JP3795112B2 - Hydraulic press mold forming trial hydraulic control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mold forming trial hydraulic pressure control method for a hydraulic press in the press working field.
[0002]
[Prior art]
Trial presses that mold prototypes and the like are used in the production of dies for press-molded products of various types and small quantities.
[0003]
Conventionally, trial presses generally employ hydraulic presses so that a wide variety of press conditions can be satisfied. And, as a press press product is a trial press for mechanical press mold production, high pressurization speed is required, so pressurizing cylinder for press molding is driven by pressurizing pump with required large volume discharge amount Or using a large-capacity accumulator.
[0004]
[Problems to be solved by the invention]
However, when a mold is manufactured with a conventional hydraulic trial press and the mold is attached to a mechanical press and molded, part of the molding material may be damaged or the thickness of the molded product may become uneven. It often happens that it cannot be molded successfully. Therefore, although the mold is corrected each time, it takes a lot of time to correct the mold.
[0005]
The main reason for this is thought to be the difference in slide speed between the hydraulic press and the mechanical press as shown in Fig. 3. It is important to match the press motion curve of the hydraulic press with the press motion curve of the mechanical press. I thought it was.
[0006]
[Means for Solving the Problems]
The present invention relates to a hydraulic press mold forming trial hydraulic control method for manufacturing a mechanical press die with a hydraulic press, and a hydraulic control circuit between a pressurizing cylinder and an accumulator of a slide has a small flow rate to a large flow rate. The hydraulic pressure control valve for the mold trial that can control the oil amount up to the flow rate is arranged, and the hydraulic pressure is divided into a number of points between the bottom dead center of the slide from the stage immediately before the mold blockage of the press motion curve of the mechanical press. The mold control trial hydraulic control valve is controlled at each of the above dividing points so that the press slide matches the press motion curve of the mechanical press, and the mold is closed to press the molding material. It is an object of the present invention to provide a mold forming trial hydraulic pressure control method for a hydraulic press.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, a hydraulic control valve for a mold trial capable of controlling the oil amount from a small flow rate to a large flow rate is arranged in a hydraulic control circuit between a pressure cylinder and an accumulator of a slide, and a press motion curve of a mechanical press. Divide the bottom dead center of the slide from the stage immediately before closing the mold into a number of points, and mold the mold at each of the above dividing points so that the slide of the hydraulic press matches the press motion curve of the mechanical press The trial hydraulic control valve is controlled so that the mold is closed and the molding material is pressure-molded.
[0008]
[Action]
The hydraulic press of the present invention controls a slide by driving a pressure cylinder with a hydraulic pump, and controls a pressure cylinder at a predetermined speed by connecting a predetermined capacity accumulator.
[0009]
In particular, a hydraulic control valve for a mold molding trial that can control the oil amount from a small flow rate to a large flow rate is arranged in the hydraulic control circuit of the pressurizing cylinder and accumulator so that it matches the press motion curve of the mechanical press. Hydraulic control is performed.
[0010]
As the hydraulic control valve, it is preferable to control the flow rate with one valve, but since it is not practically available, a predetermined amount of hydraulic control valves are juxtaposed in parallel, and these hydraulic control valves are combined to give a predetermined flow rate. The flow rate can be controlled.
[0011]
The control method is to divide the bottom dead center of the slide from the stage immediately before the mold blockage of the predetermined press motion curve of the mechanical press into a number of appropriate points, and at each divided point, the predetermined flow rate The hydraulic control is performed based on the setting of the hydraulic control valve as described above so that it matches the press motion curve of the mechanical press.
[0012]
Examples of the division control of the multiple points of the press motion curve include speed control for dividing and controlling the slide position and a position control method for dividing and controlling the slide speed.
[0013]
Moreover, as the above-mentioned multipoint division, in addition to equal division, it can be appropriately performed such as finer division as it approaches the bottom dead center and control to match the press motion curve of the mechanical press.
[0014]
Note that in the vicinity of the bottom dead center of the slide, the hydraulic pressure control of the hydraulic pump alone can be changed from the control of the hydraulic control circuit by the accumulator described above, and the hydraulic pressure can be supplied to the accumulator during that time.
[0015]
【Example】
FIG. 1 and FIG. 2 show one embodiment of the present invention described above, which is implemented in a hydraulic press of a trial press. The hydraulic press has a hydraulic tank 2 installed on the crown as shown in FIG. 1 and is connected to a pressurizing cylinder 4 through a prefill valve 3 so as to move the slide 5 up and down.
[0016]
The pressurizing cylinder 4 is connected to a hydraulic pump 7 of an axial plunger type servo pump via a switching valve 6 in three positions and four directions as shown in FIG. An accumulator 8 having a necessary capacity is connected so that the discharge can be performed.
[0017]
The accumulator 8 has a discharge amount that can supply the oil amount necessary for press molding by driving the pressurizing cylinder 4 at high speed in cooperation with the hydraulic pump 7 as required, and is small as shown in FIG. A plurality of hydraulic control valves 9 for mold molding trials of electromagnetic proportional valves are provided so that the oil amount can be controlled from a flow rate to a large flow rate, and the required flow rate control can be performed by appropriately combining them.
[0018]
Further, as shown in FIG. 2, a signal from the slide position detector 10 is transmitted to the hydraulic control valve 9 so as to coincide with the press motion curve of the mechanical press, and a required flow rate is obtained from the accumulator 8 and the hydraulic pump 7. The pressure cylinder 4 is supplied.
[0019]
The slide position detector 10 is provided with a plurality of hydraulic control valves 9 arranged in parallel so as to be able to output by dividing into a plurality of points such as equal division from immediately before the mold is closed to the bottom dead center of the slide. It is controlled so as to match the press motion curve of the mechanical press through appropriate combination.
[0020]
The above-mentioned hydraulic control valve 9 for the mold forming trial is provided with about 10 to 20 parts having the same capacity so that the oil amount can be controlled continuously and smoothly, and the opening / closing control is performed in order. Can be combined.
[0021]
11 is a pressure switch, 12 is a hydraulic pump hydraulic control circuit, 13 is an on / off control valve for shutting off the accumulator hydraulic control circuit 14, and 15 is an accumulator charging hydraulic circuit.
[0022]
When the hydraulic press 1 of the above embodiment is operated, the slide 5 descends at high speed without load as shown in FIG. 2, and the hydraulic pump hydraulic control circuit 12 is shut off immediately before the mold is closed, and the accumulator hydraulic control circuit 13 The plurality of hydraulic control valves 9 provided side by side are sequentially controlled to be opened and closed, and the slide 5 is controlled to descend in accordance with the press motion curve of the mechanical press as shown in FIG.
[0023]
Therefore, even with a hydraulic press, the slide can be controlled to move down with the press motion curve of the mechanical press, and the mold used in the mechanical press can be manufactured. It can be made.
[0024]
In the vicinity of the bottom dead center of the slide 5, the accumulator hydraulic control circuit 13 by the accumulator 8 is cut off and switched to the hydraulic pump hydraulic control circuit 12 for pressurization control by the hydraulic pump 7. Hydraulic oil can be supplied from the accumulator filling hydraulic circuit 15 of another hydraulic pump.
[0025]
In the above embodiment, one accumulator is shown. However, the number of accumulators may be a predetermined number, or a cylinder type pressure accumulation discharge limiter with a predetermined discharge amount control may be used.
[0026]
Further, as the hydraulic control valve for the above-described mold forming trial, a servo valve and other appropriate ones based on the gist of the present invention can be used.
[0027]
【The invention's effect】
As described above, according to the present invention, the slide between the bottom dead center of the slide from the stage immediately before the mold closing of the press motion curve of the mechanical press is divided into a number of points, and the slide of the hydraulic press is divided into the press of the mechanical press. The hydraulic control valve for the mold molding trial is controlled at the respective division points so as to match the motion curve, and the hydraulic control is performed, so even for a hydraulic press, the slide is controlled to move down by the press motion curve of the mechanical press. This makes it possible to manufacture a mold for use in a mechanical press, reduce the mold correction as much as possible, and shorten the mold manufacturing time.
[0028]
Then, the portion from the position immediately before the mold closing of the slide to the bottom dead center is equally divided into multiple points, and the hydraulic control valve for each mold molding trial is controlled from the divided point to slide the hydraulic press. Can be hydraulically controlled to easily match the press motion curve of the mechanical press.
[0029]
In addition, by switching the pressure control of the slide from the hydraulic control by the accumulator to the hydraulic control by the hydraulic pump near the bottom dead center of the slide, the control near the bottom dead center of the press motion curve of the mechanical press is easy, and The hydraulic oil can be easily supplied to the accumulator.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory diagram of an embodiment of the present invention;
[Fig. 2] Press motion curve diagram,
FIG. 3 is a comparison diagram of press motion curves of a conventional mechanical press press and a hydraulic press.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hydraulic press 5 ... Slide 7 ... Pressure pump 8 ... Accumulator 9 ... Hydraulic control valve 10 ... Slide position detector

