CN115351215A - Conformal Precise Forming Die for Forgings of Eccentric Water Drop End Cap - Google Patents

Abstract

The invention relates to the technical field of forging molding dies, in particular to an eccentric drop-shaped end cap forgings conformal and precise molding die, including a pre-forming die and a forming die, the cavity of the pre-forming die is a drop-shaped cavity; the cavity of the forming die includes interconnected The first cavity and the second cavity, the first cavity is drop-shaped, the second cavity is cylindrical, the center of the second cavity is concentric with the center of the forming mold, the center of the first cavity is concentric with the second cavity The center of is set eccentrically. The invention can solve the problem that the blank of the eccentric drop-shaped end cap cannot fill the cavity of the mold during the forging process.

Description

Conformal Precise Forming Die for Forgings of Eccentric Drop-shaped End Cap

technical field

The invention relates to the technical field of forging forming dies, in particular to an eccentric water drop-shaped end cap forging with shape and precision forming die.

Background technique

In the field of nuclear power, there is a lower end cover of a bursting disc device, the shape of which is shown in Figure 1. It is characterized in that there is an eccentric drop-shaped boss at the large round end, and an eccentric hole 10 is arranged on the large round end, and the eccentric hole 10 runs through the drop-shaped boss. The center of the boss, because the part is composed of a circular boss and an eccentrically arranged drop-shaped boss, has an irregular shape, which leads to difficulty in molding and a single molding method; the current conventional manufacturing method in this field is: a cylindrical blank is used The punch punches the eccentric hole, and then uses machining to turn the drop-shaped boss, but this method has the problems of low material utilization rate, large amount of turning, manufacturing cost and long manufacturing cycle; in addition, turning will destroy the flow of the material itself. Line, which in turn affects the performance of the workpiece, resulting in unstable quality.

In order to solve the above-mentioned technical problems, the commonly used method at present is to use die extrusion instead of mechanical processing. For example, the patent document CN112589028A records a kind of eccentric forging die structure. structure, and then put the billet into the mold, and stretch and upset the billet under high temperature conditions to obtain the eccentric forging. However, if the structure of the mold cavity is directly changed to manufacture the eccentric drop-shaped end cap in the present application, the deformation of the blank will be uneven, resulting in the problem that the blank cannot be filled with the mold cavity; after analysis, it is found that the prior art It is feasible, because the existing technology only has the difficulty that the shape of the forging is eccentric, so it is only necessary to set the cavity of the mold to be eccentric, and then combine some conditions for controlling the forming of the forging to solve this problem, but it puts the blank into the mold There is no need for large deformation in the process, so there is no problem that the blank is not filled with the cavity. However, for this eccentric drop-shaped lower end cap product, one end of a cylindrical blank needs to be deformed into a drop-shaped shape, and the other end is deformed into a larger cylindrical shape. When the blank is deformed into a cylindrical shape, it is easier to deform because of its regular shape, but the blank is deformed. When it is a water drop type, due to its irregular shape and uneven deformation, the billet is always not filled with the water drop type cavity of the mold.

Contents of the invention

The present invention intends to provide an eccentric drop-shaped end cap forging with conformal and precise molding die, so as to solve the problem that the blank of the eccentric drop-shaped end cap cannot fill the die cavity during the forging process.

To achieve the above object, the present invention adopts the following technical solutions:

The eccentric drop-shaped end cap forgings conforms to the shape and accurately forms the die, including the pre-forming die and the forming die. The cavity of the pre-forming die is a drop-shaped cavity; The first cavity is drop-shaped, the second cavity is cylindrical, the center of the second cavity is concentric with the center of the forming mold, and the center of the first cavity and the center of the second cavity are set eccentrically.

