JPS6016854B2 - Double sink integral molding method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for integrally molding a double sink.

As shown in Figure 1, A and B, integrally molding a so-called double sink product, which has a pair of parallel sinks from a single sheet of material (blank), reduces the number of processing steps and improves the material progress. Very effective.

However, in the conventional method, part A tends to break, so
It was not possible to mold the sink deeply. The reason for this is as follows. That is, the material for forming the central side wall B cannot flow from the portion C because the pair of sinks are adjacent to each other. Therefore, the central side wall B
The material forming the hole must flow from the bottom wall ○ and the side wall E, but it cannot flow smoothly due to friction with the punch. This friction is particularly large at the periphery of the punch bottom, and the force that squeezes the material at the F section is transmitted to the A section with the addition of the frictional force at the periphery of the punch bottom that acts on the G and H sections. Therefore, the stress at part A becomes maximum, and it breaks at this part. In view of the above points, the present invention has been developed by pushing a pair of punches into the recessed part of a fixed die through a blank holder, and when integrally molding a double sink, a core blank holder is inserted from the bottom of a portion of the blank holder located between a pair of punches. A pressurized liquid is pressurized between the blank and the bottom of the pair of punches pushed into the recessed part of the fixed die, and at the same time, this pressurized liquid is released through the punch bottom leaf valve. By doing so, the friction force between the punch and the blank is reduced, and the liquid pressure applied to the center side wall of the sink is higher than the liquid pressure applied to the other side walls, so that the friction retention effect of the center side wall is effectively exerted. This invention provides a method for integrally molding a double sink that allows the sink to be drawn deeply, and one embodiment of the method will be explained below based on the drawings.

In FIG. 2, a fixed die 1 has a partition wall 2 in the center and recesses 3a and 3b on both sides.

4 is an elevating body on the press side, and the recessed part 3 is visible from the bottom surface of the elevating body.
Punches 5a and 5b corresponding to a and 3b are vertically provided.

6 is a plank holder disposed outside the punches 5a and 5b, and 7 is a blank.

The punches 5a and 5b have one end closed at the bottom of the punch,
Holes 10a, 10b are formed whose other ends are connected to the relief valve 9 via piping 8a, 8b, and the holes 10a
, 10b and the pipes 8a, 8b provide a relief passage 1.
1a and 11b. The plank holder 6
As shown in detail in FIG.
A plurality of closed vertical holes 12 are formed at appropriate intervals in the bottom surface of the part to be replaced between a and 5b, and the upper ends of these vertical holes 12 extend from one side wall of the blank holder 6. It is connected to a horizontal hole 13 drilled in the horizontal direction, and the horizontal hole 13 is connected to a liquid injection device (not shown). Reference numerals 14a and 14b are bottom press plates located in the recesses 3a and 3b and opposed to the punch bottoms of the punches 5a and 5b. , 15b, and the elevating gears 15a, 15b are movable up and down a predetermined distance and are biased upward with a predetermined force.

Note that 16a and 16b are seal bags that seal between the blank holder 6 and the punches 5a and 6b, and 17 is a seal holder that seals between the blank holder 6 and the blank 7. When forming the double sink body, first, the blank 7 is placed on a die and then tightened using the blank holder 6 with a predetermined wrinkle pressing force Q applied thereto.

