JPH035893B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] Industrial Application Field The present invention relates to an intermediate metal fitting for a hose, which is adapted to manufacture an asymmetrical shape having a flange projecting in one direction. This invention relates to a method for forming headers of metal fittings.

Conventional technology Conventionally, when manufacturing intermediate fittings for hoses as shown in Fig. 17, due to the asymmetrical shape, the first
As shown in Figures 0 to 14, a rod-shaped material is upset in multiple stages to form a header with a conical flange e, and after forming, the temperature is approximately 850°C and the time is approximately 3 hours. After annealing and then press forming as shown in Fig. 15, the unnecessary flange f is removed by press deburring as shown in Fig. 16. Since the weight of the unnecessary flange is approximately 53% of the weight, the yield of the material is poor and the upsetting ratio of the material is high. , it has the disadvantage that cut points occur in the fiber flow of the internal structure and the strength decreases, and the work hardening rate increases due to multi-stage upsetting, making it durable for the next process of press forming. Therefore, if the annealing process is not carried out until decarburization, cracks will occur, but since the annealing is performed under the harsh conditions described above, a decarburized layer will be formed.
Such a decarburized layer has the disadvantage of causing a deterioration in quality in the future.

Problems to be Solved by the Invention The present invention is an intermediate metal for a hose, which simplifies the manufacture of an asymmetrical shape having a flange that protrudes in one direction, and improves quality by achieving good fiber flow. It is an object of the present invention to provide a method for forming a header of an intermediate metal fitting for a hose, which reduces the yield of material costs.

[Structure of the Invention] Means for Solving the Problems The present invention has been developed in view of the problems of the prior art, such as low material yield and reduced strength due to multi-stage upsetting.
Prior to manufacturing the intermediate metal fitting for a hose, which has an asymmetrical shape, a drawing expansion step is performed in which an intermediate step of a rod-shaped material is expanded into a truncated spindle shape using a lower mold on the die side and an upper mold on the punch side; The present invention attempts to solve the above-mentioned problems by using a header forming method that includes a closed forging process in which the flange is formed by expanding the thickness unevenly in one direction.

In other words, in the drawing and expansion process, carbon steel for machine structures, which has traditionally been generally used for hose intermediate fittings, is used.
For materials such as S12C to S17C, if the cross-sectional reduction rate of the diameter cross-sectional area is approximately 35% or more, narrowing is impossible due to buckling, etc., and the work hardening rate in the next process increases, so it is necessary to keep it below this limit. Squeezing is performed at the drawing part of the lower mold on the die side so as to achieve a cross-sectional area reduction rate of approximately 34% with respect to the diameter cross-sectional area of the intermediate portion, and on the punch side, the cross-sectional area reduction rate is smaller than that of the die side. By performing squeezing in the squeezing part of the upper mold with a low cross-sectional reduction rate of approximately 13.5%, we are able to provide sufficient flowability on the punch side and also make the fiber flow at the truncated spindle-shaped part in the middle part almost straight. I am accomplishing it.

In addition, in the hermetic heading process, the cross-sectional reduction rate on the die side and punch side is made different in the squeezing and expanding process to allow for fluidity on the punch side, and the flow is made only from the punch side and the middle part is By molding the flange by expanding the thickness unevenly in one direction, a continuous state of fiber flow is maintained and the work hardening rate is made approximately uniform.

Effects In the present invention, by making the cross-sectional reduction rate on the punch side lower than that on the die side in the drawing and expansion process, the flowability on the punch side has a margin, and the truncated spindle-shaped portion in the intermediate portion The fiber flow is made to be approximately straight, and the flange is formed by flowing only from the punch side in the closed heading process, and the continuous fiber flow is maintained and the work hardening rate is approximately uniform. It is.

Embodiment An embodiment of the present invention will be described below based on the drawings. First, the first mold 1 used in the drawing and expansion process will be described. The first mold 1 has a die side 2 and a punch side 3. It consists of

Reference numeral 4 designates a lower die which is press-fitted into a lower die holding ring 8 which is fixed in the die housing 5 on the die side 2 via a lower pressure plate 6 and a support block 7.

Reference numeral 9 denotes an upper die press-fitted into the punch housing 10 on the punch side 3.

