JPS5937310Y2 - Hydraulic dictation device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a hydraulic cushioning device used in a power press, and more specifically, to a hydraulic cushioning device that can operate the cushion pressure in two stages. It is.

In the drawing process of plate materials using a power press, normally,
A press die is equipped with a wrinkle suppressing mechanism, but the press die equipped with this wrinkle suppressing mechanism must be provided with a cushion that supports the wrinkle suppressing mechanism movably in the axial direction.

Below, parts manufactured by drawing based on drawings,
An example of a press mold for processing the parts and an example of the configuration of the Gui cushion will be described.

Figure 1 shows an example of an oil seal that uses a reinforcing ring manufactured by press working as a component. An oil seal is constructed by integrally attaching a cool part 2 that slides sealingly with the same section of the through shaft by means of mounting or the like.

As shown in FIG. 2, the reinforcing ring 1 is composed of a radial portion 4 and an axial portion 5, and has an L-shaped cross section.
It is processed using the press die shown in the figure.

The press die shown in FIG. 3 includes a drawing punch/hollowing gouer 11 and an outer punching gou 12, which are combined with the same name and are fixed and supported by the bolster of the power press via a brake plate.
a lower mold 10 consisting of an ejector 14 which is movably inserted in the axial direction between the drawing punch inner punching gou 11 and the outer punching gou 12, an ejector pin 15 disposed below the ejector 14 and supporting the ejector 14, etc.; In addition, a hollow punch 21 and an outer punch/drawing goug 22 are attached to the press head in combination with the same name, and are inserted movably in the axial direction between the hollow punch 21 and the outer punch/drawing gouge 220. The upper die 201C is made up of knockouts 23 and the like.

Process the reinforcing ring using this press mold as follows.

Along with the downward stroke of the press head, from the plate material 8,
The disk forming the reinforcing ring 1 is extracted by the reed drawing die 22, and then the radial portion 4 is supported by the drawing punch and hollowing goug 11, and the outer punching and drawing goug 2
2 forms the axial portion 5, and the through hole of the radial portion 4 is punched out using the hollow punch 211C to complete the reinforcing ring 1.

As will be described later, the ejector 14 of the lower die 10 is elastically supported by the die cushion via the ejector pin 15, so that it is pushed down by the punch/drawing gouer 22 as the press head descends. To,
The outer end of the circularly extracted plate material is pressed between the outer punch and drawing gouer 22 to suppress wrinkles during drawing of the axial portion 5.

Along with the upward stroke of the press head, the ejector 14 pushed by the elastic force of the gou cushion rises as the outer punch and drawing gouer 22 rises, separating the reinforcing ring 1 from the drawing punch and hollow gouer 11. Then, the reinforcing ring 1 is separated from the outer punch/drawing goug 22 by the non-knockout 23 which stops rising near the final stage of the ascending stroke of the press head.

The Gui cushion that elastically supports the ejector 14 is placed below the lower die 10 and within the through hole of the bolster 7, as indicated by the reference numeral 30 in FIG. This is applied by a coil spring, pneumatic pressure, hydraulic pressure, etc., but a hydraulic die cushion that uses hydraulic pressure is a piston inserted into a cushion sill 31 mounted and supported by a bolster 7, as shown in FIG. 32 is adapted to be given an upward elastic force by hydraulic pressure introduced into the cushion sill 31.

The elastic force applied to the piston 32 is greater than the force required to suppress wrinkles in the drawing process, the pressing force required for t, and the force necessary to separate the reinforcing ring 1 from the drawing punch/hollowing goug 11 during the upward stroke. There must be.

In the press mold illustrated in FIG. 3, as is clear from the figure, when the width dimension of the axial portion 5 of the reinforcing ring is smaller than the outer diameter dimension, the outer punch and drawing pin 22 As the wall thickness of the press die becomes thinner and the length of the thin wall portion becomes longer, there is a risk of breakage during processing.As a countermeasure, a press mold as shown in FIG. 6 has been proposed.