Claims (4)

A hydraulic press mold forming trial hydraulic control method for producing a mechanical press mold with a hydraulic press,
A hydraulic control valve for mold trials that can control the oil amount from small to large flow rates is installed in the hydraulic control circuit between the pressure cylinder of the slide and the accumulator, just before the mold is closed in the press motion curve of the mechanical press. Dividing the bottom dead center of the slide into a number of points from the stage of the above, the hydraulic control for the mold molding trial at each of the above dividing points so that the slide of the hydraulic press matches the press motion curve of the mechanical press A mold molding trial hydraulic pressure control method for a hydraulic press, wherein a valve is controlled to mold a molding material by closing the mold. Divide equally between the position immediately before the mold closing of the slide and the bottom dead center at multiple points, and at each of the divided points, the hydraulic control valve for each mold molding trial is inserted into the hydraulic press slide and the mechanical press press motion curve. 2. The mold press trial hydraulic control method for a hydraulic press according to claim 1 , wherein the control is performed so as to match the above . 3. The method for controlling the molding of a hydraulic press according to claim 2, wherein a plurality of hydraulic control valves for molding trials having the same capacity are provided side by side for opening / closing control . 4. The mold press trial hydraulic control of a hydraulic press according to claim 1, wherein the slide pressurization control is switched from hydraulic control by an accumulator to hydraulic control by a hydraulic pump near the bottom dead center of the slide. Method.

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