KR20080083121A - Forging/coining method - Google Patents

Abstract

Methods for coining or forging powdered metal parts are disclosed. One example method uses a press including a first rod, a first ram surrounding the first rod, a die plate having a die cavity, a second rod opposite the first rod, and a second ram surrounding the second rod wherein the first rod and the second rod are dimensioned to fit within the inside diameter of the part. In the method, the part is positioned within the die cavity, one of the first rod and the second rod is located as a core rod within the inside diameter of the part, and at least one of the first ram and the second ram is moved toward the other of the first ram and the second ram such that both the first ram and the second ram contact and coin or forge the wall of the part.

Description

Forging or Coining Method {FORGING ／ COINING METHOD}

The present invention relates to a method of coining or forging powdered metal parts, in particular cylindrical parts.

Powder metal processing involves converting the powdered metal into a sintered product of a given density in a compaction process. The consolidation process uses various moving presses to distribute the powder into different sections of the die and, when compacted, has a relatively uniform density distribution through the part. This movement is essential for distributing the correct amount of material in the part. Coining processes that requalify sintered dimensions and in some cases make the parts more compact are now being carried out in unsophisticated presses. In order to change the mass flow in this coining process, complex tooling is required and in most cases such tooling is part specific.

Metal forming has been improved for many years by using CNC (computer numerically controlled) hydraulic presses. These presses have a wide range of adjustability to increase the precision of the formed parts and enable a wider range of complex geometrics to be achieved. Manufacturers are no longer limited by the limitations of mechanical presses. Examples of CNC presses are disclosed in US Pat. Nos. 5,435,216, 4,721,028, and 4,116,122. However, secondary presses for coining and forging when applied to powder metal processing have not kept pace with this improved technology. Powder metal processing is where CNC forging / coining presses are indispensable.

Accordingly, there is still a need for a method for coining and forging powder metal parts.

The present invention provides a method in which a CNC forging / coining press is used to integrate processing steps. The part may be cold worked to increase the overall density and at the same time burnishing the inner or outer profile. Simultaneous pressing from the lower and upper rams may be obtained in such a press. Another feature is the ability to change the pressing rate. Small features require slower speeds in reaching the desired density compared to larger features on the same part. Now, two features may be programmed so that both parts can reach a uniform density simultaneously with respect to the final density. Also, in forging, if the area is fully densified at the center of the cross section of the part, there will be less material movement at the bottom of the part and below the central dense area due to the top down direction of the forging process. will be. This limit can be reduced by balancing the pressing speed.

One feature of the new method is to balance the press transfer requirements for powder metal processing. In almost all cases of pressing operations, redistribution of material will be necessary. Pressing operations, ie forging / coining operations, require the same movement as is required for consolidation operations. The difference is that it is necessary to use the parts of the tooling to help other parts of the tooling, such as the injection core. Timing of a closed-loop system is important in ensuring that tooling is not compromised.

As mentioned above, current methods for forging and coining include relatively simple and inaccurate machines for producing powdered metal parts. The present invention relates to a press having programmable features that can allow various movements for forging and coining complex powdered metal parts. Presses with improved capabilities allow manufacturers to combine the processes currently performed on separate machines, such as burnishing, for example. The press also allows the user to use a program that changes the pressing speed for flanged parts so as to maintain a uniform flow of material during cold or hot work of the parts. The improved functionality can also reduce the complexity of the tooling required by adding programmable rotational movements for processing products having spiral features.

In the high temperature forging process, the present invention allows the user to program various movements to reduce the time the tool member is in contact with the hot component, thereby increasing core rod tool life. In addition, the tool member may be used in combination to assist injection of a form with high dead power, for example for large core rods. This may reduce the stress on the bolts currently being used to hold such tool members, further increasing the life of the tooling.

One advantage of the present invention is to reduce the complexity of the tooling device and to add them as features to the machine. Off-loading tooling complexity to press has three distinct advantages: (1) Changes in tooling work can be achieved by program coordination, rather than costly tooling improvements. And (2) material flow can be improved in a number of ways for a given set of tooling, and (3) the overall cost of tooling is reduced because no expensive specialized adapters are needed. to be. These factors can reduce the development time and costs associated with launching new products.