Since this product is composed of a circular table and an eccentrically set drop-shaped boss, if the die forging method is used, the conventional method is to manufacture a die with the same shape as the product, and place the blank in the die for extrusion molding. However, in the actual use process, the inventor found that there is a problem that the blank is not filled with the cavity of the mold when only one forming die is used to process the blank. After analysis, it is found that the main reason is that the deformation of the blank is irregular, and the cylindrical blank is deformed into a larger cylinder. It is relatively easy to shape it, but it is not easy to deform it into a drop shape. Therefore, when a cylindrical blank is placed in a molding die with the same cavity as the product shape for an upsetting molding, a large number of blanks will go down. The flow in the cylindrical cavity leads to the lack of material in the upper drop-shaped cavity; and if the preformed blank is placed in another cavity and the same molding mold as the second pier, due to the shape of the mold The cavity is in the shape of a boss, and the metal material itself has a relatively large resistance. It is difficult for the blank left in the large end to flow into the drop-shaped cavity at the small end, and it will also cause damage to the mold; therefore, using the same cavity The mold is processed twice, which is only suitable for products with regular shape and uniform deformation.

Based on this, the inventor finally found after many times of research and practice that the cavity of the preforming mold is set in the shape of a water drop, and the cavity of the forming mold is set in the shape of the product, that is, the cylindrical blank is first upset to deform it into a water drop. shape, and then upsetting one end of the water drop shape to expand it into a cylindrical shape at the end of the product, and controlling the different deformation states of the blank through two formings, which can well control the deformation of the blank and achieve accurate material distribution, thus solving the problem of The problem that the billet cannot fill the mold cavity.

Beneficial effects: the use of the preforming die and forming die can well control the deformation of the blank, so that it can fill the cavity of the die, thereby obtaining a forging with relatively accurate size and shape; it reduces the difficulty of subsequent finishing and reduces the waste. In addition, the forging produced by using the forming die will not damage the streamline of the material itself, which improves the comprehensive performance of the product.

Further, the radius of the water drop end of the cavity of the preforming mold is consistent with the radius of the water drop end of the first cavity of the forming mold.

Setting the hole diameters of the two mold cavities to be the same can reduce the amount of deformation of the billet when it is upset in the molding die; in addition, compared to ensuring that the billet is filled with enough material to fill the mold cavity, the water drop of the preforming mold The radius of the end is set larger than the radius of the water drop end of the first cavity of the forming mold, so that the blank is more easily filled with the water drop end of the mold when it is deformed. This scheme can save about 20Kg of the billet consumption.

Further, both the cavity of the preforming mold and the cavity of the forming mold are provided with a draft angle of 2-3°.

The advantage of setting the draft angle to 2-3° is that it is convenient to remove the blank from the cavities of the two molds. If the draft angle is less than 2°, it will be difficult to demould. If the draft angle is greater than 3°, the material will be additionally increased. Dosage.

Further, symmetrical positioning grooves are provided on the outer wall of the forming mold, and the connecting line of the positioning grooves is located on the diameter of the first cavity.

Setting the positioning groove can not only facilitate the fixing of the molding die on the workbench, but also facilitate the operator to quickly find the center position of the punching hole, so as to avoid the wrong punching position.

Further, it also includes a punching device, the punching device includes a drop-shaped first punch and a second punch, the first punch matches the big end of the preforming mold cavity, and the second punch matches the preforming mold cavity. The small end of the cavity fits.

The drop-shaped first punch and the second punch are used for double-sided upsetting of the blank placed in the preforming mold. The first punch is matched with the big end of the preforming mold cavity, and the second punch is matched with the The small ends of the preforming mold cavity can reduce the gap during use, thereby reducing the flash; on the other hand, using two drop-shaped punches for double-sided upsetting is compared with one punch from one direction. Coarse, it can further ensure that the blank fills the cavity of the preforming mold.

Further, it also includes a punching head, the outer wall of the punching head and its center line form a slope with an inclination angle of 1-2°; the height of the punching head is smaller than the height of the cavity of the molding die.

The punching head is set with an inclination angle of 1-2°, which can reduce the downward pressure resistance of the punch when punching the blank. If the inclination angle is greater than 2°, it will cause a large inclination in the inner diameter of the punched inner hole; In addition, setting the height of the punching head to be smaller than the cavity of the forming mold can ensure that the punch does not punch through the blank when punching the eccentric hole, so that the core material is filled with the second cavity of the forming mold, which can fully utilize the material The purpose is to ensure that the billet is completely filled with the cavity of the molding die, so as to obtain forgings whose size and shape meet the production requirements.

