DE1007715B - Piston pump for press cylinders, especially for hydraulic pit rams - Google Patents

Description

The invention relates to a piston pump for press cylinders, especially for hydraulic pit rams. The pump is shared with at least two Piston arranged piston rod equipped. The pistons can with the exception of one against the highest pressure promoting piston automatically according to the pressure in the press cylinder in can be made ineffective in a predetermined order.

Such a pump causes the plunger to move quickly out of the press cylinder. Bumps the moving plunger on resistance, it decreases automatically while increasing its pressure its speed. The pump piston, which is only used to extend the plunger, is of a much larger cross-section than the high-pressure pump piston. The advantages of such Pump lie in a shortening of the idle time of a pressing process.

It is known, for example, two-cylinder a ° Drigen pump the low-pressure cylinder with a pressure-limiting check valve acting against a predetermined spring force equip. The pressure in the press cylinder grows so far that in the the press cylinder feeding the low pressure cylinder the pressure overcomes the spring force, so the pressure fluid Returned to the suction chamber via the pressure relief check valve. In. the press cylinder then only the small high-pressure piston delivers. The throttling of the hydraulic fluid in the Pressure relief check valve has a bad one Efficiency result.

A patent application was made for hydraulic pit rams E 8438 VI / 5 c suggested a different pump built into the pit ram. At this During the pumping stroke of the piston rod, a high-pressure piston firmly seated on the piston rod takes the Low-pressure piston frictionally with a spring. A return spring takes care of the suction stroke Return of the low-pressure piston. If the pressure increases in the press cylinder and thus in the Low pressure cylinder of the pump the required driving force for the low pressure piston greater than that Spring force of the first-mentioned spring, the low-pressure piston remains in its initial position. These Design has the disadvantage that when pumping at high pressure, i. H. when pressing, with every pumphab the former spring must be compressed. This does not mean any loss of energy, however additional effort during the pump stroke.

The invention aims to mitigate the disadvantages of the known pumps: The efficiency should be improved, and the piston rod force should be piston pump for press cylinder,

especially for hydraulic

Pit stamp

Applicant:

Eisenwerk Wianheim GmbH,
Duisburg - Wanheim

Dipl.-Ing. Wilhelm Wilkenloh and Erich Jäger,

Duisburg-Wanheim,
have been named as inventors

be fully usable for the high pressure piston during pressing.

According to the invention, each of the pistons which become ineffective from a certain delivery head assigned a suction valve, which is influenced by a control member influenced by the pressure in the press cylinder during the delivery stroke can be kept open. Preferably, the invention provides that an under the effect of a restoring force of standing control pistons acted upon by a collecting space has a control piston rod. This can therefore lift positions depending on the pressure in the collecting space take in. Height-adjustable stop pieces are arranged on the control piston rod. With these, assigned suction check valves can be kept open independently of one another.

In particular, the invention provides a pump for hydraulic pit rams or similar devices which is built into the pit punch as part of it. It can be taken from the inner stamp suck out and directly into the, representing a press cylinder. Promote outside stamp in.

In this special construction, the invention provides preferential treatment one low and one combined to form a rigid piston body. High pressure piston in front. This piston body is guided in the inner punch and in a plunger. He owns in the field of Piston rod movement has a low stroke freedom compared to the piston rod, which enables it to act as a suction valve to act. Between the piston rod and the piston body is. a ring cross-section for the The passage of hydraulic fluid is left free. As an alternative or together with the latter, dleni Low pressure cylinder and the high pressure cylinder

