JP2001219238A - Forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily change a forming punch and to improve the production efficiency. SOLUTION: This forming apparatus 10 to plastically form a work W comprises a base 12, the forming punch 14, and an annular ironing die 16 disposed above the forming punch 14. The forming punch 14 comprises a punch body 18 comprising a punch base 26 and a mandrel 28, six punch collets 20a-20f to be engaged with the mandrel 28 and separated from each other at the equal angular space, a metal sleeve 22 which is externally fitted to the punch body 18 and the punch collets 20a-20f, and a holder 24 to hold the metal sleeve 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forming apparatus for plastically working a workpiece into a predetermined shape by applying a pressing force to the workpiece with an ironing die.

[0002]

2. Description of the Related Art For example, a molding apparatus disclosed in Japanese Patent Publication No. 2729852 is known as a molding apparatus for plastically processing an outer ring of a constant velocity joint used for driving wheels of an automobile.

In this forming apparatus A, as shown in FIG. 7, a work D, for example, an outer ring for a ball joint is fitted on the tip of a punch body C constituting a forming punch B, and an ironing die E is lowered. By applying a pressing force to the work D, the inner peripheral surface of the work D is plastically worked into a predetermined shape. The punch body C is formed with a plurality of sliding contact surfaces F inclined at a predetermined angle in a direction approaching the axis toward the tip end thereof, and a punch collet G is opposed to each sliding contact surface F. It is constituted so that fitting sliding contact may be carried out. The leading end of the punch collet G has a shape corresponding to the work D so that the inner peripheral surface of the work D can be formed into a predetermined shape.

After the plastic working of the work D is completed, the lift plate I is raised under the action of the cylinder mechanism H, and each punch collet G engaged with the tip of the lift plate I is brought into contact with the sliding contact surface F. Along the axis direction.
The obliquely upward movement reduces the distance between the tips of the punch collets G as a whole, and as a result, the work D fitted on the tip of the punch body C separates from the punch body C. It becomes possible. That is, as the punch collet G slides, the distance between the front ends of the punch collets G facing each other is reduced, and a gap J is formed between the work D after plastic working and the punch collet G. (See FIG. 8). The work D after the plastic working is separated from the punch collet G using the gap J. The separated workpiece D is transported to a post-processing step by a transport device (not shown).

As a forming punch constituting a forming apparatus, a forming punch disclosed in Japanese Utility Model Publication No. 7-18448 is known.

[0008] As shown in FIG.
It has a main body portion M on which a female portion L is formed and a head portion O on which a male portion N is formed. In this shape, the male portion N fits into the female portion L, and a plurality of concave grooves P are formed on the inner peripheral surface of the female portion L, and the outer peripheral surface of the male portion N The concave groove P
Are formed in the circumferential direction, and a key member R is fitted so as to straddle the grooves P and Q. Further, the main body portion M is provided with a screw hole S in the radial direction facing the aligned grooves P and Q, and a push screw T is screwed into the screw hole S. By pressing R, the head O is connected to the main body M.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in connection with the above-mentioned conventional molding apparatus, and minimizes the occurrence of axial misalignment between an ironing die and a molding punch. By making the pressing force applied to the work by the ironing die substantially uniform, the precision of the plastic working of the work is improved, and after the plastic working of the work is completed, the work can be easily detached. It is an object of the present invention to provide a molding apparatus that performs the following.

[0008]

According to the present invention, there is provided an ironing die for applying a pressing force to a work, a forming punch having a sliding contact surface formed to be inclined with respect to an axis, In a molding apparatus including a plurality of slidable punch collets, the molding punch includes a punch body, a metal sleeve externally fitted to the punch body and the punch collet, and a holder for holding the metal sleeve. The punch body comprises a punch base and a mandrel formed separately from the punch base, and the punch collet is slidable on the sliding contact surface formed on the mandrel, and the punch collet An elastic member for pulling the collet toward the punch base side is provided (the invention of claim 1).

As a result, the occurrence of axial misalignment between the axis of the ironing die and the axis of the punch body is suppressed as much as possible, so that the pressing force is applied substantially uniformly to the workpiece by the ironing die. The plastic working of the work can be performed with high precision.

