According to the sharding scheme, the gearbox needs to be divided into 2 sets of fully automatic lost foam molds and 1 set of adhesive molds. According to the foundry manufacturer’s automatic vertical forming machine and vertical automatic glue machine, the lost mold structure and adhesive The modular structure uses the following scheme:
First, the mold adopts a thin shell with a shape-shaped structure, the wall thickness of the cavity is controlled at 12-15 mm, and the wall thickness of the gas chamber is controlled at 20 mm to ensure the strength of the mold.
Second, the mold adopts automatic demoulding mechanism to ensure smooth release of the white mold, and the deformation is less than 1 mm.
Third, the core insert is automatically pumped by the cylinder to ensure the forming precision of the white mold, and the guiding and positioning of the core pulling mechanism.
Fourth, the mold gas chamber is provided with cooling spray copper tube, the spray pipe is set reasonably, the inlet pipe is located opposite the operator, the punch is cooled by the nozzle, the mold is cooled evenly, and the molding cooling time is 50-70S.
Fifth, Use automatic gun filling to design the diameter and position of the filling port.
Sixth, the mold design 5 mm positioning stop, set 4 sets of guide post guide mechanism, the effective use height of the guide post guide sleeve is 30-40mm.
Seventh, the surface of the mold forming surface has the same air gap and reasonable arrangement. No protrusions or depressions are allowed in the molding surface to ensure that the surface is smooth and smooth, and the gas is uniform. The white mold is free from defects such as raw materials and over-burning.
Eight, the connectors and fasteners used inside the mold are made of stainless steel, and the mounting surface of the insert is provided with a positioning mechanism.
Nine, the adhesive mold is divided into upper and lower tires. The upper and lower tires are positioned by the positioning post and the positioning sleeve. The back is fastened with the automatic glue machine, and the side has a white mold positioning and shaping mechanism to prevent deformation and displacement of the white mold. It is necessary to control the amount of glue applied to the white mold by the stroke of the glue machine.
The mold is divided into upper and lower molds, and the mold structure of the upper and lower air chambers is adopted as a whole. The upper and lower air chambers are the parting surface of the mold, and the positioning mechanism and sealing system of the upper and lower molds are formed on the parting surface. . on
The shape of the molded gearbox body, the upper mold consists of the upper air chamber, the three-piece side core insert, the core pulling mechanism, the charging mechanism, the sealing system, and the spray cooling system. The five parts are composed as shown in Figure 5: The inner cavity of the gearbox body, the lower die has a lower die air chamber, a core, a movable insert, an ejection mechanism, a sealing system, and a spray cooling system. The upper and lower air chambers and the large side core inserts are made of cast aluminum alloy, the small and thin wall inserts are made of forged aluminum alloy, and the guiding system and positioning system are made of stainless steel and brass.
The three movable inserts and the core pulling mechanism of the inner chamber of the upper mold form an automatic forming of the four-sided shape of the transmission body. The core pulling mechanism is composed of a cylinder, a guide pillar, a guide sleeve and a sealing system. The cylinder is fixed on the outdoor side of the medium gas with stainless steel screws. The guiding mechanism is designed according to the size of the movable insert. The large movable guide is guided by the double guide post guide sleeve and connected by the guide post and the cylinder. The small movable insert directly connects the cylinder head and the movable insert, and the directing and straight-out of the cylinder completes the guiding and clamping of the movable insert. The working principle of automatic forming is to flush compressed air into the cylinder of the cylinder to drive the piston movement of the cylinder. The piston is connected with the movable insert through the thread or the guide rod. The piston moves the movable insert to complete the opening and closing action by moving forward and backward.
The five advantages of the automatic core-pulling mechanism:
high efficiency of white mold forming, high precision, good surface quality, good stability, and light labor intensity.
Filling mechanism design:
In order to make the white mold full and smooth, the surface of the upper mold chamber is designed to be inserted into the automatic gun, using the combination of the main and auxiliary guns, one for each side, a total of four guns Filling.
Heating and cooling design:
Install the spray copper tube in the upper and lower mold air chambers, connect the cooling water, and realize automatic spray cooling.
Sealing system design: including four parts, sealing system of upper and lower air chamber and molding machine template, sealing system of core cylinder and guide sleeve and middle air chamber, sealing system of parting surface, sealing of joint surface of material gun and middle air chamber The system; the seal between the upper and lower air chambers and the forming machine template is sealed by double sealing strips, which better controls the hot steam and the cooling water from leaking. The sealing components are generally made of silicone sealing strips or sealing rings.
The core of the lower mold is fixed on the lower mold air chamber by stainless steel screws, the movable insert is positioned and guided on the core, the automatic mold release mechanism is located in the lower mold air chamber and the parting surface, and the automatic mold release mechanism is removed from the mold. The top-out cylinder, the top column, the guide post and the guide sleeve are composed of five parts, and the stripping plate thickness is 20 mm. The mounting groove of the stripping plate is located on the parting surface of the lower air chamber, and the four corners of the trough respectively have cylinders and stripping plates. The connecting hole is provided with a copper guiding sleeve, and the cylinder and the stripping plate are connected through the guiding column. The ejector cylinder is fixed in the lower mold air chamber, and four column-mounted cylinders are respectively arranged around each connecting hole in the lower mold gas chamber. In the insert mounting groove, the remaining part of the 12MM edge is hollowed out, and the live block and the product edge are on the stripper. The working principle is that the compressed air is flushed into the cylinder of the cylinder to drive the piston movement of the cylinder, and the piston is connected by the guide rod and the stripper plate, and the piston moves up and down to complete the ejection and closing action by moving up and down.
The positioning of the upper and lower molds is positioned by a 5 mm stop and a guide post guide sleeve around the upper and lower molds. The guide post is placed on the punch, and the guide sleeve is placed on the upper mold. The guide bush guide is made of tin bronze. The second set of mold structure is similar to the first set and will not be described again.
The use of fully automatic lost foam molds and fully automated bonding processes to produce aluminum alloy truck gearboxes has five major advantages:
First, the use of automated mold structure, white mold quality, and thus the casting processing margin is small, high precision,
The appearance is good.
Second, the automatic bonding white mold, the white mold is not deformed, the glue amount is even, and the split surface is not
A coating leak will occur.
Third, it greatly saves labor costs and reduces the labor intensity of workers.
Fourth,The foundry’s casting costs are much lower than other processes.
Fifth, shorten the development cycle of the transmission case so that it can be quickly introduced to the market.
