JPS58100937A - Forging method for flanged shaft - Google Patents

Abstract

PURPOSE:To forge a flanged shaft at high material yield and dimensional accuracy and to reduce man-hours for finishing by inserting a blank material in a closed die in which a space of the same shape as the flanged shaft is formed, and pressing said material from the axial direction. CONSTITUTION:A blank material having diameter smaller than the diameter of the shaft part 2 and large enough to prevent buckling when pressed in the axial direction is inserted from upper part of a closed die 4 into a space 5a of the closed die 4. Then, a pressing head is lowered, and the material is pressed by an upper punch 8 from above in the axial direction. The material is plastically deformed and the space 5a of the die 5 is filled with the material to form a flanged shaft 1. The die is drawn out from a shrink ring 6. The die 5 is divided and a flanged shaft 1 is taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forging a flanged shaft having a flange section in the middle of the shaft section, and particularly relates to a method for forging a flanged shaft aimed at improving material yield and improving dimensional accuracy. Monotheal.

An example of a flanged shaft having a flange portion in the middle of the shaft portion is shown in FIG.

FIG. 1 is a side view showing, as an example of a flanged shaft, a flanged shaft that has two flanges in the middle of the shaft portion and the lengths of the shaft portions at both ends are approximately equal.

In FIG. 1, 1 is a flanged shaft, 2 is a shaft portion, and 3 is a flange portion.

Conventionally, casting, cutting, and forging methods are known as methods for manufacturing this type of flanged shaft.

In the casting method, a riser is required to prevent sink marks, and the material yield is only about 70%. Furthermore, due to poor dimensional accuracy, two to three cutting allowances are required, resulting in a large number of finishing steps as a post-process.

On the other hand, the cutting method not only requires a large number of man-hours for cutting but also has a material yield of about There was a drawback that it decreased to 52%.

However, in the forging method, when the mold is closed, a gap is formed between the upper mold and the lower mold (not shown), which is formed into almost the same shape as the finished product of the flanged shaft 1 (FIG. 1). A material is placed, and the upper die is pressed in the direction perpendicular to the axis by the pressure head of the press (the lower die is placed on the head of the press) to form a flanged shaft. In this method, it is necessary to use a material with a diameter of 45 mm, which is the same as the diameter of the flange portion, so the material yield is not only 52%, which is the same as in the cutting method, but also a lot of burrs are generated. If there are many burrs, the contact area between the material and the mold (the upper mold and the lower mold) becomes large, and the processing force becomes large, so a large press is required.

Further, since the structure of the mold is not a closed type, the dimensional accuracy of the molded shaft with flanges is poor, the finishing allowance is large, and there are disadvantages in that the number of finishing steps as a post-process is large.

The present invention eliminates the drawbacks of the prior art described above, and provides a flanged shaft that has a high material yield, does not require a large press, has good dimensional accuracy, and can reduce the number of finishing steps in post-processing. Its purpose is to provide a forging method.

A feature of the present invention is that, in a forging method for forming a flanged shaft having seven flange portions in the middle of the shaft portion, the shaft portion is placed in a closed mold in which a gap having approximately the same shape as the shaft portion and the flange portion of the flanged shaft is formed. Insert a material with a diameter smaller than the diameter of the part and large enough to not buckle when pressure is applied in the axial direction, press this material from the axial direction,
There is a forging method for a flanged shaft that forms a flanged shaft.

The present invention will be explained below with reference to Examples.

First, an example of forging the flanged shaft shown in FIG. 1 will be described.

FIG. 2 is a sectional view showing a closed mold used for carrying out the method for forging a flanged shaft according to the first embodiment of the present invention.

The configuration of the closed mold 4 will be explained using this Fig. 2.
6 is a mold provided with a gap 5a that is formed into almost the same shape as the shaft part 2 and flange part 3 (see FIG. 1) of the flanged shaft 1 when assembled together;
A shrink ring 7 is capable of storing the mold 5 divided into two parts and fixing them together, and 7 is a base plate on which the mold 5 is stored and a shrink ring 6 is placed and fixed thereon. , 8 is an upper punch that is attached to the pressure head (not shown) of the press and can slide on the upper part (shaft part) of the cavity 5a of the integral mold 5.

