CN103537505B - A kind of axial workpiece mold for extruding and forming and extrusion forming method - Google Patents

Abstract

The invention relates to an extrusion molding die for shaft parts, which includes a punch and a die. The punch is a split structure. The punch includes a fixed part and a movable part. The fixed part is provided with a fixed end. Connecting parts are respectively provided; the present invention also relates to an extrusion molding method for extruding shaft parts using the extrusion molding die, which includes the following steps, 1) putting the blank into the die, and placing the movable part on the upper end surface of the blank, The press drives the fixed part down and pushes the movable part to extrude the billet; 2) After the extrusion is completed, the press drives the fixed part back, ejects the movable part and the workpiece and demoulds, or the press drives the fixed part up to the workpiece from The fixed part comes out, and the press drives the fixed part to move in parallel to the side staggered from the movable part, and the movable part and the workpiece are ejected and demolded. The invention can realize extrusion forming of long shaft parts, and reduce equipment input for extrusion forming of long shaft parts.

Description

Extrusion forming die and extrusion forming method for shaft parts

technical field

The invention relates to the technical field of extrusion forming of metal materials, in particular to an extrusion forming die and an extrusion forming method for shaft parts.

Background technique

Usually, the total length L is greater than the maximum mold opening height H of the general-purpose four-column hydraulic press minus half of the distance h from the upper end of the die to the bottom of the lower mold base, that is, shaft parts with L≧(H-h)/2 are called super long shaft parts, The half-shaft part is a kind of shaft part. When the length of the half-shaft part to be formed is larger than that, due to the long diameter of the part, it is easy to be unstable when it is formed by a flat forging machine or a friction press. It cannot be formed at one time; while radial forging machines are used, the equipment investment is large, the production efficiency is low, and the versatility is not strong. Press forming.

Existing extrusion dies for forming the above-mentioned shaft parts generally include an upper die part and a lower die part. The fixed plate, the punch is fixedly connected with the punch fixed plate, the center of the punch is provided with a central through hole extending along its axial direction, the lower base is provided above the lower die base, the die is fixed on the lower base, the die includes The die fixing ring on the outer layer and the die set in the die fixing ring, the bottom center of the die is provided with a pad that can move up and down along the inner wall of the die, and the center of the lower die base and the lower backing plate is provided for the ejector rod to pass through. The ejector pin hole, the ejector pin presses against the cushion block at the bottom of the die through the ejector pin hole. When in use, put the blank into the die, the upper cylinder of the hydraulic press drives the punch to squeeze the billet downward, the metal flows along the moving direction of the punch to form the flange head, and a part of the metal flows in the opposite direction to the moving direction of the punch Enter the center through hole of the punch to form the rod; after the extrusion is completed, the upper die seat drives the punch to return, the workpiece stays in the die, and the workpiece is pushed out of the die by the ejector rod to achieve demoulding.

In the existing extrusion die, when demoulding, the upper die seat drives the punch up to the maximum mold opening height of the hydraulic press, and the ejector rod pushes out the workpiece to make the workpiece escape from the die. In order to smoothly remove the workpiece After the mold is opened, the lower end surface of the punch needs to be higher than the position of the upper end surface after the workpiece is completely released from the die. Therefore, the length of the shaft parts that can be formed by using this extrusion die is affected by the height of the hydraulic press and the ejector pin ejection. Due to the limitation of the stroke, the maximum length L of the shaft parts that can be formed is generally no more than half of the maximum opening height of the hydraulic press, so the existing extrusion dies cannot realize the smooth demoulding of the extruded super long shaft parts .

Contents of the invention

The purpose of the present invention is to provide an extrusion molding die for shaft parts to solve the problem in the prior art that the super long shaft parts cannot be demoulded smoothly. The purpose of the present invention is also to provide an extrusion molding method for extruding shaft parts using the above extrusion molding die.

In order to solve the above problems, the technical solution adopted by a shaft part extrusion mold in the present invention is:

An extrusion mold for shaft parts, including a punch and a die, the punch is a split structure, the punch includes a fixed part and a movable part, the fixed part is provided with a plate for fixing with the punch The fixed end of the fixed connection, the fixed part and the movable part are respectively provided with connecting parts for mutual connection.

