JPH03268830A - Manufacture of nut blank material for bearing fastening nut - Google Patents

Abstract

PURPOSE:To shorten the working time of the fastening nut for bearing by executing the working of plate thickness machining, the center hole punching, and the punching of accuracy and then making the material to the semiprocessed goods of the nut blank material on the progressive press process. CONSTITUTION:On the progressive feeding process, the plate thickness of the material M is controlled to the prescribed dimension with the plate thickness making punch 1 and the volumetric variance of semiprocessed goods of the nut blank material M' after punch is eliminated. Next, the semiprocessed goods is subjected to closed forging with the forging female die 32, 42 and is made to the finished goods of nut blank material M'. And on the progressive feeding process, the central hole of the nut blank material 50 is punched with the central hole punch 2, the outer shape part of the nut blank material 50 is, at first, half blanking is executed with the outer shape halt- punch 4 and then is accurately punched with the punch 6 of accurately punching. Accordingly, the yield of the material is improved, the large load is not generated at the punch and the female die of each process by dividing respectively the punching processes, the working is executed with the usual press machine and the service life of the progressive die is prolonged.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method of manufacturing a nut material for a bearing tightening nut.

``Prior art and its problems'' Nuts for tightening bearings are manufactured by cutting a material from a bar, milling the outer periphery of the material, and finishing it with a lathe or single-purpose machine. However, since these processes are all cutting processes, it was not possible to expect a significant reduction in processing time.

"Problems to be Solved by the Invention" The present invention has been made in view of the above-mentioned problems. The purpose of the present invention is to provide a method for manufacturing Nando materials.

``Means for Solving #, H'' In order to solve the above problems, according to the present invention, a plate thickness determining process is performed in which at least the part of the plate-shaped material that will become the nut material is pressed to make the plate thickness equal to a predetermined dimension. The material is made into a semi-finished nut material through a center hole punching process to punch out a center hole in the nut material, a half-outline punching process to half-cut the outer part of the nut material, and a precision punching process to separate the nut material from the material. Provided is a method for manufacturing a nut material for tightening nuts for bearings, which comprises performing a progressive pressing step and a closed forging step in which the semi-finished product is sized by closed forging to produce a finished nut material. .

``Function'' When tightening nuts for bearings, high accuracy is required in the thickness dimension, and the tolerance of the thickness dimension is stricter than the tolerance of material plate thickness according to the JIS standard.

According to the above configuration of the present invention, in the progressive pressing step,
By performing plate thickness determining processing to make the plate thickness of the material uniform to a predetermined dimension, variations in the volume of the semi-finished nut material after punching are eliminated. Next, the semi-finished product is sized by closed forging to produce a finished nut material. In closed forging,
If there are variations in the volume of the material, there will be variations in the thickness of the product, but since the volume of the semi-finished product of the nut material has been eliminated, there will be no variations in the thickness during closed forging, and the cutting process will be easy. Can be omitted.

Furthermore, in the progressive pressing process, instead of sequentially cutting out the outer shape of the nut material, the outer shape of the nut material is first half punched and then precision punched. For this reason, the yield of materials is improved, and by dividing the processing of the external shape into half punching and precision punching, there is no large load on the punch and female die in each process, which can be done using a normal press machine. processing, and prolongs the life of the progressive press die.

Then, in the subsequent process, a thread is threaded into the center hole of the nut material obtained in this manner, and the nut is tightened for the bearing as a completed product.

"Example" Next, the method of the present invention will be described as the structure and operation of an apparatus for carrying out the method.

First, the progressive press die will be explained with reference to Section 1 and FIG. 2. FIG. 1 is a sectional view of a progressive press die, and FIG. 2 is a plan view of its lower die. As shown in Fig. 2, this progressive press mold is composed of seven processing stages P1 to P7 and four idle stages 11 to r4 that follow processing stages P4 to P7, respectively. In Figure 1, idle stages 13 to I4 are omitted and the machining stage p is mainly shown.
1 to P7 will be shown.

