SU1323413A1 - Hydraulic overload safety device for power press - Google Patents

Abstract

The invention relates to mechanical engineering, in particular to the design of hydraulic safety devices against overloading of mechanical presses. The aim of the invention is to increase reliability. The device contains mounted in the slide hydraulic rod connecting rod 2, pneumohydraulic- (L with FMG /

Description

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cue pump 3 connected by channels with check valves with hydraulic support and filling tank 4; in the cavity of the cover 30 of the pneumatic cylinder 9 there is

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differential spool, interaction 5 piston 12 under compressed air or

Pushing when the fluid from the spring 37, providing discharge

half a tank 4 into the cavity 7 in terms of the fluid of the required pressure in succession with the piston 12 pneumatic cavity 7. 1 hp f-ly, 4 ill.

The invention relates to mechanical engineering, namely to hydraulic safety devices against overloading of mechanical presses.

The purpose of the invention is to increase reliability.

FIG. 1 shows a device, a longitudinal section; in fig. 2 is a view A of FIG. one; in fig. 3 shows the node I in FIG. one; in fig. 4 is a section BB in FIG.

The hydraulic safety device against overloading the mechanical press contains a hydraulic rod mounted in the slider 1 of the press and also mounted on the slider 1 pneumatic-hydraulic plunger pump 3 with a filling tank 4.

The hydrosuit includes 1 cup 5 mounted in the bore of the slider, and a piston L in it, which forms a chamber 7 with the cup cavity 5 and is filled with working fluid.

The pneumatic-hydraulic plunger pump 3 consists of a hydraulic cylinder 8 coaxially with each other and a pneumatic cylinder 9 rigidly connected with it.

A cylindrical hollow 11 is made in the housing 10 of the hydraulic 1Shchindra 8, on the side opposite to the pneumatic cylinder 9, communicating with the cavity of the filling tank 4 tightly connected to the end of the housing 10 of the hydraulic cylinder 8.

The piston 12 of the pneumatic cylinder 9 is rigidly connected to the plunger 13 entering the working cavity 14 of the hydraulic cylinder 8. The latter are not connected with the panels 15 and 16 fastened to its housing 10. The cavity 14 is hydraulically

the cylinder 9 by means of a shank 44 and with a glass 43. The plunger 13 at the same time performs reciprocating movements under the action of the

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five

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five

The cylinder 8 is connected by a channel 17 through the check valve 18 installed therein and the filter 19 with a cavity 11 communicating with the tank 4.

Channel 17, in turn, is connected via channels 20 and 21 with the chamber 7 of the hydraulic support. At the same time, channel 21 communicates with camera 7 through a non-return valve 22. Channel 21 is connected to a sensor, which sends a signal to the press control system (not shown) that the hydraulic safety device is ready for operation, and in case of press overload, a signal to turn off the press. Sensor Contains plunger 23, spring 24, rigidly connected to plunger 23, pusher 25, which interacts with a limit switch 26 electrically connected to the control system, and also threaded cup 27 for adjusting spring force 24. valves 18 and 22, as well as their quick change in case of failure without disassembling the entire device, the latter are mounted in panel 1 5.

In the other panel 16 connecting the hydraulic cylinder 8 with the plunger 1 and the "glass 5", a retaining valve 28 is placed, mounted in the channel 29, connecting the hydraulic support to the filling tank 4, I

The pneumatic cylinder 9 is provided with a cylinder 30 attached to its end, with a cylindrical cavity 31 formed therein, in which a control spool 32 is mounted. The device is equipped with an abutment 34 that is adjustable along the longitudinal axis 33 of the pneumatic cylinder 9, through which

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axial channel 35, as well as threading 36, interacting with counter threading, made in the cap 30. The stop 34 is fixed in the cover 30 under the spool 32. To return the piston 12 of the pneumatic cylinder 9 to the lowest position up to the stop with the gear 30 in the device spring 37 is provided.

The control valve 32 is made differential with three working platforms 38-40. The area of the working platform 40 is larger than the area of the working platform 39, the area of the working platform 38 is smaller than the area of the working platform 39. The largest and smallest areas 40 and 38 are equipped with end cuffs 41 and 42.

The spool 32 is fixed between the stop 34 and the piston 12 with the ability to interact with the latter. For this, a threaded cup 43 is screwed into the central threaded hole in the piston 12 with a hole in the bottom part for the passage of the shank 44 of the spool 32 and the cylindrical ring 45 fixed on the shank 44, the outer diameter, which is larger than the diameter of the hole in the bottom of the cup 43. At that The connection between the ring 45 and the bottom of the cup 43 corresponds to the stroke of the piston 12.

