Integrated mould for low-pressure casting of wheels

Abstract

The present invention provides an integrated mold for casting of wheels. The integrated mold has an upper mold, integrated side molds and a lower mold, wherein the number of the integrated side molds is four in the circumferential direction of the wheel mold. Thermal deformation circular arc compensation surfaces are formed by processing on an upper and lower one-fourth circular arc part of each integrated side mold, and compensation surfaces are formed by processing on key parts of 45-degree matching surfaces of the adjacent integrated side molds. The integrated side molds can effectively solve the problems such as imprecise matching of the matching surfaces, parting-line flashes of the matching surfaces and adhesion of aluminum caused by thermal deformation of the integrated side molds.

Claims

1. An integrated mould for low-pressure casting of wheels, comprising: an upper mould, integrated air-cooled side moulds and a lower mould, and further comprising: thermal deformation circular arc compensation surfaces with endpoints of (B), (D), (G) and (I), which pass through points (K) and (L) respectively, are formed by processing on upper and lower one-fourth circular arc matching surfaces of the integrated side moulds, that is on the circular arc surfaces of the integrated side moulds, which are matched with side walls of the upper mould and the lower mould; the two points, K and L, are located on the thermal deformation circular arc compensation surfaces, the distance from the point (K) to an original circular arc point (C) is from 0.2 mm to 0.5 mm, and the distance from the point (L) to an original circular arc point (H) is from 0.2 mm to 0.5 mm; the points (B) and (D) are located on an original circular arc of the lower one-fourth circular arc matching surface, the points (G) and (I) are located on an original circular arc of the lower one-fourth circular arc matching surface, and they are 60 to 80 mm apart from corresponding 45-degree matching surfaces respectively; compensation surfaces are formed by processing on the 45-degree matching surfaces of the adjacent integrated side moulds, such that when the 45-degree surfaces of the adjacent integrated side moulds are matched in a cold state, V-shaped gaps are formed on the 45-degree matching surfaces of the side moulds, and the clearance of the gaps on the circumference of the inner sides of the side moulds is 0.2 mm to 0.4 mm; and the 45-degree surfaces of the integrated side moulds are the matching surfaces of four side moulds.

2. The mould according to claim 1, wherein the distance from the point (K) to the point (C) is 0.3 mm, and the distance from the point (L) to the point (H) is 0.2 mm.

3. The mould according to claim 1, wherein the clearance of the gaps on the circumference of the inner sides of the side moulds is 0.3 mm in the matching state of the 45-degree matching surfaces of the integrated side moulds.

4. The mould according to claim 1, wherein the range of the V-shaped gaps of the 45-degree matching surfaces of the integrated side moulds is set between points (M) and (N), the point (M) is a cusp of a 15-degree matching surface of the side moulds with the lower mould, and the point (N) is a point of tangency of a 9-degree slope of the inner rim of a hub with the circular arc.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The embodiments of the present invention are described below in details with the reference to the accompanying drawings, wherein

(2) FIG. 1 is a matching form of side moulds of the mould for low-pressure casting of wheels in the prior art, and in FIG. 1, reference numeral 1 represents an upper mould, reference numeral 2 represents a side mould, and reference numeral 3 represents a lower mould;

(3) FIG. 2 is a schematic diagram of side mould matching in the prior art;

(4) FIG. 3 is a schematic diagram of thermal deformation compensation surfaces of the upper and lower one-fourth circular arc matching surface parts of the integrated side mould of the present invention and thermal compensation of an 45-degree matching surface of the integrated side moulds; and

(5) FIG. 4 is a schematic diagram of thermal deformation matching of 45-degree matching surfaces of the integrated side moulds.

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1: Manufacturing of the Mould

(6) The mould is manufactured by reasonably setting thermal deformation compensation quantity between the side moulds, and among the matching surfaces of the side moulds and the circular arc side surfaces of the lower mould according to the thermal deformation rule of the mould on the premise that the casting technology is not affected.