Accordingly, the present invention provides a coining or forging method having a wall having an inner diameter. In one form, the part is a powder metal part. This method comprises a first rod, a first ram surrounding the first rod, a die plate having a die cavity, a second rod facing the first rod, and a second ram surrounding the second rod. Wherein the first rod and the second rod are sized to fit within the inner diameter of the part. In this method, the part is disposed in a die cavity, one of the first rod and the second rod is positioned as a core rod inside the internal diameter of the part, and at least one of the first ram and the second ram is formed with the first ram and the first ram. By moving towards each other out of the two rams, both the first ram and the second ram contact and coin or forge the wall of the part. By pushing one of the first rod and the second rod acting as the core rod to the other of the first rod and the second rod, one of the first rod and the second rod acting as the core rod is part Is injected from the inner diameter of the.

In one version of the method, the first rod is the lower rod, the second rod is the upper rod, the first ram is the lower ram, and the second ram is the upper ram. The first and second rams are sized to be mounted within the die cavity, and both the first and second rams are moved toward each other such that both the first and second rams are in contact with the wall of the component or coined or Forging is carried out.

In another version of the method, the first rod is a lower rod, the second rod is an upper rod, the first ram is a stationary lower ram, and the second ram is an upper ram. The first ram and the second ram are sized to be mounted in the die cavity, and the second ram moves toward the first ram such that both the first ram and the second ram are in contact with the wall of the part and coined or forged. Conduct.

In another version of the method, the part has an outwardly extending flange on the end of the part. In this version of the method, the first rod is a lower rod, the second rod is an upper rod, the first ram is a stationary lower ram, and the second ram is an upper ram whose outer diameter is substantially equal to the outer diameter of the flange. . The first ram and the second ram are sized to be mounted in the die cavity, and the second ram moves toward the first ram such that both the first ram and the second ram are in contact with the wall of the part and coined or forged. Conduct.

In another version of the method, the part is a gear having an inner surface with a helical tooth. In this version of the method, the first rod is a core rod, the first rod is rotatable, and the first rod is helically rib sized to be slidingly complementary to the helical teeth of the gear. It has an outer surface with a rib. In this version of the method, the first rod vibrates within the gear prior to ejecting the first rod from the gear to rotationally burn the helical teeth of the gear.

In another version of the method, the part is a gear having an inner surface with helical teeth. In this version of the method, the first rod is a core rod, the first rod is rotatable, and the first rod has an outer surface with a spiral lip dimensioned to be slidably complementary to the helical teeth of the gear. Has The second rod has an outer surface with helical ribs dimensioned to be slidably complementary to the helical teeth of the gear. In this version of the method, the first rod vibrates within the gear prior to ejecting the first rod from the gear using the second rod to rotationally burn the helical teeth of the gear.

In another version of the method, the first ram and the second ram are dimensioned to be mounted in a die cavity, the method being configured to facilitate mass transfer and to provide burnishing of the outer surface of the part. Vibrating the first ram and the second ram when the second ram coines or forges the wall of the part. Preferably, the frequency of vibration is high.

In another version of the method, the part is a gear having an inner surface with a helical tooth, the first rod is a core rod, and the first rod is dimensioned to be slidably complementary to the helical tooth of the gear. It is an upper rotatable rod having an outer surface with a spiral lip. In this version of the method, the first rod, the second ram and the die table move towards the second ram so that the first ram and the second ram contact the walls of the part and coin and forge. The gear may comprise a second inner surface having a diameter less than the diameter of the inner surface with the helical teeth of the gear, such that the second rod may be rotated to the second inner surface of the gear to burnish the second inner surface of the gear. Sized to be slidably mounted within the surface.

In another version of the method, the part is a gear having an inner surface with helical teeth, the second rod is a core rod, and the second rod is dimensioned to be slidably complementary to the helical teeth of the gear. It is a lower rotatable rod having an outer surface with a spiral lip. This version of the method includes moving the first rod, the first ram and the die table toward the second ram such that both the first ram and the second ram contact the wall of the part for coining or forging. do.

