HIGH-PRESSURE PLUNGER PUMP AND METHOD FOR THE FUNCTIONAL INTERRUPTION OF A FLUID FLOW

Abstract

A high pressure plunger pump, having at least one plunger arrangement which comprises a working space connected to a valve seat suction line and a valve seat pressure line, in which a plunger is arranged in an axially reciprocable manner, wherein the valve seat pressure line is closeable by a pressure valve and the valve seat suction line by a suction valve, and the suction valve can be kept in an open position in a controlled manner as required by means of a counter-pressure device, is designed so that the counter-pressure device has a supply line via which a control fluid can be guided to the suction valve for keeping the suction valve open, wherein a low-pressure pump is connected to the supply line for generating pressure of the control fluid.

Claims

1. High-pressure plunger pump, having at least one plunger arrangement which has a working space connected to a valve seat suction line and a valve seat pressure line, in which a plunger is arranged in an axially reciprocable movable manner, wherein the valve seat pressure line is closeable by a pressure valve and the valve seat suction line by a suction valve, and the suction valve can be kept in an open position in a controlled manner as required by means of a counter-pressure device, wherein the counter-pressure device has a supply line via which a control fluid can be guided to the suction valve for keeping open the suction valve, wherein a low-pressure pump is connected to the supply line for generating pressure of the control fluid.

2. High-pressure plunger pump according to claim 1, wherein a control valve is provided upstream of the low pressure pump and a shut-off valve is provided upstream of a hydraulic consumer which is in connection with the valve seat pressure line, which are simultaneously closeable for the functional interruption of a fluid flow emerging from the hydraulic consumer.

3. High-pressure plunger pump according to claim 1, wherein the control valve and the shut-off valve can be actuated via a preferably programmable controller.

4. High-pressure plunger pump according to claim 1, wherein the suction side of the low-pressure pump and the suction side of the high-pressure plunger pump are connected to a common fluid source.

5. High-pressure plunger pump according to claim 1, wherein the supply line opens into a control channel in which a pin of the suction valve is guided axially displaceable, wherein the control fluid is applied with low pressure to the free end face of the pin acting as a plunger.

6. High-pressure plunger pump according to claim 1, wherein the pressure force of the control fluid is greater than the spring force of a compression spring, with which the suction valve can be pressed against a valve seat.

7. High-pressure plunger pump according to claim 1, wherein a gap seal is formed between the pin and the wall of the channel.

8. High-pressure plunger pump according to claim 1, wherein the supply line, the control channel, the valve seat suction line and the valve seat pressure line are provided in a valve seat ring, wherein the suction valve can be applied in a spring-loaded manner to the valve seat ring on the side facing the associated plunger and the pressure valve on the opposite side.

9. Method for functionally interrupting a fluid flow emerging from a hydraulic consumer of a high-pressure plunger pump, in which an axially movable suction valve is kept in an open position in a controlled manner as required and independently of the position of the associated plunger, wherein the suction valve is held hydraulically in the open position which is controlled as required.

10. Method according to claim 9, wherein a fluid similar to a pressure fluid is used as a control fluid.

11. Method according to claim 9, wherein the control fluid and the pressure fluid are drawn from a common fluid source.

12. Method according to claim 9, wherein during the functional interruption a nozzle supply line is closed on the one hand by the pressure valve and on the other hand by a shut-off valve associated with a hydraulic consumer, e.g. a nozzle, while maintaining the working pressure.

13. Method according to claim 9, wherein a control valve, with which a control fluid acting on the suction valve can be activated, and the shut-off valve are closed simultaneously during the functional interruption of the fluid flow and remain closed.

14. Method according to claim 9, wherein when arranging a plurality of suction valves each associated with a plunger, these are simultaneously brought to and held in an open position for functional interruption of the fluid flow and remain closed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 shows a partial section of a high-pressure plunger pump in a longitudinal sectional view;

[0026] FIG. 2 shows a partial section of the illustration in FIG. 1 in an enlarged view;

[0027] FIG. 3 shows a schematic diagram of the high-pressure plunger pump;

[0028] FIG. 4 shows a functional measurement sheet of high-pressure plunger pump.

