CN201455198U

CN201455198U - Lost-foam casting voltage-sharing moulding flask

Info

Publication number: CN201455198U
Application number: CN2009201255233U
Authority: CN
Inventors: 郭显常; 张建中; 孙永远; 魏祖平
Original assignee: ZUNYI JINTIAN FOUNDRY CO Ltd
Current assignee: ZUNYI JINTIAN FOUNDRY CO Ltd
Priority date: 2009-07-09
Filing date: 2009-07-09
Publication date: 2010-05-12
Anticipated expiration: 2019-07-09

Abstract

A lost-foam casting voltage-sharing moulding flask comprises a screen cloth, a screen plate, funnel-shaped clapboards, a round moulding flask and an extraction opening, wherein the screen plate with the inner diameter equal to that of the round moulding flask is arranged at the position with a certain height upward inside the bottom of the round moulding flask; the screen plate is designed as follows: a circle which takes a center of a circle as a center, three concentric rings and the four funnel-shaped clapboards below the three concentric rings are connected into a whole and combined together in a laminating manner so as to form a big end A with four pieces of conical and funnel-shaped clapboards and a small end B with the funnel-shaped clapboards; and the pumping hole is arranged at the central part of the bottom part of the round moulding flask, namely at the position of the small end B of the funnel-shaped clapboard. The moulding flask with the structure is adopted to pump negative pressure to the inside of the moulding flask so as to lead the negative pressure to be uniform and consistent, and the pressure detection result deviation of all parts of the moulding flask is smaller than 0.001MPa; and the use effect is obvious through the practical production, so that the problem that the negative pressure of the existing lost-foam casting voltage-sharing moulding flask in China is nonuniform, is solved.

Description

Lost foam casting is all pressed sandbox

Technical field

The utility model relates in the foundry industry and to solve the uneven technology of negative pressure in the lost foam casting sandbox, provides a kind of lost foam casting all to press sandbox, reaches the lost foam casting sandbox negative pressure uniformity consistency of bleeding when sandbox is bled.

Background technology

The harmony of negative pressure is directly connected to the cast article quality in the lost foam casting sandbox, and whether casting cycle cheek inside vacuum everywhere is evenly distributed, and is to be directly connected to the key that can casting achieve success.Once the gas bias current must take place in vacuum skewness in the sandbox, cause waste product in batch, cause enormous economic loss.Simultaneously, produce bias current and very easily cause molten iron to break through coating, gently then cause vacuum tube, vacuum tube valve blockage, heavy then molten iron is once enter water-ring vacuum pump, and the instantaneous generation gases at high pressure of molten iron and water will cause equipment explosion.

Traditional lost foam casting sandbox can't satisfy the negative pressure homogeneity, and the traditional sandbox that uses at first adds sieve plate as wire screen, vacuumizes knot by bottom or side, because the characteristic of gas, from the nearest place of bleeding point, gas flow rate is fast; From bleeding point place far away, gas flow rate is slow, thereby causes each site pressure of sandbox unbalanced, has pressure reduction.Add the sandbox of exhaust tube structure in length and breadth after improve to adopt, though branch bottom surface and two sides vacuumize simultaneously, same different from the distance of bleeding point owing to going into the gas pore, be difficult to accomplish the negative pressure unanimity, another sandbox structure is to adopt five faces to bleed, the further homogenizing negative pressure of bleeding in theory just, but the requirement that does not solve the negative pressure homogeneous fully.At this present situation, design this lost foam casting and all pressed sandbox, solved this difficult problem.

Summary of the invention

The purpose of this utility model provides a kind of lost foam casting and all presses the sandbox structure, solves the lost foam casting sandbox negative pressure uniformity consistency of bleeding.

The technical scheme that solves: lost foam casting sandbox internal partition is designed to the infundibulate dividing plate of bleeding, it at the thickness that equates with circular sandbox internal diameter the hole of uniform Φ 8mm on the steel plate of 4mm, its pitch of holes is 25mm, make the rotary strainer plate, being provided with the center of circle in the sieve plate bottom surface is 3 concentric circles at center, wherein Zui Xiao circular diameter is D0, and all the other are followed successively by D1, D2, D3, and the infundibulate end diameter is respectively d0, d1, d2, d3.To be made as arithmetic progression between D0, D1, D2, the D3, its difference is 200mm, i.e. D1=D0+200, and D2=D1+200, D3=D 2+200 sets D0=200mm, D1=400mm then, D2=600mm, D3=800mm.For easy to make, minimum funnel sectional area is made as equilateral triangle, and given its end diameter is 40mm, between the cross section of big end of infundibulate dividing plate and infundibulate dividing plate small end, calculate with bernoulli equation, because big end and the less 200mm that is about of the small end funnel cross section discrepancy in elevation, for diameter is conical funnel and the D1-D0 of D 0, D2-D1, D3-D2 annular funnel; P1-P2=2/1P (r is arranged ₂ ²-r ₁ ²) be that stacked each funnel forms that the big end section pressure of funnel is P between passage ₁Its funnel small end cross section pressure is P2, and its pressure differential deltap P all equates, again since in the unit interval gas flow by funnel upper and lower (big small end) cross section equate, i.e. V1A1=V2A2A, V2=A1/A2V1 is so there is Δ P=P1-P2=1/2P (r ₂ ²-r ₁ ²).