The press die shown in FIG. 6 is fitted with an outer punch/ejector 16 and an outer periphery of the outer punch/ejector 16 in place of the ejector 14 in the press die shown in FIG.
? - The remaining material ejector 17, which is supported by It differs from the press mold shown in FIG. 3 in that the hollow punch 21 is combined with a
In the processing of the reinforcing ring shown in FIG. 2, during the downward stroke of the power press, the outer punch/drawing chair 5 and the outer punch/ejector 16 perform the outer punching work, and the drawing punch/hole punch/pull 11 performs the outer punching work. The hollowing punch 21 performs the hollowing work, the drawing punch and hollow punch 11 and the outer punching and drawing pin 25 perform the drawing work, and the remaining material ejector 17 is pushed by the spring force 18 to remove the remaining material. External punch and ejector 16
During the upward stroke of the power press, the outer punch/ejector 16 pushes up the reinforcing ring 1 and separates it from the drawing punch/intermediate punch 11, and near the final point of the upward stroke, the non-punch out 23 lifts the reinforcing ring 1. When the reinforcing ring 1 is stopped, the reinforcing ring 1 is separated from the outer punching pin and drawing pin 25.

As is clear from the figure, in this press mold, the elastic force of the pull-out punch/ejector 16 is supported via the ejector pin 15. The reduction blade must be capable of supporting the external removal force when performing external removal work.

This external extraction force is the pressing force to suppress wrinkles during drawing process.
Alternatively, the reinforcing ring 1 is pushed up and separated from the squeeze punch and hollowing guide 11, which requires a force that is several times as strong as the force used to push out the ring.

Therefore, in order to perform drawing or hollowing while keeping the spring force above this outer punching force, the force that must be applied to the press head is the outer punching force and the drawing or hollowing. This requires a force that is the sum of the force required for It is.

The inventor believed that the diseconomies of the power press ability brought about by the above-mentioned conventional evening extraction limit the elastic force that can resist the almost instantaneously generated external extraction force to the point in time when the extraction operation is performed. First, we focused on the effect of holding the pressure over the entire range of the downward stroke and upward stroke, and installed a high EEIJIJ-) valve and a low pressure I in the hydraulic pipe line that applies elastic force to the hydraulic shock cushion.
A limit switch linked to the stroke of the power press connects the J-F valve and the directional control valve, and activates the high-pressure IJ I7-F valve just before the outer extraction process, allowing the hydraulic pressure during the outer extraction process to be used as a high-pressure relief. By maintaining the pressure set by the valve, the high pressure relief valve is opened immediately after the completion of the extraction process, and the hydraulic pressure is maintained at the set pressure of the low pressure relief valve in the remaining region of the stroke. It was devised that a reinforcing ring of the same size could be manufactured using a power press with the same capacity as when using the press mold shown in FIG. 3.

FIG. 7 shows an embodiment of the piping for the hydraulic cushion according to the present invention.

A high-pressure relief valve 36 and a low-pressure relief valve 37 are arranged in connection with a hydraulic pipe 34 that connects the hydraulic pump 33 to the cushion cylinder 31, and a directional control valve 38 is operated by a limit switch (not shown) VC attached to the power press.
When the directional control valve 38 is switched, the high-pressure IJ
The IJ-F valve 36 will not open below its own set pressure, and when the pressure inside the cushion cylinder 31 is maintained at the set pressure of the high pressure relief valve 36 and the directional control valve 38 is restored by the limit switch, the high pressure relief valve 36 will open. is in an open state, and the pressure inside the cushion cylinder 31 is maintained at the set pressure of the low pressure relief valve 37.

The operation of the power press equipped with the hydraulic cushion device configured as described above is as follows.

At an appropriate point in time before the outer punching time t of the downward stroke a of the stroke curve of the power press shown in the upper part of Fig. 8, the directional control valve 38 shown in Fig. 1 is operated to control the high pressure IJ IJ.
- In order to prevent the pressure relief valve 36 from opening below the set pressure (for example, 120 to 4/cn4), the pressure curve P of the hydraulic cushion shown in the lower diagram of FIG. /crA) The ring protrusion wrinkle suppressing pressure Po determined by K gradually rises, and just before the outer extraction processing time t, the outer extraction pressure PmaXVC due to the set pressure of the high pressure relief valve 36 is reached, showing sufficient resistance against the outer extraction force. , At the same time as the external punching process is completed, the directional control valve 38
The high E IJ valve 36 is opened by the operation of , and the pressure in the hydraulic line 34 is reduced to the ring protrusion L restraining pressure P due to the set pressure of the low pressure relief valve 37 .

