JPH0829363B2 - Coining punch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a coining punch used when a coining process is performed on the edge of a workpiece on the burr side also for deburring.

(Prior Art) As the coining punch as described above, there is, for example, one used in a coining die for drilling a hole of a wheel disc of a tire wheel shown in FIG.

The coining punch indicated by 1 in the figure is supported by a cam driver 2 fixed to a lower base (not shown) of a lower mold so as to be slidable in a direction indicated by an arrow A in the figure, and
A punch holder 3 supported by a lower base so as to be vertically movable.
In the coining die, the coining punch 1 is lowered by the downward movement of the punch holder 3 which is pushed down as the upper die is lowered. , A wheel disk 5 as a work sandwiched between the punch holder 3 and the die holder 4 of the upper die by sliding in a direction obliquely downward with respect to the cam driver 2 and sliding in a direction in which the punch holder 3 advances and projects. The hole 5a of the die holder 4 and the coining punch 6 embedded in the die holder 4 in cooperation with each other
As shown in FIG. 4A, the edge on the side where the burr 5b generated by punching is protruding is crushed, and a chamfered portion 5c as shown in FIG. 4B is formed at the edge.

(Problems to be Solved by the Invention) However, in the above-mentioned conventional coining punch 1, it is caused by crushing the burr 5b in a fine gap between the slide surface 1a with respect to the punch holder 3 and the punch holder 2. There is a problem that dust may enter and cause a bite on the sliding surface 1a and the supporting surface on the punch holder 3 side, which may prevent the coining punch 1 from moving back and forth with respect to the punch holder 3.

The present invention provides a coining punch that advantageously solves the above-mentioned problems.

(Means for Solving the Problem) A coining punch of the present invention is slidably supported by a punch holder, and cooperates with a coining die based on a movement protruding from the punch holder to perform coining on a burr side edge of a work. A scrap stopper member is provided in the vicinity of the front end of the sliding surface for the punch holder, the scrap stopper member closely slidingly contacting the punch holder, and the scrap receiving groove is further provided on the sliding surface. May be provided.

(Operation) According to this coining punch, the scrap stopper member is brought into close sliding contact with the punch holder in the vicinity of the front end portion of the sliding surface, and the scrap generated by the crushing of the burr is generated between the sliding surface of the coining punch and the punch holder. Since it is prevented from entering the gap, it is possible to prevent the sliding surface of the punch or the supporting surface on the punch holder side from having little or no bite, and it is possible to maintain a smooth forward / backward movement of the coining punch with respect to the punch holder.

Further, in addition to the above dust-retaining member, if a dust-retaining groove is provided on the sliding surface of the coining punch, fine dust that could not be blocked by the dust-retaining member can be accommodated in the groove.
The smooth operation of the coining punch can be maintained more reliably.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a vertical cross-sectional view of a coining die for punching holes in a wheel disk of a tire wheel in a closed state using an embodiment of the coining punch of the present invention, and FIG. 2 is an opening diagram of the coining die. It is a vertical cross-sectional view showing a state,
Since this coining type has the same structure as the conventional type shown in FIG. 3 except for the coining punch, the same parts as those shown in FIG. 3 are denoted by the same reference numerals.

That is, in the figure, 2 is a cam driver, 3 is a punch holder, 4 is a die holder, 5 is a wheel disk as a work, 6 is a coining die, and 7 is a coining punch of this embodiment.

Here, the cam driver 2 is fixed to the lower holder 8 via a backing plate 9, and supports the coining punch 7 so as to be slidable in a direction indicated by an arrow A in the drawing.
The punch holder 3 is slidably in contact with the outer peripheral surface of the cam driver 2 and supported by the cam driver 2 so as to be able to move up and down. The punch holder 3 is constantly urged upward by a spring 10 via a pin 11 and is shown by a bolt 12 in FIG. The ascending end position is specified as the position.

Further, an annular slit 13 is provided around the punch holder so as to be lifted and lowered by a lower holder 8, and the stripper 13 is elastically attached upward through a push rod 14 by a cushion device (not shown). The rising limit position is specified at the position shown in FIG. 2 from the stroke of the cushion device.

A locating pin 15 is erected on the punch holder 3, and the locating pin 15 is fitted in a bolt hole of the wheel disc 5 to align the circumferential position of the hole 5a with the coining punch 7.

On the other hand, the die holder 4 is fixed to the upper holder 16, and the coining die 6 is embedded in the die holder 4 with a spacer 17 interposed therebetween.

Further, the die holder 4 includes a punch holder pressing pin.
18 and a stripper push-down pin 19 are erected downward, and an ejector rod 20 is supported so as to be able to move up and down.The ejector rod 20 is constantly urged in a protruding direction by a spring 21 and a bolt 22. Thus, the protrusion limit position is specified at the position shown in FIG.

The coining punch 7 here has a shaft portion 23 slidably fitted in the hole 3a of the punch holder 3,
The high-strength head 24 screwed to the shaft portion and the shaft portion 23
And a ring-shaped spacer 25 interposed between the head portion 24 and a chamfered portion 5c shown in FIG. 4 (b) in the hole 5a of the wheel disk 5 at the tip portion of the head portion 24. A frustoconical molding surface for forming is formed.