As shown in FIG. 1, a material thickness determining punch which presses the material M with the upper surface of the female die 14 to make the thickness of the material M uniform is attached to the outermost row of the punch holder 9. , center hole bunch 2. Upper C chamfer punch 3. Outline half punch 4. Outer circumference C surface pressing punch 5. A precision punch 6 and a punch 7 are arranged in sequence. A shim (not shown) is interposed between the upper end of the material thickness determining punch 1 and the punch plate 1o. The thickness of the shim is appropriately selected in order to calculate the variation in the thickness of the material M from the final process and adjust the thickness of the material M to the optimum thickness. The center hole punch 2 is a punch for punching the center hole 51 of the nut material 50 shown in FIGS. This is a punch for forming the chamfered portion 56A.The outer half punch 4 is a punch for half punching the outer shape portion 53 including the 4111 dips 52 of the nut material 50, and its tip is inserted into the female die 14. The diameter is about 0.3 to 0.5 m/- larger than the outer diameter of the hole 4A, and the tip is rounded with a radius of about 01 to Ow/+m.In the progressive type, each stage P1 ~The height of the processing area of P7 is the same, and the half-outline processing is performed at the bottom dead center of the slide of the press machine, so for the purpose of adjusting the cutout length, the north end surface of the half-outline punch 4 and the punch A shim (not shown) is interposed between the plate 10 and the plate 10. The thickness of the shim is appropriately selected depending on the half-blank length. This is a punch for pressing the nut material 50 against the outer periphery C chamfer push-up counter 22 (described later) to form a C chamfer portion 54 on the lower edge side of the outer periphery. The M-dense punch 6 is formed with a female die portion 6A, and has an inner diameter counter 6B.
is inserted. A knockout bin 28 is in contact with the upper end of the inner diameter counter 6B. An upper pressure device (not shown) is provided above the knockout bin 28 . The punch-off punch 7 is a punch for punching out the semi-finished product of the punched nut material 50 downward.

The punch holder 9 also has two pilot hole punches (not shown) for punching pilot holes 61 shown in FIG. Twenty pilot punches (not shown) are provided for this purpose.

These punches 1 to 7 are provided with eight chamfers and a tapered portion at their tips to make the cut surface of the nut material 50 smooth. The punch holder 9 is the punch plate 1
0 and an upper die set 11 to a slide of a press machine (not shown). Note that the press machine is equipped with an automatic material feeding device. A stripper 8 is attached below the punch plate 10 via an elastic member (not shown).

The female die 14 is provided with a lower C chamfering punch 19 at a position opposite to the upper C chamfering punch 3, and a half punching push-up counter 21. Outer circumference C chamfer push-up counter 22
．． Workpiece push-up counters 26 are sequentially arranged, and a workpiece removal pit hole 7A is further bored. The lower C-chamfering punch 19 is a punch for forming a C-chamfering portion 56B on the lower edge side of the punched center hole 51. A push-up bin 20 is connected to the lower end of the half-pull push-up counter 21. The entrance of the half-blanking hole 4A on the upper surface of the female die 14, into which the half-blanking push-up counter 21 is inserted, has an eight-chamfered portion and an 8-chamfered portion to prevent breakage or cracks from occurring in the outer portion 53 of the nut material 50 during half-blanking. A tapered portion is formed. The outer periphery C-chamfer push-up counter 22 is a counter for forming a C-chamfer 54 on the lower edge side of the outer periphery of the nut material 50 whose outer shape 53 has been half punched out. A convex portion 22A having a slightly smaller diameter than the center hole 51 is provided at the center of the upper surface of the outer circumference C-chamfered push-up counter 22. A push-up bin 24 is connected to the F end of the outer circumference C-chamfered push-up counter 22. The workpiece push-up counter 26 is a counter for pushing up the nut material 50 whose outer portion 53 has been completely cut and trapping it in the material M. The workpiece push-up counter 26 is formed longer than the half-blanket push-up counter 21 and the outer circumferential C surface push-up counter 22. Work pushing counter 26
An inner diameter punch 27 is inserted through the hole. Inner diameter bunch 27
A plurality of push-up bins 25 are connected to the lower end of. Female die 14 through which the workpiece push-up counter 26 is inserted
The entrance of the cut hole 6C on the upper surface is made so that the clearance with the precision punch 6 is 1% or less of the thickness of the material M, and 8 chamfered parts and a tapered part are formed, and below that, a straight part and a relief part are formed. The parts are formed sequentially. At the bottom of the push-up bins 20, 24, 25, there is a lower pressure device 2.
3 is provided. A diagonal hole 15A is bored in the counter holder 15 below the workpiece removal hole 7A.