In the molding apparatus having the above-described configuration, it is preferable that the punch base and the mandrel are integrally connected by a fastening member. Accordingly, the length of the mandrel having the sliding contact surface on which the punch collet slides can be reduced as much as possible, and accordingly, the length of the punch collet can be reduced. In addition,
When manufacturing a mandrel that is a part to which a work is fitted, a durable and expensive material is used so as to withstand repeated plastic working of the work, which has been a factor of cost increase. However, according to the configuration of the present invention, the length of the mandrel and the punch collet can be made as short as possible, so that the material cost can be reduced, and the manufacturing cost of this type of molding apparatus itself can be reduced. Will lead to

Preferably, a rod is attached to each of the plurality of punch collets, the elastic member is wound around the rod, and the punch collet is constantly pulled toward the punch base by the elastic member. The invention of claim 3). Thus, after the workpiece is detached, the elasticity of the elastic member is used without waste, and the punch collet can be reliably and quickly returned to the original position. Moreover,
The punch base and the mandrel can be easily separated simply by removing the forming punch from the forming apparatus, separating the rod from the punch collet, and relaxing the fastening member. For this reason, for example, when plastically processing a work having a different shape, the mandrel and punch collet need to be replaced each time with a work corresponding to the shape of the work. Since the collet is configured to be detachable from the molding device,
The work of replacing the mandrel and the punch collet is facilitated, and the versatility of the molding apparatus is improved.

Furthermore, it is more preferable that the sliding contact surface, the elastic member and the rod are arranged at an equal angle to the axis of the punch body (the invention of claim 4).
That is, according to this configuration, the elastic member is contracted at the same time that the punch collet slides along the sliding contact surface formed on the mandrel, and immediately after the work separates from the punch collet, the elastic force is applied. Below, the punch collet is returned to the position before sliding. At this time, since the sliding contact surface, the elastic member, and the rod are inclined in parallel with each other, the punch collet can be smoothly moved up and down along the sliding contact surface without applying an extra load to the punch collet. It is possible to slide in the direction. Therefore, there is an advantage that it is not necessary to use a complicated mechanism such as a cylinder mechanism, the configuration of the molding apparatus itself is simplified, and the size and cost can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a molding apparatus according to the present invention will be described below in detail with reference to FIGS. Although the use of the molding apparatus is not limited, it is preferably used, for example, for manufacturing an outer ring of a constant velocity joint used for driving wheels of an automobile.

FIG. 1 shows a molding apparatus 10 according to the present embodiment.
As shown in FIG. 1, the base includes a base 12, a forming punch 14 provided on the base 12, and an annular ironing die 16 disposed above the forming punch 14.

As shown in FIGS. 1 and 2, the forming punch 14 has a punch body 18 and six punch collets 20a which are engaged with the punch body 18 and are separated from each other at an equal angle.
To 20f, the punch body 18 and the punch collet 20
a to 20f, and a holder 24 for locking the metal sleeve 22.

The punch body 18 is formed in a substantially truncated cone shape and includes a punch base 26 made of die steel and a mandrel 28 made of high-speed steel. A concave portion 30 is formed at the upper end of the punch base 26, and an annular mounting portion 32 for mounting the metal sleeve 22 is provided at the lower end thereof so as to protrude outward. A first fastening hole 34 is formed substantially at the center of the punch base 26 in the axial direction.
6 (see FIG. 1).

Further, the punch base 26 is formed with a plurality of holes 36a to 36f spaced apart at equal angles about the axis of the punch base 26. This hole 36a
To 36f are the small diameter portions 37a to 37f and the small diameter portions 37a to 37f.
Large diameter portions 39a to 39f formed to have a diameter larger than 37f. The axes of the holes 36a to 36f are inclined by a predetermined angle (axial oblique direction) in a direction approaching the axes of the punch base 26 and the mandrel 28.

The mandrel 28 has one end portion 38 formed substantially flat, and a convex portion 42 provided at the other end portion 40 and fitted into the concave portion 30. Six notch grooves 44a to 44 from 38 to the other end 40
f is provided. In this case, the notch grooves 44a and 44
d, 44b and 44e, and 44c and 44f are arranged symmetrically with respect to the axis of the mandrel 28. The projection 42 has a second fastening hole 46 facing the first fastening hole 34 (see FIG. 1).