In 30 there is an annular projection 46, located in the cylindrical cavity 31 above the largest working platform 40 of the spool 32, as well as through vertical channels 47 located inside the annular protrusion 46, which communicate cylindrical

the cavity of the cover and the sub piston cavity 40 of the action of the end cuff 41 with a col 48 of the pneumatic cylinder. For supplying compressed air, a channel 49 is provided in the device; it is made in the cavity 30 and supplied to the cylindrical cavity 31. For exhaust of the air from the piston cavity 48 in the cavity 30, a channel 50 is made

The device has an adjustable valve for controlling the limiting pressure of the working fluid that occurs in the hydraulic bearing when the press is overloaded (not shown),

The device works as follows

In the initial position, the piston 12 of the pneumatic cylinder 9 is in its lowest position and pressed by the spring 37 to the cover 30,

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the spool 32 is located between the stop 34 and the piston 12. The end cuff 42 overlaps the channel 35 of the stop 34. The annular protrusion 46 forms a gap with the toddler 41. The spherical end of the shank 44 of the spool 32 contacts the end of the piston 12. The chamber 7 of the hydraulic bearing and all the channels are filled-working by the body. In order to create pressure of the working fluid in the chamber 7 of the hydraulic support, at which the press performs technological operations, the plunger pump 3 is actuated.

To do this, compressed air through the channel 49, the gap between the annular protrusion 46 and the cuff 41, the channels 47 is fed into the piston cavity 48, It acts on the piston 12 and, overcoming the resistance of the spring 37, moves it together with the plunger 13, resulting in the working fluid from the cavity 14 of the hydraulic cylinder 8 through the channels 17, 20, 21 through the check valve 22 is injected into the chamber 7 of the hydraulic support. In the process of moving the piston 12, the spool 32 is pressed against the stop 34 by the resultant force arising due to the effect of compressed air on working platforms 40 and 39, which have a different area.

25

thirty

At the end of the stroke of the piston 12, the bottom of the threaded cup 43 interacts with the ring 45, as a result of which the piston 12 moves the spool 32. When this happens, the channel 35 is unlocked and the channels 47 are locked due to the coupling 5

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five

Target projection 46,

As the compressed air supply to the sub-piston cavity 48 stops, the piston 12 moves in the opposite direction under the action of the spring 37, and the air from the sub-piston cavity 48 is forced into the atmosphere through the channels 50 and 35.

The channels 47 in the process of moving the piston 12 in the opposite direction are blocked by the pressure of compressed air to the platform 39 and the air displaced from the piston cavity 48 to the platform 38 of the spool 32 Filling the cavity 14 of the hydraulic cylinder 8 with the working fluid from the filling tank 4. channel 17 through filter 19 ti

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check valve 18 during the return stroke of the plunger 13.

At the end of the return stroke, the piston 12 interacts with the spherical end of the shank 44, displacing the valve 32 in the direction of the stop 34. At the same time, the channel 35 is blocked by the end cuff 42, and the annular projection 46 moves away from the end cuff 41. As a result, the compressed air re-enters into the piston cavity 48 and moves the piston 12 and the plunger 13, which, through the channels 17, 20, 21, through the check valve 22, pumps a new portion of the working fluid into the chamber 7 of the hydraulic bearing, i.e. The plunger pump cycle is repeated. In the process of pumping the working fluid into the chamber 7, the check valve 18 cuts off the filling tank 4 from the cavity 14.

As the pressure of the working fluid in the chamber 7 of the hydraulic support increases, the pressure in the channel also increases. 21, which is transmitted to the piston 23 of the sensor.

After reaching a predetermined pressure of the working fluid in the chamber 7, the plunger 13 stops and the piston 23 compresses the spring 24, acts on the limit switch 26, which gives an enabling signal to turn on the press.

When the press is overloaded, a valve is activated, which controls the limiting pressure in chamber 7 (not shown). The piston 6 moves down, and the working fluid from chamber 7 through channel 29 through retaining valve 28 is poured into the filling tank 4. Due to a sharp drop in pressure in chamber 7, the piston 23 is returned to its original position by the action of spring 24. The pusher 25 moves away from the end switch 26. The press stops.

The economic effect of using the proposed invention to 137

This is due to increased reliability and ease of use.

Claims (2)

1. Hydraulic safety device against overloading a mechanical press containing a hydraulic rod of a connecting rod mounted in a slider, connected by a cannon with a check valve installed in them, respectively, with a hydraulic bearing and filling tank, a pneumatic-hydraulic plunger pump mounted on a slider with a pneumatic cylinder c. The control valve is located in the cavity, characterized in that, in order to increase reliability, it is equipped with an abutment adjustable along the axis of the pneumatic cylinder, a cylindrical ring, a cup with a hole and a spring, the spool is made differential with a large and small working platform and shank and installed between the stop and the piston of the pneumatic cylinder coaxially with the latter, the spring is installed in the pneumatic cylinder with the ability to cooperate with the piston, the cylindrical ring is fixed on the shank of the slide valve, the glass with the hole is mounted on the pneumatic cylinder piston, in a crush there is an annular protrusion protrusion, communicating the cavity Krsh1ki and podpisnevuyu cavity of the pneumatic cylinder, while the shank of the valve is placed in the hole of the glass with the possibility of interaction of cyl Indrical ring with the inner surface of the glass, and the shank - with a pneumatic cylinder piston. 2. The device according to claim 1, characterized in that it is equipped with a panel mounted on the housing of the hydraulic cylinder of the pump, while the check valves are mounted in the panel. Vida / 15 -F25 itzt tid FIG. 2 Fig.Z Bb 21. H 27