JPH0137796Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The knock-out device drive unit of a press machine according to this invention is optimal for workpieces such as printed circuit boards and nameplates where the workpieces should not be contaminated by oil. It is.

<Prior Art> A conventional knockout device for a press machine is disclosed in Japanese Utility Model Application Publication No. 132735/1983. Its general configuration is shown in FIG. That is, the movable frame plate 2 is connected to the lower surface of the ram 1 of the press machine with bolts 7.
A cylinder inner hole C and a recess C' for accommodating the piston 8 and the piston pad 8a formed integrally with the piston 8 are bored from the lower surface, and the piston 8 and the piston pad accommodated in the inner hole C and the recess C'. The piston pad 8a is moved downward by pressure oil supplied from an oil passage 15, and returned upward by return springs 19 provided at a plurality of locations around the peripheral edge of the piston pad 8a. The lower surface of the piston pad 8a comes into contact with the upper end surface of the knockout pin 9, and is driven downward to cause the presser plate 5 to perform a knockout operation. Since the hydraulic power source operating this type of knock-out device requires high-speed follow-up performance, it is best to use an air-to-hydraulic pressure intensifier, and the technology for this is disclosed in Publication of Utility Model Publication No. 54-37112. There is.

<Problems to be solved by the invention> In the conventional knockout device, the return spring 19 of the piston 8 and the piston pad 8a is
Since they are provided at multiple locations near the outer periphery, each of them needs to act equally, but it is difficult to process the springs and mounting portions and adjust them during installation. When the acting force of each spring is non-uniform, a straining action is applied to the piston 8, which adversely affects the movement of the piston. For this reason, there is a problem that the life of the knockout device drive section is shortened, and there is also a problem that oil leakage is promoted. Generally, this type of sliding surface leaks oil, albeit slightly, and the amount of oil leakage increases. The leaked oil should be removed from the power transmission body insertion hole 17 and the knockout pin guide hole 1 in the figure.
2. It passes through the punching pin through hole 13 and reaches the lower surface of the presser plate 5. Therefore, if the processed product is a printed wiring board or name plate that should not be contaminated by oil, some kind of countermeasure is required.

<Means for solving the problem> The means according to this invention is such that a frame plate is fixed to the ram of a press machine, and within the frame plate, the ram is moved by hydraulic pressure in the downward direction of movement and retreated by a return spring. A knock-out device drive unit for a press machine, which is provided with a hydraulic device having a piston that moves forward and backward together with the piston, and a piston pad that is formed under the piston so as to move forward and backward together with the piston, and whose lower surface is formed as a knock-out pin driving surface. The piston of the hydraulic device is formed into an annular piston, and the cylinder is formed by a cylinder liner and a cylinder inner cylinder fitted into an inner hole of the annular piston, and the return spring is arranged concentrically within the cylinder inner cylinder. It is characterized by

<Operation> In the means of this invention, the return spring is provided concentrically with the piston, and the acting force of the return spring against the piston is always applied to the center of the piston, so that the piston is not subjected to any crushing action.

<Example> In Fig. 1, 1 is a ram of a press machine, 30
31 is an upper mold with a presser plate for knockout, and 31 is a lower mold, which are substantially the same as those in a conventional knockout device. The difference from the conventional one is that
The frame board 32 and its internal structure include an annular piston 33, a cylinder liner 34, a cylinder inner cylinder 35, a piston pad 36, and a power transmission body 37. These details are shown in FIGS. 2 and 3 and will be described below.

The annular piston 33 has an inner hole 33a, an upper large diameter outer peripheral part 33b, and a lower diameter small diameter outer peripheral part 33c,
It is formed separately from the piston pad 36 and is connected to the piston pad 36 with a bolt 38.

The cylinder liner 34 has inner peripheries 34a and 34 that fit into outer peripheries 33b and 33c of the annular piston 33.
It has b.

The cylinder inner cylinder 35 has an outer periphery 35a that fits into the piston inner hole 33a, a large diameter portion 35b whose outer periphery fits into the inner hole at the upper end of the cylinder liner 34 and forms the upper end wall of the cylinder, and a ring-shaped portion that protrudes inward at the lower end. It has a spring support protrusion 35c.

The piston pad 36 is a disk having an outer diameter larger than the outer diameter of the cylinder liner 34, and has a spring bearing shaft 39 extending upwardly from the upper surface of the center portion and having a collar-shaped spring bearing 39a at the upper end. are attached by bolts 40, and a return spring 41 is supported between the spring receiver 39a and the spring support protrusion 35c.

The return spring 41 is a coil spring and is arranged concentrically with the annular piston 33.