(7) I. as shown in FIG. 3, five points A, B, C, D and E lie on a common circle (a circular arc line before modification), and three points B, K and D lie on a common circle, thus forming thermal deformation compensation parts. The distance from the point K to the point C is the longest and is 0.3 mm, and as approaching the points B and C, the two circular arcs are gradually close to each other until they are intersected with each other. The points A, B, E, C and D form a modified circular arc line; and the points B and D are located on the original circular arc, points G and I are located on the original circular arc, and they are 60 mm apart from corresponding 45-degree matching surfaces respectively;
II. as shown in FIG. 3, five points F, G, H, I and J lie on a common circle (a circular arc line before modification), and three points G, L and I lie on a common circle, thus forming the thermal deformation compensation parts. The distance from the point L to the point H is the longest and is 0.2 MM, and as approaching the points G and I, the two circular arcs are gradually close to each other until they are intersected with each other, and the F, G, L, I and J form a modified circular arc line;
III. 0.3 MM of thermal deformation compensation quantity is adopted in the key range of the 45-degree matching surfaces of the integrated side moulds, such that the matching surfaces of the integrated side moulds are precisely matched in a hot state;
IV. programming milling is performed on the B, K and D thermal compensation circular arc surface and the G, L and I thermal compensation circular arc surface which are formed on the one-fourth circular arcs of the integrated side moulds, and after the rotation degrees of the 45-degree surfaces are calculated according to the compensation quantity, the thermal compensation gap parts of the 45-degree matching surfaces of the integrated side moulds are subjected to gradual milling in the range of M and N of the key parts of the 45-degree surfaces.

(8) The above mould is recorded as an experimental group 1, and in addition, moulds are also obtained by manufacturing according to the following parameters:

(9) Experimental group 2: the distance from the point (K) to the point (C) is 0.2 mm; the distance from the point (L) to the point (H) is 0.5 mm, and the clearance of the gaps on the circumference of the inner sides of the side moulds is 0.2 mm; and the points B and D are located on the original circular arc, the points G and I are located on the original circular arc, and they are 60 mm apart from the corresponding 45-degree matching surfaces respectively.

(10) Experimental group 3: the distance from the point (K) to the point (C) is 0.5 mm, the distance from the point (L) to the point (H) is 0.2 mm, and the clearance of the gaps on the circumference of the inner sides of the side moulds is 0.4 mm; and the points B and D are located on the original circular arc, and the points G and I are located on the original circular arc and are 80 mm apart from the corresponding 45-degree matching surfaces respectively.

(11) Experimental group 4: the distance from the point (K) to the point (C) is 0.3 mm, the distance from the point (L) to the point (H) is 0.2 mm, and the clearance of the gaps on the circumference of the inner sides of the side moulds is 0.2 mm; and the points (B) and (D) are located on the original circular arc, and the points (G) and (I) are located on the original circular arc and are 70 mm apart from the corresponding 45-degree matching surfaces respectively.

(12) Control group: a conventional aluminum wheel casting mould with integrated side moulds, the difference between which and the experimental group 1 lies in that conventional aluminum wheel casting mould with the integrated side moulds does not include the thermal deformation compensation parts.

Embodiment 2: Pilot Test

(13) The mould of the experimental group 1 in the embodiment 1 is used for testing of A356 aluminum alloy hub casting under the normal operating conditions of the mould (the temperature of the molten aluminum is 700 degrees Celsius, and the temperature of the mould is maintained in a normal temperature field). The results show that in the casting testing of 5,000 castings, compared with the control group, the mould has the advantages that the proportion of parting-line flashes of the matching surfaces of the castings is decreased from 100% to 2%, and the proportion of adhesion of aluminum is decreased from 65% to 0.3%. Meanwhile, the service life of the mould is tested according to the same method. The test proves that the service life of the mould is prolonged from 30,000 castings to 40,000 castings, and in overall consideration of the loss caused by parting-line flashes, prolonging of the service life of the mould, stability of on-site production take and the like, the casting cost of every 10,000 hubs is saved by RMB 24,700 (approximately USD $3,878).

(14) The experimental groups 2-4 are also tested. The results show that the proportion of the parting-line flashes of the matching surfaces of the castings is all decreased below 5%, the proportion of adhesion of aluminum is all decreased below 0.7%, and the service life of the mould is all prolonged to more than 38,000 castings. The moulds of the above experimental groups greatly reduce the production cost of the hubs and bring good economic and social benefits.