The cross-sections of the cutout grooves 44a to 44f are substantially wedge-shaped, and the cutout grooves 44a to 44f are inclined by a predetermined angle in a direction approaching the axis of the mandrel 28 (axial oblique direction). Having sliding contact surfaces 48a to 48f,
A tapered surface 5 that is sharply inclined in the axial direction of the mandrel 28 from the sliding contact surfaces 48a to 48f to the one end 38.
0a to 50f extend (see FIGS. 1 and 2). The inclination angles of the sliding surfaces 48a to 48f with respect to the axis of the mandrel 28 are set to the same angles as the inclination angles of the axes of the holes 36a to 36f with respect to the axis of the punch base 26. Therefore, the holes 36a, 36b, 36
The axes of c, 36d, 36e, 36f and the sliding contact surface 48
a, 48b, 48c, 48d, 48e, and 48f are in parallel with each other.

The projections 52a to 52f sandwiched between the notch grooves 44a to 44f include straight portions 54a to 54f extending vertically upward from the contact surface with the punch base 26,
Formed portions 56a to 56f are formed from the straight portions 54a to 54f to the one end 38 (see FIGS. 1 and 2). The surfaces of the linear portions 54a to 54f are polished with high precision, while the forming portions 56a to 56f have a predetermined curved shape for processing the inner peripheral surface of the work W, as described later. .

The notch grooves 44a to 44f are respectively provided with punch collets 20a to 20f, respectively.
4f, punch collets 20a and 20d, 20b
And 20e, 20c and 20f are spaced apart from each other at equal angles, and are opposed to each other so as to be in sliding contact with each other.

The punch collets 20a to 20f are respectively provided with leg portions 58a to 5a which come into contact with the punch base 26.
8f, tapered portions 60a to 60f inclined by a predetermined angle from the ends of the legs 58a to 58f in a direction approaching the axis of the mandrel 28, and the tapered portions 60a to 60f.
From the flat portions 62a to 62f and the curved portions 64a continuous from the flat portions 62a to 62f to the tip surfaces 66a to 66f orthogonal to the axis of the mandrel 28.
６４64f. Screw holes 68a to 68f are formed in the bottom surfaces of the legs 58a to 58f (see FIGS. 1 and 3). The legs 58a to 58 formed on the punch collets 20a to 20f are similar to the linear portions 54a to 54f formed on the protrusions 52a to 52f.
The surface of f is polished with high precision.

A positioning pin 70 for centering the punch base 26 and the mandrel 28 is interposed between the inner peripheral surface of the concave portion 30 and the outer peripheral surface of the convex portion 42 (see FIG. 2). 1 and 3). The positioning pin 7
0, the punch base 26 and the mandrel 28
Are aligned. Then, the punch base 26 and the mandrel 28 are connected by the fastening bolts 72 screwed into the first fastening holes 34 and the second fastening holes 46.

In the holes 36a to 36f formed in the punch base 26, rods 74a to 74f are provided.
Penetrate, and the rods 74a to 74f are screw holes 68a formed in the bottom surfaces of the punch collets 20a to 20f.
Ｆ68f. The rods 74a to 74f have upper surfaces of the large diameter portions 39a to 39f of the holes 36a to 36f and flange portions 75a to 7 of the rods 74a to 74f.
5f are wound around coil springs 76a-76f.

As described above, the holes 36a to 36f
Of the punch base 26 and the shaft of the mandrel 28 (the punch body 18).
Of the rod 7) at the same angle with respect to the
Similarly, the coil springs 4a to 74f, the coil springs 76a to 76f, and the sliding surfaces 48a to 48f are also inclined in parallel (see FIGS. 1 and 2).

The punch base 26 and straight portions 54a-54 provided on the protruding portions 52a-52f of the mandrel 28, respectively.
54f and leg portions 58a to 58f provided on the punch collets 20a to 20f are formed with claw portions 22a at lower ends thereof to concentrically hold the punch body 18 and the punch collets 20a to 20f. The fitted annular metal sleeve 22 is fitted outside (see FIGS. 1 and 2). The claw portion 22a of the metal sleeve 22 is
6 is mounted on an annular mounting portion 32 formed therein, and its periphery is surrounded by the holder 24.

The holder 24 has a claw 78 around the lower end.
And a large circular opening 80 in the center thereof.
Are formed. The claw portion 78 is placed on the base 12, and the metal sleeve 22 and the punch body 18 are positioned in the opening 80. The top flat surface 82 of the holder 24 is provided with a plurality of bolt holes 84a to 84f arranged at equal intervals.
The holder 24 is screwed and fixed to the base 12 by passing bolts 86a to 86f through the base plate 12 (see FIG. 2).