709 508/124

Denes control member 25. The suction valves 23 and 24 contain, conical: valve body 26 with to the outside prominent extensions. 33. The control organ 25 contains a control piston 27 provided with a bucket cuff seal, which is movable against a spring 28. The control piston 27 sits on one Control piston rod 29 which penetrates the base of the control valve 25. On the control piston rod 29 sit Anschiägstücke 30, their. Altitude through

arranged a sleeve seal acting at the same time as a check valve. Between the high pressure cylinder and the press cylinder there is one at the same time
Cuff seal acting as a check valve
arranged so that despite the presence of several
Pump cylinder only with a single valve in the
Press cylinder is promoted. One under the effect
the restoring force standing, from the press cylinder of the
Outside stamp from pressurized, to. the piston rod guided control cylinder can be adjusted by the pressure in the screws 31. The piston rod is guided in a bearing 32, depending on the stroke position of the piston rod, depending on the compression space.

take in. The during the Praßhub in the direction of foot According to Fig. 2 is in a dienemr as a suction chamber 35

Plate-moving piston rod can, at low pressure, the cylindrical inner punch 36 of a pit in the press cylinder. A pump is installed in the piston body over the control ram. Take the inner wall of a cylinder with you in a non-positive manner. At high pressure in the outer punch 37 serves as the wall of a press cylinder ------ - · . ~ .. ^ Outer punch 37 contains a guide bush 38

and a base plate 39. It receives a plunger 40 which closes the press cylinder 59 at the top and attached to the lower end of the inner punch 36

Bottom of the low pressure cylinder is ao by sealing effect. At the upper end of the inner punch 36 is seated of the control cylinder against the suction chamber closed punch head 41. The plunger 40 contains a and open to the high pressure cylinder. While high pressure cylinder 43. The upper edge of the plunger the form-fitting entrainment of the piston body 40 is the bottom of a low-pressure cylinder 44. In through the piston rod, the bores to the center axis of the pit ram remain a hollow one The suction chamber is open, on the other hand that of the piston rod45 is then 25 with a band-like thickening .: The ring cross-section leading to the high pressure cylinder against the piston rod 45 is guided in a chamber 47 the suction chamber closed. The at the beginning of the suction and the partition between the high pressure cylinder 43 ■ stroke moving in the direction of the punch head and pressing cylinder 59. A common piston body The piston rod can first move forward to the piston body. 48 carries a low-pressure piston 49 and a lift and then through a drive plate 30 pressure piston 50. It is in the inner punch 36 and in the the piston rod. That way are

Press cylinder can the piston rod the piston body Take it along over one end face. During the frictional entrainment of the piston body via the control cylinder, there are holes in the

Both cylinders open towards the suction chamber during the suction stroke.

In the drawing, an embodiment according to the invention is shown. It shows

1 shows a longitudinal section through a pump with low, medium and high pressure pistons in general Design type,

Fig. 2 shows a longitudinal section through a pump

Intermediate cover 51 out. The piston body 48 forms with a piston rod 45 a ring cross-section 52 which is open on both sides. It rests on a driver disk 53 of the piston rod 45 and is movable towards 35 upwards. Its bottom contains holes 58. In the intermediate cover 51 sits a sleeve seal 54, which against a spring 72 in. Direction High pressure cylinder 43 is movable. In the-final ;, wall 42 of the high pressure cylinder 43 sits a Manr

Nieder- and Hochdruddcolben in special design, single _40- sleeve seal 56, which is movable against a spring 57 in the direction of a hydraulic pit ram, and the press cylinder 59 is movable. On the piston no

Fig. 3 is a longitudinal section through parts of a pump rod 45 sits a Steuerzylirtder 60, the bottom according to Fig. 2 in a different embodiment. lies below the collar-like thickening 46 and