In another version of the method, the method includes positioning the part in a die cavity. In a version of this method, the first rod is the upper rod, the second rod is the lower rod, the first ram is the upper ram, and the second ram is the lower ram. A version of this method includes extending the lower end of the first rod beyond the lower end of the first ram, positioning the lower end of the first rod within the inner diameter of the part, and placing the part in the die cavity by the first rod. Step, positioning the second rod as a core rod inside the inside diameter of the part, and the first ram and die table so that both the first ram and the second ram can be in contact with the wall of the part to effect coining or forging. Moving to the second ram. The part can be a gear having an inner surface with a helical tooth, and the second rod has a helical lip dimensioned to be slidably complementary to the helical tooth of the gear for rotational burnishing of the helical tooth. It may be a lower rotatable rod having an outer surface. In addition, the first rod may have an outer diameter less than the outer diameter of the second rod to avoid contact with the first rod having the helical teeth.

In another version of the method, the first rod is an upper rod, the second rod is a lower rod, the second rod has an outer diameter greater than the outer diameter of the first rod, the first ram is the upper ram, The second ram is the lower ram. A version of this method comprises the steps of: positioning the second rod as a core rod inside the inside diameter of the part, and allowing both the first and second rams to be in contact with the wall of the part to effect coining or forging. Moving the rod, the first ram and the die table towards the second ram. The part may be a gear having an inner surface with helical teeth, such that the second rod has a helical lip dimensioned to be slidably complementary to the helical teeth of the gear for rotating burnishing of the helical teeth. It may be a rotatable rod having an outer surface. This version of the method may further comprise moving the die plate downward to eject the coined or forged part.

In another version of the method, the method includes providing the press with means for varying the pressing speeds of the first and second rams to maintain a uniform mass flow during cold or hot work of the part. Means for changing the pressing speed may include a process of communicating with the hydraulic system to control the downward and upward movement of the first ram and the second ram.

In another version of the method, the method includes providing the press with means for varying the upward and downward movement rates of the first rod and the second rod to maintain a uniform mass flow during cold or hot operation. The means for varying the upward and downward movement speeds may comprise a process of communicating with the hydraulic system to control the downward and upward movement of the first rod and the second rod.

In another aspect, the present invention provides a method of coining or forging a part. In one embodiment, the part is a powdered metal part. The method utilizes a press comprising a core rod, a ram surrounding the core rod, and a die plate having a die cavity, the core rod being sized to be mounted inside the inner diameter of the part. The part is located inside the die cavity and the core rod is located within the inside diameter of the part. The ram is moved so that the ram can be coined or forged in contact with the part, the core rod being axially moved back and forth inside the part before removing the core rod from the part to burnish the inside diameter of the part. Vibrates along.

In one version of this method, the part is a gear having an inner surface with a helical tooth, the core rod is rotatable and the core rod is slidably complementary to the helical tooth of the gear to burnish the part. It has an outer surface with helical ribs dimensioned. In another version of the method, the press comprises a second core rod, the second core rod being rotatable and having an outer surface having a spiral lip dimensioned to be slidably complementary to the helical teeth of the gear. Has The second core rod is located inside the inside diameter of the part and oscillates back and forth along the axial direction inside the part prior to removing the second nose from the part to burnish the inside diameter of the part. The second rod will have an outer diameter smaller than the outer diameter of the core rod. The press may comprise a second ram such that the ram and the second ram can be moved toward each other to coin or forge the part.

In another version of the method, the lower end of the core rod extends beyond the lower end of the ram and is located within the inner diameter of the part. The part is then positioned inside the die cavity by the first rod. In another version of this method, the press comprises a second core rod, and the part comprises a second inner surface having a diameter smaller than the diameter of the inner surface of the part, and the second core rod is the second inner surface of the part. It is sized to slide mount in.

In another aspect, the present invention provides a method for coining or forging a part. In one embodiment, the part is a powdered metal part. This method uses a press comprising a die plate having a ram and a die cavity. In this way, the part is located within the die cavity, the ram is moved so that the ram contacts the part, and the ram is vibrated back and forth to coin or forge the part when the ram contacts the part.