Further, an intermediate cavity 11 is formed according to the outer shape of the intermediate part to be formed into a truncated spindle shape of the material b as shown in FIG. A drawing part is formed at a predetermined position so that the reduction rate of the diameter cross-sectional area of the lower cavity of the lower mold 4 is approximately 34%, which is less than the limit of drawing. The reduction rate of the diameter cross-sectional area of the cavity is
A constricted portion is formed at a predetermined position so as to achieve a reduction in area of about 13.5%, which is lower than the reduction in area of .

Reference numeral 12 denotes an ejector pin which is brought into contact with and supported at the lower end of the drawn and expanded material b, and the ejector pin 12 is a knockout pin 1 connected to a knockout mechanism (not shown) on the die side 2.
It is in contact with 3.

Reference numeral 14 denotes a punch that presses downward by contacting the upper end of the rod-shaped material a, and the punch 14 is pressed downward by a compression spring 16 fixed to an elevating slide member 15 via a fixed punch 17. .

18 is a knockout pin on the punch side 3.

Next, as shown in FIG. 7, the middle part of the material b formed into a truncated spindle shape is expanded unevenly in thickness in one direction to form the material c having a flange 19. To explain the mold 20, the second mold 20 is also composed of a die side 2 and a punch side 3, similar to the first mold 1.

Reference numeral 21 denotes a lower die which is press-fitted into a lower die holding ring 8 fixed in the die housing 5 on the die side 2 via a lower pressure plate 6 and a support block 7.

22 is an upper die press-fitted into the punch housing 10 on the punch side 3.

Also, a cavity 23 is formed using the lower die 21 and the upper die 22 according to the outer shape of the flange 19 of the material c, and the axis of the lower die 21 and the upper die 22 is aligned with the punch 1.
4 and the axis of the ejector pin 12.

Reference numeral 24 denotes a guide member fixed to the elevating slide member 15 having a flange 25 at the upper end.The punch housing 10 is slidably inserted into the guide member 24, and the sliding stroke of the punch housing 10 is restricted. A concave groove 26 is carved, and the concave groove 2
The ball 27 whose end is engaged with the guide member 2
It is fixed at 4.

28 indicates when the punch housing 10 is in a free state;
It is a compression spring that presses downward, and the compression spring 2
8 has a predetermined elastic force so as to restrict upward return even when forged.

Note that the other mechanisms are the same as those of the first mold 1, so explanations will be omitted.

Next, the method for forming a header of an intermediate metal fitting for a hose according to the present invention will be described. First, the punch side 3 of the first mold 1 is positioned upward, and the rod-shaped material a shown in FIG. 5 is placed in the lower mold 4. By placing the material a and moving the elevating slide member 15 downward, the intermediate portion of the material a is bulged into a truncated spindle shape in the shape of the intermediate cavity 11, and the material a is bulged into a truncated spindle shape on the die side 2. The drawing part of the lower mold 4 is used to fill the lower cavity so that the cross-sectional area of the intermediate cavity 11 is reduced by approximately 34% with respect to the diameter cross-sectional area of the intermediate cavity 11, and on the punch side 3, the drawing part of the upper mold 9 The upper cavity is filled so that the cross-sectional area of the intermediate cavity 11 is reduced by approximately 13.5% with respect to the diameter cross-sectional area of the intermediate cavity 11.
A drawing and expanding process is performed to form the material b shown in the figure.

In this state, the fiber flow in the truncated spindle shape of the intermediate portion of the material b is in a state close to a straight line.

Next, the punch side 3 of the second mold 20 is positioned upward, the material b is placed on the lower mold 21 of the second mold 20, the elevating slide member 15 is formed downward, and the punch side 3 is placed on the lower mold 21. The housing 10 is brought into contact with the lower die 21 and the upper die 22 to close the cavity 23, and the elevating slide member 15 is further made downward to bring the punch 14 into contact with the upper end of the material b and press it. By doing this, the cross-sectional reduction rate of the punch side 3 in the drawing and expansion process is lower than the cross-sectional reduction rate of the die side 2, so there is a margin in the fluidity of the punch side 3 (because the work hardening rate is low). Due to this, the material flows only from the punch side 3, causing the middle part of the material b to bulge unevenly in one direction, filling the cavity 23, forming the flange 19, and forming the material c shown in FIG. 7. A closed heading process is then carried out.

