JPS5927743A - Press-working method of eccentric rivet and its die - Google Patents

Abstract

PURPOSE:To mass-produce a rivet having a prescribed eccentric quantity, by forming a cut base material to an eccentric blank by a drawing die having an expanded hole part and a small hole part, and thereafter, executing preliminary forming and finish forming by a forming die. CONSTITUTION:A wire rod 13 is inserted into a cutting die 9 of a cutting mechanism 8, is cut to prescribed size by a cutter 11 and is transferred to the following stage. Subsequently, a cut base material 14 is inserted into a forming device 15 by a drawing pin 17 and an eccentric blank 19 is formed. In this case, a die hole 21 of a drawing die 4 is constituted of an expanded hole part and a small hole part, and also the expanded hole part and the small hole part are connected by a curved face. Accordingly, the cut base material 14 is inserted easily, also compressive force applied to the drawing die 4 is softened by the curved face, and the eccentric blank 19 can be formed. Thereafter, the eccentric blank 19 is transferred to a forming device 26, and is formed to an eccentric rivet 1 having a desired shape, by a preliminary forming punch and a finish punch 29.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a forging method and mold for an eccentric rivet that can be quickly and accurately obtained.

For example, as shown in Figure 1e, an eccentric rivet has a head (
2) and a shaft part (31. Moreover, Oi
The J marking head (2) and the l'liJ marking shaft part (3) are located opposite to each other. Conventionally, this type of biased rivet has been formed by cutting or die forging, which has caused many unavoidable processing problems. ＋i'iI When forming an eccentric rivet by cutting and forming it from one piece, expensive special tools and special jigs are required, and moreover, forming the uneven and U-shaft parts requires highly skilled techniques. was requested. As a result, many man-hours were required for machining, the manufacturing cost for the uneven and U-ribe was extremely high, and mass production was impossible.

Furthermore, in order to avoid the fatal drawbacks mentioned above, eccentric rivets are formed by die forging (even if the eccentric rivets are formed by die forging, it is possible to secure production volume compared to the cutting process described above). However, the surface roughness after the die forging process was poor and the occurrence of beams, etc. was unavoidable.As a result, the rivets that deviated after the die forging process required cutting as a finishing process, and a large amount of This was inconvenient for production.Also, because the axial center of the head may change due to the cutting process, it is not possible to achieve a predetermined deviation/b amount between the head and the details, and the shape is particularly complicated. In the case of eccentric rivets with small dimensions, the change in the axis of the head due to the cutting process is relatively large, and it is difficult to maintain a predetermined amount of eccentricity. The predetermined deviation/U amount could not be achieved.

The present invention aims to eliminate the above-mentioned drawbacks, and embodiments will be described below based on the drawings.

In FIGS. 2 and 3, the apparatus for cold heading of an eccentric rivet consists of a cutting mechanism 18), a drawing device (15), and a forming device (2).

The Ai+ cutting mechanism (8) consists of a cutting die 7 t91, a transfer device (1α), and a wire stripper (12+).A through hole of the wire rod (131) passes through the cutting die (9). .Also, the transfer device 0 (I is the cutter α1) is moved along the end face of the cutting die (9), and the cutting element IFA'
tl41 is transferred to the next process. Further, m
J mark wire material strike.

The pad 02+ is arranged corresponding to the cutting die (9) and is configured to be held in a predetermined position.

Further, the drawing device (n+J) (151 is composed of a drawing die (41), a drawing die holder (16l), a drawing bottle 07+, and a knockout bottle holder).The drawing die (41) is provided with a mold hole t2+1. mJ marking hole 2+1
is formed in a cohesive manner with the enlarged part 15), the throttle hole part (6), and the small hole part 17). The ampullae (5) is the cutting element 4'
: A' It consists of a first cylindrical hole portion 1 having a diameter (φD) slightly larger than the outer diameter of t141, and a throttle hole portion (a curved surface portion connected to 61) that is the first cylindrical hole portion 1251. The curved surface portion α) is composed of a large curved surface (LIRA.), ψB) and a small curved surface tr) connecting the large curved surface IRI, ψρ and the aperture hole portion; 61.

Moreover, the IiS expansion hole portion 15) and the throttle hole portion (6) have an eccentricity d between the axis of the expansion portion (5) and the axis of the throttle hole portion (6). There are several locations. Furthermore, the small hole portion (7) is composed of a tapered hole portion @ and a second cylindrical hole portion cl31.