Further, the draft angle of the preforming mold and the forming mold is 3°; this angle is the optimal draft angle.

Further, the outer wall of the first punch forms an inclination angle of 3° with its center line; when in use, the first punch matches the large end of the preforming mold cavity, and the cavity of the preforming mold is provided with With a draft angle of 3°, setting the first punch at a matching inclination angle can ensure that the first punch completely enters the cavity of the preforming mold during upsetting, thereby reducing burrs and flying of the blank. side.

Description of drawings

Fig. 1 is the structural representation of lower end cap product of the present invention;

Fig. 2 is the structural representation of preform mold of the present invention;

Fig. 3 is the front sectional view of preform mold of the present invention;

Fig. 4 is the structural representation of molding die of the present invention;

Fig. 5 is the front sectional view of molding die of the present invention;

Fig. 6 is the structural representation of the first punch of the present invention;

Fig. 7 is the structural representation of the second punch of the present invention;

Fig. 8 is a schematic structural view of the punching head of the present invention.

Detailed ways

The following is further described in detail through specific implementation methods:

The marks in the accompanying drawings include: preforming mold 1, third cavity 2, forming mold 3, first cavity 4, second cavity 5, positioning groove 6, first punch 7, second punch 8. Punching punch 9. Eccentric hole 10.

Embodiment one

As shown in Figure 1-8, the eccentric drop-shaped end cap forgings conforms to the shape and accurately forms the die, including the punching device, pre-forming die 1 and forming die 3, and the cavity of the pre-forming die 1 is a drop-shaped cavity as shown in Figure 2 For the convenience of description, the through holes are collectively referred to as the third cavity 2 below.

As shown in Figures 4 and 5, the cavity of the molding die 3 includes a first cavity 4 and a second cavity 5 that communicate with each other, the first cavity 4 is a drop shape, the second cavity 5 is cylindrical, and the second cavity The center of the second cavity 5 is consistent with the center of the molding die 3; the first cavity 4 is eccentrically arranged relative to the second cavity 5, and the eccentric distance between the center of the first cavity 4 and the center of the second cavity 5 in this embodiment is 22.5mm; the outer wall of the molding die 3 is provided with symmetrical positioning grooves 6, and the positioning grooves 6 are located on the diameter of the first cavity 4; the cavity of the preforming mold 1 and the cavity of the forming mold 3 are all provided with The draft angle of 2-3°, in this embodiment, the draft angle is 3°, the radius of the water drop end of the third cavity 2 of the preforming mold 1 is consistent with the radius of the water drop end of the first cavity 4 of the forming mold 3 , the radius of the droplet end is represented by R.

As shown in Fig. 6, Fig. 7 and Fig. 8, the extrusion device includes a drop-shaped first punch 7, a second punch 8, and a cylindrical punch 9, the first punch 7 and the preforming mold 1 The large end of the third cavity 2 is matched, the second punch 8 is matched with the small end of the third cavity 2 of the preforming mold 1, and the outer wall of the first punch 7 is inclined at an angle of 3° to its center line. slope. , the outer wall of the punching punch 9 and the center line of the punching punch 9 form an inclined plane with an inclination angle of 2°; the height of the punching punch 9 is less than the height of the molding die 3 cavities. The height of the head 9 is equal to the height of the first cavity of the molding die 3 .

When the mold in this embodiment is in use, a set of forging hydraulic unit is required. The forging hydraulic unit includes a workbench, a press and a flat anvil arranged on the power output shaft of the press. The power output shaft of the press has multiple , can be connected with the first punch 7, the second punch 8 and the punching punch 9 in the present application or the power output part of the press can directly apply pressure to several punches.

Since the billet needs to be heated to 850-1180°C during forging, in order to reduce the temperature loss of the billet, the mold needs to be preheated to above 300°C before use. The problem that leads to the reduction of the service life of the mold.

