JP2004230459A - Die cushion device for press - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die cushion device for presses which is provided with a small and simple locking device capable of being attached to the die cushion later. <P>SOLUTION: In this die cushion device 11 having a die cushion ram 15 which is fit into a die cushion cylinder 13 freely ascendably and descendably, this die cushion for presses is a device provided with a bottom surface plate 14 in the lower end part of a die-cushion cylinder, also a top surface plate 21 in the upper end part of the die-cushion ram and a plurality of locking cylinders 17 are provided between the top surface plate and the bottom surface plate. The lower part of the locking cylinder is fixed to the bottom surface plate and also the tip part of an upper piston rod 23u is connected to the top surface plate. A conduit 27 by which upper and lower oil chambers 25 (a, b) are communicated on the locking cylinder and also a flow rate control valve 31 and an electromagnetic stop valve 33 are provided in series on the conduit. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a die cushion device for a press machine. More specifically, the present invention relates to a die cushion device of a press machine provided with a locking device.
[0002]
[Prior art]
The die cushion device is a device for preventing generation of “wrinkles” when performing drawing by a press. The die cushion device is housed below a bed of a press and is of a pneumatic type or a hydraulic type.
[0003]
When the above-described drawing is performed, there are a case where the drawn product does not affect even if the die cushion is raised at the same time as the completion of the drawing, and a case where the product is destroyed when the die cushion is raised. In this case, it is necessary to stop the die cushion from rising until the upper die rises to an appropriate height, and a device that performs this function is a locking device (for example, see Non-Patent Document 1).
[0004]
The schematic configuration of this locking device is such that a locking cylinder is provided in series below the die cushion cylinder, and the upper end of the piston rod of the locking cylinder is connected to a die cushion ram slidably fitted to the die cushion cylinder. is there. In addition, the oil chambers above and below the locking cylinder communicate with each other via a pipe, and a pilot check valve operated by an electric signal is provided in the pipe.
[0005]
In the above configuration, when the pilot check valve is OFF, the oil freely flows between the upper and lower oil chambers, so that the die cushion ram can be lowered. When the pilot check valve is turned ON, the oil between the upper and lower oil chambers becomes lower. Is blocked, so that the rise of the die cushion ram is locked.
[0006]
[Non-patent document 1]
Hiroyasu Nakata, "Theory and Practice of Press", Corona Publishing, first published February 20, 1973, p. 200-202, FIG. 5.6.
[0007]
[Problems to be solved by the invention]
The die cushion device described above is located under the bed of the press and is quite large in size. Also, the structure of the die cushion needs to be changed depending on the presence or absence of the locking device. When retrofitting a locking device, pneumatic and hydraulic piping work is required.
[0008]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a die cushion device for a press machine having a small and simple locking device that can be retrofitted to the die cushion device. It is to provide.
[0009]
[Means for Solving the Problems]
As a means for solving the above-mentioned problem, a die cushion device for a press machine according to claim 1 is a die cushion device for a press machine having a die cushion ram fitted to a die cushion cylinder so as to be able to move up and down. At the lower end, an integral lower plate extending outward from the die cushion cylinder is provided, and at the upper end of the die cushion ram, an integral upper plate extending outward from the die cushion ram is provided. A plurality of locking cylinders are provided between the lower plates, a lower portion of the locking cylinder is fixed to the lower plate, and a tip end of an upper piston rod of the locking cylinder is connected to the upper plate to be provided. Provision of a pipeline connecting the upper and lower oil chambers Together provided a flow control valve and the electromagnetic on-off valve in series with the conduit, it is an gist to control the vertical movement of the die cushion ram by controlling opening and closing the solenoid valve.
[0010]
According to a second aspect of the present invention, there is provided a die cushion device for a press machine according to the first aspect, wherein the locking cylinder is a double rod type cylinder.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 is an explanatory view of a die cushion device of a press machine according to the present invention.
[0013]
A bolster 7 for mounting and fixing the lower mold 5 is mounted on a bed 9 of the main body frame 3 on the main body frame 3 of the press machine 1. The die cushion device 11 includes a die cushion ram 15 that is fitted to the die cushion cylinder 13 so as to be able to move up and down, a double rod type locking cylinder 17 that controls the raising and lowering operation of the die cushion ram 15, and the like.
[0014]
At the lower end of the die cushion cylinder 13, an integral lower plate 14 extending outward from the die cushion cylinder 13 is provided. The lower plate 14 is attached to a bracket 19 provided integrally with the main body frame 3 below the bed 9 by a suitable fixing means such as a bolt.
[0015]
A die cushion ram 15 is fitted to the die cushion cylinder 13 so as to be able to move up and down. An upper surface plate 21 extending outward from the die cushion ram 13 is attached to the upper end of the die cushion ram 15. It is.
[0016]