In one version of this method, the press has a second ram. The second ram is moved so that the second ram is in contact with the part, and the second ram is oscillated back and forth to coin or forge the part when the second ram is in contact with the part. In one form, the ram and the second ram are sized to be mounted inside the die cavity. In another form, the part has a flange that extends outwardly at the end of the part, the second ram has an outer diameter that is substantially equal to the outer diameter of the flange, and both the ram and the second ram are in contact with the part and The second ram moves towards the ram to coin or forge. In another version of this method, the press has a core rod sized to fit inside the inner diameter of the part, which core rod is located within the inner diameter of the part prior to coining.

In another aspect, the present invention provides a method of coining or forging a part. In one embodiment, the part is a powdered metal part. This method uses a press comprising a die plate having a ram and a die cavity. The part is located in the die cavity and the ram is moved so that the ram contacts the part. The pressing speed of the ram is changed after the ram contacts the part and coines or forges the part. The means for varying the pressing speed may be a processor in communication with the hydraulic system to control the up and down movement of the ram.

The press may comprise a core rod sized to be mounted within the inner diameter of the part, and means for varying the up and down movement speed of the core rod. The core rod is located within the inner diameter of the part before or after placing the part in the die cavity, and the musk and downward motion speeds of the core are varied within the inner diameter of the part. The means for changing the up and down movement speed may be a processor in communication with the hydraulic cylinder to control the up and down movement of the core rod.

In another version of this method, the press has a second ram which opposes the core rod and has a second ram surrounding the second core rod, the core rod surrounding the ram, the core rod and the first rod. 2 The rod is sized to fit within the inner diameter of the part. The core rod and the second core rod are located inside the inner diameter of the part, and the ram and the second ram are moved toward each other so that both the ram and the second ram can coin or forge in contact with the part. The ram and the second ram are sized to be mounted within the die cavity. The core rod and the second core rod are also rotatable.

DETAILED DESCRIPTION Referring to the following detailed description, the accompanying drawings, and the appended claims, these features, aspects, and advantages of the present invention will be better understood.

In the following description of the drawings, similar reference numerals are given to similar elements between the drawings.

1A-1J show a press of performing a series of steps of a first exemplary embodiment of a method of coining or forging a part in accordance with the present invention, the axis of the lower rod, the lower ram, the upper rod, and the upper ram. A cross-sectional view taken along a vertical plane including a.

2a to 2i show a press, which carries out a series of steps of a second exemplary embodiment of a method of coining or forging a part according to the invention, with the axis of the lower rod, the lower ram, the upper rod, and the upper rod; Sectional view along the vertical plane including the ram.

3A-3F show a press of performing a series of steps of a third exemplary embodiment of a method of coining or forging a part in accordance with the present invention, the axis of the lower rod, the lower ram, the upper rod, and the upper ram. A cross-sectional view taken along a vertical plane including a.

4A-4F show a press of performing a series of steps of a fourth exemplary embodiment of a method of coining or forging a part in accordance with the present invention, the axis of the lower rod, the lower ram, the upper rod, and the upper ram. A cross-sectional view taken along a vertical plane including a.

5 shows a helical gear that may be forged using the method shown in FIGS. 3A-3F.

6 shows a helical gear that may be forged using the method shown in FIGS. 4A-4F.

7A-7D show a press of performing a series of steps of a fifth exemplary embodiment of a method of coining or forging a part in accordance with the present invention, the axis of the lower rod, the lower ram, the upper rod, and the upper ram. A cross-sectional view taken along a vertical plane including a.

1A-1J, a press performing a series of steps of a first exemplary embodiment of a method of coining or forging a part in accordance with the present invention is directed to an axis of the lower rod, lower ram, upper rod, And a cross section along a vertical plane including an upper ram. The press, shown generally at '10', shows the upper core rod 20, the upper ram 30, the die plate 40, the lower core rod 50, and the lower ram 60 having a common axis A. Include.

The upper core rod 20 is mounted to rotate on a piston (not shown) of a cylinder (not shown). The piston and cylinder are part of the upper core rod hydraulic system for controlling the downward and upward movement of the upper core rod 20. The upper core rod hydraulic system is controlled by a processor in communication with the upper core rod hydraulic system. The processor is a microprocessor, computer, microcomputer or other circuit capable of handling inputs and outputs for controlling the upper core rod hydraulic system in accordance with programmed routines. An exemplary control system for such a hydraulic cylinder is disclosed in US Pat. No. 4,721,028, which patent is incorporated herein with other patents cited herein.

