WO2019114241A1

WO2019114241A1 - Casting device and casting method therefor

Info

Publication number: WO2019114241A1
Application number: PCT/CN2018/092564
Authority: WO
Inventors: 李进敏; 王涛
Original assignee: 李进敏; 王涛
Priority date: 2017-12-12
Filing date: 2018-06-25
Publication date: 2019-06-20
Also published as: CN108057865A; CN108057865B

Abstract

A casting device, comprising a centrifugal lower die (10), a centrifugal upper die (20), a sand mold (30), a die ejection device (50), and a centrifuge; the centrifugal lower die forms an accommodating chamber (12), and a guide rod (60) is penetratingly provided at an outer side of the accommodating chamber in the centrifugal lower die; a mold cavity (21) that accommodates the sand mold is provided on the centrifugal upper die, a feeding pouring channel (31) being formed at a bottom surface of the sand mold, while a top surface of the feeding pouring channel is provided a sprue (36); an at least two-ring casting chamber (32) is provided at the periphery of the feeding pouring channel, each casting chamber being inwardly recessed from a bottom surface of the sand mold, and each casting chamber being provided with a connecting path (35) that is in communication with the feeding pouring channel; the die ejection device comprises a die lifting plate (51) that is provided within the accommodating chamber and an ejection shaft (52) that is connected below the die lifting plate; a die ejection plate (50) is provided below the centrifugal lower die and drive equipment is provided below the die ejection plate; two ends of the guide rod are fixed on the centrifugal upper die and the die ejection plate, respectively. A casting method, comprising the following steps: top die device extension, top die device retraction, centrifugal pouring, die ejection, molded body ejection, and feeding sprue removal. Casting pieces manufactured by using the casting device of the casting method are even in structure, reducing defects such as blisters.

Description

Casting device and casting method thereof

Technical field

The present invention relates to a molding technique, and more particularly to a casting apparatus and a casting method thereof.

Background technique

Casting is a method of casting a liquid metal into a casting cavity that conforms to the shape of the part, and after cooling and solidifying, to obtain a part or blank. The existing casting methods are generally divided into gravity casting and centrifugal casting. Gravity casting refers to the process of injecting molten metal into the mold under the action of gravity. The molten metal flows through the sprue, the runner and the gate, and the molten metal The flow path is long, the filling is slow, and casting defects such as pores and sand slag are easily generated. The existing centrifugal casting refers to injecting liquid metal into a mold that rotates at a high speed, so that the molten metal is filled with a mold under the action of centrifugal force, and a large centrifugal force generated by high-speed rotation causes a poor inner hole roughness of the product to be formed. Improve.

Summary of the invention

The invention provides a casting device and a casting method thereof, which solve the problems of long flow path of gravity casting and poor roughness of inner hole of centrifugal casting in the prior art.

The technical solution of the present invention is implemented as follows:

A casting device comprising a centrifugal lower mold, a centrifugal upper mold disposed on the centrifugal lower mold, a sand mold disposed in the centrifugal upper mold, and a top mold device disposed under the sand mold, the top end of the centrifugal lower mold The inner recess is formed into a receiving cavity, and a middle portion of the receiving cavity is provided with a through hole. The centrifugal lower die is provided with a guiding hole on the outer side of the receiving cavity, and a guiding rod is movably disposed in the guiding hole, and the centrifugal upper die corresponds to The position of the receiving cavity is provided with a cavity extending through the upper and lower surfaces of the centrifugal upper die, the bottom surface of the sand type is recessed inwardly to form a feeding runner, and a gate is provided in the middle of the top surface of the feeding sprue position, the feeding is provided The periphery of the runner is provided with at least two annular casting cavities corresponding to the shape of the casting to be cast, each casting cavity being recessed by the bottom surface of the sand type, and each casting cavity is provided on the side close to the feeding runner Filling the connecting passage connecting the runner, the top mold device comprises a starting plate received in the receiving cavity of the centrifugal lower die and supported under the sand mold, connecting the top of the perforated hole disposed in the middle of the starting template and passing through the centrifugal lower die a shaft and a spacer are disposed on the top template below the centrifugal lower mold and In the driving device below the top template, the two ends of the guiding rod are respectively fixed on the centrifugal upper mold and the top template, and the bottom end of the top shaft passes through the top template and is located below the top plate, and the driving device can provide upward driving force to drive The top template and the top shaft are moved up. The casting apparatus further includes a centrifuge disposed below the centrifugal lower mold, the centrifuge having a rotational speed of 100-300 rpm.