Further, the female die 14 is provided with 14 lift turbines 13 having an annular groove 13A under the neck.
is forced upward by an elastic member 13B such as a coil spring. The female die 14 is placed in a counter holder 15. It is attached to a bolster of a press machine (not shown) via a counter plate 16 and a lower die set 17.

Next, the first closed forging die will be explained with reference to FIG. This first closed forging die is used to form eight chamfers 55 on the back side of the C-chamfered part 54 on the outer periphery of the nut material 50, and to correct the C-chamfered parts 56A and 56B at both ends of the center hole 51. It is something. First forged punch 3
The center hole 3 of the first forged female die 32 is located below the center of the die.
2A, the convex portion 31A that fits into the nut material 50, and the center hole 5 of the nut material 50.
A C-chamfer correction section 31B for correcting the C-chamfer 56B of No. 1, and an outer circumference C-turn contact section 31C that comes into contact with the C-chamfer 54 on the outer periphery of the nut material 50 are formed. A slightly flat portion 31D is formed further outward of the outer circumferential C-turn contact portion 31C to prevent chipping or cracking.

The first female forging die 32 has a center hole 32A and an annular recess 32B on which the nut material 50 is placed.

The annular recess 32B includes an 8-chamfer forming part 32C for forming an 8-chamfer 55 on the outer periphery of the nut material 50, and a C-chamfer correction part 32D for correcting the C-chamfer 56A of the center hole 51 of the nut material 50. It is formed. Further, a push-up pin 33 is inserted below the annular recess 32B of the female forging die 32 so as to be vertically movable. Push-up bottle 33
A pressure device 34 is provided below. Such a first closed forging die is attached to a general-purpose press machine different from the press machine to which the sequential press die is attached.

Next, the second closed forging die will be explained with reference to FIG. This second closed 1% forging die is for finishing the overall external shape of the nut material 50. A second forged female die 42 is located below the center of the second forged punch 41.
Convex portion 41A that fits into the center hole 42A of the nut material 50
C for finishing the C chamfered portion 56A of the center hole 51 of
A chamfered portion 41B is formed. The second female forging die 42 is provided with a center hole 42A and four annular parts 42B on which the nut material 50 is placed. Annular recess 42
On B, an outer circumferential C-chamfered part 42C for finishing the C-chamfered part 54 on the outer periphery of the nut material 50 and a C-chamfered finished part 42D for finishing the C-chamfered part 56B of the center hole 51 of the nut material 50 are formed. has been done. Further, the bottle 43 is pushed up below the annular recess 42B of the forged female die 42.
is inserted so that it can be moved up and down. A pressure device 44 is provided at the bottom of the push-up bin 43. A second like this
A closed forging die is attached to a general-purpose press machine different from the press machine to which the progressive press die is attached.

"Operation" The operation of this embodiment with the above configuration will be explained.

In the progressive press die shown in Figs. 1 and 2, the material qM, which is a coiled material or short material, is fed from the left to the right at a constant feed pitch in conjunction with the vertical movement of the slide of the press. The six materials M that are intermittently fed are inserted into the annular groove 13A under the neck of the lid bin 13 and fed.

In the first processing stage P1, plate thickness determination processing and pilot hole 61 punching are performed. In the plate thickness determining process, the material M is strongly pressed between the upper surface of the female die 14 and the lower surface of the plate thickness determining punch 1 to form a portion M of the material M that will become the nut material 50, as shown by the shaded area in the second section. Adjust the thickness of ゛ to the specified dimensions. The pilot hole 61 is punched out using a pilot punch (not shown). After the second processing stage P2, the tip of a pilot bin (not shown) is inserted into the pilot hole 61, so that the feed pitch of the material M is kept constant.

In the second processing stage P2, a center hole punching process is performed in which a center hole 51 is punched out.Here, the blank punched by the center hole punch 2 passes through the hole 18 shown in FIG. is discharged.

In the third processing stage P3, the upper and lower edges of the center hole 51 are chamfered. ” - side C chamfering punch 3 and lower side C chamfering punch 1 each have 8 chamfered portions and a tapered portion formed at their tips, and both of these bunches 3.19
By pressing the material M at the upper r edge of the center hole 51, C
A chamfered portion 56A56B is formed. This C chamfering is not a cutting process but a crushing process, and the volume of the material M does not change. Therefore, the excess thickness escapes in the inner diameter direction and the center hole 51 is deformed, or the excess thickness is removed in the sixth processing stage described later. It is removed during the M-density punching process at P6.