The drawing die holder (16) is provided with a drawing die fitting hole 1201. Then, the drawing die (4) is press-fitted into the drawing die fitting hole (5).
The attached drawing die (4) is held by the drawing die holder. The squeeze bottle (
17l is arranged so as to move forward or backward to a predetermined position in the enlarged part (5) of the mold cavity f2+1 in the drawing die (4).

mJ knockout bottle (18) is a drawing die halter (
Mold hole f2 inserted through the drawing die (4) t from the rear of I6)
It is inserted so that it can move forward or backward in the +1 direction.

6 + J forming device
and knockout bin a81. A molding die fitting hole GZ is bored in the molding die holder (support). A molding die tray is press-fitted into the molding die fitting hole GZ, and the molding die tray is held by a molding die holder (support). A mold hole (211) corresponding to the circumferential surface of the IJ bed flll is bored in the molding die (211). ) and the small diameter hole (■) that holds the shaft (3).
341, and MiJ small diameter small diameter part T34
(The drawing hole (211) in the drawing die (4) is arranged with an offset amount (mo) of 61.
'll be recorded. In addition, mJ finish forming bunch c
] 11 has a shape suitable for forming the head (2) of the desired eccentric rivet (1), and is arranged so as to be movable forward and backward facing the forming die tray. mJ note, cut out bin (Igl is mold hole C from the back of the molding die holder!
It is inserted so that it can move forward and backward.

Using the apparatus configured as described above, the forging method for uneven, IJ and IJ according to the present invention is shown in FIGS.
Let me explain with a diagram.

"First step" (cutting step) FIG. 3 1ll shows the cutting process of line 1' 113).

After leaving the cutting machine groove (8 days), the wire rod (+31) is inserted into the through hole of the wire rod (13I) of the cutting die (9).
When the tip of the J-marked wire (131) reaches the wire rod stopper 021, the 1iil-marked wire (+3) is cut by the cutter 01)1. In addition, the line 011 (13) is cut in a constant direction because the wire rod bar αa is held at a predetermined position.

The cut material (14) thus cut is transferred to the front of the next process device by a transfer device (10).

"Second step" (drawing step) FIG. 3 1ll)) shows the drawing step of the cut material ++41 using the drawing die 14).

The above-mentioned drawing device C15 (in which the T transferred from the previous process) No. 11 cutting piece 1J (141 is the drawing bottle (17
+ is inserted into the first cylindrical hole part t251) of the enlarged part 15). Further, as the aperture bottle 071 advances mJ to a predetermined position in the ampullae (5), #+J cutting piece 1'
+141 is guided by the curved surface portion (241) of the enlarged portion (5) and is pushed out into the throttle hole portion (6) while lowering the resistance caused by burrs on the cut surface.

Furthermore, the cut material 1 that has been extruded into the aperture hole (6)
141 passes through the tapered hole part @ of the small hole part (7), and passes through the second cylindrical hole part C! 31 Reached t, knockout bin t18!
t is in contact with this. As a result, the cut material circle mI is regulated by the drawing bin (17) and the knockout bin fIal, and the eccentric blank (
19) is [1a]. After that, when the GiJ drawing bottle surface retreats, the mI eccentric blank +191 becomes the mold hole t2+
1), and is discharged from the output bin 081t, and then transferred to the next process while maintaining the predetermined position of the shaft portion.

[Third Step'' (Forming Step) FIG. 3 1l shows the preforming step of the eccentric blank (Igl), and FIG. In the above example, the U blank (+9) transferred from the O1I process is inserted from the mold hole 011 opening shaft part 13) by the preforming bunch 1, and as the preforming bunch moves forward, The shaft portion (3) is inserted into the small diameter hole portion 1341). At the same time, the above example U blank (19) is restricted by the preformed bunch ■ and the knockout bin 081,
The enlarged diameter portion (35) is preformed, and the preliminarily biased part (35) is preformed. Next, when the finish forming punch Gll moves forward to the forming surface, the preliminary bias (c > IJ mark) is regulated by the finish forming punch (31) and the 7th cutout I/bin (181), and the head Part (2) is finished molded. Thereafter, the desired eccentric rivet 11) is ejected from the mold cavity (2+1) by a knockout bin Li81.

As explained above, in the present invention, the cutting pieces 4 and 1 are once formed into an eccentric blank using a die, and then,
The eccentric blank is transferred to one molding die, and the desired shape of eccentric 1L>ribe, 1. Here, the offset/U position of the shaft part is set, and the offset/U position of the shaft part during the forming process becomes accurate, and the predetermined number/U amount of the head of the offset rivet and the shaft part is achieved. Ru.