The upper ram 30 is mounted on a piston (not shown) of a cylinder (not shown). The piston and cylinder are part of the upper ram hydraulic system for controlling the downward and upward movement of the upper ram 30. The upper ram hydraulic system is also controlled by the processor.

The die plate 40 is mounted on a piston (not shown) of a cylinder (not shown). The piston and cylinder are part of a die plate hydraulic system for controlling the downward and upward movement of die plate 40. The die plate hydraulic system is also controlled by the processor. The die plate 40 has a cylindrical die cavity 42.

The lower core rod 50 is mounted on the support shaft 52 for rotational movement. The support shaft 52 is mounted on a lower rod support 54 mounted on a piston (not shown) of a cylinder (not shown). The piston and cylinder are part of the lower core rod hydraulic system for controlling the downward and upward movement of the lower core rod 50. The lower core rod hydraulic system is controlled by the processor.

Lower ram 60 is mounted on support 62 mounted on a piston (not shown) of a cylinder (not shown). The piston and cylinder are part of the lower ram hydraulic system for controlling the downward and upward movement of the lower ram 60. The lower ram hydraulic system is also controlled by the processor.

Accordingly, the downward and upward movement of the upper core rod 20, the upper ram 30, the die plate 40, the lower core rod 50, and the lower ram 60 of the press 10 are programmed in the processor. It can work according to a routine. In this regard, commercially available CNC hydraulic presses may be suitably modified to operate according to the method of the present invention. A user initiated control input may be provided to the processor to set operating parameters of the hydraulic press. For example, the processor allows the user to select the up and down stroke speeds of each hydraulic cylinder, the position at which the stroke is reversed, or the tonnage at which the stroke is reversed. Other user control inputs may also be provided to the process depending on the particular features required in the press. For example, the rotational movement of the upper core rod 20 and the lower core rod 50 can be controlled by the process.

Still referring to FIGS. 1A-1J, a series of steps of a first exemplary embodiment of a method of coining or forging a part in accordance with the present invention is shown. In FIG. 1A, a hollow cylindrical part 70 is loaded into the die cavity 42 and a lower core rod 50 is inserted into the hollow interior of the part 70. The upper ram 30 is then moved into the die cavity 42 to close the die plate 40 as shown in FIG. 1B. The upper core rod 20 and the lower core rod 50 then contact as shown in FIGS. 1B and 1C. 1D-1H, the upper ram 30 and the lower ram 60 move in the same amount in opposite directions to consolidate the part 70, while the upper core rod 20 and the lower core rod 50. Moves downward at a faster speed and begins to burnish the inner surface 74 of the wall 72 of the component 70. The upper ram 30 and the lower ram 60 continue to move in the same amount to densify the part 70.

During the densification process, the upper core rod 20 and the lower core rod 50 cause upward and downward movement during the process until the part 70 reaches its final dimensions. This upward and downward movement of the upper core rod 20 and the lower core rod 50 serves to densify and burnish the inner surface of the part. In case the part 70 is a gear having a helical tooth on the inner surface, the outer surface of the upper core rod 20 has a helical lip dimensioned to be slidably complementary to the helical tooth of the gear. something to do. The outer surface of the lower core rod 50 may also have a spiral lip that is dimensioned to be slidably complementary to the helical teeth of the gear. Since the upper core rod 20 and the lower core rod 50 are mounted for rotational movement, the upper core rod 20 and the lower core rod 50 are rotated and cut off the helical teeth of the gear during the upward and downward movement. It plays a role. The upper ram 30 and the lower ram 60 also have less upward and downward high frequency movement capability during consolidation of the component 70 to assist in material movement during forging and to provide burnishing of the outer surface of the component 70. .

In FIG. 1I, the upper core rod 20 and the upper ram are moved to the home position, while the die plate 40 is moved downward for exposure of the finished component 70. After removal of the finished part 70, the press 10 is in the loading position shown in FIG. 1J so that another part 70 can be loaded into the die cavity 42 for processing.