With aforesaid known conditions substitution formula result of calculation such as little table (mm)

D0	d0	D1	d1	D2	d2	D3	d3
D0	d0	D1	d1	D2	d2	D3	d3	200	40	400	80	600	120	800	160

Make four on conical hopper dividing plate by listed size in the table, be welded in the conical hopper formula dividing plate that the sieve plate bottom surface forms stacked combination by driven dimension, be loaded on the stacked small end afterbody of infundibulate that circular sandbox bottom pumping mouth is located at circular sandbox bottom center, the plane is 200mm from sandbox bottom height on the sieve plate, be covered with wire screen on the sieve plate face, form the stacked sandbox structure of all pressing of dispellable mould casting infundibulate.

Adopt the beneficial effect of the technical program obvious through result of use, sandbox pressure measurement result error is no more than 0.001Mpa.

Description of drawings

Fig. 1 is existing traditional lost foam casting sandbox structural representation;

Fig. 2 bleeds for lost foam casting of the present utility model and all presses the sandbox structural representation.

Among the figure: 1-wire screen, 2-sieve plate, 3-infundibulate dividing plate, the circular sandbox of 4-, 5-bleeding point.

The specific embodiment

Lost foam casting described in the utility model all presses sandbox embodiment contrast accompanying drawing further to be described in more detail in down:

Its structure is formed and is comprised, wire screen 1, sieve plate 2, infundibulate dividing plate 3, circular sandbox 4, bleeding point 5, in circular sandbox 4 bottoms, be provided with the sieve plate 2 that equates with circular sandbox 4 internal diameters, it is the circle in center and three donuts and following four infundibulate dividing plates 3 that sieve plate 2 is made as with the center of circle, and connect as one stacked combining with sieve plate 2, form conical four infundibulate dividing plates 3, the big end of infundibulate dividing plate 3 is that the small end of A and infundibulate dividing plate 3 is B, and the central authorities that bleeding point 5 is located at circular sandbox 4 bottoms are the small end B place of infundibulate dividing plate 3.Sieve plate 2 is that the steel plate of 4mm is made by thickness, the hole of uniform 8mm on it, and pitch of holes is 25mm, being provided with the center of circle in sieve plate 2 bottom surfaces is three concentric circles at center, form the big end A of a funnel dividing plate 3 respectively, wherein Zui Xiao circular diameter is D0, and all the other are followed successively by D1, D2, D3 infundibulate dividing plate 3 small end B diameters are respectively d0, d1, d2, d3, to be made as arithmetic progression between D0, D1, D2, the D3, difference is 200mm, i.e. D0=200mm, D1=400mm, D2=600mm, D3=800mm.The small end B diameter d 0 of infundibulate dividing plate 3 is 40mm, d1=80mm, d2=120mm, d3=160mm.For the cross section d0 with minimum funnel easy to make is made as equilateral triangle, the height of plane from sandbox 4 bottoms is 200mm on the sieve plate 2, and is equipped with wire screen 1 on sieve plate 2.

Claims

1. a lost foam casting is all pressed sandbox, it comprises: wire screen (1), sieve plate (2), infundibulate dividing plate (3), circular sandbox (4), bleeding point (5), it is characterized in that: in circular sandbox (4) bottom, go up certain altitude and be provided with the sieve plate (2) that equates with circular sandbox (4) internal diameter, it is that the circle in center and three donuts and following four infundibulate dividing plates (3) connect as one stacked combining that sieve plate (2) is made as with the center of circle, form the big end A of conical four infundibulate dividing plates (3) and the small end B of infundibulate dividing plate (3), bleeding point (5) is located at the central authorities of circular sandbox (4) bottom, i.e. the small end B place of infundibulate dividing plate (3).

2. lost foam casting according to claim 1 is all pressed sandbox, it is characterized in that: sieve plate (2) is that the steel plate of 4mm is made by thickness, the hole of uniform Φ 8mm on it, and pitch of holes is 25mm.

3. lost foam casting according to claim 1 is all pressed sandbox, it is characterized in that: being provided with the center of circle in sieve plate (2) bottom surface is the concentric circles at center, the big end A that forms each infundibulate dividing plate (3) respectively, wherein Zui Xiao circular diameter is D0, all the other are followed successively by D1, D2, D3, infundibulate dividing plate (3) small end B diameter is respectively d0, d1, d2, d3 is with D0, D1, D2, be made as arithmetic progression between the D3, its difference is 200mm, that is: D0 is 200mm, D1 is 400mm, and D2 is 600mm, and D3 is 800mm, the small end B diameter d 0 of infundibulate dividing plate (3) is 40mm, D1 is 80mm, and D2 is 120mm, and D3 is 160mm.

4. lost foam casting according to claim 1 is all pressed sandbox, it is characterized in that: the cross section d0 of minimum funnel is made as equilateral triangle more in making.

5. lost foam casting according to claim 1 is all pressed sandbox, it is characterized in that: it is 200mm that sieve plate (2) is gone up the height of plane from the sandbox bottom, and is equipped with wire screen (1) on sieve plate (2).