The connecting portion includes a concave notch provided on one of the fixed part and the movable part and a convex notch provided on the other.

The hole portion of the concave stop is a conical hole, and the convex column portion of the convex stop is in the shape of a truncated cone matching the concave stop.

It also includes an upper backing plate and an upper mold base, which are provided with a part relief hole communicated with the center through hole of the punch, and the center line of the through hole is in line with the punch The center line of the center through hole of the mold coincides.

A stepped surface is provided on the outer peripheral surface of the movable part, and the stepped surface is arranged away from the fixed end of the fixed part.

A diameter-reducing portion is provided on the outer peripheral surface of the movable part.

In the present invention, the technical scheme adopted by the extrusion molding method for extruding the shaft parts by using the above-mentioned extrusion molding die is:

An extrusion forming method for extruding shaft parts using the above extrusion forming die, comprising the following steps,

1) Put the billet into the die of the extrusion molding die, the movable part is placed on the upper end surface of the billet in the die, and the press drives the fixed part down to push the movable part to extrude the billet;

2) After the extrusion is completed, the press drives the fixed part up and back, and the movable part and the parts filled in the movable part are ejected from the die and demolded, or the press drives the fixed part up to the parts from the fixed part After the middle is ejected, the press drives the fixed part to move in parallel to the side staggered from the movable part, and the movable part and the parts filled on the movable part are ejected from the extrusion die and demolded.

The demoulding in the above step 2) is to put the movable part and the workpiece filled in the movable part into the cooling water to separate the workpiece from the movable part.

When cooling water cannot be used to separate the workpiece from the movable part, place the movable part filled with the workpiece on a backing ring with a certain height or at least two spacers provided separately, so that the small end of the movable part extends into the pad In the inner hole of the ring or in the gap between the pads, the step surface set on the outer peripheral wall of the movable part is supported on the pad ring or the pad, and a press is used to apply pressure to the workpiece to separate the workpiece from the movable part.

In the extrusion molding die for shaft parts proposed by the present invention, the punch adopts a split fixed part and a movable part, and the fixed part and the movable part are connected by a connecting part provided on both, so that the fixed part and the movable part are combined The mold can be pushed when extruded, and can be separated when the mold is opened. When the mold is opened, the press drives the fixed part to move up to make the workpiece come out of the fixed part, and then continue to move up to eject the workpiece from the die. The distance of the stroke is equal to the smooth demoulding, or after the workpiece is disengaged from the fixed part, the press drives the fixed part to move to one side, so that the fixed part gets out of the way when the movable part is ejected, the required return distance of the press Small, so when the mold opening height of the press is constant, the smooth demoulding of long shaft parts can be realized, so that the extrusion molding of long shaft parts can be realized, and the extrusion molding of long shaft parts can be reduced. equipment investment.

Further, the hole of the concave stop is set as a tapered hole, and the convex column of the convex stop is in the shape of a truncated cone matching the tapered hole, which can realize accurate centering and pressing of the fixed part and the movable part.

Further, on the backing plate and the upper mold base, a product relief hole communicating with the central through hole of the punch is provided, so that shaft parts with longer lengths can be extruded.

Further, a stepped surface is provided on the movable part, and the stepped surface is set away from the fixed end of the fixed part, so that it can be placed on the backing ring or at least two separately provided pads for smooth demoulding during demoulding.

