JPH039916Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to a press, particularly one in which a pressure accumulator and an auxiliary cylinder are provided inside an upper ram, and the auxiliary cylinder is actuated by the pressure accumulator.

(Prior art) Conventionally, when the auxiliary operation of the upper ram (for example, the air compression operation of a powder molding press) is performed using a fluid cylinder, the air is generally operated after the end of pressurization to complete extrusion of the molded product. The molded product is held down from above until the molded product is completely extruded from the die, and when the molded product is completely extruded from the die, the feeder is advanced from the rear, the molded product is dropped into the front of the press, and new powder is filled for the next process. . Therefore, it is necessary to operate the cylinder and raise the upper punch as soon as possible after the molded product is extruded from the die. However, since the cylinder is installed in the frame and the air tank is installed outside the press, the length of piping connecting the two is long, causing a delay in operation and preventing the upper punch from rising quickly, which takes time to fill the powder. There was an inconvenience that the number of molded pieces per minute decreased.

On the other hand, in order to avoid such inconveniences, it is best to install air tanks and cylinders as close to the upper ram as possible, but since various devices are attached to the upper ram, air tanks and cylinders should be installed outside the upper ram. etc. was difficult to install.

(Purpose of the invention) This invention was made to solve the above-mentioned conventional problems, and its purpose is to:
By providing an air tank and an auxiliary cylinder inside the upper ram, the upper punch can be raised rapidly when the extrusion of the molded product is completed, thereby lengthening the powder filling time and increasing the number of molded pieces per minute. In particular.

(Structure of the invention) In order to achieve the above object, the present invention provides a pressure accumulating section and an auxiliary cylinder inside the upper ram to directly use the upper ram as a pressure accumulating tank, and two pressure accumulating sections are installed inside the upper ram. At the same time, the two pressure accumulators are connected via pipes to two cylinder chambers separated by pistons in the auxiliary cylinder, respectively, and pressurized fluid is transferred to each cylinder chamber by a switching valve provided in the pipes. The pressure is configured to selectively flow into the cylinder chamber from the pressure accumulator to operate the auxiliary cylinder.

(Example) The present invention will be explained below based on the illustrated embodiment. Figures 1 to 5 show the structure and operation of a powder forming press as a press according to the present invention. A main shaft 2 is rotatably supported on the upper part, and the main shaft 2 is rotatably driven by a drive source (not shown) via a reduction gear mechanism (not shown) or the like. An eccentric disk 3 is fixed to the main shaft 2, and a holder 4 is attached to this eccentric disk 3.
An upper ram 6 is connected via a pin 5 so as to be able to move up and down.

The upper ram 6 is provided with an auxiliary cylinder 7 for auxiliary operation of the upper ram 6, and the auxiliary cylinder 7 is constructed as follows.
That is, a cylinder chamber 8 is formed inside the upper ram 6 and is open to the die set S side, which will be described later, and this cylinder chamber 8 is closed by a rod cover 11. A piston 9 with a rod 10 is slidably housed in the cylinder chamber 8, and a piston rod 10 is slidably supported on the rod cover 11. This piston rod 10 is equipped with a flange 10a,
When the piston 9 moves up, the flange 10a comes into contact with the rod cover 11.

S is a die set, and this die set S includes an upper punch 13 fixed to the piston rod 10 of the auxiliary cylinder 7 via a punch plate 12, and a die provided on a die plate 16 fixedly connected via a pull-down plate 14 and a rod 15. 17. It is formed by a lower punch 19 provided on the fixed plate 18 on the machine frame 1, and a core rod 20 provided on the lowering plate 14.

A lower ram 21 that is slidably supported in the vertical direction on the machine frame 1 is connected to the lowering plate 14, and the lower ram 21 can be raised and lowered by a filling cylinder (not shown). . Also,
A lever (not shown) is connected to the lower ram 21, and by operating this lever using a cam and a rod (not shown) provided on the main shaft 2, the lower ram 21 can be moved up and down in a predetermined manner. It's getting old.

In the present invention, the upper ram 6 is provided with air tanks 22 and 23 as pressure accumulators, and the auxiliary cylinder 7 is operated by pressurized air fed from these air tanks 22 and 23. ing. In the illustrated embodiment, a pair of air tanks 22,
23 are formed symmetrically inside the upper ram 6, and as shown in FIG.
4, 25 to an air pressure source 26, and its outlet side is connected to different cylinder chambers 8a, 8b of the auxiliary cylinder 7 via switching valves 27, 28 and conduits 29, 30. In this way, when the auxiliary cylinder 7 is operated with air, which is a compressible fluid, an air compression operation can be performed.

(Function) In the above configuration, first, the outline of the function of the present invention will be explained based on the stroke diagram of FIG. 6. The upper punch 13 is lowered along the A curve by the upper ram 6, and the upper punch 13 is dice 17
Once inserted, the powder within the die 17 is pre-compacted. After preliminary compression, the die 17 also descends as shown by line B, during which compression is performed, and pressurization is completed at point b (180 degree position).

