LOW-PRESSURE CASTING BOTTOM MOLD FOR ALUMINUM ALLOY HUB

Abstract

A low-pressure casting bottom mold for an aluminum alloy hub is provided. The low-pressure casting bottom mold for the aluminum alloy hub is composed of an upper surface facing a cavity and a lower surface facing a die casting platform, wherein the bottom mold lower surface facing the die casting platform comprises an iron sheet cover, the iron sheet cover is fixed at a position, corresponding to a wheel spoke, of the bottom mold lower surface, and a sealed space is formed between the iron sheet cover and the bottom mold lower surface in a surrounding manner; the iron sheet cover comprises air inlets at one side close to a wheel center and air outlets at one side close to a rim; and the air inlets are connected with air tubes.

Claims

1. A low-pressure casting bottom mold for an aluminum alloy hub, comprising an upper surface facing a cavity and a lower surface facing a die casting platform, wherein the bottom mold lower surface facing the die casting platform comprises an iron sheet cover, the iron sheet cover is fixed at a position, corresponding to a wheel spoke, of the bottom mold lower surface, and a sealed space is formed between the iron sheet cover and the bottom mold lower surface in a surrounding manner; the iron sheet cover comprises air inlets at one side close to a wheel center and air outlets at one side close to a rim; and the air inlets are connected with air tubes.

2. The low-pressure casting bottom mold for the aluminum alloy hub according to claim 1, wherein the iron sheet cover is fixed to the bottom mold lower surface in a welding manner.

3. The low-pressure casting bottom mold for the aluminum alloy hub according to claim 1, wherein the distance between the iron sheet cover and the bottom mold lower surface is 10-20 mm.

4. The low-pressure casting bottom mold for the aluminum alloy hub according to claim 1, wherein the thickness of the iron sheet cover is 1-3 mm.

5. The low-pressure casting bottom mold for the aluminum alloy hub according to claim 4, wherein the thickness of the iron sheet cover is 2 mm.

6. The low-pressure casting bottom mold for the aluminum alloy hub according to claim 1, wherein the number of the air inlets is 1-3.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The following describes embodiments of the disclosure in details with the accompanying drawings, wherein:

[0015] FIG. 1 is a schematic diagram of cooling arrangement of a low-pressure casting wheel bottom mold in the prior art; and

[0016] FIG. 2 is a schematic diagram of an improved cooling scheme of a low-pressure casting wheel bottom mold provided by the disclosure.

[0017] In the figures, numeric symbols are as follows: 11—bottom mold, 12—point cooling air, 21—air tube, 22—iron sheet, 23—air inlet, and 24—air outlet.

DETAILED DESCRIPTION

Embodiment 1

[0018] The FIG. 1 is a cooling arrangement form of a low-pressure casting wheel bottom mold in the prior art.

[0019] The FIG. 2 is an improved cooling structure of a low-pressure casting wheel bottom mold provided by the disclosure, wherein the former cooling air holes are cancelled, and a layer of iron sheet (1) with the thickness of 2 mm is welded on an area corresponding to a spoke; an interval of 15 mm needs to be reserved between the iron sheet (1) and the mold surface; small holes are formed in an inner end face and an outer end face of the welded iron sheet, the small holes in the outer end face are air paw insertion holes (3), and the small holes in the inner end face are air discharging holes (4), thereby forming an air flowing channel from the periphery to the center; and air tubes (2) are arranged at the root of a bottom mold outer-side spoke, the positions of the air paws correspond to a cavity formed by the iron sheet and the bottom mold, and the number of the air paws is set to 3 according to the width of the spoke. Due to such improvement design, when cooling air starts, compressed air flows in the cavity from outside to inside, so that a temperature gradient increasing from the spoke root to the center is formed, which greatly facilitates the feeding of molten aluminum; and meanwhile, uniform and stable surface cooling instead of the original point cooling manner is formed on the whole spoke area.

[0020] Pilot production is performed in a research and development workshop located in the engineering technology institute of CITIC Dicastal Co., Ltd. According to the embodiment 1 provided by the disclosure, a low-pressure casting mold is modified, and casting is performed on three low-pressure casting machines. By comparison, a local super-cooling situation does not occur on the surfaces of castings any longer. Therefore, the problem that white spots, segregation and the like are liable to occur on the surfaces of wheel products is solved radically, and the product quality and the yield are improved largely.