In one of a pressurized fluid, for example, a sealing edge 71 and its sealing pressure oil surrounded pump according to FIG. 1 contains a 45 nut 61 on the piston rod 45 is guided. It is a cylindrical pump housing 1 with a low pressure ge. a spring 62 movable upwards. The cylinder 2, one. Medium pressure cylinder 3, a high pressure cylinder 4 and a collecting space 5. On one
Piston rod 6 sit a Niederdrudckolben, 7, a
annular central pressure piston 8 and an annular 50
ger high pressure piston 9. Seated in pump housing 1
a Versdiluß cover 10. In one for the low pressure piston 7 and the medium pressure piston 8 common piston body are an outlet valve 11 for
the medium pressure piston 8 and an outlet valve 12 for 55
the Niederdruddcolben 7. The valves are with a
Inclined bore 13 below and with an axial bore 14 and a transverse bore 15 with the
Collective space 5 connected. Between the medium pressure cylinder 3 and the high pressure cylinder 4 there is a man- 60 between the bottom of a control cylinder 74 and a chain seal 16. Between. Hochdrud <cylinders 4 _{emer 3SL he} d piston rod supported stop sleeve and collection chamber 5 is a Mansdiettendichtung 75 a spring 75. The open, on a collar-like 17 leading to the collecting space 5 sliding down against a spring 18 thickening 77 end of the control cylinder is movable 74th Between the collecting space 5 and encryption bösitzt an annular surface 84 and carries a Diditring closing nut 19 is a stitch tablets seal 20. On 6 ₅ 78 which fits sits in a corresponding recess of a pump housing 1 a connection piece 21 for the piston body 79th Piston pressure line, a suction valve 22 for the high-pressure rod 80 below the control piston 77 also carries a sealing cylinder 4, a suction valve 23 for the low-pressure ring 81, the cylinder 2 in the bore of the cross-section of the ring 82, and a suction valve 24 for the central vane - fits in. The bottom of the piston body 7 & has cylinder 3 and a. 70 Bores 83, ,,,,:,

movable upwards against a spring 62. The inner space of the control cylinder 60, which is sealed off by man-made diaphragm seals, is connected to the interior of the hollow piston rod 45 via transverse bores 63. . the wall of the inner punch 36 is seated with a crank 65 provided with a square pin 64, the eccentric pin of which engages in a link piece 66 fixedly connected to the piston rod 45. The end of the piston rod 45 slides in a base of the chamber, the other base of which is formed by an outlet valve body 68 under the action of a spring 67. This can by means of eccentric pin 69; a crank 70 can be lifted off the valve seat.
In the design of pump parts according to FIG. 3

Piston body 48 in contact, but the entrainment takes place through the. End face 55 of piston rod 45. The bores remain in this state 58 opened during the pressing stroke of the piston rod, so that 5 the pressure oil from the low pressure cylinder 44 into the Suction chamber 35 can flow back. The low pressure calving is now ineffective.

In the transition phase of the low pressure piston becoming ineffective, i. H. in the state in which the

During the outward stroke of the piston rod 6 one
The pump according to FIG. 1 flows through the low-pressure cylinder 2
via the suction valve 23 to pressure oil. The medium pressure cylinder 3 is pressurized through the outlet valve
11 and over the holes. 13, 14, 15, the plenum 5 and the connection clip 21 promoted in a press cylinder. At the same time, pressure oil is released from the
High pressure cylinder 4 via the check valve
acting cuff seal 17 and over the
Collection space 5 promoted in the press cylinder. When the control cylinder 60 is already slightly raised, on the inward stroke of the piston rod 6, the medium-pressure downward stroke of the end face 55 only has a small exhaust cylinder 3 and the high-pressure cylinder 4 above the suction level, to the opposite surface of the piston body 48.Dana is valves 24 and 22 on . The low-pressure cylinder 2 otherwise requires the free path of the pressure oil flowing out of the low-pressure cylinder via the outlet valve 12 and via the bore 44, greatly throttled. In this gene 14, 15, the plenum 5 and the connection 15 transition stroke, the pressure oil is able to trim under less 21 in the press cylinder. If the piston, the great pressure loss over the pressure cylinder acting as a valve, encounters resistance when moving out, that is to say Cuff diaphragm 54 in the high-pressure cylinder 43, the pressure in the control valve 25 increases, the overflow increases. Due to the presence of the cuff seal acting as a control piston 27 after a corresponding outward valve, a new equilibrium position compared to the 20 movement can even be dispensed with entirely on the ring cross-section 52. Spring 28 a. In the case of a predetermined pressure, however, that means that when the innierstnpels is moved out, the stop piece 30, which is set on the control piston rod 29 by means of screw 31, comes with the
Extension 33 of the valve body 26 of the suction valve 23 to the stop and holds it open
Niederdnickkolben 7 is then not in the promotion
more involved. The piston pushes the press cylinder
eventually comes to very great resistance, so it comes
also the stop piece 30 associated with the suction valve 24 with the extension 33 of this valve in 30 spring 67 standing discharge valve body 68 can be in contact, and the medium pressure piston 8 is just, - exceeding a maximum pressure in the chamber 47 if ineffective. In this state of the pump, only the high-pressure piston 9 is still delivering.