A material having a diameter smaller than the diameter of the shaft portion 2 of 30 mm and having a diameter that does not buckle when pressurized in the axial direction, that is, 29.
When a material of mmφ x length 362 is inserted from above, the pressure head is lowered, and pressure is applied from above with the upper punch 8 in one direction in the axial direction of the material, the material is plastically deformed. Then, it fills the cavity 5a of the mold 5, and the molded product shown in FIG. 1, that is, the flanged shaft 1, is molded. Next, by removing the mold 5 from the shrink ring 6 and dividing the mold 5, the flanged shaft 1 can be easily taken out.

According to this forging method, since the flanged shaft 1 is formed using the closed mold 4, the material yield is good (abrasive yield is almost 100%), and the flange is formed with high dimensional accuracy (cutting allowance of 0.5 or less). The attached shaft 1 can be obtained. Moreover, since the dimensional accuracy is good, the number of man-hours for cutting in the post-process can be significantly reduced.

Furthermore, in the conventional forging method described above, a large diameter material is used, which causes a lot of burrs in the shaft parts, etc.
The burrs will be sheared in the subsequent trimming process, and this shearing will cut the streamlines of the material. In contrast, in this embodiment, since there is almost no burr in the shaft portion, there is no need to cut streamlines, and therefore a flanged shaft with excellent strength can be manufactured.

By the way, the flow lines of the material when the flanged shaft 1 is molded using the closed mold 4 shown in FIG. 2 will be explained.

Figures 3 and 4 show streamlines of the material near the flange part of the flanged shaft formed using the closed mold shown in Figure 2, based on simulation calculations (simulation calculations using the upper bound method). , Fig. 3 is a flow line diagram during molding, Fig. 4 is a streamline diagram of a completed product, and Fig. 5 is a flanged shaft molded using a closed mold similar to the closed mold shown in Fig. 2. Although the streamline section showing the streamline of the actual molded product is filled with material, no material flows into the lower flange section. When the molding is completed, the fourth
As shown in the figure, the lower flange is also filled with material, but the flow lines are disturbed near the root of the upper flange. When we examine the deformation, we find that when material first fills the upper flange and then flows into the lower flange, the material in the upper flange, which has already been filled, does not move and the material flows from the top. As a result, internal shear occurs near the base of the upper flange, disrupting the streamlines.

The flow lines of the actual molded product of the flanged shaft formed using a closed mold similar to the closed mold shown in FIG. 2 are as shown in FIG. 5, and in this example, the center of the flange part is Although the calculation conditions differ from the above calculation conditions in that the axis is slightly offset from the center axis of the shaft and the corners of the root of the flanged model are rounded, the upper flanged model has a disturbance in the streamlines near the root. What occurs corresponds well to the above-mentioned subtraction result.

The magnitude of such streamline disturbance is affected by the shape of the upper flange.If the flange is small, the disturbance of the streamline is small and hardly a problem, but if the flange is large, the disturbance is large. Become.

(9) FIG. 6 is a sectional view showing a closed mold used for carrying out the method for forging a flanged shaft according to the second embodiment of the present invention, and FIGS. 7 and 8 are closed molds according to FIG. 6. This figure shows the flow lines of the material near the flange part, based on simulation division, of a flanged shaft that was formed using a mold and simultaneously pressurized with an upper punch and a lower punch. Streamline diagram, Figure 8 is a streamline diagram of the completed molded product, Figure 9 is a flange formed by using a closed mold similar to the closed mold shown in Figure 6 and pressurized simultaneously with the upper and lower punches. FIG. 2 is a flow line diagram showing the streamlines of an actual molded product of the attached shaft.

In FIG. 6, parts with the same numbers as in FIG. 2 are the same parts. In this closed mold 4A, a lower punch 9 is disposed below the mold opposite to the upper punch 8, and the lower punch 9 is capable of sliding in the lower part of the cavity 5a (shaft rope). It is attached to a pressure source (not shown) such as a hydraulic cylinder located at the bottom of the bed of the press. Note that 7a is a lower punch 9 drilled in the base plate 7A.
Noga (10) It is an id hole.