, and the pressure P necessary and sufficient for protruding the ring or suppressing wrinkles is maintained until the pressure is changed by the next operation of the directional control valve 38.
.

Be kept. Since the hydraulic cushion device according to the present invention has the above-mentioned structural requirements, the following effects are brought about.

The pressure inside the hydraulic cushion is controlled by a high pressure I7 leaf valve and a low pressure relief valve connected to the hydraulic pipe line that apply pressure to the hydraulic cushion, as well as a switching valve that is switched by a limit switch directly connected to the stroke of the power press. Since the pressure is kept high only at the time of outer removal of the downward stroke of the Kahower press, and the pressure is kept low during the rest of the downward stroke and during the upward stroke, the drawing punch and hollow gouer 11 shown in FIG. When processing a metal plate using a lower die 10 having a punch/ejector 16 and a surplus material ejector 17, an upper die having a hollow punch 21, and an outer punch/drawing pin 25, a drawing punch/center is used. Compared to the case of the prior art, which uses a mold consisting of a lower die having a punching goug 11, an outer punching gouge 12, and an ejector 14, and an upper mold having a hollowing punch 21 and an outer punching punch/drawing goug 22, the power is reduced. There is no need to increase the press capacity in any way, and the economy of processing is maintained.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional views showing examples of products and parts produced by mechanical equipment using the hydraulic cushion device according to the present invention, and Figure 3 is a cross-sectional view of a press mold for processing the parts shown in Figure 2. 4 is an external view showing the arrangement of the hydraulic cushion used in press working, FIG. 5 is a sectional view showing the structure of the hydraulic cushion, and FIG. 6 is the second hydraulic cushion.
Figure 7 is a cut-away diagram showing an example of an improved press die used for processing the parts shown in the figure, Figure 7 is a piping diagram showing an embodiment of the hydraulic gusseting device according to the present invention, and Figure 8 is the hydraulic gusseting system according to the present invention. FIG. 3 is a diagram showing the operation of the device. 1...Reinforcement ring, 2...Seal piece, 4
......Radial direction part, 5...--Axial force inside, 7.
... Bolster, 8 ... Plate material, 10 ...
...Lower die, 11... Squeezing punch and hollowing guide, 12... Outer punching guide, 14... Ejector, 15... Ejector pin, 16・・・・・・
・Outer punch and ejector, 17...Excess material ejector, 18...Spring force, 20...Upper die, 21...Middle punch , 22... Outer punch and squeezing guide, 23... Knockout, 25... Outer punch and squeezing guide, 30...
...Gui cushion, 31...Cushion cylinder, 32...Piston, 33...
Hydraulic pump, 34...Hydraulic pipe line, 36...
...High pressure relief valve, 37...Low pressure relief valve, 38...Direction switching valve, a...Downward stroke, t...Outer punching time, P...
・Pressure curve of hydraulic pressure cushion, PO・・・・・・
Ring protrusion wrinkle suppression pressure, PmaX...External removal pressure.

Claims (1)

[Scope of utility model registration request] Extended from the cushion cylinder fl-31 and U piston 32, attached to the bolster 7 of the power press, there are a drawing punch/inner puncher 11, an outer punch/ejector 16,
When press working is performed using a lower die 10 having a surplus material ejector 17, a hollow punch 21, and an upper die 20 having an outer punch and a drawing die 25, the outer punch is removed via the ejector bin 15. Punch and ejector 16
, a high-pressure relief valve 36, a low-pressure relief valve 37, and a riment connected to the stroke of the power press in a hydraulic line 34 that supplies pressure to the Gui cushion 30 that elastically supports the surplus material ejector 17. A switch activates the directional valve 38 so that the hydraulic pressure in the cushion 30 rises to the set pressure of the high pressure relief valve 36 at a certain point in the press stroke, and at another part of the press stroke. A hydraulic cushion device designed to maintain the pressure set by the low pressure relief valve 37.