Preferably, the center of the feeding runner is located at the center of the circle where the sand mold is located, and the center of the circle where each casting cavity is located is located on the same circle, and the center of the circle is concentrically arranged with the center of the circle where the feeding runner is located.

Preferably, the periphery of the gate extends upward to form a first-class track.

Preferably, the top shaft is provided with an abutting platform for moving up against the top shaft, and the top mold device further includes a guide sleeve disposed under the top template, the guide sleeve includes a cylindrical sleeve of the bottom wall and an abutting wall extending outwardly from a periphery of the sleeve at a position near the top end thereof, the upper surface of the abutting wall abutting below the top template, the top shaft being movable The grounding is disposed in the sleeve and the bottom end thereof extends to the outer side of the bottom wall of the sleeve, and the driving device drives the sleeve to move the top template upward, and the sleeve abuts against the abutting table to drive the top shaft.

Preferably, the abutting table of the top shaft is located below the lower surface of the top template, and the surface of the starting template is lower than the top end of the receiving cavity of the centrifugal lower mold, and the distance of the abutting table is lower than the lower surface of the top template. The top surface of the template is flush with the upper surface of the centrifugal lower mold when the top template is placed against the lower surface of the centrifugal lower mold.

Preferably, the top mold device further comprises a top mold member disposed under the guide sleeve, the top mold member comprising a bottom wall, a side wall extending upward from a periphery of the bottom wall, and abutting at a top end of the side wall The drive device drives the top mold member to move up.

Preferably, the cross section of the cavity extends gradually from the bottom to the top, and the outer peripheral surface of the sand mold forms a slope corresponding to the inner wall of the cavity.

Preferably, the centrifugal lower die protrudes upwardly from the periphery of the receiving cavity to form a convex ring, and the lower surface of the centrifugal upper die at the position outside the cavity forms a shape corresponding to the upper surface of the centrifugal lower die at the position outside the receiving cavity. The shape of the fit.

A casting method comprising the following steps:

1. The top mold device is extended, and the driving device drives the top mold member to push the guiding sleeve upward to drive the top template to run upward, so that the top template pushes the guiding rod upward to move the centrifugal upper mold upward, and the guiding sleeve moves up during the process. The bottom wall abuts against the abutment of the top shaft so that the top axial direction moves the template upward until the top surface of the template is flush with the upper surface of the centrifugal lower mold. At this time, the top template abuts against the centrifugation. Below the lower mold, the top mold reaches the maximum stroke;

2. Purging the impurities in the casting device by air gun, placing the sand mold on the template, and retracting the top mold device, so that the centrifugal upper mold falls and the inner peripheral surface of the cavity of the centrifugal upper mold abuts against the sand mold;

3. Start the centrifuge, drive the centrifugal mold to rotate by the centrifuge, the molten metal is injected by the sand gate, and the molten metal is quickly filled into the cavity through the connecting channel by the feeding runner under the action of centrifugal force, to be charged. After the type is completed, the centrifuge stops rotating; the position of the feeding sprue forms a feeding gate, the casting cavity position forms a casting, and the feeding gate is connected with the bottom end of the casting;

4. The top mold device is extended, repeating the first step of the action, so that the sand mold is ejected, and the top of the mold is centrifuged to the maximum stroke;

5. Push out the molded body formed by the casting and the feeding gate, replace the sand type, and then carry out the next pouring;

6. Remove the filler gate from the casting.

Preferably, in step 6, the feeding method of the feeding gate is a lathe, a water jet, a punching machine, an electric spark or a gas cutting.