In the fourth processing stage P4, half-blanking of the outer portion 53 including the groove 52 of the nut material 50 is performed. The half-outline punch 4 is formed larger than the entrance of the outer hole 4A on the upper surface of the female die 14, and the half-outer punch 4 does not contact the upper surface of the female die 14 even at the bottom dead center 6. Eight chamfered portions and a tapered portion are provided at the entrance of the outer shape hole 4A on the upper surface to prolong the life of the outer half punched bunch 4 and the female die 14, and the outer shape portion 5 of the nut material 50 is
3 to prevent breakage or cracks from occurring. By performing such half punching, the punching load can be reduced compared to the precision punching at the sixth processing stage P6, which will be described later. When the slide of the press descends, an elastic member (not shown) of the stripper 8 and an elastic member 13 of the lid bin 13
While compressing B, the half-outlined bunch 4 bites halfway into the material M. At this time, the half-blanked portion of the material M is inserted into the rounded chamfer and tapered portion of the external hole 4A on the upper surface of the female die 14, and the half-blanked portion is easily discharged upward from the female die 14. Do it like this. This facilitates the outer periphery C chamfering process in the subsequent fifth processing stage P5, and eliminates the effects of expansion and contraction of the material during the outer periphery C chamfering process. When the slide rises past the bottom dead center, the half-blanked portion of the material M overcomes the pushing up force of the lid bin 13 and forms a half-blanked hole 4A on the upper surface of the female die 14.
However, it is forcibly discharged upward by the half-pull push-up counter 24 which is pushed up via the push-up bin 24 by the lower pressure device 23.

In the fifth processing stage P5, outer circumference C chamfering processing is performed.
In the outer circumference C chamfering process, the half-cut outer part 5 of the material M
3, a C-chamfered portion 54 is formed on the lower edge side of the outer periphery.

A large sag and taper are formed in the half-blanked outer shape portion 53, and it is necessary to release the excess thickness when forming the C-chamfered portion 54. However, the excess thickness is released in the inner diameter direction, and the C-chamfered portion of the outer periphery is To ensure that the chamfered portion 54 is properly deformed. In addition, the excess thickness is removed by pushing up the outer circumference C chamfering counter 22.
It comes into contact with a convex portion 22A formed at the center of the hole 51 and stops, thereby preventing it from flowing into the inner diameter direction of the center hole 51 to a large extent. In this process as well, when the slide passes the bottom dead center, the half-opened part of the material f4M is left behind on the female die 14 side, but the outer periphery C chamfered push-up counter 22 is pushed up by the lower pressure device 23 via the push-up bin 24. ,
The half-opened portion is forcibly ejected upward.

In the sixth processing stage P6, from material M to nut material 5
Perform precision punching to separate the 0.

As the slide of the press descends, the half-blanked portion of the material M is first cut. Nut material 50 is material M for the first time here
be separated from This separation is performed on the slightly connected part after half-cutting,
It does not put a large burden on the precision punching bunch 6 and the entrance of the external punching 66C on the upper surface of the female die 14.
The separated nut material 50 further descends, passes through the entrance of the external punching hole 66C of the female die 14, the tapered portion of the R-chamfered portion, the straight portion, and reaches the escape portion at the bottom dead center. The separated nut material 50 is pushed upward by the workpiece push-up counter 26 which is pushed up via the push-up bin 25 by the lower pressure device 23. During this pushing up process, the outer shape 53 of the nut material 50
In addition, the center hole 51 is formed in the female die portion 6A formed at the inner diameter portion of the inner diameter bunch 27 and the precision punching bunch 6.
The shaving process is performed by The shaving process generates a very small amount of scraps, which are discharged to the outside by the inner diameter counter 6B which is pushed down via the knockout bin 28 by an upper pressure device (not shown).

Here, the workpiece push-up counter 26 includes a half-blanking push-up counter 21 and an outer circumference C chamfer push-up counter 22.
Since the nut material 50 is formed longer than the material M, the nut material 50 is forcibly confined within the material M and advances to the next processing stage.

In the seventh processing stage P7, the nut material 50 is removed. The nut material 50 is separated from the material M by the removal bunch 7, and is discharged to the lower right through the workpiece removal hole 7A and the diagonal hole 15A.

In the deburring process performed here, burrs generated on the nut material 50 are removed.