In this state, the fiber flow in the flange 19 is made continuous as shown in FIG. 18, and the work hardening rates on the die side 2 and punch side 3 are made substantially uniform.

Note that the axes of the upper die 22 and the lower die 21 are aligned with the punch 14.
The upper die 22 and lower die 21 can be made compact by being eccentric to the axis of the ejector pin 12, and the stroke can be restricted by the groove 26 and the ball 27, and the compression spring 28 can be attached downwardly. It is possible to prevent the punch housing 10 from being pulled out, and the closed state between the upper die 22 and the lower die 21 can be maintained by the above action without increasing the elastic force of the compression spring 28. The elastic force can suppress the occurrence of external burrs, and the compression spring 2
8 has a buffering effect in the event of a collision with the upper mold 22 and lower mold 21, so it is also possible to reduce impact noise and the like.

After forming the header on material c, the 8th
As shown in the figure, the press forming process is completed and the material d
After that, a press deburring process is carried out as shown in FIG.

〔Effect of the invention〕

In short, in the present invention, the middle part of the rod-shaped material a is formed into the material b, which is bulged into a truncated spindle shape. At the same time, in the case of the punch side 3, the reduction rate of cross section is reduced to approximately 34% with respect to the middle part by the drawing part of the upper die 9.
Since the drawing and expansion process is performed to narrow down the area to 13.5%, the area reduction rate on the die side 2 is lower than the limit, and the area reduction rate on the punch side 3 is lower than that on the die side 2. Even in a certain hermetic heading process, it is possible to provide a margin of fluidity on the punch side 3, and it is also possible to form a material b in which the fiber flow in the truncated spindle-shaped portion of the intermediate portion is made almost linear.

In addition, since the intermediate part is caused to flow from the punch side 3 and bulge unevenly in one direction to form and sharpen the material c having the flange part 19, a sealed heading process is performed, so that the fluidity of the punch side 3 is reduced as described above. By having a margin in the flange, it is possible to flow only from the punch side 3, so even if the flange 19 is formed with uneven thickness bulging in one direction at the middle part, as shown in FIG. , it is possible to maintain a continuous state of fiber flow,
Moreover, because the cross-sectional area reduction rate on the punch side 3 is low, the work hardening rate only increases to the work hardening rate on the die side 2, so the work hardening rate of the material c can be made almost uniform, and the product Quality is improved by stabilizing the strength even when the conditions of the annealing process for press shaping are set to a gentle setting (temperature approximately 760°C, time 30 minutes). At the same time, its practical properties are extremely great, such as energy saving, and the ability to significantly improve material cost yields and reduce costs.

[Brief explanation of the drawing]

The figure shows one embodiment of the present invention.
The figure is a sectional view before forging in the first mold used in the header forming method for intermediate fittings for hoses according to the present invention, FIG. 2 is a sectional view after forging the same, and FIG. FIG. 4 is a cross-sectional view showing the same before forging, FIGS. 5 to 7 are process diagrams of the header forming method for intermediate metal fittings for hoses according to the present invention, and FIGS. 8 and 9 are Figures and process diagrams of press forming and press deburring after header forming of the present invention, Part 1
Figures 0 to 16 are process diagrams of the conventional molding method, Figure 17 is a perspective view showing the product shape of the intermediate metal fitting for hoses, Figure 18 is a diagram showing the fiber flow of material c, and Figure 19 is the flow of material d. It is a figure showing the fiber flow of. 2...Dice side, 3...Punch side, 4...Lower die, 9...Upper die, 19...Brim portion, 21...Lower die,
22... Upper mold.

Claims (1)

[Claims] 1. In order to make the middle part of the rod-shaped material into a bulge-molded material in the shape of a truncated spindle, on the die side, the cross-sectional reduction rate is approximately 34% with respect to the middle part by the drawing part of the lower die. At the same time, on the punch side, a drawing bulge step is performed in which the center section is narrowed so that the cross-sectional area reduction rate is approximately 13.5% with respect to the middle section by the drawing section of the upper die, and the middle section is narrowed down from the punch side. A method for forming a header of an intermediate metal fitting for a hose, characterized by comprising a closed forging process of forming a flange by causing fluidity to bulge unevenly in one direction.