The beneficial effects of the invention are:

The casting device produced by the casting device and the casting method thereof have uniform microstructure, and the density segregation can be prevented compared with the existing high-speed centrifugal rotation. The metal flow path of the casting device is short compared to the existing flow. Gravity casting with long diameter reduces the probability of gas and impurities being trapped in high temperature molten metal, and reduces defects such as pores and blisters; since the manufactured molded body has a supplementary gate, it provides a supplementary metal liquid for the casting, effectively The casting defects such as shrinkage and shrinkage of the casting profile are eliminated, and the overall structure of the product is uniform and uniform, and the adverse effect on the sealing performance and mechanical properties of the product due to uneven stress after the application of the force is reduced.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

Figure 1 is a schematic structural view of a casting apparatus of the present invention;

Figure 2 is a plan view of the sand mold of Figure 1;

Figure 3 is a schematic structural view of Figure 1 in a top mold state;

Fig. 4 is a schematic view showing the structure of a molded body obtained by casting using the casting apparatus of Fig. 1.

In the picture:

10, centrifugal lower mold; 20, centrifugal upper mold; 30, sand type; 50, top mold device; 11, clamping mouth; 12, receiving cavity; 13, perforation; 14, convex ring; 15, guiding hole; Guide rod; 21, cavity; 32, casting cavity; 31, feeding runner; 33, flow channel; 35, connecting road; 36, gate; 51, starting template; 52, top shaft; 53, top template; 54, guide sleeve; 55, top mold member; 56, abutment table; 540, sleeve; 541, abutting wall; 550, bottom wall; 551, side wall; 552, abutting edge; 71, feeding gate 72, castings.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

As shown in FIG. 1, the casting device can be used to produce a ring body such as a floating seal ring, a piston ring, a flange, and a gasket. The present invention is described by taking a floating seal ring as an example. The casting apparatus includes a centrifugal lower mold 10, a centrifugal upper mold 20 disposed on the centrifugal lower mold 10, a sand mold 30 disposed in the centrifugal upper mold 20, and a top mold device 50 disposed under the sand mold 30.

The outer peripheral surface of the centrifugal lower die 10 is provided with a clamping opening 11 for positioning thereof. The center of the top end of the centrifugal lower mold 10 is recessed inwardly to form a receiving cavity 12, and a receiving hole 12 is formed in the middle of the receiving cavity 12. The centrifugal lower mold 10 protrudes upward from the periphery of the receiving cavity 12 to form a convex ring 14. The centrifugal lower mold 10 is provided with a guide hole 15 on the outer side of the convex ring 14, and a guide rod 60 is bored in the guide hole 15.

The centrifugal upper mold 20 is correspondingly disposed on the centrifugal lower mold 10. The centrifugal upper mold 20 is provided with a cavity 21 penetrating the upper and lower surfaces of the centrifugal upper mold 20 at a position corresponding to the receiving chamber 12. The cross section of the cavity 21 extends from the bottom to the top in a tapered manner, that is, the inner peripheral surface of the cavity 21 forms an annular slope which gradually extends inwardly from the bottom to the top. The position of the centrifugal upper mold 20 outside the cavity 21 is provided with a fixing member for fixing the end of the guide rod 60 corresponding to the guide rod 60. The lower surface of the centrifugal upper mold 20 at the position outside the cavity 21 is shaped to match the shape of the upper surface of the centrifugal lower mold 10 at the position outside the housing chamber 12, that is, the centrifugal upper mold 20 is located outside the cavity 21. The surface and the upper mold 10 of the centrifugal lower mold abut against each other on the outer surface of the housing chamber 12 without a space.