Next, a first closed forging process is performed using the first closed forging die shown in FIG. This process involves pressing the C-chamfered portions 6A and 56B at both ends of the hole 51 and correcting the parallelism between the back surface and the front surface.
After placing the nut material 50 with the nut 11 facing upward, the slide of the press is lowered, and the nut material 50 after processing is pushed up into the bin 33 by the pressure device 3f34.
is pushed up and discharged upward.

Here, a flat part 31 is provided on the outer periphery of the lower surface of the ffi bread bread 1.
Because D is provided, the upper edge side of the outermost circumferential portion of the outer circumference C chamfered portion 54 of the nut material 50 does not come into contact with the forging punch 31, and the excess material rises slightly upward, but this rise is due to the second It is removed in the closed 11i forging process.

Next, the second closing shown in FIG. Using the I forging die, the second
A closed forging process is performed. In this process, the nut material 50
This process is performed by placing the nut material 50 in the annular recess 42B of the female die 42 with the outer circumference C chamfer 54 facing down, and then lowering the slide of the press. The nut material 50 after processing is pushed up via the push-up bin 43 by the pressure device 44 and discharged upward.

The nut material 50 manufactured in this manner is subjected to barrel polishing, and then a female thread is engraved in the center hole 51 to form a finished product of a tightening nut for a bearing.

"Other Embodiments" The present invention is not limited to the details of the above embodiments. For example, C of the upper and lower edges of the center hole in the progressive press process.
The chamfering process may be performed after the half-blanking process of the outer shape. Further, the closed fK manufacturing process may not be divided into two processes, but may be performed in a - process.

"Effect of the Invention J As described above, the manufacturing method of the bearing tightening nut of the present invention is to determine the plate thickness by pressing at least the part of the plate-shaped material that will become the nut material, and adjusting the plate thickness to a predetermined dimension. The material is made into a semi-finished nut material through processing, a center hole punching process that punches a center hole in the nut material, a half-outline punching process that half-cuts the outer shape of the nut material, and a precision punching process that separates the nut material from the material. A progressive press process,
The present invention is characterized by performing a closed forging step in which the semi-finished product is sized by closed forging to produce a finished nut material. For this reason, first, by aligning the thickness of the material to a predetermined dimension in the progressive pressing process, we can eliminate variations in the volume of the semi-finished nut material after punching, and then cut to prevent variations in the thickness dimension in the closed forging process. Since machining is omitted, the time required at the machining facility is greatly shortened, and the nut material used for tightening bearings can be obtained at low cost.

In addition, in the progressive pressing process, instead of sequentially cutting out the outer shape of the nut material, the outer shape of the nut material is first half punched and then precision punched, which improves the material yield. In addition, by dividing the external shape processing into half punching and precision punching, large loads are not generated on the punch and female die in each process.
The life of the progressive press die is extended, and the nut material of the nut can be stably tightened over a long period of time using a general-purpose press machine without using an expensive special press machine. be.

[Brief explanation of drawings]

1 to 4 show an embodiment of the present invention, FIG. 1 is a sectional view showing an upper mold and a lower mold of a progressive press mold, FIG. 2 is a plan view of the lower mold, and FIG. is a sectional view showing the upper die and lower die of the first closed forging die, and Fig. 4 is a cross-sectional view showing the upper die and lower die of the first closed forging die. ! FIG. 5 is a sectional view showing an upper die and a lower die of a forging die, FIGS. 5 and 6 show a nut material, FIG. 5 is a front view, and FIG.
FIG. 12. Material thickness determining punch, 289. center hole punch,
4.8 Outer half punch, 682. Precision punch, 141. Female die, 31.41 forged punch,
32, 42. ,,Forged female die, 50,, Nut material, 51,, Center hole, 53,,. External shape, Mll, material, M'1. The part that becomes the nut material. Figure 3 Figure 1 4 2Ll

Claims (1)

[Claims of Claims] A method for manufacturing a nut material for a tightening nut for a bearing, comprising: a plate thickness determining process in which at least a portion of a plate-shaped material that will become the nut material is pressed to make the plate thickness equal to a predetermined dimension; and a center of the nut material. A progressive pressing process in which the material is made into a semi-finished nut material through a center hole punching process to punch a hole, a half-outline punching process to half-cut the outer part of the nut material, and a precision punching process to separate the nut material from the material. A closed forging step of sizing the semi-finished product by closed forging to produce a finished nut material.