The specific embodiment process is:

First place the cylindrical blank in the third cavity 2 of the preforming die 1 in Figure 2, then use the drop-shaped first punch 7 and the second punch 8 in Figures 6 and 7 to upset the blank. During operation, the second punch 8 can be pressed against the small end of the third cavity 2 according to the condition of the equipment, and the press presses the first punch 7 to squeeze the billet, so that the billet is deformed and filled with the third cavity 2; or First place the preforming mold 1 on the workbench, with the small end of the third cavity 2 facing up, use the second punch 8 to first squeeze the billet to the large end of the third cavity 2, and then turn over the preforming mold 1 and the blank, and then use the first punch 7 to squeeze out to obtain a drop-shaped blank.

Then the molding die 3 in Fig. 5 is placed on the workbench, the flipping molding die 3 makes its second cavity 5 upwards, the small end of the droplet-shaped blank is put into the molding die 3 downwards, and the The anvil upsets the billet to make one end of the drop-shaped billet into a cylindrical shape, so that the cylindrical shape of the large end of the product is preliminarily formed; then the billet and the forming mold 3 are turned over, so that the first cavity 4 of the forming mold 3 is facing upwards, and punched by punching The head 9 punches the core material part of the blank into the second cavity 5, so that the cylindrical section of the blank completely fills the second cavity 5, and the punch 9 can press the two positioning grooves 6 when punching the eccentric hole 10. The center of the connecting line is positioned instead of the center of the molding die 3.

Finally, a counter punch is used to punch out the punch 9 from the bottom of the forming die 3 as shown in Figure 5 to obtain a complete eccentric hole 10; the formed forging is cooled by water cooling, and then the forging is removed by finishing burrs, so as to obtain a complete lower end cover product.

What is described above is only an embodiment of the present invention, and common knowledge such as specific technical solutions and/or characteristics known in the solutions are not described here too much. It should be pointed out that for those skilled in the art, without departing from the technical solutions of the present invention, some modifications and improvements can also be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation of the present invention effect and utility of patents. The scope of protection required by this application shall be based on the content of the claims, and the specific implementation methods and other records in the specification may be used to interpret the content of the claims.

Claims (8)

1. The conformal and precise molding die for the eccentric drop-shaped end cap forging is characterized in that it includes a pre-forming die and a forming die, and the cavity of the pre-forming die is a drop-shaped cavity; the cavity of the forming die includes interconnected first A cavity and a second cavity, the first cavity is drop-shaped, the second cavity is cylindrical, the center of the second cavity is concentric with the center of the molding die, and the center of the first cavity Set eccentrically to the center of the second cavity. 2. The conformal and precise forming die for eccentric drop-shaped end cap forgings according to claim 1, wherein the radius of the drop end of the cavity of the preforming die is consistent with the radius of the drop end of the first cavity of the forming die. 3. The eccentric drop-shaped end cap forging according to claim 2, characterized in that: the cavity of the preforming mold and the cavity of the forming mold are both provided with a draft angle of 2-3° Spend. 4. The eccentric drop-shaped end cap forging according to claim 3, characterized in that: symmetrical positioning grooves are arranged on the outer wall of the forming mold, and the connecting line of the positioning grooves is located at the first on the diameter of a cavity. 5. The eccentric drop-shaped end cap forging according to claim 4, characterized in that: it also includes a punching device, which includes a drop-shaped first punch and a second punch, The first punch matches the big end of the cavity of the preforming mold, and the second punch matches the small end of the cavity of the preforming mold. 6. The eccentric drop-shaped end cap forging according to claim 5, characterized in that: it also includes a punch, the outer wall of the punch and its center line form an inclination angle of 1-2 ° slope, and the height of the punching punch is less than the height of the molding die cavity. 7. The eccentric drop-shaped end cap forging according to claim 6, characterized in that: the draft angle of the preforming die and the forming die is 3°. 8. The conformal and precise forming die for eccentric drop-shaped end cap forgings according to claim 7, characterized in that: the outer wall of the first punch and its center line form a slope with an inclination angle of 3°.

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