CN1056643A

CN1056643A - Injection device with hydraulic die-casting machine of pressure peak device when eliminating injection

Info

Publication number: CN1056643A
Application number: CN91103431.5A
Authority: CN
Inventors: 罗伯特·布拉佳斯丁尼
Original assignee: INTERNATIONAL PRESS DEVELOPMENT ESTABLISHMENT
Current assignee: INTERNATIONAL PRESS DEVELOPMENT ESTABLISHMENT
Priority date: 1990-05-22
Filing date: 1991-05-22
Publication date: 1991-12-04
Also published as: IT9020394A1; IT9020394A0; WO1991017850A1; EP0530244A1; DE69116361D1; DE69116361T2; ES2080948T3; ATE132781T1; IT1248476B; EP0530244B1

Abstract

Injection device comprises injection oil cylinder (9), hydraulically operated shot piston (10), fluidic accumulator (1), it is used for when shot stroke the high speed shot piston being operated, pressure multipier (12), it is used for the piston (10) at the end of the shot stroke of piston (10) operation low speed heavy pressure.This device also comprises auxiliary cylinder/piston apparatus (6.7), and it is set between shot piston (10) and the accumulator (1), so that the piston (7) of permission described servicing unit under the effect of accumulator (1) is mobile.Described shot piston (10) is to move according to moving of described auxiliary piston (7).The cross section of auxiliary cylinder (6) is bigger than the cross section of injection oil cylinder (9).

Description

Injection device with hydraulic die-casting machine of pressure peak device when eliminating injection

The present invention relates to be used for the injection device of hydraulic die-casting machine, this device is provided with to eliminating the device of pressure peak when the injection.

This class injection device of prior art comprises the injection oil red; The shot piston that can in injection oil cylinder, slide; Valve gear, it be suitable for making this injection oil cylinder at first shot piston at a slow speed mobile phase be communicated with the fluid transfer pump; And sequentially be communicated with a fluidic accumulator in the fast moving stage second time of shot piston.Such device also comprises pressure multipier, and its effect is to raise to act on fluid pressure on the shot piston, with the 3rd short distance mobile phase of the low speed heavy pressure that is used for shot piston.The 3rd mobile phase makes molten metal arrive all sites in casting chamber, fills up the hole that is difficult for loading and stitches, thereby reach desired tight ness rating.

The shortcoming of this prior art is, when the end in piston fast moving stage, piston move apart facing to the deposite metal, these deposite metals have been full of the ante-chamber of injection sleeve pipe fully, so just make piston produce continuous pressure peak, fusing casting material is produced strong impact, and this pressure peak is inevitable and uncontrollable at one time.

The objective of the invention is to overcome this shortcoming, eliminate described pressure peak by using an injection device.

The injection device that is used for hydraulic die-casting machine according to the present invention can be realized such purpose, and this device comprises injection oil cylinder, the hydraulically operated shot piston, and fluidic accumulator, it is used for making during shot stroke shot piston with high speed motion; And pressure multipier, it is used for when piston shot stroke end shot piston being moved with high pressure low speed; It is characterized in that, described device further comprises auxiliary cylinder/piston apparatus, it is arranged between shot piston and the accumulator, to allow under the effect of accumulator, the piston of described servicing unit moves, and described shot piston is to move according to moving of described auxiliary piston, and the cross section of described auxiliary cylinder is bigger than the cross section of described injection oil cylinder.

Shot piston is with the different of auxiliary piston cross section and speed that auxiliary piston moves is lower than the speed that shot piston moves, and can controllably arrive the end of stroke, thereby avoids being produced pressure peak by the metal of injection.

Purpose of the present invention can also be expressed by following measure: be provided with valve gear between described accumulator and described auxiliary cylinder/piston apparatus, described valve gear can be controlled, so that regulate the flow of fluid, thereby controls moving of described piston.Described auxiliary piston is adapted to supply fluid to the one side that this auxiliary piston has little diameter from described accumulator, and has bigger diameter at its opposite face, and this face is to be connected with the fluid of described shot piston.

Described auxiliary piston with accumulator together, turn round as pressure multipier equally, the fluid that piston has on the face of larger cross-section communicates with accumulator, and the fluid that piston has on the face of small cross sections communicates with accumulator by described valve gear, experiences pressure by the described shot piston of valve gear.

With reference to the accompanying drawings, in conjunction with the explanation of two embodiment, characteristics of the present invention will be more clear, certainly, below exemplary explanation the present invention is not construed as limiting.

