JPH03133535A - Extension tool of forming device - Google Patents

Abstract

PURPOSE: To prevent a flash by expanding a parting line face outside a longitudinal direction center axis of an expanding sleeve so that the expanding sleeves having even number segments of four or more are turned to a state a profile part outside the parting line is closed in expanding. CONSTITUTION: The expanding sleeve having a punch 1 and an expanding sleeve 2 is provided with a punch hole, into which a free end part of the punch is fitted in tight contact, and segments 8, 9 movable in a radial direction having an outside profile corresponding to an inner face shape of a work separated by parting lines. The parting lines 22 are formed by boundary faces of the neighboring segments. When the expanding sleeve 2 having even number segments 8, 9 of four or more is expanded, the parting line 22 faces are expanded outside a longitudinal direction center axis of the expanding sleeves 2 so that a profile part outside the parting lines 22 is turned to a closed state. By this method, a width of the parting lines between segments is not increased in expanding and a flash is not generated, a finish working is not required.

Description

Detailed description of the invention [Industrial field of application] The present invention relates to an expander (exp
anding tool).

[Prior Art] Extenders, such as those used in forging dies and having segments separated by radial dividing lines, are described in German Patent No. 3004024 and European Patent Application No.
It is known from the document No. 0013545. These dividing lines open to create a gap when the expansion sleeve is expanded.
During the forging process, plasti, resin or fluid material from the workpiece can flow into the gaps, leaving flash on the inner surface of the workpiece. This is undesirable and must be removed by finishing. This is the case, for example, when creating a flanche in a recess in an outer link member of a human-operated linkage of a motor vehicle that uses balls to transmit the driving force. Efforts have therefore been made to forge hollow workpieces without producing undesirable flash on the interior surface, thereby eliminating the need for finishing the workpiece to remove flash.

[Problem to be solved by the invention]

The object of the invention is to provide an improved dilator of the type mentioned at the outset, in which the width of the dividing line between the segments does not increase when the dilator sleeve is expanded.

[Means and operations for solving the problems] The present invention has solved the above problems by the configuration described in the characterizing part of the latter part of claim 1 of the claims. The even number of segments (at least 4) and the position of the plane of the partition line outside the central longitudinal axis of the expansion sleeve (i.e., not radially) to prevent the separation line from opening when expanding the expansion sleeve. This prevents material from the processed product from entering the forging process. The workpiece thus produced has no flash on its inner surface and therefore does not require finishing.

Preferably, each inner segment is arranged between two adjacent outer segments, and the plane of the partition line follows the outer contour of the expansion sleeve (
so that it converges towards the outer shell). Each inner segment thereby becomes a drive segment that is wedge-shaped in cross-section and can be moved radially outwardly by a punch to move an adjacent outer segment radially outwardly. It has been found to be advantageous to have an expansion sleeve with six segments whose partition lines form a triangular shape when the expansion sleeve is viewed in cross section.

For the radially outward movement of the inner segment, it is advantageous if the free end portion of the punch and/or the corresponding receiving hole of the expansion sleeve are conical.

Each segment may be rigid and generally radially movable, or elastically deformable and thereby radially movable.

In a further development of the invention, the segments may be attached to a punch and moved axially. Inside and (
or) the outer segment may be attached to the free end portion of the punch and/or to an adjacent portion of the punch.

Each segment is radially immovably attached to one end of the punch, but preferably capable of radial elastic deformation. The outer segments can be connected to each other at one end by a segment washer arranged at the free end portion of the punch and movable axially relative to the punch. This segment washer is movable in the axial direction in contact with a pin disposed at the tapered tip of the free end of the punch, or
It is fixed to a pin which is held movably in the axial direction within the axial hole of the punch. In the latter case, the pin can be biased towards the free end portion of the punch by a spring. To assist in elastic deformation, grooves may be provided on the inner interface of each outer segment directly adjacent the segment washer.

Advantageously, the inner segments are connected to each other at one end by a segment ring which is arranged for axial movement in a portion adjacent to the free end portion of the punch. An end of the outer segment opposite the segment ring may be supported on a segment washer.