Between the upper surface plate 21 and the lower surface plate 14 at the lower end of the die cushion cylinder 13, a double rod type locking cylinder 17 is disposed substantially vertically, and the lower part of the double rod type locking cylinder 17 is The top end of the upper piston rod 23u of the locking cylinder 17 is connected and fixed to the upper surface plate 21 while being fixed to the lower surface plate 14. The tip of the lower piston rod 23b is free.
[0017]
It is desirable that a plurality of the locking cylinders 17 are evenly arranged around the die cushion cylinder 13.
[0018]
The upper oil chamber 25a and the lower oil chamber 25b above the locking cylinder 17 are filled with oil, and the upper and lower oil chambers (25a, 25b) communicate with each other via a pipe 27 provided outside. . A flow control valve 31 with a check valve 29 and a normally open solenoid on-off valve 33 for opening and closing the flow of oil flowing through the pipe are provided in series in the pipe 27. The above-mentioned locking cylinder 17 is provided with a pipe line 27 between the upper and lower oil chambers (25a, 25b) and a flow control valve 31 for controlling the flow of oil and an electromagnetic on-off valve 33 in advance and modularized as a locking device (unit). ). Therefore, the locking device can be easily retrofitted to the die cushion device without the locking device without performing pneumatic piping.
[0019]
The die cushion cylinder 13 is always in communication with a pneumatic source 37 via a pipe 35. The check valve 29 provided in the flow control valve 31 acts so that the oil from the lower oil chamber 25b flows freely when the oil flows from the lower oil chamber 25b to the upper oil chamber 25a, and shuts off the reverse flow. It is inserted in such a direction.
[0020]
Also, an appropriate number of pressure pins 39 whose upper ends are engaged with a wrinkle holder (not shown) are provided so as to contact the upper surface of the upper plate 21 through through holes provided in the bolster 7 and the bed 9. is there.
[0021]
Next, the operation of the die cushion device of the present embodiment will be described. For example, at the time of starting the drawing when performing the drawing, the die cushion ram 15 is located at the rising end as shown on the right side of FIG. 1, and at this time, the solenoid SOL of the solenoid valve 33 is Is OFF.
[0022]
Therefore, when the slide (not shown) of the press machine is lowered and the die cushion ram 15 is lowered via the pressure pin 39, the oil in the oil chamber 25b below the locking cylinder 17 passes through the check valve 29. Therefore, the die cushion ram 15 can move down as the slide descends.
[0023]
Also, as shown on the left side of FIG. 1, when the solenoid SOL of the solenoid on-off valve 33 is turned on when the slide descends to the bottom dead center, the oil flow in the pipe line 27 is interrupted. Is fixed, and the rise of the die cushion ram 15 can be stopped.
[0024]
The solenoid SOL of the solenoid on-off valve 33 can be turned on and off at an arbitrary timing by a cam switch (not shown) provided in the press machine.
[0025]
As described above, in the die cushion device of the present invention, since the locking cylinder 17 is modularized (unitized), the locking device can be easily retrofitted to the die cushion device without the locking device without performing pneumatic hydraulic piping. be able to.
[0026]
Further, since the locking cylinder 17 is a cylinder of both rods having the same upper and lower oil chambers, an extra oil tank for return oil is not required when the piston moves.
[0027]
Further, the flow control valve 31 provided in the locking cylinder of the die cushion device according to the present invention is necessary when setting the rising speed of the die cushion, but is not necessarily required only for performing the locking operation.
[0028]
【The invention's effect】
According to the first or second aspect of the present invention, since the locking cylinder is modularized with the flow control valve and the electromagnetic on-off valve mounted thereon, the mounting to the die cushion device is easy.
[0029]
Further, the locking device can be easily retrofitted to the die cushion device without the locking device without performing the pneumatic piping. Further, since the locking cylinder is a cylinder of both rods having the same upper and lower oil chambers, it is not necessary to install an extra oil tank for return oil when the piston moves, and the die cushion device can be made compact.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a die cushion device of a press machine according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Press machine 3 Main frame 5 Lower mold 7 Bolster 9 Bed 11 Die cushion device 13 Die cushion cylinder 14 Lower plate 15 Die cushion ram 17 Locking cylinder 19 Bracket 21 Upper plate 23u Upper piston rod 23b Lower piston rod 25a Oil chamber 25b on lower piston rod 25a Lower oil chamber 27 Pipe 29 Check valve 31 Flow control valve 33 Electromagnetic on-off valve 35 Pipe 37 Pneumatic pressure source 39 Pressure pin

Claims (2)

In a die cushion device of a press machine having a die cushion ram which is fitted to a die cushion cylinder so as to be able to move up and down, an integral lower surface plate extending outward from the die cushion cylinder is provided at a lower end of the die cushion cylinder, and At the upper end of the die cushion ram, an integral upper plate extending outward from the die cushion ram is provided, a plurality of locking cylinders are provided between the upper plate and the lower plate, and a lower portion of the locking cylinder is attached to the lower plate. The locking cylinder is fixed, the tip of the upper piston rod of the locking cylinder is connected to the upper plate, a pipe is provided for communicating the upper and lower oil chambers to the locking cylinder, and a flow control valve and an electromagnetic valve are provided in the pipe. An on-off valve is provided in series to control the opening and closing of the electromagnetic on-off valve Press machine of the die cushion apparatus and controls the vertical movement of the die cushion ram by Rukoto. The die cushion device for a press machine according to claim 1, wherein the locking cylinder is a double rod type cylinder.

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