Fig. 1 has shown an embodiment, and the device among the figure remains static;

Fig. 2 display unit is just in the injection stage;

Fig. 3 display unit is just in the pressure multiplier stage;

The return stage of Fig. 4 display unit after the injection;

Fig. 5-Fig. 8 is according to an alternative embodiment of the invention, and its operational phase is identical with Fig. 1-Fig. 4.

Consult Fig. 1 below earlier to Fig. 4, injection device comprises a quick accumulator 1, and this accumulator comprises a cylindrical cavity 14 again, and piston 15 slides in chamber 14.The top of cylindrical cavity 14 is full of the nitrogen 2 that has pressure, and nitrogen 2 is from gas tank 19, and the bottom in chamber is full of fluid 30, and fluid 30 is from connecting pipe 5, and is subjected to the thrust of piston 15.Valve gear comprises valve body 31 and variable action bolt 32, under the effect of this valve gear, makes the piston 7 of auxiliary cylinder/piston apparatus 6,7 move, and this auxiliary cylinder/piston apparatus also is equipped with linear speed converter 71.The front end of cylindrical cavity 6 is full of fluid 40.Be provided with check valve 60 in the pipeline 8, by moving of piston 7, the fluid in the pushing pipeline 8, thus shot piston 10 is moved in corresponding injection oil cylinder 9, this oil cylinder is provided with this valve of fast decompression valve 65(originally as a kind of type known).

Be provided with injection rod 42 in injection oil cylinder and

shot piston

9,10, pipeline 11 is provided with check valve 61, by pipeline 11 described injection oil cylinder is connected with pressure multipier 12 with shot piston 9,10.This pressure multipier comprises accumulator 13, and this accumulator comprises oil cylinder 16 and piston 17 again.The top of cylindrical cavity 16 is full of nitrogen 18 under pressure, and the nitrogen 18 with pressure slides piston 17; The bottom in chamber 16 is full of fluid 50, and this fluid is pushed by pipeline 51 by piston 17 under the valve gear effect; This valve gear comprises valve body 20 and variable action bolt 21, under the effect of valve gear and fluid, makes oil cylinder/piston pay 53,52 actions, thereby drives fluid 54, and the shot piston 10 in oil cylinder 9 is slided.

To Fig. 4 institute order demonstration, Figure 1 shows that the situation of beginning as Fig. 1.At this

moment piston

15,17,7,52,10 remains static in

oil cylinder

14,16,6,53,9 separately, and opening of bolt 32 begun the injection stage.Demonstrate piston 15 among Fig. 2 and under nitrogen 2 effects, shift to the bottom in corresponding chamber 14 with pressure, press against the fluid 30 of 14 bottoms, chamber, and the pipeline 5 by being provided with

valve gear

32,31, make the fluid of above-mentioned pressurized enter auxiliary cylinder 6, thereby auxiliary piston 7 is moved.The mobile pushing fluid 40 of this piston, and make this fluid enter injection oil cylinder 9 by pipeline 8, thus make shot piston 10 fast moving, simultaneously, pressure-reducing valve 65 is opened.In this stage, the casting material of the fusing in injection oil cylinder 9 is being extruded by bar 42 near injection mouth place (not shown).With respect to injection oil cylinder 9, it is big that the diameter of auxiliary cylinder 6 is wanted, and the speed of this situation auxiliary piston 7 during the stroke of auxiliary piston 7 is lower than shot piston 10 speed, thereby be easy to control.

As shown in Figure 3, at the end in this stage, auxiliary piston 7 arrives its stroke endpoint with controllable speed in oil cylinder 6.This moment, the speed of piston 10 eased down to the speed of only being kept by the inertia of casting material material because auxiliary piston 7 no longer provides shot piston 10 pressure flow bodies.

Like this, when auxiliary piston 7 arrives the terminal point of its stroke with conditional speed, also avoided the strong pressure of 10 pairs of fusing castings of shot piston material simultaneously, thereby eliminated disadvantageous pressure peak.

The depressurization that another very important advantage is an accumulator 1 is at the periphery of the piston item 70 of auxiliary piston 7, so the pressure of accumulator 13 changes and reduce greatly, like this to accumulator repeat accumulation of energy require low, thereby energy savings.The piston 7 lower speed of accumulator 13 have reduced the danger that piston is blocked, and have also reduced the wearing and tearing of sealing gasket in the accumulator 13.

The effect of pressure multipier 12 is according to a kind of controllable mode.As shown in Figure 3, in this stage, piston 17 is promoted by the nitrogen with pressure 18 on oil cylinder 16 tops, thereby begun its stroke, under the effect of

valve gear

20,21, fluid 50 is pushed pipeline 51, pay 53 by oil cylinder/piston, 52 and control corresponding fluid 54, cause shot piston 10 in corresponding oil cylinder 9 to have the slip effect of the pressure that doubles.