Description of drawings

Fig. 1 is a schematic structural view of an embodiment of a shaft part extrusion molding die of the present invention;

Fig. 2 is the billet structural diagram to be extruded among the present invention;

Fig. 3 is the structural representation of extruded workpiece among the present invention;

Fig. 4 is a principle diagram of forced demoulding in the present invention.

detailed description

An embodiment of an extrusion mold for shaft parts of the present invention: as shown in Figures 1 to 4, the extrusion mold includes an upper mold part and a lower mold part, and the upper mold part includes a detachably connected upper mold base 9, The upper backing plate 8, the punch fixing plate 7 and the punch fixedly connected with the punch fixing plate 7, the center of the punch is provided with a central through hole extending along its axis, the punch is a split structure, and the punch includes a fixed part The movable part 5 below 6, the fixed part 5 has a fixed end for fixed connection with the punch fixed plate 7, a stepped surface is arranged on the outer peripheral surface of the movable part, and the stepped surface is set away from the fixed end of the fixed part, so as to facilitate the workpiece It is taken out together with the movable part, and a diameter-reducing part is also provided on the outer peripheral surface of the movable part. The diameter of the diameter-reducing part is smaller than the diameter of its adjacent two sides. The part includes a concave stop provided on the lower end surface of the fixed part 6 and a convex stop provided on the upper end of the movable part 5. The concave stop has a conical hole and an upper stop surface, and the convex stop has a lower stop surface and a protruding stop surface. The convex column on the lower end surface of the stop, the convex column is a truncated conical shape that fits with the hole of the concave stop, the convex column of the truncated cone is guided and matched with the conical hole of the concave stop, and the convex stop The lower stop surface of the mouth is matched with the upper stop surface of the concave stop. When the mold is clamped and extruded, the fixed part 6 is pressed down under the guidance of the concave stop and the convex stop and pushes the movable part 5 down. When the blank is extruded, when the mold is opened, the fixed part 6 moves up and finally separates from the movable part 5, and the upper backing plate 8 and the upper mold base 9 are provided with a part relief hole connected with the center through hole of the punch. The center line of the part relief hole coincides with the center line of the center through hole of the punch, so that the extruded part extends to the part part relief hole of the backing plate, so that a longer part can be extruded; The mold part includes a detachably connected lower mold base 1, the lower mold base 1 is provided with a lower backing plate 2 and a die assembly arranged on the lower backing plate 2, and the die assembly includes an outer die retaining ring 3 And the die 4 arranged in the die fixed ring 3, the upper end surface of the die 4 is in cooperation with the step surface of the movable part to stop and limit, and the bottom of the die cavity of the die 4 is provided with a mold cavity wall that can be moved along the die 4. The pad 11 that moves up and down, the lower mold base 1 and the lower backing plate 2 are provided with a mandrel perforation for wearing a mandrel 12 , and the mandrel 12 upper end presses on the mandrel 11 .

The extrusion forming method of extruding a shaft part by using the above-mentioned extrusion forming die comprises the following steps: 1) Put the blank shown in Figure 2 into the die 4, the diameter of the blank is D, and the height is H, and the The lower end of the movable part 5 of the punch is placed below the upper end surface of the die cavity of the die 4, the cavity wall of the die 4 guides the movable part 5 of the punch, and the lower end of the movable part 5 presses against the upper end face of the blank, The press drives the fixed part 6 of the punch to go down, the concave stop on the lower end surface of the fixed part 6 matches the convex stop on the upper end surface of the punch, and the upper stop surface of the concave stop presses against the convex stop. The lower stop surface pushes the movable part 5 downward to extrude the billet, and as the extrusion force increases, the metal moves in the same direction as the movement direction of the punch to form a head with a diameter D of the workpiece 10 as shown in Figure 3 part of the metal moves in the direction opposite to the movement direction of the punch into the central through hole of the punch and continues to flow to form a rod with a diameter d of the workpiece 10 as shown in Figure 3, and finally extruded into For long-axis parts with a total length of L, a part relief hole connected to the center through hole of the punch is provided on the upper backing plate and the upper die base, so that the length of the extruded part can be longer; 2) After the extrusion is finished, the hydraulic press quickly returns, and the hydraulic press drives the fixed part 6 to move up and separate the fixed part 6 from the movable part 5, so that the rod part of the formed part is released from the fixed part 6, and the fixed part 6 continues to rise to the maximum opening. The mold height or the side cylinder of the hydraulic press drives the fixed part to move horizontally to one side, the lower cylinder of the hydraulic press moves to push the ejector rod 12, and the ejector rod 12 presses the part 10 through the pad 11 at the bottom of the die, and the part 10 together with the movable part 5 to push out the die 4 together, the flange surface of the workpiece 10 is just pushed to the upper surface of the die 4, and the workpiece 10 is connected to the movable part 5 of the punch by clamping the reduced diameter part of the movable part with a clamping tool Remove to demould. When demolding, first use cooling demoulding, put the movable part filled with the workpiece into the cooling water, and use the different shrinkage rates of the workpiece and the movable part to separate the workpiece from the movable part; if the cooling water cannot be used to separate the workpiece from the movable part If the parts are separated, forced demoulding is adopted, and the movable part filled with parts is placed on the gasket ring 13 with a certain height, as shown in Figure 4, the small end of the movable part extends into the inner hole of the gasket ring 13, and the movable part The stepped surface provided on part of the peripheral wall is supported on the end surface of the backing ring 13, and a press is used to apply pressure F to the workpiece to separate the workpiece from the movable part.