After the above parts are assembled as shown in FIG. 3, they are inserted into the inner hole 32a of the frame board 32,
As shown in FIG. 2, the cylinder liner 34 is assembled by fixing it with bolts 42. In the figure, 43 is a pressure oil supply path, 44 is an upper chamber of the cylinder, 45 is a lower cylinder chamber, and 46 is a drain discharge path. Further, the power transmission body 37 has an upper end connected to the ram 1.
The lower end is in contact with the lower surface of the upper mold 30 (the upper substrate 3
The cylinder liner 34 is press-fitted into the circular holes 48a, 48b, and 48c vertically penetrating the frame plate 32, cylinder liner 34, and piston pad 36 at the circular hole 48b of the cylinder liner 34. It is movably inserted into the other circular holes 48a and 48c, and has a length equal to the thickness of the frame board 32. This is piston pad 3
This is to prevent distortion of the die 30 caused by punching resistance since the upper surface of the upper die 30 is not supported by the ram 1 side in a certain range of 6.

The upper mold 30 is substantially the same as that shown in FIG.
d is supported by a support portion 30e so as to be movable up and down, and a knockout pin 30f is provided so as to be movable by vertically penetrating the upper and lower bases 30a and 30b. In FIG. 1, 49 is an upper mold clamp, 50 is a lower mold clamp, and 51 is a workpiece (for example, a printed circuit board).

The knock-out device drive unit of this embodiment is configured to connect the conventional air-to-hydraulic pressure intensifier to the pressure oil supply path 4.
When pressurized oil is supplied to the cylinder 3, hydraulic pressure acts on the upper chamber 44 of the cylinder, so the annular piston 33 moves downward against the return spring 41, and the piston pad 36 pushes the presser plate 30d via the knockout pin 30f to release the presser. The punching pin 30 is attached to the plate 30d after the punching operation.
The workpiece 51 that is lifted with the punching pin 30
Remove from c, make knock out effect. Also,
When the oil pressure in the pressure oil supply path 43 is lowered by exhaust from the pressure intensifier, the annular piston 3
3 and piston pad 36 return to their original raised positions.

In addition, when it is necessary to detect whether or not knockout has been reliably performed for high-speed automatic operation, as shown in Figs. 2 and 4, the frame plate 3
A notch 60 is provided at the appropriate location of the piston pad 36.
A window 61 is bored that reaches the inner hole 32a where the
The cam dog 62 may be attached to the piston pad 36, and a limit switch 63 may be provided in the notch 60 correspondingly.

Further, oil leaking downward from the outer periphery of the annular piston 33 is discharged from the lower chamber 45 through the drain discharge passage 46, and oil leaking downward from the inner periphery of the annular piston 33 accumulates inside the cylinder inner cylinder 35 and below it. However, since the piston is not subjected to any crushing action, the amount is small, and it is not necessarily necessary to provide a discharge passage.

<Effects of the invention> According to this invention, since the return spring is installed concentrically in the center of the cylinder, the annular piston always operates smoothly without being subjected to any crushing action, and is suitable for long-term use. I can endure it. In addition, by providing a cylinder liner, a lower chamber can be formed in the cylinder, making it possible to prevent oil leakage, and there is no contamination of workpieces due to oil leakage. Furthermore, since the cylinder liner and cylinder inner tube are not as large as the frame plate, they can be easily processed to be suitable for high-speed and frequent use, and in particular, the sliding surfaces can be processed into high-quality products.

[Brief explanation of drawings]

Fig. 1 is a partial vertical cross-sectional view showing an outline of one embodiment of this invention, Fig. 2 is a partially enlarged cross-sectional view taken along line A-A in Fig. 1, Fig. 3 is a partially enlarged detailed view of Fig. 1, and Fig. 4 The figure is a partially enlarged cross-sectional view taken along the line B--B in FIG. 2, and FIG. 5 is a partial longitudinal sectional front view of a conventional knockout device. 1...Ram, 30...Upper mold, 31...Lower mold, 3
2... Frame plate, 33... Annular piston, 34... Cylinder liner, 35... Cylinder inner cylinder, 36...
Piston pad, 37...power transmission body, 41...return spring.

Claims (1)

[Scope of utility model registration request] A frame board is fixed to the ram of a press machine, and a hydraulic device is installed in the frame board, which has a piston that moves along the downward direction of the ram using hydraulic pressure and retreats with a return spring. In a knock-out device drive section of a press machine, the piston pad is configured to move forward and backward together with the piston pad, and the lower surface thereof is formed as a knock-out pin driving surface. A knockout device drive unit for a press machine, characterized in that the knockout device drive unit is formed by a cylinder inner tube that fits into the inner hole of the annular piston, and the repeating spring is arranged concentrically within the cylinder inner tube.