Should be pointed out that the deceleration on last stage end piston 7, the increase of pressure in the oil cylinder 9 when this stage is in shot piston 10 and treating not produce on the fusing casting material of injection and do not wishing the pressure peak that occurs.

Consult Fig. 4 now, will make

respective pistons

15,7,10,52, the 17 extensive wilful positions in oil cylinder 14.6.9,53,16 at the end in this stage to primary condition.

Fig. 5-Fig. 8 has shown similar injection device, and the difference of it and the foregoing description is that auxiliary piston 7 is still action in the scope of pressure multipier 12.

More precisely, piston 7 has a part and the part that diameter is bigger that diameter is smaller, wherein the smaller part and oil cylinder 6 co-operatings of diameter.The fluid 30 of oil cylinder 6 provides from accumulator 1 by check valve 85, and oil cylinder 6 communicates with injection oil cylinder 9 by valve 87.Valve 87 has a unsteady bolt 88; Part and oil cylinder 86 co-operatings that diameter is bigger, from accumulator 13, valve 20 has can control bolt 21 to the fluid 50 of oil cylinder 86 by valve 20; By check valve 61, oil cylinder 86 communicates with injection oil cylinder 9.

In Fig. 5-Fig. 8, also shown two

check valves

91 and 92, be used to provide fluid to replenish accumulator 1 and 13 with pressure; Also shown valve 13 among the figure, it has the bolt 94 that floats, and when shot piston was prepared to get back to its resting position, valve 94 made fluid pressure, thereby piston 10 is returned.

In the running, from resting position shown in Figure 5, bolt 32 is opened and is made fluid 30 be fed to oil cylinder 6 by check valve 85, piston 7 is moved forward, by check valve 61, the mobile of piston 7 moved the shot piston 10 in the injection oil cylinder 9, and injection oil cylinder 9 has valve 65 openings.Here it is injects stage (Fig. 6) of casting cavity with metal crimp.

When the shot stroke of piston 10 will wane to the close, bolt 21 is open-minded, high-pressure fluid flows into auxiliary cylinder 86 from accumulator 13, here, high-pressure fluid makes auxiliary piston 7 moving to travelling backwards, because piston 7 both sides area differences, thereby in oil cylinder 6, produce multiplication pressure, this pressure is opened valve 87, again this pressure is sent to shot piston 10(Fig. 7 by fluid), so just on the deposite metal that is pushed by piston rod 42, produce the pressure multiplier effect.

When casting is finished,

valve

31,32 and 21,10 cuts out once more, because the effect of valve 65, shot piston 10 is returned, and pressure reducing fluid is by valve 93(Fig. 8).

Claims

1, the injection device that is used for hydraulic die-casting machine, comprise injection oil cylinder (9), hydraulically operated is pressed piston (10), fluidic accumulator (1), it is used for making when shot stroke shot piston (10) with high speed motion, and pressure multipier (12), it is used for when piston (10) shot stroke end piston (10) being moved with high pressure low speed, it is characterized in that, described device further comprises auxiliary cylinder/piston apparatus (6,7), it is arranged between shot piston (10) and the accumulator (1), and allow under the effect of accumulator (1), the piston of described servicing unit (7) moves, and described shot piston (10) is to move according to moving of described auxiliary piston (7), and the cross section of described auxiliary cylinder (6) is bigger than the cross section of described injection oil cylinder (9).

2, according to the described injection device of claim 1, it is characterized in that, between described accumulator (1) and described auxiliary cylinder/piston apparatus (6.7), be provided with valve gear (31.32), described valve gear can be controlled, so that regulate the flow of fluid (30), thereby control moving of described piston (7).

3, according to the described injection device of claim 2, it is characterized in that, described auxiliary piston (7) is adapted to from described accumulator (1) fluid (30) to be supplied to this auxiliary piston (7) and has the one side of little diameter, and having bigger diameter at its opposite face, this face is to be connected with the fluid of described shot piston (10).

4, according to the described injection device of claim 2, it is characterized in that, the same accumulator of described auxiliary piston (7) (13) together, turn round as pressure multipier equally, the fluid that piston (7) has on the face of larger cross-section communicates with accumulator (13), and the fluid that piston (7) has on the face of small cross sections communicates with accumulator (1) by described valve gear (31,32), experiences pressure by the described shot piston of valve gear (87) (10).