To reduce friction between the inner and outer segments, the outer segments and segment washers may be provided with support surfaces that slope radially outwardly from about 2 DEG to 10 DEG.

〔Example〕

Hereinafter, the present invention will be specifically explained using cross sections.

FIG. 1 is an axial sectional view taken along line 1 in FIG. 2, showing a specific example of the present invention.

FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1.

FIG. 3 is a sectional view taken along the line III--III in FIG. 1.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 1.

The expansion device according to the present invention is used for manufacturing a hollow workpiece (not shown), and includes a punch (1) and an expansion sleeve (2).
). The punch (1) has a free end (hereinafter referred to as "punch lower end") (3), an intermediate cylindrical part (4) and a conical part (5) at the upper end. This conical part (5) fits into a punch holding plate (6) into which the punch (1) can be inserted replaceably from above, which also has attachment means (7), only the outline of which is shown in the figure. ) to the punch holder (not shown).

The expansion sleeve (2) is attached to the punch (1) at the lower punch end (3) and connects the three outer segments (8) and 3.
It has two inner segments (9). The inner segments (rings) alternate with the outer segments (8) and define the shape of the receiving hole (10) for the punch lower end (3). The receiving hole (10) is provided to receive the punch lower end (3), and like the punch lower end (3), it has a conical shape and gradually tapers downward.

The outer and inner segments) (8), (9) can be moved radially from the unexpanded position to the expanded position and back again by elastic deformation. In the expanded position, these segments define an outer contour that corresponds to the inner contour of the workpiece to be manufactured. In this example, the workpiece is an outer link member of a human-operated linkage for an automobile. Therefore, the outer contour of the expansion sleeve (2) is
It is spherical and has equally spaced outward protrusions (11) corresponding to the recesses on the inner surface of the outer link member described above. These recesses are for accommodating balls that transmit driving force.

In particular, as shown in FIG. 2, the cross-section of the outer segment (8) is generally arc-shaped and the cross-section of the inner segment (9) is generally wedge-shaped. The inner boundary surface (1) of the outer segment (8)
2) is opposite the outer boundary surface (13) of the inner segment (9), which converges towards the outer contour of the expansion sleeve.

The inner and outer boundary surfaces (12), (13) form a partition line (22) separating the outer segment (8) and the inner segment (9). These dividing lines are located outside the longitudinal central axis of the expansion sleeve (2), i.e.
It extends not in the radial direction but in the direction of the dividing line that cuts through the expansion sleeve (2), which has a substantially circular cross section, and has a triangular shape when the expansion sleeve (2) is viewed in cross section.

As mentioned above, the partition line (22) is connected to the outer segment (8
) and the inner segment (9), so that the inner segment (9) becomes the driving segment of the outer segment (8) during radial outward movement, i.e. when expanding the expansion sleeve (2). , move these outward. The return movement to the non-expanded position involves both segments (
This is done by the elastic restoring force generated within 8L (9).

During these radial movements of both segments (8), (9) in both directions, the inner and outer interfaces (12) (13) remain in contact with each other. That is, the expansion sleeve (2
) is in the expanded position, the partition line (22) remains closed and does not admit fluids or plastic workpiece materials.

The mutually opposing and radially extending inner boundary surfaces (14) of the inner segments (9) keep in contact with the inner boundary surfaces (14) of the outer segment (8) during the radial movement of the inner segments (9).
2) covered by. Thus, the expansion sleeve (2)
is widened and the inner boundary surface (14) of the inner segment (9)
This prevents workpiece material from penetrating into the gap (23) even when the gap (23) is at its widest.