The material is inserted from the top into the gap 5a of the closed mold 4A constructed in this way, and the material is pressurized simultaneously from both the upper and lower directions in the axial direction, and the material is applied to the upper flange portion by the pressure of the upper punch 8. The lower flange portion is filled with pressure by the lower punch 9.

The upper punch 8 and the lower punch 9 are pressurized at the same time to form 1~
The streamlines of the material of the flanged shaft 1 (streamlines calculated by simulation) are as shown in Figure 7.8.
The material flows evenly into the upper and lower flange parts, and there is almost no disturbance in the streamlines near the roots of the upper flange part. Regarding the streamlines of the actual molded product shown in FIG. 9, the disturbance of the streamlines near the root of the upper flange portion has been eliminated.

In this way, if the closed mold 4A according to FIG. 6 is used to simultaneously pressurize the material from two directions in the axial direction, the disturbance of the streamline near the root of the upper flange part is eliminated, and the above-mentioned The reliability in terms of strength of the flanged shaft 1 is further improved than that formed using the closed mold 4 shown in FIG. 2.

(11) Next, an example of forging a flanged shaft having different lengths of shaft portions at both ends as shown in FIG. 10 will be described.

FIG. 10 is a side view showing, as another example of a flanged shaft, a flanged shaft having two flanges in the middle of the shaft portion and having different lengths of the shaft portions at both ends;
FIG. 11 is a sectional view showing a closed mold used for carrying out a method for forging a flanged shaft according to a third embodiment of the present invention.

In Fig. 10, IA is a shaft with a flange, 2a is a 3rd part of the shaft, 2b is a 1st part of a shaft (6 parts of a shaft, 2b
is longer than the shaft 3 part 2a) 5.3a is the flange part on the shaft 8 part 2a side, 3b is the flange part 2a)
This is the flange part on the b side.

The closed mold 4B shown in FIG. 11 is for molding the flanged shaft IA shown in FIG.
In FIG. 1, the same parts as in FIG. 6 are denoted by the same numbers. However, the shaft 3 part 2a is molded on the upper side, and the upper part of the cavity 5b of the mold 5A (shaft 3 part 2a
The gap (12) in which the shaft 1 part 2b is formed is shorter than the lower part (the gap in which the shaft 1 part 2b is formed).

A material having a diameter smaller than the diameter of the shaft 8 part 2a and the shaft part 2b and having a diameter that does not buckle when pressurized in the axial direction is inserted into the cavity 5b of the closed mold 4B constructed in this way from above. , this material is pressurized from two directions, upper and lower in the axial direction, at different timings.

That is, first, the lower punch 9 is fixed (fixed by closing the hydraulic circuit, etc.), and the material is pressurized from above using only the upper punch 8. As a result, the material flows only into the upper flange portion of the gap 5b, as shown in FIG. 3 above. When the upper flange is filled with material (i.e.
When the 72728 part 3a is formed), the pressure applied by the upper punch 8 is stopped, and the upper punch 8 is fixed. In this state, it is clear from the streamlines in FIG. 3 that almost no material flows into the lower flange portion of the gap 5b. Next, the lower punch 9 is unfixed, and the material is pressed up from below to fill the lower flange with the material (
That is, 79721 parts (13) 3b was molded).

By employing such a process, it is possible to forge a flanged shaft IA in which the lengths of the shaft portions at both ends are different, without disturbing the streamlines, as shown in FIG. 8 above.

By the way, when forging a flanged shaft having different lengths of the shaft portions at both ends as in this embodiment, as described above, the timing of the pressurization of the upper punch 8 and the lower punch 9 may be staggered during the forming. is effective for the following reasons.

