SU747740A1 - Hydraulic press - Google Patents

Description

one

The invention relates to the processing of metals by pressure, in particular, to hydraulic presses for extrusion.

A hydraulic extrusion press is known, which contains a power source with a suction and injection nozzle connected by means of a pipeline with a slider drive located in the guide beds, as well as with an ejector drive located coaxially with the slider 1.

The disadvantage of the press is that the reduction of the force of extrusion occurs only at the end of the deformation stroke, and also that the press has a complex structure.

The purpose of the invention is to simplify the design and ensure the constancy of the ratio of the speeds of the slide and ejector.

This goal is achieved by the fact that the press is equipped with a control valve connected at the inlet to the drive unit. ejector and, at the outlet, with the suction inlet of the power source.

FIG. 1 is a schematic diagram of a press; in fig. 2 - the circuit equivalent to the concept | press during the deformation stroke;

Fig.3.4 - variants of the device for. adjusting the speed ratio of the slider and ejector; FIG. 5 is a schematic of the deformation of the workpiece. 5 A hydraulic press contains a bed 1 with fixed crossbars, one of which is equipped with a hydraulic actuator of the slide, including the hydraulic cylinder 2 with the drive 3 and 10 with the rod 4 to which the slide 5 attached to the bed guide is attached, a punch 6 with a punch 7 attached to the slider 5, the workpiece 8 being in

15 to the matrix 9 fixedly attached to the press table, a hydraulic actuator of the ejector consisting of a hydraulic cylinder 10 with a plunger 11f to which a mobile yoke 12 is attached

20 mounted on it by the ejector 13, guided along the die 9, the stops 14 attached to the movable cross member, which serve to limit

: stroke of the slide 5, and a hydraulic actuator, including a pump 15, driven by an electric motor 16 connected to it by means of a clutch, hydrodistributor 17 connected to the hydraulic drive of the slide and hydraulic actuator

30 ejector and used for pushing the workpiece | the ratios of the velocity of the slider and ejector on the course of deformation.

The press works as follows. After loading the workpiece 8 into the matrix 9, the electric motor 16 drives the action of the pump 15, which sucks the working fluid from the tank through the directional valve 19 included in position a and delivers it through the directional control valves 17 and

18c, the working fluid presses on the punch 7 by moving the rod 4 with the slider 5 towards the workpiece. At the same time, the working fluid from the lower cavity of the upper hydraulic cylinder 2 is discharged through the hydraulic distributor 18 into the drain tank. As soon as the punch 7 touches the workpiece 8, the approach stroke ends, the valve

19 switches to position b and the liquid from the lower cylinder 10 begins to be pumped to the upper cylinder 2, driven downwardly by the yoke 12, and its speed is less than the speed of the slide. 5, This ensures the movement of the workpiece in the Extrusion Process relative to the fixed matrix 9. The frictional forces acting from the matrix on the workpiece decrease and this reduces the specific pressure on the punch 7 and increases its durability. At the end of the deformation stroke, the stops 14 are in contact with the slider 5, which provides the necessary thickness: at the bottom of the workpiece. When this happens the switching valves

17 and 18 in position b, and the hydraulic distributor 19 in-position a, and the pump from the tank begins to supply fluid to the lower cavity of the hydraulic cylinder 2, ensuring the rise of the slide upwards. The liquid from the upper cavity of the hydraulic cylinder 2 through the hydraulic distributor 17 is fed into the hydraulic cylinder 10, acts on the plunger 11, which causes n upward movement of the yoke 12 and the ejector 13 pulls out detail B.

The speed of movement of the slider 5 and the traverse 12 can be expressed by the following equations:

vt

 (g)

4de .V - the speed of the slide)

 traverse speed; Q - pump flow rate; S (- the area of the piston of the upper cavity of the hydraulic cylinder 2, the area of the plunger 11 of the hydraulic cylinder 10.,

Divide: equation (1) by equation (2), we get:

V.

(3)

H s

For speed V to be greater than speed Vj, it is necessary that area Sj be greater than area S

Consequently, in the proposed press, the ratio of the speeds of the slider and the traverse along the whole course of deformations is maintained.

The value of the ratio of the speeds of the slider and crosshead can be changed within the specified limits in one of the following ways.

In the first method (Fig. 3), a throttle flow control valve 20 connected to a slug tank is included in the press hydraulic system. The speed of movement of the slide and the crosshead can be expressed by the following equations:

(5) subject to (b), we get

  52. /. / -,)

V, S, V Q / By changing the flow rate, you can adjust the ram speeds of the slide and the crosshead.

In the second method (FIG. 4) a pump Hj is switched on in the hydraulic system of the press, with adjustable capacity. The speeds of the slider and the traverse can be expressed by the following equations:

(eight)

Si Q. (9)

2

Si

Q Q + ig (and in equation (8) on the equation taking into account (10), we get:

V-1 .. S5L and X QAJ

one

(111

Qi

V,

This adjustment method makes it possible to reduce the area of the plunger $ 2. , which allows to reduce the size of the hydraulic cylinder 10, and hence the press.

Claims (1)

1. USSR author's certificate No. 338061, cl. B 30 E 1/32, 1971. Pi / PG