2A-2I, cross-sectional views of a press 10 for performing a series of steps of a second exemplary embodiment of a method of coining or forging a part in accordance with the present invention. In FIG. 2A, a cylindrical part 70 is disposed adjacent to the die cavity 42. Referring to FIG. 2B, the upper core rod 20a is moved downward to line up with the cylindrical part 70 having the die cavity 42. It can be seen that the upper core rod 20a has a diameter smaller than the inner diameter of the lower core rod 50 and the component 70. Next, as shown in FIG. 2C, the upper core rod 20a is moved upward and the upper ram 30 is moved downward to capture the component 70. Then, as shown in FIG. 2D, the upper core rod 20 a and the upper ram 30 move downward to position the component 70 into the die cavity 42.

Referring to FIG. 2E, the lower core rod 50 is inserted into the part 70 and the upper core rod 20a, the upper ram 30, the die plate 40, and the lower ram 60 are moved downward. . No material movement occurs in the part 70. Then, as shown in FIG. 2F, the upper core rod 20 a, the upper ram 30, the die plate 40, and the lower core rod 50 are moved downward to forge the part. In FIG. 2G, the upper core rod 20a and the lower core rod 50 are moved downward to eject the lower core rod 50. Since the upper core rod 20a has a smaller diameter than the lower core rod 50, the upper core rod 20a does not contact the component 70 at the time of ejection of the lower core rod 50. This helps injection of the lower core rod 50. Subsequently, as shown in FIG. 2H, the upper core rod 20a and the upper ram 30 move up to a top-dead-center, and the die plate 40 moves downward to allow the component 70 to move. ) Is injected. In FIG. 2I, the die plate 40, the lower core rod 50, and the lower ram 60 move to their initial positions, thereby allowing placement and loading of other components 70. Accordingly, the method of FIGS. 2A-2I provides for placing parts in a die cavity. This method is particularly useful when placing out of round parts in a die cavity.

In Figures 3A-3F, a press is shown in cross section for carrying out a series of steps of a third exemplary embodiment of a method of coining or forging a part in accordance with the present invention. In particular, the press sequence of FIGS. 3A-3F may be used to forge the helical gear 70a as shown in FIG. 5. Referring to FIG. 5, gear 70a includes a cylindrical wall 72a having an inner surface 74a with helical teeth 75a and an outer surface 76a with helical teeth 77a. .

3A-3F, in FIG. 3A, the press 10 is in a position where the gear 70a is loaded into the die cavity 42. In FIG. 3B, the lower core rod 50 is inserted into the gear 70a and the upper core rod 20a, the upper ram 30, the die plate 40 and the lower ram 60 are the materials of the gear 70a. It moves downward without moving. In FIG. 3C, the upper core rod 20 a, the upper ram 30, the die plate 40 and the lower core rod 50 are moved downward to forge the gear 70 a. Lower core rod having an outer surface having a helical lip dimensioned to be slidably complementary to the helical teeth 75a of the gear 70a for burnishing the helical teeth 75a of the gear 70a. 50 may have. The lower core rod 50 is mounted for rotational movement so that the lower core rod 50 can rotate and burnish the helical teeth 75a of the gear 70a during the upward and downward movement. In FIG. 3D, the upper core rod 20a and the lower core rod 50 are moved downward to eject the lower core rod 50. Since the upper core rod 20a has a smaller diameter than the lower core rod 50, the upper core rod 20a does not contact the component 70 when the lower core rod 50 is injected. In FIG. 3E, the upper core rod 20a and the upper ram 30 rise to the top dead center-center and the die plate 40 moves downward to eject the gear 70a. Subsequently, as shown in FIG. 3F, the die plate 40, the lower core rod 50, and the lower ram 60 may be moved to their initial positions, thereby loading other components 70.

4A-4F, cross-sectional views are shown for carrying out a series of steps of a fourth exemplary embodiment of a method of coining or forging a part in accordance with the present invention. In particular, the press sequence of FIGS. 4A-4F may be used to forge the helical gear 70b as shown in FIG. 6. Referring to FIG. 6, the gear 70b includes a cylindrical wall 72b having an inner surface 74b having a helical tooth 75b and an outer surface 76b having a helical tooth 77b. . The lower end of the gear 70b has an inwardly facing flange 79 on the inner surface 74b. The flange 79 forms a reduced inner smooth inner surface on the end of the gear 70b.