After extrusion molding with this extrusion die, when the workpiece 10 is separated from the fixed part 6 during mold opening, it is only necessary to ensure that the distance from which the fixed part 6 continues to rise to the maximum mold opening height is not less than that of the workpiece 10 from the die 4 The ejected distance can achieve smooth demoulding; or start the side cylinder of the hydraulic machine to drive the fixed part to move horizontally to one side, then the fixed part only needs to be raised to separate the workpiece 10 from the fixed part. Therefore, when this die is used for extrusion molding, when the mold opening height is constant, the smooth demoulding of long-length shaft parts can be achieved, that is to say, this extrusion die can be used to extrude rods and shafts with long lengths. Component.

In this embodiment, the connection part is the concave stop on the fixed part and the convex stop on the movable part. partly on.

In this embodiment, the hole portion of the concave stop is a conical hole, and the convex column portion of the convex stop is a truncated cone. In other embodiments of the present invention, the hole portion of the concave stop can also be set to a spherical shape. Correspondingly, the protruding pillars of the mouth are arranged in a spherical structure.

In this embodiment, the movable part filled with parts is placed on the backing ring for forced demoulding. In other embodiments of the present invention, the movable part filled with parts can also be placed on at least two separate On the block pad, the step surface of the movable part is supported on the pad, and the press is used to apply downward pressure to the workpiece, so that the workpiece moves downward and separates from the movable part.

An embodiment of the method for extruding and forming shaft parts using the above-mentioned extrusion die in the present invention: as shown in Figure 1, the method includes the following steps: 1) Put the blank as shown in Figure 2 into the die 4 Among them, the diameter of the blank is D and the height is H. The lower end of the movable part 5 of the punch is placed below the upper end surface of the cavity of the die 4, and the cavity wall of the die 4 guides the movable part 5 of the punch. The lower end of the movable part 5 is pressed against the upper end surface of the blank, and the press drives the fixed part 6 of the punch to go down. The upper stop surface of the spigot presses the lower stop surface of the convex spigot, thereby pushing the movable part 5 downward to extrude the billet. With the increase of the extrusion force, the metal moves in the same direction as the movement direction of the punch to form a The diameter of the workpiece 10 shown in Figure 3 is the head flange structure of D, and a part of metal moves into the central through hole of the punch along the direction opposite to the movement direction of the punch and continues to flow to form the workpiece 10 as shown in Figure 3 The rod part with a diameter of d is finally extruded into a long-axis part with a total length of L, and a part relief hole connected with the central through hole of the punch is opened on the upper backing plate, so that the extruded The length of the workpiece is longer; 2) After the extrusion is completed, the hydraulic press returns quickly, and the hydraulic press drives the fixed part 6 to move up and separate the fixed part 6 from the movable part 5, so that the rod part of the formed part is released from the fixed part 6 , the fixed part 6 continues to rise to the maximum mold opening height or start the side cylinder of the hydraulic press to drive the fixed part to move horizontally to one side, the lower cylinder of the hydraulic press moves to push the ejector rod 12, and the ejector rod 12 presses the workpiece through the cushion block 11 at the bottom of the die 10. Push the part 10 together with the movable part 5 out of the die 4, the flange surface of the part 10 just pushes to the upper surface of the die 4, and use the clamping tool to clamp the reducing part of the movable part to clamp the part 10 moves out together with the movable part 5 of the punch, and demoulding is carried out. When demolding, first use cooling demoulding, put the movable part filled with the workpiece into the cooling water, and use the different shrinkage rates of the workpiece and the movable part to separate the workpiece from the movable part; if the cooling water cannot be used to separate the workpiece from the movable part If the parts are separated, forced demoulding is adopted, and the movable part filled with parts is placed on the gasket ring 13 with a certain height, as shown in Figure 4, the small end of the movable part extends into the inner hole of the gasket ring 13, and the movable part The stepped surface provided on the peripheral wall is supported on the end surface of the backing ring 13, and a press is used to apply pressure F to the workpiece to separate the workpiece from the movable part.