During the downward stroke of a pump according to FIG. H. when the crank 65 is turned, the sealing edge 71 35 comes into play of the control cylinder 60 with the piston body 48 in contact. The one located in the low pressure cylinder 44 Pressurized oil is when the piston rod 45 is moved further downward through the bores 58 and the

Ring cross-section 52 in, the high-pressure cylinder 43- 40 inner punch 36 from. In Fig. 2, this Abdichfördert takes place. At the same time, the penetration of the device through the sealing edge 71. The entrainment of the · The high-pressure piston 50 enters the high-pressure cylinder 43 in the piston body 79 through the control cylinder 74 displaced pressure oil from this cylinder. The displacement now over the ring surface84. With increasing oil Both cylinders are loaded with spring 57 and moved by the increasing oil pressure Cuff seal 45 acting as a check valve in the control cylinder 74 of this in the direction of the stop the. Press cylinder 59 promoted. In the case of sleeve 76 so far. until he stops with this the crank 65 caused the upward stroke of the piston. In this state, the sealing ring 78 engages rod 45, the piston body 48 initially no longer remains in the recess in the piston body 79 its bottom dead center. He won't get into it until later. The piston body 79 is carried along Driving plate 53 of the piston rod carried along, 50 by the lower edge of the collar-like thickening 77. so that between the sealing edge 71 of the control cylinder the ring cross-section 82 is duTch the sealing ring 81 and the piston body 48, an annular gap is formed. sealed while the holes 83 opposite Through this, oil from the suction chamber 35 can remain open via the suction chamber 35, the bores 58 in the low pressure cylinder 44 and in the per se advantageous sealing

about the, ring cross-section 52 in the. High pressure 55 Fig. 3 is the required stroke of the driving surfaces Cylinder 43 flow in until the piston rod 45 is larger than the piston body 79 compared to the has reached top dead center. In this way of working - - - -

the pump is pressurized oil into the press cylinder 59 conveyed and the inner punch 36 is lifted out of the outer punch until the punch head 41 60 comes to rest with the hanging wall, d. H. is charged. The load increases with further pumping the pressure in the press cylinder 59 and thus also in that via the transverse bores 63 The control cylinder 60 connected to the press cylinder. In 65 interaction with the spring 62, the control cylinder takes new equilibrium positions, and finally comes with its bottom with the lower edge the collar-like thickening 46 to the stop. Now the sealing edge 71 no longer comes with the 70

36 to accept a somewhat poorer degree of efficiency, since there is always a in the cuff seal 54 some pressure drop takes place.

To steal the pit punch, the drain valve body 68 is actuated by means of the crank 70 with eccentric 69 lifted from the valve seat, so that the pressurized oil through the hollow piston rod out of the press cylinder 59 can escape. The under the effect of

also open automatically. In this way, the pit punch is given the property of being resilient in the event of overload to be.

