JPS5941811B2 - 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 Fig. 1A, the integral molding of a so-called double sink product, which has a pair of parallel sinks from a single sheet of material (blank), is extremely effective in reducing the number of processing steps and improving material yield. It is valid. However, with the conventional method, it was not possible to form the sink deeply because the captive portion was prone to breakage. The reason for this is as follows. In other words, the material for forming the center side wall (old) cannot flow in from the (Cl portion) because the pair of sinks are adjacent to each other.Therefore, the material for forming the center side wall (old) cannot flow into the bottom wall (Q). ) and the side wall (it must flow from the part of the body, but it cannot flow smoothly due to friction with the punch. This friction is particularly large at the periphery of the bottom of the punch, and the force that squeezes the material at part D is ( The frictional force of the peripheral edge of the punch bottom acting on the (3) section and the handle section is applied to the (A) section.Therefore, the stress on the captive section becomes maximum, and it breaks at this section.The present invention In view of the above points, the present invention provides an integral molding method for a double sink that allows the sink to be drawn deeply by applying hydraulic pressure from the bottom of the punch and reducing the frictional force between the punch and the blank. An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a fixed die, which has a partition wall 2 in the center and recesses 3a and 3b formed on both sides. Reference numeral 4 denotes an elevating body on the press side, from the bottom of which punches 5a and 5b corresponding to the recessed portions 3a and 3b are vertically provided.

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

The punches 5a and 5b are formed with holes 10a and 10b, one end of which is connected to the pump 9 via conduits Ba and 8b, and the other end of which opens at the bottom of the punch. Ila and Ilb are located in the recessed portions 3a and 3b and are connected to the punches 5a and 5b.
is a bottom presser plate facing the bottom of the punch, and the bottom presser plate Il
a, llb are lifting rods 12a that pass through the die 1;
12b, and the lifting rods 12a, 12
b can be moved up and down a predetermined distance and is urged toward Hijikata with a predetermined force. In addition, 13 is a relief valve, 14a, 14b
15 is a sealing device for sealing between the blank holder 6 and the punches 5a and 5b; 15 is the blank holder 6;
a sealing device for sealing between the blank T and the blank T, 16a;
16b is a sealing device that seals between the die 1 and the lifting rods 12a and 12b. When integrally forming a double sink, first, the blank T is placed on the die 1 and is tightened by applying a predetermined wrinkle pressing force Q using the blank holder 6. Next, pump 9 is driven 1 and punch 5 is
Pressure fluid is injected between the punch bottoms a and 5b and the blank 7, and a fluid pressure P is applied. As a result, blank 7 becomes die 1
At the same time as the blank expands within the recesses 3a and 3b, the flange portion sandwiched between the die 1 and the blank holder 6 begins to narrow down. At this time, if the bottom of the sink is free, the bulge of the sink will be almost spherical, so
It is held down with a predetermined force F2 by the bottom holding plates 11a and 11b. In this state, while increasing the hydraulic pressure P, the punches 5a, 5
b with a predetermined force F1. As the molding progresses, the bottom press plate 11
After a and 11b have descended to the lower limit, the punch 5a
, 5b, the pressurized fluid between the punch bottom and the blank 7 is removed via the relief valve 13. When the punches 5a, 5b are thus lowered to predetermined positions, the molding is completed. In this way, since the hydraulic pressure P is applied to the bottom of the punch, the contact area between the punches 5a, 5b and the blank 7 is small, and the friction between the bottom press plates 11a, 11b and the blank 7 is due to the sliding of flat soil. Since the force is small, the material flows smoothly into the central side wall (B) in FIG.

Moreover, since the central side wall (B) is pressed against the wall surface of the die 1 by the hydraulic pressure P, the stress in the part (A) is reduced due to the frictional holding effect. Therefore, even if you narrow down the sink deeply (
4) There is no risk of parts breaking. In addition, the punches 5a, 5
Although narrowing can be achieved without pressing b, the width of the plate at the center side wall (B) is reduced as the side wall (g) in FIG. 1 is narrowed down, so wrinkles occur in this area.

Further, the bending radius of the (G) part and the bending radius of the (self) part are slightly different, and the accuracy is poor, so correction is necessary. As in this embodiment, if the punches 5a and 5b are pushed in while increasing the hydraulic pressure P, wrinkles can be prevented from forming on the central side wall (B), and the bottom press plates 11a and 11b can be lowered to their lower limits. After that, punches 5a, 5 are removed while removing the pressure liquid.
If b is lowered to a predetermined position, part (G) and (
) can be precisely formed to a predetermined bending radius. In the above embodiment, an example was explained in which the bottom press plates 11a and 11b were configured to be able to move up and down, and an upward force F2 was applied to them, but the bottom press plates 11a and 11b were fixed at predetermined positions. Good too.

Moreover, when pushing the punches 5a and 5b, in addition to applying the hydraulic pressure P, if a compressive force that compresses the blank 7 in the direction between the punches is applied to the outer peripheral part of the blank 7, the center side wall ( 8) The flow of material into the section can be made smoother.

Furthermore, if the bottom press plates 11a and 11b 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 11a and 11b can be eliminated. I can do it.

As explained above, according to the double sink integral molding method according to the present invention, since liquid pressure is applied from the bottom of the punch,
Since the frictional force between the punch bottom and the blank is reduced and the material flows smoothly into the center side wall, the bent portion at the upper end of the center side wall is less likely to break, and the sink can therefore be drawn deeply.

[Brief explanation of the drawing]

FIG. 1A is a plan view of the double sink product, the opening in the same figure is a longitudinal sectional front view, and FIG. 2 is a longitudinal sectional front view showing an embodiment of the present invention. 5a, 5b...Punch, 7...Blank.

Claims (1)

[Claims] 1. When molding a pair of parallel sinks, while pressurizing liquid between the punch bottom of the pair of punches and the blank,
A double sink integral molding method characterized by pushing the pair of punches.