In this embodiment, demoulding is first carried out with cooling water. When the cooling water cannot separate the workpiece from the movable part, forced demoulding is used. In other embodiments of the present invention, it can also be directly carried out by forced demoulding. demoulding.

In this embodiment, the movable part filled with parts is placed on the backing ring for forced demoulding. In other embodiments of the present invention, the movable part filled with parts can also be placed on at least two separate On the block pad, the step surface of the movable part is supported on the pad, and the press is used to apply downward pressure to the workpiece, so that the workpiece moves downward and separates from the movable part.

Claims (8)

1. A shaft part extrusion molding die, comprising a punch and a die, characterized in that: the punch is a split structure, the center of the punch is provided with a central through hole extending along its axis, the punch The mold includes a fixed part and a movable part, the fixed part is provided with a fixed end for fixed connection with the punch fixed plate, and the fixed part and the movable part are respectively provided with connecting parts for mutual connection; the connecting part is One of the fixed part and the movable part is provided with a concave stop and the other is provided with a convex stop. 2. The extrusion molding die for shaft parts according to claim 1, characterized in that: the hole of the concave seam is a conical hole, and the convex column of the convex seam coincides with the concave seam Fitted frustoconical shape. 3. The extrusion molding die for shaft parts according to any one of claims 1-2, characterized in that it also includes an upper backing plate and an upper die seat, and the upper backing plate and the upper die seat are provided with The central through hole of the punch communicates with a part relief hole, and the center line of the part relief hole coincides with the center line of the central through hole of the punch. 4. The extrusion molding die for shaft parts according to claim 3, wherein a stepped surface is provided on the outer peripheral surface of the movable part, and the stepped surface is arranged away from the fixed end of the fixed part. 5 . The extrusion molding die for shaft parts according to claim 3 , wherein a diameter-reducing portion is provided on the outer peripheral surface of the movable part. 6 . 6. An extrusion molding method for extruding a shaft part using an extrusion molding die as claimed in claim 1, characterized in that: comprising the following steps, 1) Put the billet into the die of the extrusion molding die, the movable part is placed on the upper end surface of the billet in the die, and the press drives the fixed part down to push the movable part to extrude the billet; 2) After the extrusion is completed, the press drives the fixed part up and back, and the movable part and the parts filled in the movable part are ejected from the die together and demolded, or the press drives the fixed part up to the part from the fixed part. After the part comes out, the press drives the fixed part to move in parallel to the side staggered from the movable part, and the movable part and the parts filled in the movable part are ejected from the extrusion die and demolded. 7. The extrusion molding method according to claim 6, characterized in that: the demoulding in the above step 2) is to put the movable part and the workpiece filled in the movable part into the cooling water to separate the workpiece from the movable part . 8. The extrusion molding method according to claim 7, characterized in that: when cooling water cannot be used to separate the workpiece from the movable part, the movable part filled with the workpiece is placed on a backing ring with a certain height or at least On the two separate pads, the small end of the movable part extends into the inner hole of the pad ring or the gap between the pads, and the step surface set on the outer peripheral wall of the movable part is supported on the pad ring or the pad. The press applies pressure to the part to separate it from the moving parts.