4A-4F, in FIG. 4A, the press 10 is in the position where the gear 70b is loaded in the die cavity 42. In FIG. 4B, the upper core rod 20, the upper ram 30, and the lower core rod 50a move downward to insert the gear 70b into the die cavity 42. In order to burnish the helical teeth 75b of the gear 70b, the upper core rod 20 has a helical lip which is dimensioned to be slidably complementary to the helical teeth 75b of the gear 70b. It may have an outer surface having. The upper core rod 20 is rotatably mounted so that the upper core rod 20 can rotate and burnish the helical teeth 75b of the gear 70b during the upward and downward movement. The lower core rod 50a has a smaller diameter than the upper core rod 20 so that the lower core rod 50a can burnish the inner surface of the flange 79 on the end of the gear 70b. In FIG. 4C, the upper core rod 20, the upper ram 30, the die plate 40 and the lower core rod 50a are moved downward to forge the gear 70b. In FIG. 4D, the upper core rod 20 is moved upward to eject the lower core rod 50a. Instead, the lower core rod 50a can eject the upper core rod 20. In FIG. 4E, the upper core rod 20 and the upper ram 30 are moved to the top dead center-center, and the die plate 40 and the lower core rod 50a are moved downward to eject the gear 70b. In FIG. 4F, the die plate 40 and the lower core rod 50a are moved to their initial positions, thereby allowing the loading of another gear 70b.

7A and 7D are cross-sectional views illustrating a press that performs a series of steps of a fifth exemplary embodiment of a method of coining or forging a part in accordance with the present invention. In particular, the press sequence of FIGS. 7A and 7F is used to forge a part 70c including a cylindrical wall 70c having an outer surface 76c having an outwardly facing flange 81.

Referring to FIGS. 7A-7D, in FIG. 7A, the press 10 is in a position where the component 70c is loaded in the die cavity 42c of the die plate 40c. The die plate 40c has a ledge 44c located below the upper surface 46c of the die plate 40c. When the component 70c is loaded into the die plate 40c, the flange 81 facing out of the component 70c is placed on the ledge 44c. In FIG. 7B, the lower core rod 50 is inserted into the component 70c and the upper core rod 20a, the upper ram 30, the die plate 40c and the lower ram 60 are the materials of the component 70c. It moves downward in the absence of movement. It can be seen that the upper core rod 20a has a smaller diameter than the lower core rod 50. In FIG. 7C, the upper core rod 20a, the upper ram 30, the die plate 40c and the lower core rod 50 are moved downward to forge the part 70c. In order to burnish the inner surface of the gear 70b, the lower core rod 50 is dimensioned to be slidably complementary to the inner surface of the gear 70b. In FIG. 7D, the upper core rod 20a and the lower core rod 50 move downward to eject the lower core rod 50. The upper core rod 20a and the upper ram 30 will then move to top dead center-center, the die plate 40c will have a smaller diameter than the lower core rod 50, and the upper core rod 20a will When injecting the core rod 50, it is not in contact with the component 70c. Subsequently, the die plate 40c, the lower core rod 50 and the lower ram 60 are moved to their initial positions, thereby allowing loading of other components 70c as shown in FIG. 7A.

Although the present invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that the present invention may be practiced using embodiments other than those described above for non-limiting description. For example, the present invention is particularly useful for coining and / or forging powder metal parts, but the present invention may also be applied to wrought metal parts. Accordingly, the scope of the claims should not be limited to the embodiments included in the detailed description.

The present invention relates to a method for forging or coining powdered metal parts.