Next, the horizontal hole 13 and the vertical hole 12 are filled with a liquid injection device (not shown).
Plank holder 6 and blank 7 from the bottom of the part sandwiched between punches 5a and 5b of plank holder 6 through
Pressure fluid is injected between the two and a hydraulic pressure P is applied. As a result, the blank 1 expands within the recesses 3a and 3b of the die, and at the same time, the flange portion sandwiched between the die 1 and the plank holder 6 begins to be squeezed. At this time, if the bottom of the sink is free, the bulge of the sink will have a nearly spherical shape, so it is pressed down with a predetermined force F2 by the bottom press plates 14a and 14b. In this state, the punches 5a and 5b are pushed in with a predetermined force F while increasing the hydraulic pressure P.
At this time, when the hydraulic pressure P, reaches a predetermined pressure, the pressure liquid between the punch bottom and the blank 7 is released and separated 11a, 11b.
and is discharged to the outside via the relief valve 9. This creates a pressure difference between the hydraulic pressure P applied to the central side wall B in FIG. 1 and the hydraulic pressure P2 applied to the other side walls E and bottom wall D. This pressure difference is caused by the viscous resistance of the liquid, and the liquid pressure P is larger than the liquid pressure P2. Molding progresses,
When the bottom press plates 14a, 14b descend to the inner lowering limit, press-fitting of the pressurized liquid is stopped, and the punches 5a, 5b are further pushed in.
At this time, the dark pressure liquid between the punch bottom and the blank 7 is removed via the relief channels 11a, 11b and the relief valve 9. When the punches 5a, 5b are thus lowered to predetermined positions, the molding is completed. In this way, since the hydraulic pressure P2 is applied to the bottom of the punch, the contact area between the punches 5a, 5b and the blank 7 is small, and the bottom holding plates 14a, 1
Since the friction between the blank 4b and the blank 7 is sliding on a plane and the frictional force is small, the material flows smoothly into the central side wall B in FIG.

Furthermore, since the central side wall B is pressed against the wall surface of the die 1 by a hydraulic pressure P that is greater than the hydraulic pressure P2 of other parts, the frictional retention effect is effectively exhibited and the stress in the A part is significantly reduced. Therefore, there is no fear that part A will break even if the sink is squeezed deeply. Note that since the pressure difference between the hydraulic pressures P and P2 is caused by the viscous resistance of the pressure liquid, it is preferable to use a pressure liquid with high viscosity. In addition, as in this embodiment, if the punches 5a, 5b are lowered to a predetermined position while removing the pressure liquid after the bottom press plates 14a, 14b have been lowered to the lower limit, the G portion and the H portion can be moved to a predetermined position. This is preferable because it can be formed with high precision to a bending radius of .

Further, in the above embodiment, an example was explained in which the bottom press plates 14a and 14b were configured to be able to rise and fall freely, and an upward force F2 was applied. It may be fixed at the lower limit.

Furthermore, when pushing the punches 5a and 5b, in addition to applying hydraulic pressure, if a compressive force that compresses the plank 7 in the direction between the punches is applied to the outer circumferential portion of the blank 7, the center side wall B The flow of parts to the parts can be made even smoother.

Furthermore, if the bottom press plates 14a, 14b are made of, for example, endless belts and are movable toward the partition wall 2 side of the die 1, the frictional force between the blank 7 and the bottom press plates 14a, 14b can be eliminated. I can do it. As explained above, according to the method for integrally molding a double sink according to the present invention, the sho liquid is injected between the blank holder and the blank from the bottom of the portion of the blank holder located between the pair of punches. , pressure is applied between the bottom of the pair of punches pushed into the recessed part of the fixed die and the blank, and at the same time this pressure liquid is released from the bottom of the punch via the relief valve, so the frictional force between the bottom of the punch and the blank is reduced. The material flows smoothly into the center side wall, and the center side wall is pressed against the side wall of the die with greater hydraulic pressure than other parts, so the friction retention effect of the center side wall is effectively exerted, and the upper end of the center side wall is The bent part of the sink is difficult to break, so the sink can be narrowed deeply.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1A is a plan view of the double sink product, the opening of the figure is a vertical front view of the same, Figure 2 is a vertical front view showing an embodiment of the present invention, and Figure 3 is the bottom surface of the blank holder. It is a diagram.

5a, 5b... punch, 6... blank holder, 7...
Plank, 11a, 11b...Escape channel.

Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. When integrally molding a double sink by pushing a pair of punches through the blank holder into the recessed part of the fixed die, pressurized liquid is applied between the blank holder and the blank from the bottom of the part located between the pair of punches of the blank holder. Pressure is applied between the blank and the bottom surfaces of the pair of punches that are press-fitted and pushed into the recessed portions of the fixed dies, and at the same time, one end of the pressurized liquid is opened at the bottom of the pair of punches and the other end is A method for integrally molding a double sink, characterized in that the pair of punches is pushed in while releasing the air through a relief channel connected to a relief valve.