In particular, if the shape is complex and the legal deviation is small,
Even when molding a rivet, there is an effect that a predetermined eccentricity between the head and the shaft can be achieved. In addition, after forging, there is no occurrence of burrs, and a high quality surface roughness can be obtained only by forging, so there is no need for cutting as a finishing process, which reduces the number of machining steps, and reduces unevenness. a) The production cost of IJ beds will be reduced and the production of nails will become possible.

In addition, the present invention has a drawing die with a drawing hole in the middle and a drawing hole.
It is formed from an enlarged part and a small hole part, and the enlarged part and the throttle hole part are connected by a curved surface part, and the throttle hole part and the small diameter hole part are connected by a tapered hole part. Therefore, when inserting the cut material into the enlarged portion, an eccentric blank is effectively formed without being blocked by the cut surface of the cut material or the like. In addition, as the drawing pin advances to the predetermined position of the enlarged part, the material to be cut inside the enlarged part can be riveted with the desired bias without causing any damage to the curved surface of the die hole or the tapered hole e, or any other damage. It has the effect of shaping.

[Brief explanation of drawings]

Fig. 1 is a front view of an eccentric rivet obtained from the present invention, Fig. 2 is a front view of a drawing die of the present invention, and Fig. 3 is a front view of an eccentric rivet obtained from the present invention.
(bl tcl (di is a sectional view of the main part showing each step of the present invention. 1 eccentric rivet, 2 head, 3 shaft part,
4 Drawing die, 5 Ampulla, 6
Throttle hole section, 7 Small hole section, 8 Cutting mechanism, 9
cutting die, 10 transfer device, 11 force,
Evening, 12 wire stripper, bar, 13 wire rod, 14 cutting material, 15 drawing device,
16 Aperture die holder, +7 aperture)) L”
18 ノ, cutout hole, 19 bias/U blank, 20 drawing tie fitting hole, 21 type
hole, 22 teno (hole part, 23 second cylindrical hole part, 24 curved surface part, 25 first cylindrical hole part,
26 Molding device, 27 Molding die, 2
8 Formed tie sleeve + χ round, 29 Preformed punch, 30 Preliminary biased IU1 nobetsu), 31 Double formed punch, 32 Formed tie fitting hole, 33 Large diameter hole, 34 Small diameter hole, 35 Expanded diameter part, Patent application Person Nitto Seiko Co., Ltd. Figure 1 6--~'5RBb";'

Claims (1)

[Claims] 1) The wire +131 is cut to a predetermined size t by a cutting machine net t81, and the cut material 041 is drawn by a drawing device f+51.
Transfer the cutting material to the front of the machine and squeeze the cut material round with the
Dainu 141's mold hole c! 1) Swollen hole part (5)
Insert the aperture pin Q71 one more time into the expanded hole (5).
Move the cut material circle forward to the specified position.
The knockout pin 081t is pushed out and brought into contact with the knockout pin 081t to form a biased blank (19) having an enlarged diameter portion 051 and a shaft portion (3).
), and then the eccentric blank (19+) is discharged from the mold hole (21) of the drawing die (4) with a knock-out bottle spool, and is also transferred to the front of the molding device (2).
n+1 E (Pre-formed punch with IN core blank)
Blank a biased toward mold hole t2+1 on the molding die surface from t
Insert from the shaft part +31 marked, and then insert the preformed punch (
By moving the shaft portion (3) forward, the shaft portion (3) is inserted into the mold cavity 2.
At the same time as inserting into the small diameter hole (341), the mold hole (inflated diameter part 65 in the head forming hole of 211) is preformed, and then the head (2) is formed into a head by a finishing punch. Final molding is performed to the desired shape corresponding to the molding hole, and then the desired biased rivet is inserted into the mold hole f21+ of the molding die Zn.
IJ is characterized by being ejected by a knockout pin (08). Heading processing method. 2) Drill a mold hole 121) in the drawing die (4), and connect the mold hole (21) to the expanding hole (5), the drawing hole (6), and the small hole (
7), and the expanded hole portion (5) is cut into a cutting material (14).
The first cylindrical hole portion 1251 has a diameter (φD) slightly larger than the outer diameter of 01j, and the aperture hole portion (
60 consecutive curved parts (up to), and ml
Examples of curved surfaces are large curved surfaces (G) A), (Rρ and the large curved surface ψA). It is composed of a small curved surface 1rl that connects the head ρ and the aperture hole (6), and the axis/U of the enlarged hole (5) and the axis/U of the aperture hole (6). The enlarged part (5) and the aperture hole part (6) are arranged so that they have a distance between them, and the small hole part (7) is arranged between the tapered hole part and the aperture hole part (7). A mold characterized in that it consists of two cylindrical hole parts.