Referring to FIG. 2 at the same time, the outer peripheral surface of the sand mold 30 forms a slope corresponding to the inner wall of the cavity 21. The bottom surface of the sand mold 30 is recessed inwardly to form a supplementary runner 31. The feeding runner 31 has a circular cross section and its center is located at the center of the circle in which the sand mold 30 is located. The sand mold 30 is provided with a gate 36 in the middle of the top surface of the position of the filler runner 32. The periphery of the gate 36 extends upward to form a first-stage passage 33 which extends from the bottom to the top. In this embodiment, the periphery of the feeding runner 32 is equidistantly provided with four annular casting cavities 32 corresponding to the shape of the casting to be cast. Each casting cavity 32 is recessed inwardly from the bottom of the sand mold. The center of the circle in which each of the casting cavities 32 is located is located on the same circle, and the center of the circle is concentrically arranged with the center of the circle in which the feeding sprue 31 is located. Each of the casting cavities 32 is provided with a connecting passage 35 communicating with the feeding runner 31 on a side close to the feeding runner 32. In the specific implementation, the number of the casting cavities 32 is not limited by the embodiment, and it may also be two or more, and the number of the casting cavities 32 is 2-16.

The top mold device 50 includes a template 51 received in the receiving cavity 12 of the centrifugal lower mold 10, a top shaft 52 connected to the middle portion of the starting template 51 and passing through the perforation 13 of the centrifugal lower mold 10, and is spaced apart from the centrifuge. The top die plate 53 below the lower die 10, the guide bushing 54 disposed under the top die plate 53, and the top die member 55 located below the guide bushing 54.

The stencil 51 is received in the receiving cavity 12 of the centrifugal lower mold 10, and its outer edge is flush with the edge of the bottommost end of the sand mold 30. The top surface of the starting template 51 is slightly lower than the top end of the receiving cavity 12. The starting template 51 is supported below the sand mold 30. The top shaft 52 is movably disposed within the perforations 13 of the centrifugal lower die 10. The abutment portion 56 is provided in the middle of the outer surface of the top shaft 52. The abutment table 56 has an annular stepped shape with its surface facing downward. The outer diameter of the top shaft 52 at the lower portion of the abutment table 56 is smaller than the outer diameter of the upper portion of the abutment table 56. The top die plate 53 is disposed in parallel below the centrifugal lower die 10 and abuts against the lower end of the guide bar 60 and is fixed. The top plate 53 is provided with a through hole for the top shaft 52 to pass through the top shaft 52. The abutment table 56 of the top shaft 52 is slightly lower than the lower surface of the top plate 53. The distance of the abutment table 56 from the lower surface of the top die plate 53 is the same as the distance from the receiving cavity 12 of the centrifugal lower die 10, which is 1 mm. The guide sleeve 54 is disposed under the through hole of the top die plate 53 and includes a cylindrical sleeve 540 having a bottom wall and an abutting wall 541 formed by the sleeve 540 extending outwardly from the periphery of the top end. The top end of the sleeve 540 is inserted into the through hole of the top die plate 53 and sleeved on the outer periphery of the top shaft 52 above the abutment table 56. The top shaft 52 passes through the bottom wall of the sleeve 540 and extends to the same. Below. The upper surface of the abutting wall 541 abuts against the lower surface of the top die plate 53. A driving device is further disposed below the top mold member 55. In the present embodiment, the top mold member 55 is cylindrical, and includes a bottom wall 550, a side wall 551 extending upward from the periphery of the bottom wall 550, and an abutting edge 552 connected to the top end of the side wall 551.

In a specific implementation, the casting device further includes a centrifuge disposed under the centrifugal lower mold and a relay electrically connected to the centrifugal electromechanical. The centrifuge is rotated at 100-300 rpm.

The casting method using the casting device includes the following steps:

1. The top mold device 50 is extended, and the driving device drives the top mold member to push the guiding sleeve 54 upward to drive the top template 53 to move upward, so that the top template 53 pushes the guiding rod 60 upward to move the centrifugal upper mold 20 upward. The bottom wall of the sleeve 54 abuts against the abutment 56 of the top shaft 52 during the upward movement of the sleeve 54 so that the top shaft 52 is upwardly moved up the template 51 until the top surface of the template 51 is opposite the upper surface of the centrifugal lower mold 10. Flush, at this time, as shown in Figure 3, the top template 53 abuts below the centrifugal lower mold 10, the top mold reaches the maximum stroke, the mechanism stops running; the maximum stroke of the top mold is 40 mm;