Claims (23)

As a method for coining or forging a part: Providing a press comprising a core rod, a ram surrounding the core rod, and a die plate having a die cavity, wherein the core rod is sized to fit inside the inner diameter of the part. Providing step; Positioning the part in a die cavity; Positioning the core rod within the inner diameter of the part; Moving the ram such that the ram contacts and coines or forges the part; And Vibrating the core rod within the component prior to removing the core rod from the component. Method for coining or forging a part. The method of claim 1, The part is a gear having an inner surface with a helical tooth, The core rod is rotatable, The core rod has an outer surface with helical ribs dimensioned to be slidably complementary to the helical teeth of the gear. Method for coining or forging a part. The method of claim 2, Providing a second core rod to the press, the second core rod having an outer surface having a spiral lip rotatable and dimensioned to be slidingly complementary to the helical teeth of the gear, Providing a second core rod to the press; Positioning the second core rod inside the inner diameter of the part; And Vibrating the second core rod within the component prior to removing the second core rod from the component. Method for coining or forging a part. The method of claim 1, Providing a second ram to the press; And Moving the ram and the second ram toward each other such that both the ram and the second ram contact and coin or forge the component. Method for coining or forging a part. The method of claim 1, Extending a lower end of the core rod beyond a lower end of the ram; Positioning the lower end of the core rod within the inner diameter of the component; And Positioning the part in a die cavity by a first rod; Method for coining or forging a part. The method of claim 1, Providing a second core rod to the press; Positioning the second core rod within the inner diameter of the part; And Vibrating the second core within the component prior to removing the second core rod from the component. Method for coining or forging a part. The method of claim 1, Providing a second core rod to the press, The second rod has an outer diameter smaller than the outer diameter of the core rod. Method for coining or forging a part. The method of claim 1, Providing a second core rod to the press, The component comprises a second inner surface having a diameter smaller than the diameter of the inner surface of the component, the second core rod being sized to be slidably mounted within the second inner surface of the component Method for coining or forging a part. The method of claim 1, The part is a powdered metal part Method for coining or forging a part. As a method for coining or forging a part: Providing a press comprising a die plate having a die cavity and a ram; Positioning the part within the die cavity; Moving the ram such that the ram contacts the component; And Vibrating the ram when the ram contacts the part to coin or forge the part. Method for coining or forging a part. The method of claim 10, Providing a second ram to the press; Moving the second ram such that the second ram contacts the component; And Vibrating the second ram when the second ram contacts the part to coin or forge the part. Method for coining or forging a part. The method of claim 11, The ram and the second ram are sized to fit within the die cavity. Method for coining or forging a part. The method of claim 10, Providing the press with a core rod sized to fit within an inner diameter of the part; And Positioning the core rod within the inner diameter of the component Method for coining or forging a part. The method of claim 10, Providing a second ram to the press, The component has a flange extending outwards on an end of the component, the second ram having an outer diameter substantially equal to the outer diameter of the flange, both the ram and the second ram contacting the component The second ram is moved towards the ram for coining or forging. Method for coining or forging a part. The method of claim 10, The part is a powdered metal part Method for coining or forging a part. As a method for coining or forging a part: Providing a press comprising a ram, a die plate having a die cavity, and means for varying the pressing speed of the ram; Positioning the part within the die cavity; Moving the ram such that the ram contacts the component; And Varying the pressing speed of the ram after the ram contacts the part to coin or forge the part. Method for coining or forging a part. The method of claim 16, The means for varying the pressing speed includes a processor in communication with a hydraulic system to control the downward and upward movement of the ram. Method for coining or forging a part. The method of claim 17, Providing the press with a core rod sized to fit within an inner diameter of the part; Providing the press with means for varying the downward and upward movement speeds of the core rod; Positioning a core rod within the inside diameter of the part before or after positioning the part in the die cavity; And Varying the rate of downward and upward movement of the core rod within the inner diameter of the part; Method for coining or forging a part. The method of claim 18, The means for varying the downward and upward movement speeds includes a processor in communication with a hydraulic system to control the downward and upward movement of the core rod. Method for coining or forging a part. The method of claim 19, Providing the press with a second core rod facing the core rod and a second ram surrounding the second core rod, the core rod surrounding the ram, the core rod and the second rod being the component Providing the press with a second core rod and a second ram sized to be mounted within an inner diameter of the press; Positioning the core rod and the second core rod within the inner diameter of the part; And Moving the ram and the second ram toward each other such that the ram and the second ram contact and coin or forge the wall of the component. Method for coining or forging a part. The method of claim 20, The ram and the second ram are sized to fit within the die cavity. Method for coining or forging a part. The method of claim 20, The core rod and the second core rod are rotatable Method for coining or forging a part. The method of claim 16, The part is a powdered metal part Method for coining or forging a part.

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