The ironing die 16 is, as shown in FIG.
A first tapered portion 88 inclined at a predetermined angle in a direction approaching each other with respect to the axis of the ironing die 16, a straight portion 90 extending vertically upward from the first tapered portion 88, From the second tapered portion 9 inclined at a predetermined angle in a direction away from the axis of the ironing die 16.
And 2. Further, the ironing die 16 is connected to a driving mechanism (not shown). Under the operation of the driving mechanism, the ironing die 16 is vertically movable in the axial direction of the forming punch 14.

The molding apparatus 10 according to the present embodiment is basically configured as described above, and its operation and effects will be described below.

First, as shown in FIG. 4, a punch body 1 constituting a forming punch 14 by a transport mechanism (not shown).
The work W is fitted to the forming punch 14 so as to face one end 38 of the mandrel 28 of FIG. At this time, the inner peripheral surface of the work W is
Molding portions 56a to 56f formed in 52f and curved portions 64a to 64 formed in punch collets 20a to 20f
It is roughened in advance so as to fit with f.

Next, as shown in FIG. 5, under the action of a driving mechanism (not shown), the ironing dies 16
While applying a pressing force to the outer peripheral surface of the punch body 18 in the axial direction of the punch body 18. Thereby, the protrusion 52a
Forming portions 56a to 56f provided in the punch collets 20a to 20f and the curved portions 64a provided in the punch collets 20a to 20f.
The work W is sandwiched between the work W and the ironing die 16, and the inner peripheral surface of the work W is plastically worked into a predetermined shape by the forming portions 56a to 56f. At this time, the workpiece W includes the curved portions 64a to 64a.
An undercut portion W1 is formed so as to match the shape of 4f.

After the plastic working of the work W is completed, the work W is vertically displaced under the action of a transfer mechanism (not shown). At this time, the work W is engaged with the punch collets 20a to 20f by the undercut portion W1 formed on the work W,
Following the work W, the punch collets 20a to 20f slide upward on the sliding contact surfaces 48a to 48f integrally with the work W.

As the punch collets 20a to 20f slide on the sliding surfaces 48a to 48f, the rods 74a to 74f penetrating through the holes 36a to 36f formed in the punch base 26 are formed by the rods 74a to 74f. It moves upward in 36a-36f. Accordingly, the holes 36a to 36
f and the upper surfaces of the large diameter portions 39a to 39f and the rods 74a to 74f.
The coil springs 76a to 76f seated on the 74f flange portions 75a to 75f contract to increase the resilience (see FIG. 6).

The sliding contact surfaces 48a to 48f are formed to be inclined by a predetermined angle in a direction approaching the axis of the mandrel 28, so that the punch collets 20a to 48f are formed.
As 20f slides up the sliding contact surfaces 48a to 48f, the distance between the front ends of the opposed punch collets 20a to 20f is reduced as a whole. As a result, when the work W is displaced by a predetermined distance, a gap 94 is formed between the work W and the punch collets 20a to 20f (see FIG. 6). The work W can be easily separated from the punch collets 20a to 20f using the gap 94.

The separated workpiece W is transported to the next step by a transport mechanism (not shown), and is subjected to predetermined post-processing.

The work W is transferred to the punch collets 20a to 20f.
From the punch collets 20a-2
0f slides downward along the sliding contact surfaces 48a to 48f under the action of the elastic force of the coil springs 76a to 76f.
This repulsive force is applied to the mandrel 2 forming the forming punch 14.
8 is applied to the punch collets 20a to 20f until the work W returns to the position before the work W was fitted.

In the present embodiment, the punch base 26, the straight portions 54a to 54f provided on the protrusions 52a to 52f of the mandrel 28, and the legs 58a to 58f provided on the punch collets 20a to 20f. The metal sleeve 22 fits around the punch base 2 and
6 between the inner peripheral surface of the concave portion 30 formed in the mandrel 6 and the outer peripheral surface of the convex portion 42 formed in the mandrel 28.
Is interposed. Thereby, the punch collet 20
a to 20f are reliably maintained concentric with the punch body 18. Moreover, since the surfaces of the linear portions 54a to 54f and the legs 58a to 58f are polished with high precision as described above, the punch body 18, the punch collets 20a to 20f, and the metal sleeve 22 are polished.
Can be contacted without having a gap between them.

Accordingly, the punch collets 20a to 20
The occurrence of misalignment between the punch body 18 including the mandrel 28 fitted with f and the ironing die 16 can be suppressed as much as possible. Thereby, when the pressing force is applied to the work W by the ironing die 16,
The pressing force can be applied to the work W substantially uniformly,
Therefore, the workpiece W can be plastically processed with high accuracy. As a result, the work in the post-processing step for the work W is facilitated.