Both segments I-(8) and (9) are respectively punched (
It is attached to the - end of 1) in such a way that it cannot move in the radial direction but can be elastically deformed in the radial direction. For this purpose, the outer segment (8) is fitted with a segment washer (15) at its lower end.
) are connected to each other. Segment washer (15)
is adapted to move axially on a pin (16) projecting from the tapered tip of the lower punch end (3) by means of a screw (17) located in a recess (24) in the outer shell of the expansion sleeve (2). Install. This type of installation uses a recess (24) in the lower end of the outer shell of the expansion sleeve (2), in this example undercutting the pre-forged outer link member of the human-actuated linkage at the upper free end. It can be used as long as it is transformed so that it can be used. If the entire inner surface of the workpiece is to be forged in a single operation, both segments (8), (9) are removed by a cover or otherwise so that there is no interruption in the outer shell of the expansion sleeve (2). )
You can choose whether to attach it to the punch (1).

For example, the segment ring of the inner segment (9) is supported against the annular protrusion of the punch holder, and the outer segment (8)
The expansion sleeve (2) may be attached to the intermediate cylindrical part (4) of the punch by attaching the segment ring of the inner segment (9) to the segment ring of the inner segment (9). In this case, the segment washer (15) can be omitted. an inner interface (12) directly adjacent to the segment washer (15) to facilitate elastic deformation of the outer segment (8);
A groove (18) is provided in each of the grooves.

The inner segment (9) has its upper end connected to the segment ring (
19). The segment ring (19) is connected to the punch intermediate cylindrical portion (4) in contact with the punch lower end portion (3).
It is arranged so that it can move in the axial direction. Inner segment (9
) becomes a support surface (2o) that is supported in contact with the upper support surface (21) of the segment washer (15).

These support surfaces (20), (21) have pins (1
6) Add a slope that slopes downward toward the outer contour of the expansion sleeve (2).

The operation of the expansion sleeve described above to form an undercut in a preforged outer link member of a human-actuated linkage is as follows.

The punch (1) with the expansion sleeve (2) in its unexpanded state is driven by a downward movement of the punch holder into an outer link member (not shown) arranged in a forging die (not shown). Segment washer (15) of expansion sleeve (2)
) comes into contact with the inner surface of the workpiece, and when the punch (1) is further lowered, the segment washer (15) rises in the axial direction together with the outer segment (8), and the inner segment (9) supporting it rises. move together.

In this case, the segment washer (15) on the pin (16)
The length H above or the depth T below the screw (17) of the recess (24) determines its momentum. segment ring (
The part of the inner segment (9) below the punch (
1) is held so that it does not move in the radial direction,
The conical surface of the lower end of the punch (3) forces it to be elastically deformed radially outward, ie, expanded. The downwardly inclined support surfaces (20), (21) assist this radial movement of the inner segment (9) relative to the segment washer (15).

As the inner segment (9) widens, its outer boundary surface (1
3) causes the respective adjacent outer segments (8) on the segment washers (15) to be pressed.

The segment washers (15) are held radially stationary on the pins (16), but each outer segment (8) is forced to be elastically deformed radially outwards, ie spread out. When both segments (8) and (9) abut against the inner surface of the pre-forged outer link member, the expansion sleeve (
The expansion movement of 2) is completed and the sleeve, together with the punch lower end (3), becomes a pressure support for the forces applied when deforming the upper free end of the pre-forged outer link member.

The dividing line (22) between the inner and outer segments 1 - (8), (9) remains closed at all times, i.e. even when the expansion sleeve (2) is expanded, so that fluids and plastic workpieces Material cannot penetrate into the partition lines or into the gaps (23) covered by the partition lines between the inner segments (9) during the forging process. In this way, flashing on the inner surface of the workpiece is reliably prevented and there is no need for further finishing of the workpiece.

As soon as the deformation process is finished, the punch is raised by the punch holder and the conical receiving hole (10
) from the conical surface. Therefore, both segments (8)
, (9) returns to the non-expanded position due to the elastic restoring force generated during expansion. The diameter of the expansion sleeve (2) is then reduced so that it can be drawn out of the fully forged outer link member.

It is suitable for all kinds of pressure forming tools for producing hollow workpieces using deformable materials.