2. The impurities in the casting device are blown off by the air gun, the sand mold 30 is placed on the template 51, and the top mold device 50 is retracted, so that the centrifugal upper mold 20 is dropped and the inner peripheral surface of the cavity 21 of the centrifugal upper mold 20 is abutted. On the sand mold 30, return to the state of Figure 1;

3. Start the centrifuge, and drive the centrifugal die 10 to rotate by the centrifuge. The rotation speed is 100-300 rpm, and the molten metal is injected from the flow channel 33 of the sand type 30 (as indicated by the arrow in the figure), and the molten metal is under the action of centrifugal force. The feeding runner 31 is quickly filled into the casting cavity 32 via the connecting passage 35, and the pouring temperature is 1420-1580 ° C. After the filling is completed, the centrifuge stops rotating; the feeding runner 31 is positioned to form the feeding gate 71, casting The cavity 32 is positioned to form a casting 72 that is coupled to the bottom end of the casting 72, as shown in FIG. In a specific implementation, the rotation time of the centrifuge is 20-180 seconds;

4. The top mold device 50 is extended, repeating the first step of the action, so that the sand mold 30 is ejected, and the upper mold 20 is centrifuged to the maximum stroke;

5. The molded body formed by the sand mold 30 and the casting 72 and the supplementary gate 71 is pushed out, the sand mold is replaced, and the next pouring is performed.

6. The filler gate 71 is removed from each casting 72, and the feeding gate 71 is removed by a lathe, water jet, punch, electric spark or gas cutting to obtain the desired casting.

The casting machine adopts a centrifuge speed of 100-300 rpm, and the casting structure produced under the centrifugal speed range is uniform, and the density segregation can be prevented compared with the existing high-speed centrifugal rotation. The metal flow of the casting device The short diameter is less than the existing gravity casting, which reduces the probability of gas and impurities being trapped in the high temperature molten metal, and reduces defects such as pores and blisters. Since the manufactured molded body has the supplementary gate 71, it provides the filler metal liquid for the casting 72, effectively eliminates casting defects such as shrinkage and shrinkage of the casting profile, and makes the overall structure of the product uniform and uniform, and reduces the force after application. Uneven stress causes adverse effects on product sealing performance and mechanical properties. The casting method can realize simultaneous molding of a sand-type multi-casting cavity, which can realize mass production only by replacing the sand type 30, reduces the requirement of the continuous casting on the centrifugal mold, and avoids the impact of the high temperature of the molten metal and the high centrifugal force on the mold directly. Improve the service life of the mold, suitable for a large number of automated production.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., which are included in the spirit and scope of the present invention, should be included in the present invention. Within the scope of protection.