That is, consider the case where the closed mold 4B shown in FIG. 11 is used and the upper punch 8 and the lower punch 9 pressurize at the same time with the same pressing force. In this case, since frictional force acts between the shaft part and the inner wall of the mold 5A during molding, the pressing force of the upper punch 8 and lower punch 9 is not directly transmitted to the flange part, and the pressing force to the flange part is reduce Since the length of the shirt) b section 2b is longer than the shaft 3 section 2a, the pressing force applied to the 79721 section 3b is smaller than that of the 72728 section 3a. In particular, as the coefficient of friction (14) becomes larger and the length of the 79726 part 2b becomes longer, the pressing force of the lower punch 9 is reduced, and the pressing force becomes considerably smaller near the 79726 part 3b, and the material is pressed by the lower punch 9. It will not be possible to raise it. In this case, the streamlines of the material are similar to those shown in FIG. 4, and the effect of providing the lower punch 9 is hardly apparent. Therefore, by applying pressure to the material at different timings as described above, it is possible to form a flanged shaft IA with excellent strength and reliability without any disturbance of the streamlines.

By the way, by using the closed type 4B shown in FIG. 11 in which the lower punch 9 is disposed opposite to the upper punch 8, and by shifting the timing of pressurization, a flanged shaft IA with different lengths of the shaft portions at both ends is produced. Instead of the above-mentioned method of forging, it is also possible to forge the flanged shaft IA by other methods.

The first method will be explained using FIG. 12.

FIG. 12 is a sectional view showing a closed mold (15) used for carrying out a method for forging a flanged shaft according to a fourth embodiment of the present invention.

In FIG. 12, the same parts as in FIG. 11 are denoted by the same numbers. This closed type 4C does not have a lower punch.1. The material is pressurized only from above.

Into the cavity 5b of the closed mold 4C constructed in this way, a material having a diameter smaller than the diameter of the shaft part a 2a and shaft part b 2b (Fig. 11o) and large enough not to buckle when pressurized in the axial direction is inserted. is inserted from above, and first pressurizes the material with the upper punch 8, filling the upper flange 2 part of the gap 5b with the material, forming one 72798 part 3a, and then stopping the pressurization. Here, the mold 5A, which is still fitted into the link ring 6 and which still houses the semi-molded product (not shown) therein, is turned over and pressurized again with the upper punch 8, so that the mold 5A is placed under the cavity 5b. By filling the flange part (at this time, the lower flange part is above the upper flange part) with the material and molding the other 79726 part 3b,
It is possible to form a flanged shaft (IA) without disturbing the streamlines.

(16) Another method will be explained using FIG. 13.

FIG. 13 is a sectional view showing a closed mold used for carrying out a method for forging a flanged shaft according to a fifth embodiment of the present invention.

In FIG. 13, the same parts as in FIG. 12 are denoted by the same numbers. These closed types also do not have a lower punch, and pressurize the material only from above. Still, in FIG. 13(a), a gap 5C having almost the same shape as the shaft part and one 79726 part 3b of the flanged shaft (shaft) IA (FIG. 10) is formed,
FIG. 13(b) shows a first closed mold 4D for molding the flange/b part 3b, and FIG.
A second closed mold 4C for molding the 798 part 3a is shown.

When a material is inserted into the first sealed mold 4D configured as described above and pressurized from above with the upper punch 8, the material is plastically deformed and fills the gap 5C, forming one 72726 part. 3b is molded 17). Next, the mold 5B is removed from the shrink ring 6, and a semi-molded product (not shown) in which one of the 79726 portions 3b is formed is taken out. This semi-molded product is inserted into the divided mold 5A, the mold 5A is integrated, and as shown in FIG. 13 (1)), it is stored and fixed inside the shrink ring 6 of the closed mold 4C (at this time , the previously formed 79726 part 3b is stored in the flange 2 part below the gap 5b). Here, apply pressure from above with the upper punch 8 to create another 72798
By molding the portion 3a, it is possible to mold the flanged shaft IA without disturbing the streamlines.

The method of forging the flanged shaft 1-IA using the closed mold 4B shown in FIG. Unlike the method that requires a special press with a pressure source, the method shown in FIGS. 12 and 13 has the advantage that it can be formed using a general press.

Note that the forging method according to FIGS. 11 to 13 may be applied to the forming of the flanged shaft 1 shown in FIG. The effect is even greater when applied to the molding of flanged shafts IA having shaft portions of different lengths.

Furthermore, this is not a problem if the material does not require a large pressing force, such as aluminum, but in the case of iron-based materials, the processing force becomes large, which may cause problems in terms of mold strength and press capacity. be.