Further, as described above, the punch body 18 includes the punch base 26 and the mandrel 28. In this case, the mandrel 28, which is a portion where the work W is fitted, is made of a durable and expensive material so as to withstand repeated plastic working of the work W. According to this, the manufacturing cost of the mandrel 28 can be reduced by shortening the length of the mandrel 28 as much as possible, and the molding device 10
This leads to lower manufacturing costs of the device itself.

Further, the forming punch 14 is removed from the base 12 by loosening the bolts 86a to 86f, and the punch body 18 is removed.
The punch base 26 and the mandrel 28 can be easily separated by detaching the holder 24 and the metal sleeve 22 from each other, separating the rods 74a to 74f from the punch collets 20a to 20f and relaxing the fastening bolt 72. . For example, when a workpiece W having a different shape is subjected to plastic working, the punch collet is replaced each time in accordance with the shape of the workpiece W.
It is necessary to replace both 0a to 20f and the mandrel 28. However, in the present embodiment, since the punch collets 20a to 20f are configured to be detachable from the molding device 10, the punch collets 20a to 20f can be easily replaced. For this reason, it becomes possible to easily cope with the forming processing of various workpieces.
The versatility of the molding device 10 is improved.

[0041]

As described above, according to the present invention,
Since the occurrence of axial misalignment between the ironing die and the forming punch is suppressed as much as possible, and the pressing force applied to the work by the ironing die can be substantially uniformly applied, the plasticity of the work is reduced. Processing accuracy can be improved. Moreover, after the plastic working of the work is completed, the work can be easily detached. Therefore, since there is no need to use a complicated mechanism such as a cylinder mechanism for sliding the punch collet, a unique effect is obtained in that the configuration of the molding apparatus itself can be simplified, and the size and cost can be reduced. . Further, since the resilient force of the coil spring is used to return the punch collet to its original position, the molding process itself is sped up, and since the structure is a single cylinder, a molding device can be manufactured at low cost. Furthermore, the versatility of this type of molding apparatus is improved, for example, it is possible to cope with various types of work by simply replacing the punch collet with a work that matches the shape of a new work.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a molding apparatus according to the present embodiment.

FIG. 2 is a partial cross-sectional perspective view showing a forming punch in the present embodiment.

FIG. 3 is a sectional view taken along line III-III of the forming punch of FIG.

FIG. 4 is an explanatory view showing a state where a work is fitted on the forming punch.

FIG. 5 is an explanatory diagram showing a state immediately after processing the work.

FIG. 6 is an explanatory view showing a state immediately before the work is released from the forming punch.

FIG. 7 is an explanatory view showing a state before a workpiece is processed by a conventional molding apparatus.

FIG. 8 is an explanatory view showing a state immediately before the work is detached from the molding apparatus.

FIG. 9 is an explanatory view showing a conventional forming punch.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Molding apparatus 14 ... Molding punch 16 ... Ironing die 18 ... Punch body 20a-20f ... Punch collet 22 ... Metal sleeve 24 ... Holder 26 ... Punch base 28 ... Mandrel 48a-48f ...
Sliding contact surface 72: fastening bolts 74a to 74f ...
Rods 76a to 76f: Coil spring W: Work W1: Undercut

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takeshi Tatsumi 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. F-term (reference) 4E087 CA27 CA46 EC19 EC52 HA22

Claims (4)

[Claims] An ironing die for applying pressure to a workpiece, a forming punch having a sliding contact surface formed to be inclined with respect to an axis, and a plurality of punch collets slidable on the sliding contact surface. In the molding apparatus, the molding punch comprises: a punch body; a metal sleeve externally fitted to the punch body and the punch collet; and a holder for holding the metal sleeve. A punch base and a mandrel formed separately from the punch base, wherein the punch collet is slidable on the sliding contact surface formed on the mandrel and moves the punch collet toward the punch base. A molding device having an elastic member for stretching. 2. The molding apparatus according to claim 1, wherein said punch base and said mandrel are integrally connected by a fastening member. 3. The molding apparatus according to claim 1, wherein a rod is attached to each of the plurality of punch collets, and the elastic member is wound around the rod, and the punch collet is formed by the elastic member. A forming apparatus characterized by being constantly pulled toward the punch base. 4. A molding apparatus according to claim 3, wherein said sliding contact surface, said elastic member and said rod are arranged at an equal angle to the axis of said punch body. apparatus.