[0029] In FIGS. 1 and 2, a head portion of a high-pressure plunger pump 21 is shown, having a plunger arrangement 1, which has a working space 16 connected to a valve seat suction line 6 and a valve seat pressure line 15, in which a plunger 2 is arranged axially movable back and forth, according to the arrow in FIGS. 1 and 2.

[0030] The valve seat pressure line 15 can be closed by a pressure valve 4 and the valve seat suction line 6 by a suction valve 5, wherein the suction valve 5 can be kept in an open position in a controlled manner as required by means of a counter-pressure device 7.

[0031] As shown, the counter-pressure device 7 comprises a supply line 9, which is in connection via a connecting line 10 with a low-pressure pump 20 (FIG. 3), via which a control fluid can be guided to the suction valve 5, wherein the connecting line 10 extends between the valve seat suction line 6 and the pressure valve.

[0032] The suction valve 5 has a valve cone which sits close in a spring-loaded manner in the closed position of the suction valve 5 by means of a compression spring 13 against a valve seat of a valve seat ring 3, namely on the side facing the plunger 2.

[0033] A pin 12 acting in the sense of a plunger is connected to the valve cone of the suction valve 5 on the side facing away from the plunger 2, which pin is axially displaceably guided in a concentric control channel 11 of the valve seat ring 3 and into which the supply line 9 opens, so that the supplied control fluid is applied with pressure to the end face of the pin 12. In this case, the pin 12 and the channel 11 are dimensioned so that there is a low-friction gap seal between the two.

[0034] FIG. 2 shows an enlarged detail of the plunger arrangement 1 in the region of the valve seat ring 3.

[0035] It can be recognized that the suction valve 5 is in an open position, i.e. the passage between the valve seat suction line 6 and the working space 16 is open, wherein the plunger 2 is in an upper dead center. A bottom dead center UT is indicated by dashed lines. Since the strokes of the plunger 2 are carried out continuously, the fluid is pushed back in a pressure stroke of the plunger 2 into the valve seat suction line 6 and thus into a fluid source 22 (FIG. 3).

[0036] While the suction valve 5 is open and remains open for a predetermined time via the control fluid, namely against the pressure of the compression spring 13, the pressure valve 4 closes the valve seat pressure line 15 by the fluid flow being under pressure in the pressure line 8 with the assistance of a compression spring 14.

[0037] In order to terminate the functional interruption of the fluid flow, both a control valve 19, which is visible in FIG. 3, as well as a shut-off valve 18 are opened, which is provided directly upstream of a hydraulic consumer such as a nozzle 17 in this example, so that, on the one hand, the suction valve 5 closes due to the now missing control pressure and the pressure valve 4 opens, while the pressure fluid is supplied via the valve seat pressure line 15 and a pressure line 8 to the nozzle 17.

[0038] During this so-called functional time of the fluid flow, the low-pressure pump 20 conveys pressureless into the fluid source 22 common to the high-pressure plunger pump 21.

[0039] For simultaneous switching of the control valve 19 and the shut-off valve 18, a controller 23, which is likewise recognizable in FIG. 3, is provided, which is programmable according to the intervals of the functional interruption of the fluid flow.

[0040] For functional interruption, therefore, the control valve 19 and the shut-off valve 18 are simultaneously closed, so that control fluid is conveyed via the low-pressure pump 20 into the control channel 11 and the suction valve 5 is kept open according to the closing time of the control valve 19.

[0041] In FIG. 3, three plunger arrangements 1 of the high-pressure plunger pump 21 are shown in a circuit diagram, the suction valves 5 of which are simultaneously actuatable. The plunger arrangements 1 are designed in a suitable manner so that in function the fluid pressure applied to the nozzle 17 remains the same over the entire functional duration.

[0042] FIG. 4 shows a functional measuring sheet of the high-pressure plunger pump 21 according to the invention, wherein the operating pressure is plotted on the ordinate axis and the operating times on the abscissa axis.

[0043] The functional duration is recognizable with F, in which the fluid is applied at a pressure of about 3400 bar over a period of about 0.6 sec.

[0044] Thereafter, the function of the fluid flow is interrupted over a period NF, in which the suction valve 5 is opened.

[0045] It can be seen in FIG. 4 that the same fluid pressure is present in the time span NF in the pressure line 8 as in the functional time span F, namely approximately 3400 bar.