In the other embodiment for the cooperation of the control cylinder and piston body according to FIG. 3 seals when the piston rod moves downwards 80 the control piston 74 with the sealing ring 78 the recess of the piston body 79 relative to the

Sealing according to FIG. 2, so that in certain cases an arrangement according to FIG. 2 and in other cases an arrangement according to FIG. 3 appears advantageous.

Claims (12)

Patent claims: 1. Piston pump for press cylinders, especially for hydraulic pit rams, with at least two pistons arranged on a common piston rod, which with the exception of one against the highest pressure promoting piston automatically according to the pressure in the press cylinder in predetermined: sequence can be made ineffective., characterized in that each of which depends on a certain funding level Ineffective pistons (7, 8 or 49) are assigned a suction valve (23, 24 or 58, 71) is controlled by a control element (25 or 60, 61, 62) influenced by the pressure in the press cylinder can be kept open during the delivery stroke. 2. Piston pump according to claim 1, characterized in that that a standing under the effect of "a restoring force, from a collecting space (5) from the pressurized control piston (27) has a control piston rod (29), which is thus from the Pressure in the collecting chamber (5) can assume dependent stroke positions. 3. Piston pump according to claim 2, characterized in that on the control piston rod (29) in the height adjustable stop pieces (30) are arranged, with which associated suction valves (23, 24) can be kept open independently of one another. 4. Piston pump for hydraulic pit rams or similar devices according to claim 1, characterized in that it is part of the pit punch or the similar device is, can suck out of the inner punch (36) and directly into. den.Ein press cylinder representing outer stamp (37) can order into it f. 5. Piston pump according to claim 4, characterized in that that they have a low (49) and combined to form a rigid piston body (48) has a high pressure piston (50) which is guided in the inner ram (36) and in a plunger (40) is and in the area of the piston rod movement a low stroke freedom compared to the Piston rod (45), which enables it to act as a suction valve. 6. Piston pump according to claim 5, characterized in that between the piston rod (45) and the piston body (48) has an annular cross section (52) for the passage of pressure fluid is serene. 7. Piston pump according to claim 5, characterized in that between the low pressure cylinder (44) and the high-pressure cylinder (43) a sleeve seal (54) which also acts as a check valve is arranged. 8. Piston pump according to claim 6 and / or 7, characterized in that between the high pressure cylinder (43) and the pressing cylinder (59) also act as a check valve Cuff seal (56) is arranged so that despite the presence of several pump cylinders (43, 44) is promoted only with a single valve in the press cylinder (59). 9. Piston pump according to claim 8, characterized in that one under the action of a Restoring force standing, from the press cylinder (59) of the outer die (37) acted upon, on the Piston rod (45) guided control cylinder (60) stroke positions depending on the pressure in the press cylinder (59) can occupy opposite the piston rod (45). 10. Piston pump according to claim 9, characterized in that the piston rod (45) moving in the direction of the base plate (39) during the pumping stroke at low pressure in the press cylinder (59) can take along the piston body (48) via the control cylinder (60) in a non-positive manner ¹ and at high pressure in the press cylinder can take the piston body (48) with it in a form-fitting manner via an end face (55). 11. Piston pump according to claim 10, characterized in that during the non-positive Entrainment of the piston body (48) via the; Control cylinder (60) bores (58) in the bottom of the low-pressure cylinder (49) by sealing effect of the control cylinder (60) against the suction chamber (35) and closed to the high pressure cylinder (43) are open and that during the positive entrainment of the piston body (48) through the piston rod (45) the bores (58) to the suction chamber (35) remain open and the to the high pressure cylinder (43) leading annular cross ^ section (52) against the suction chamber (35) closed is. 12. Piston pump according to claim 11, characterized marked that the beginning of the Saughubeg piston rod moving in the direction of the punch head (41) first of all to the piston body (48) advance and then take it with you through a drive plate (53) of the piston rod (45) so that during the suction stroke: both cylinder chambers (43, 44) are open to the suction chamber (35). 1 sheet of drawings © 7OJ 508/124 4.