Further, an annular groove is formed around the head portion 24, and an O-ring 26 as a scrap stopper member is fitted in the annular groove. In addition, in this example, an O-ring 26 is provided around the shaft portion. Three annular residue receiving grooves 23a are formed.

In such a coining mold, the wheel disc 5 is placed on the stripper 13 in the mold open state shown in FIG. 2, and the upper holder 16, the die holder 4, and the coining die 6 are arranged.
And the upper holder made up of the lower holder 8, the cam driver 2,
When the die is lowered toward the lower die including the punch holder 3, the coining punch 7, the stripper 13 and the like, first, the ejector rod 20 comes into contact with the wheel disc 5 and pushes it against the stripper 13 and then retreats, and then the die holder 4 moves the wheel. Before contacting the disk 5, the stripper push-down pin 19 contacts the stripper 13 and lowers it. As the stripper 13 descends, the wheel disc 5 descends and fits into the punch holder 3, and the punch holder 3 and the die holder 4 form the wheel disc 5.
After pinching, the punch holder push-down pin 18 pushes down the punch holder 3.

By pushing down the punch holder 3, the coining punch 7, which also functions as a positive-moving cam, slides diagonally downward to the left in the figure with respect to the cam driver 2, and the punch holder 3
In contrast, as shown in FIG. 4 (a), the inner edge of the hole 5a of the wheel disk 5 from which the burr 5b is projected is moved forward as a result of sliding forward in a direction obliquely upward to the left in the figure. As shown in FIG. 1, the coining die 6 is crushed as a pad and a chamfered portion 5c as shown in FIG. 4 (b) is formed at the edge thereof.

Then, when the upper die is lifted, the stripper 13 lifts the wheel disk 5 from the punch holder 3 to the position shown in FIG. The protrusion prevents the wheel disc 5 from adhering to the die holder 4.

On the other hand, the coining punch 7 is also retracted to the position inside the punch holder 3 shown in FIG.
Slide against.

By the way, when the coining process is performed, a part of the burr is broken down into the inside of the wheel disc 5 due to the crushing of the burr and becomes a scrap, but here, the coining punch 7 is used.
Due to its elasticity, the O-ring 26 provided on the head portion 24 of the head is in close contact with the inner peripheral surface of the hole 3a of the punch holder 13 that supports the shaft portion 23 of the coining punch 7, so that most of the above residue is left. The O-ring 26 prevents the O-ring 26 from entering a minute gap between the outer peripheral surface of the shaft portion 23 and the inner peripheral surface of the hole 3a, and the fine dust that cannot be prevented by the O-ring 26 has entered the gap. However, in this example, the residue is caused by the forward / backward movement of the shaft portion 23 with respect to the punch holder 3 and thus the residue receiving groove.
It will be housed in 23a.

Therefore, according to the coining punch 7, it is possible to reliably prevent the occurrence of bite on the outer peripheral surface of the shaft portion 23 and the inner peripheral surface of the hole 3a due to the scraps generated by the coining process, so that the coining punch 7 can be smoothly moved with respect to the punch holder 3. The forward and backward movement can be maintained.

Although only one hole 5a is shown in the drawing in the figure, there are actually a plurality of holes 5a in the circumferential direction. Correspondingly, the coining punch 7 and the coining die 6 are also centered on the axis C shown. There are several in the circumferential direction,
At the same time, they perform the coining process.

Although explained based on the illustrated example above, the present invention is not limited to the above-mentioned example. For example, the coining punch may be a plate-shaped one used for crushing the outer edge of the work, and in such a case, The scrap retaining member may be a rigid member that is pressed by a spring or the like to come into close contact with the punch holder. Of course, the work may be something other than the above wheel disc.

(Effects of the Invention) Thus, according to the coining punch of the present invention, it is possible to prevent the sliding surface of the punch or the supporting surface on the punch holder side from being hardly or completely prevented, and to maintain the smooth movement of the coining punch with respect to the punch holder. can do.

If a scrap receiving groove is provided on the sliding surface of the coining punch in addition to the scrap stopper member, the smooth operation of the coining punch can be maintained more reliably.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a coining mold using an embodiment of the coining punch of the present invention in a mold closed state, FIG. 2 is a vertical cross-sectional view showing the coining mold in a mold open state, and FIG. Fig. 4 (a) is a sectional view showing the coining punch of Fig. 4, Fig. 4 (a) is a workpiece before coining, and Fig. 4 (b) is the same.
[Fig. 3] is a cross-sectional view showing a work after coining. 3 ... Punch holder, 5 ... Wheel disc 6 ... Coining die, 7 ... Coining punch 23a ... Waste receiving groove, 26 ... O-ring

Claims (2)

[Claims] 1. A coin holder is slidably supported by a punch holder (3) and cooperates with a coining die (6) on the basis of a movement protruding from the punch holder to perform coining on a burr side edge of a work (5). In the coining punch, a scraping stop member (26) that is in close sliding contact with the punch holder is provided in the vicinity of the front end of the sliding surface with respect to the punch holder. 2. The coining punch according to claim 1, wherein a scrap receiving groove (23a) is provided on the sliding surface.