[Brief explanation of the drawing]

Fig. 1 shows a specific example of the present invention. Fig. 2 is an axial sectional view taken along line 1, Fig. 2 is a sectional view taken along line
The figure is a sectional view along the line ■-■ in Figure 1, and Figure 4 is the TV in Figure 1.
It is a sectional view along the -IV line. It should be noted that the reference numerals in the drawings are shown in addition to the constituent elements corresponding to the illustrated embodiments in the claims, and therefore, duplicate descriptions will be omitted. (Effect of the invention〕

Claims (1)

[Claims] 1. A punch and an expansion sleeve, the expansion sleeve having a hole into which the free end of the punch fits closely, and an outer hole separated by a partition line and corresponding to the inner shape of the workpiece. a radially movable segment having a contour;
The dividing line has at least four even segments (8, 9) in the expander of the forming device for producing hollow workpieces formed by the interfaces of adjacent segments, and the expander sleeve (2) is expanded. characterized in that the surface of the partition line (22) extends outside the longitudinal central axis of the expansion sleeve such that when the partition line (22) is opened, a portion of the outer contour of the partition line (22) is in a closed state. Extender of the forming device. 2. An inner segment (9) is arranged between two adjacent outer segments (8), and the surfaces of the partition lines (22) on both sides of each inner segment (9) are arranged on the outer side of the expansion sleeve (2). converging towards a contour, each inner segment (9) being approximately wedge-shaped in cross-section and capable of being moved radially outwardly by said punch (1) to move each said outer segment (8) radially outwardly. 2. The dilator of claim 1, wherein the dilator is a drive segment. 3. The expansion sleeve (2) has six segments consisting of three outer segments (8) and three inner segments (9), and the plane of the partition line (22) cross-sections the expansion sleeve. The dilator according to claim 1, which has a triangular shape when viewed. 4. The free end (3) of said punch (1) and/or the receiving hole (10) of said expansion sleeve (2) are conically shaped for radially outward movement of said inner segment (9). The expansion tool according to claim 2 or 3, characterized in that: 5. Dilator according to claims 1 to 4, characterized in that each segment (8, 9) is rigid and generally radially movable. 6. The dilator according to claim 5, wherein each of the segments is held radially inward by a spring or the like. 7. The dilator according to claim 1, wherein each of the segments is elastically deformable and movable in the radial direction. 8. Dilator according to claims 1 to 7, characterized in that said segments (8, 9) are mounted for axial movement on said punch (1). 9. characterized in that said inner and/or outer segments (9, 8) are axially movably mounted on the free end (3) of said punch (1) and/or on its adjacent part (4); The expansion tool according to claim 8. 10. The segment (8, 9) is radially immovably attached to the punch (1) at one end, but is capable of elastic deformation in the radial direction. Expansion device. 11. The outer segment (8) is connected to the punch (1)
The segment washer (15
11. The dilator according to claim 10, wherein the dilator is connected to one another at one end by a pair of dilators) and is axially movable relative thereto. 12. The segment washer (15) is axially movably attached to a pin (16) arranged at the tapered tip of the free end (3) of the punch (1), or 12. The dilator according to claim 11, wherein the dilator is attached to a pin movably held in the axial direction in the hole of the dilator. 13. The dilator according to claim 12, wherein the pin axially movably held in the axial hole of the punch is biased toward the free end of the punch by a spring. 14. Each said outer segment (8) has its inner boundary surface (12) in direct contact with said segment washer (15).
Claims 11 to 1 characterized in that it has a groove (18).
3. The extension tool described in 3. 15. The inner segment (9) is connected at one end by a segment ring (19) disposed movably in the axial direction on the punch portion contacting the free end (3) of the punch (1). The dilator according to claims 2 to 14. 16, the segment ring of the inner segment (9) (
The end opposite to the segment washer (19) is attached to the segment washer (19).
5) Claims 11 to 15 characterized in that it is supported on
Extension device as described. 17. Claim 16, characterized in that the bearing surfaces (20, 21) of the inner segment (9) and the segment washer (15) have a slope that descends radially outward.
Extension device as described. 18. The dilator of claim 17, wherein the slope is approximately 2° to 10°.