In such cases, heating the material can significantly reduce its deformation resistance (for example, 545C has a
At a temperature of 900C, the deformation resistance is equivalent to that of aluminum at 20C, so a preheated material may be inserted into the closed mold.

As explained in detail above, according to the present invention, in a forging method for forming a flanged shaft having a flange portion in the middle of the shaft portion, a void having substantially the same shape as the shaft portion and the flange portion of the flanged shaft is formed. A material having a diameter smaller than the diameter of the shaft portion and large enough to not buckle when pressure is applied in the axial direction is inserted into the closed mold, and this material is then pressurized from the axial direction (19) to form a flanged shaft. Therefore, it is possible to provide a forging method for a flanged shaft that has a high material yield, does not require a large press, has good dimensional accuracy, and can reduce the number of finishing steps as a post-process. can.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of a flanged shaft, and FIG. 2 is a sectional view showing a closed mold used for carrying out the method for forging a flanged shaft according to the first embodiment of the present invention.
Figures 3 and 4 show the flanged shaft molded using the closed mold shown in Figure 2, based on simulation calculations.
Figure 3 shows the flow line of the material near the flange part, Figure 3 is a flow line diagram during molding, Figure 4 is a streamline diagram of the completed molded product, and Figure 5 is a flow line diagram of the closed mold according to Figure 2. A flow line diagram showing the streamlines of an actual molded product of a flanged shaft molded using a similar closed mold, FIG. 6 is a forging method for a flanged shaft according to the second embodiment of the present invention. (20) Figures 7 and 8 are cross-sectional views showing a closed mold used for carrying out the process, using the closed mold according to Figure 6, and showing a flanged shaft formed by simultaneous pressing with an upper punch and a lower punch. , which shows the streamlines of the material in the vicinity of the two flange parts based on simulation division. Figure 7 is a streamline diagram during the process of forming, Figure 8 is a streamline diagram of a completed product, and Figure 9 is a streamline diagram of the material in the vicinity of the two flange parts. Figure 10 is a flow line diagram showing the streamlines of an actual completed product of a flanged shaft formed by simultaneous pressure with an upper punch and a lower punch using a closed mold similar to the closed mold shown in Figure 6. , a side view showing another example of a flanged shaft, and FIGS. 11 to 13 are sectional views showing a closed mold used for carrying out the method for forging a flanged shaft according to the third to fifth embodiments of the present invention. It is. 1, IA...Shaft with flange, 2, 2a, 2b.
...Shaft part, 3, 3a, 3b...Flange part, 4
゜4A, 4B, 4C, 4D... Sealed type, 5.5A. 5B... type, 5a, 5b, 5C... void, 8...
Upper punch, 9...lower punch. Agent Patent attorney Kosaku Fukuda (and 1 other person) (21) No. 1 Himu 2 Figure

Claims (1)

[Claims] 1. In a closed mold with a flanged gap having a flange section in the middle of the shaft section, a diameter smaller than the diameter of the shaft section and large enough not to buckle when pressurized in the axial direction is provided. 1. A method for forging a flanged shaft, the method comprising: inserting a material having a flange thereon, and pressurizing the material from the axial direction to form a flanged shaft. 2. A method for manufacturing a flanged shaft according to claim 1, wherein a preheated material is inserted into a closed mold. 3. A method for manufacturing a flanged shaft according to claim 1, wherein a material is pressurized from two axial directions to form a flanged shaft having two flange portions. 4. A flanged shaft having two flange portions is formed by pressurizing the material from two axial directions at different times.
Forging method of flanged shaft described in section. 5 Pressure is applied only from above in the axial direction of the material, and after forming one flange part, the pressurization is interrupted, the mold with the semi-formed product stored inside it is turned over, and pressure is applied again. The method for forging a flanged shaft according to claim 1, wherein a flanged/yaft having two flange parts is formed by forming another flange part. 6. Apply pressure from the axial direction of the material only from above,
One of the flange parts is molded using a closed mold that has a void that has almost the same shape as the shaft part of the flanged shaft and one flange part, and then a void that has almost the same shape as the finished product of the flanged shaft is molded. A flanged shaft according to claim 1, wherein a flanged shaft having two flange parts is molded by molding the other flange part using a molded closed mold. Forging method.