After the above pressurization is completed, the piston rod 10 of the auxiliary cylinder 7 is moved from the air tank 22 to the cylinder chamber 8.
The upper punch 13 is pushed out by the pressurized air forced into the interior a, and the upper punch 13 is held at the same height as at the end of the pressurization, and extrusion is started at point c (210 degree position). Note that point d (approximately 270 degrees position) from point b completion of pressurization
In the process up to the end of extrusion, the upper punch 13 is maintained in a lowered state as shown by line C, and even if the upper ram 6 rises, the upper punch 13 does not rise. After starting extrusion at point c, the die 17 moves to line B
The extrusion is lowered one step as shown in , and extrusion is completed at point d. At this time, the upper punch 13 is rapidly raised by the piston rod 10 of the auxiliary cylinder 7 as shown by line C, and then raised together with the upper ram 6 as shown by line A.

Next, the action of the present invention shown in the above stroke diagram will be explained in more detail based on FIGS. 1 to 5. FIG. 2 shows the powder molding press at the compression end position b in FIG. 6. The pressing force of the upper ram 6 acts on the piston rod 10 via the rod cover 11 and the flange 10a, pushing down the upper punch 13. At the same time as this compression ends, the switching valve 28
is in the closed state, the switching valve 27 is in the open state, pressurized air is sent from the air tank 22 to one cylinder chamber 8a of the auxiliary cylinder 7, the piston rod 10 protrudes, and the upper punch 13 moves from the end of pressurization until the end of extrusion. During the stroke, the upper punch 13 descends and is held in a state where the upper end of the molded product W is held down, and even if the upper ram 6 rises, the upper punch 13 does not rise.

FIG. 3 shows the powder molding press at extrusion end position d in FIG. 6, with the die 17 in its lowest position and the upper surfaces of the die 17 and core rod 20 becoming flush with the upper surface of the lower punch 19. At this point, extrusion of the molded product W is completed. At the same time as this extrusion is completed, the switching valve 27 is closed, the switching valve 28 is opened, and the pressurized air is forcedly sent from the air tank 23 to the other cylinder chamber 8b of the auxiliary cylinder 8. The piston rod 10 then rises as shown in FIG. 4 and stops with the flange 10a in contact with the rod cover 11. Since this lifting of the piston rod 10 is carried out by pressurized air from the air tank 23 built into the upper ram 6, the pipe line 30 connecting the air tank 23 and the auxiliary cylinder 7 is short, and the operation of the auxiliary cylinder 7 is delayed. The piston rod 10 rises almost instantaneously at the end of extrusion.
Therefore, the time for filling powder using a feed shoe (not shown) during the next molding can be accelerated.

In addition, although the illustrated embodiment describes a case where the application is applied to a powder molding press, the present invention is not necessarily limited to this. This can be applied to a press that performs auxiliary operation of the upper ram.

(Effects of the invention) The invention consists of the above structure and operation,
A pressure accumulator and an auxiliary cylinder are installed inside the upper ram,
Since the auxiliary cylinder attached to the upper ram is operated by the pressurized fluid from the pressure accumulator, the pipe connecting the pressure accumulator and the auxiliary cylinder can be shortened, and the delay in the operation of the auxiliary cylinder can be minimized. It can be eliminated. In particular, in the present invention, two pressure accumulators are formed inside the upper ram, and pressurized fluid is selectively flowed from these pressure accumulators into the cylinder chambers on both sides of the piston of the auxiliary cylinder to operate the auxiliary cylinder. Coupled with the shortened path, the reciprocating operation of the piston can be switched instantaneously, and the delay in the operation of the auxiliary cylinder can be more effectively eliminated. Therefore, in the case of powder molding presses, etc., after the molded product is extruded, the auxiliary cylinder holding the molded product can be quickly raised.
It can be said that the powder filling time for the next molding is earlier, the molding time per molded product is shortened, and the number of molded products per unit time is increased, thereby improving work efficiency. Furthermore, since the pressure accumulator and the auxiliary cylinder are provided inside the upper ram, various devices can be attached to the outside of the upper ram.

[Brief explanation of the drawing]

The drawings show a powder molding press as an embodiment of the press according to the present invention. Figure 1 is a vertical cross-sectional view of the powder molding press at the filling position, and Figure 2 is a vertical cross-section of the powder molding press at the compression completion position. figure,
FIG. 3 is a vertical cross-sectional view of the powder molding press at the extrusion completion position, FIG. 4 is a vertical cross-sectional view of the powder molding press immediately after extrusion is completed, and FIG. 5 is a pneumatic circuit diagram.
Figure 6 shows the upper ram, upper punch, and
It is a stroke diagram showing the relative positional relationship of dice. Explanation of symbols, 2...Main shaft, 6...Upper ram, 7...
... Auxiliary cylinder, 8 ... Cylinder, 9 ... Piston, 10 ... Piston rod, 10a ... Flange, 11 ... Rod cover, 13 ... Upper punch, 22, 23 ... Air tank, 24, 25, 2
9,30...Pipeline, 26...Air pressure source, 27,2
8...Switching valve.

Claims (1)

[Scope of utility model registration request] A pressure accumulating part and an auxiliary cylinder are provided inside the upper ram to make the upper ram a direct pressure accumulating tank, and two pressure accumulating parts are formed inside the upper ram, and the two pressure accumulating parts are connected to the auxiliary cylinders through pipes. The auxiliary cylinder is operated by selectively flowing pressurized fluid into each cylinder chamber from each pressure accumulating section by means of a switching valve provided in the pipe line. A press characterized in that it allows