Claims

A casting device, comprising: a centrifugal lower mold, a centrifugal upper mold disposed on the centrifugal lower mold, a sand mold disposed in the centrifugal upper mold, and a top mold device disposed under the sand mold, the centrifugal lower mold The top portion of the top portion is recessed inwardly to form a receiving cavity, and a central portion of the receiving cavity is provided with a through hole. The centrifugal lower die is provided with a guiding hole on the outer side of the receiving cavity, and a guiding rod is movably disposed in the guiding hole. The centrifugal upper mold is provided with a cavity penetrating the upper and lower surfaces of the centrifugal upper mold at a position corresponding to the receiving cavity, and the sand type is received in the cavity, and the bottom surface of the sand type is recessed inward to form a feeding runner, and is at the position of the feeding sprue. The top surface of the top surface is provided with a gate, and the periphery of the feeding runner is provided with at least two annular casting cavities corresponding to the shape of the casting to be cast, and each casting cavity is recessed by the sand-shaped bottom surface, and each casting cavity A connecting passage communicating with the feeding runner is disposed on a side close to the feeding runner, and the top mold device comprises a starting plate received in the receiving cavity of the centrifugal lower die and supported under the sand type, and the connection is set in the starting template The middle portion passes through the perforated top shaft of the centrifugal die, a top template disposed under the centrifugal lower mold and a driving device disposed under the top mold, the two ends of the guiding rod are respectively fixed on the centrifugal upper mold and the top template, and the bottom end of the top shaft passes through the top template and is located at Below, the driving device can provide an upward driving force to drive the top template and the top shaft up, and the casting device further comprises a centrifuge disposed under the centrifugal lower mold, the rotating speed of the centrifuge is 100-300 rpm.
The casting device according to claim 1, wherein the center of the feeding runner is located at a center of a circle where the sand mold is located, and the center of the circle where each casting cavity is located is located on the same circle, and the center of the circle is filled with the filling The center of the circle where the road is located is set concentrically.
The casting apparatus of claim 1 wherein the periphery of the gate extends upwardly to form a first pass.
The casting device according to claim 1, wherein the top shaft is provided with an abutting table for moving up against the top shaft, and the top mold device further comprises a bottom plate. a guide sleeve comprising a cylindrical sleeve having a bottom wall and an abutment wall extending outwardly from a circumference of the sleeve near the top end thereof, the upper surface of the abutment wall abutting against the top Below the template, the top shaft is movably disposed in the sleeve and has a bottom end extending to the outside of the bottom wall of the sleeve, and the driving device drives the sleeve to move the top template upward, and the sleeve abuts against the abutment Drive the top shaft.
The casting device according to claim 4, wherein the abutting table of the top shaft is located below the lower surface of the top plate, and the surface of the stencil is lower than the top end of the receiving cavity of the centrifugal lower die. The distance between the lower table and the lower surface of the top template is the same as the distance from the receiving cavity of the lower die to the lower die. When the top template abuts against the lower surface of the centrifugal lower die, the top surface of the template and the centrifugal lower die are The upper surface is flush.
A casting apparatus according to claim 4, wherein said top mold unit further comprises a top mold member disposed below the guide sleeve, the top mold member including a bottom wall and a side wall extending upward from a periphery of the bottom wall And connecting the abutting edge provided at the top end of the side wall, the driving device drives the top mold member to move up.
A casting apparatus according to any one of claims 1 to 6, wherein a cross section of the cavity extends gradually from a bottom to the top, and an outer peripheral surface of the sand type forms an inner wall corresponding to the cavity. Beveled.
The casting device according to any one of claims 1 to 6, wherein the centrifugal lower die protrudes upward from a periphery of the receiving cavity to form a convex ring, and the lower surface of the centrifugal upper die is formed at a position outside the cavity. The shape of the upper surface of the mold at the position outside the receiving chamber is matched to the shape.
A casting method, characterized in that the casting method is carried out by using the casting device according to claim 6, the casting method comprising the following steps:

1. The top mold device is extended, and the driving device drives the top mold member to push the guiding sleeve upward to drive the top template to run upward, so that the top template pushes the guiding rod upward to move the centrifugal upper mold upward, and the guiding sleeve moves up during the process. The bottom wall abuts against the abutment of the top shaft so that the top axial direction moves the template upward until the top surface of the template is flush with the upper surface of the centrifugal lower mold. At this time, the top template abuts against the centrifugation. Below the lower mold, the top mold reaches the maximum stroke;

2. Purging the impurities in the casting device by air gun, placing the sand mold on the template, and retracting the top mold device, so that the centrifugal upper mold falls and the inner peripheral surface of the cavity of the centrifugal upper mold abuts against the sand mold;

3. Start the centrifuge, drive the centrifugal mold to rotate by the centrifuge, the molten metal is injected by the sand gate, and the molten metal is quickly filled into the cavity through the connecting channel by the feeding runner under the action of centrifugal force, to be charged. After the type is completed, the centrifuge stops rotating; the position of the feeding sprue forms a feeding gate, the casting cavity position forms a casting, and the feeding gate is connected with the bottom end of the casting;

4. The top mold device is extended, repeating the first step of the action, so that the sand mold is ejected, and the top of the mold is centrifuged to the maximum stroke;

5. Push out the molded body formed by the casting and the feeding gate, replace the sand type, and then carry out the next pouring;

6. Remove the filler gate from the casting.
The casting method according to claim 9, wherein in step 6, the feeding gate is removed from the casting by a lathe, a water jet, a punch, an electric spark or a gas cut.