematic structural view of the bulging die of the present invention.

FIG. 4 is a schematic view of the top view of the bulging die of the present invention

Fig. 5 is a schematic structural diagram of the bulging male die of the present invention.

Fig. 6 is a schematic structural diagram of the bulging die of the present invention.

Detailed Description