EP2558731A1

EP2558731A1 - Pressure/flow regulator

Info

Publication number: EP2558731A1
Application number: EP11712484A
Authority: EP
Inventors: Christian Spielvogel; Friedemann Nordt; Carola Diebold
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2010-04-16
Filing date: 2011-03-30
Publication date: 2013-02-20
Also published as: CN103097742A; DE102010048070A1; CN103097742B; US9441747B2; US20130199631A1; WO2011128027A1

Abstract

The invention relates to a pressure/flow regulator (3), comprising a pressure control valve (17), a flow control valve (19), and a first control connection (A) for setting a variable displacement pump (5), wherein the control connection can be discharged to a tank (T) by the flow control valve by means of a control edge of the pressure control valve that is open in the idle position of a valve piston of the pressure control valve.

Description

description

Pressure and flow controller

The invention relates to a pressure-flow regulator according to the preamble of patent claim 1.

Pressure flow regulators have a pressure control valve and a flow control valve, each having a valve bore and a common control pressure connection, via which a pivoting angle of a variable displacement pump is controlled.

In the publication DE 101 36 416 A1 and in the prospectus of Sauer Danfoss 520L0519 Rev FN July 2009 pressure flow regulator are disclosed in which the regulated from the flow control valve pressure fluid to the control pressure port always passes the pressure control valve.

In the document DE 101 36 416 A1 and in DE 199 04 616 A1, in each case a pressure-flow regulator is shown, whose pressure control valve connects the control connection to a tank via a control edge of the flow control valve that is open in the rest position of the flow control valve.

For all o.g. Publications is regulated via the so-controlled pressure medium of the control port, a swivel angle of a variable.

A disadvantage of the said pressure-flow regulators is the effort that is necessary for the production of the channels.

In contrast, the invention is based on the object to provide a pressure-flow regulator with reduced manufacturing costs.

This object is achieved by a pressure-flow regulator with the features of claim 1. The pressure-flow regulator according to the invention has a pressure control valve and a flow control valve and a first control port, wherein the control port is relieved from the flow control valve via a open in a rest position of a valve piston of the pressure control valve control edge of the pressure control valve to a tank. Thus, the production cost of the pressure-flow regulator is reduced because the channels are designed less expensive.

Further advantageous embodiments of the invention are described in the dependent claims.

In a particularly preferred application, a pivoting angle of a variable displacement pump is adjusted via the pressure flow regulator. For this purpose, the first control port is connectable or permanently connected to a control chamber of an actuating cylinder of the variable displacement pump.

The control port is preferably connected via a first straight channel to the pressure regulating valve and to the delivery flow control valve, wherein the first channel is a valve bore of the pressure regulating valve and a valve bore of the

Flow control valve approximately at right angles cuts.

In a preferred embodiment, the valve piston is received in the valve bore of the pressure control valve, wherein the first channel can not be interrupted by the valve piston.

It is preferred if a control collar of the valve piston of the pressure regulating valve is narrower than the first channel, so that the control collar can be flowed around. Thus, the connection from the flow control valve to the control port can not be shut off by the valve piston of the pressure control valve.

A preferred development of the pressure-flow regulator according to the invention has a tank connection, which is connected via a second straight channel with the pressure control valve and with the flow control valve. It is preferred if the second channel also intersects the valve bore of the pressure control valve approximately at right angles and the valve bore of the flow control valve intersects approximately at right angles or opens into it.

If the second channel is narrower than a control collar of the valve piston of the pressure regulating valve arranged there, the second channel can be shut off by the control collar of the pressure regulating valve.

A preferred development of the pressure-flow regulator according to the invention has a second control connection, which is connected to a working line of the variable displacement pump, so that pump pressure is applied to the control connection. In this case, the control port is connected to a respective end-side pressure chamber of the pressure control valve and the flow control valve, so that acts by the pump pressure, a force in the opening direction of the two valve piston.

In a further development of the control port is connected via a third straight channel with the two pressure chambers, whereby the third channel, the valve bore of the pressure control valve and the valve bore of the flow control valve intersects approximately at right angles.

Preferably, the second channel and the third channel are parallel to the first channel. This reduces the production costs for the channels.

Preferably, the first channel and / or the second channel and / or the third channel is a bore. Thus, the channels can be easily made with a drill.

Preferably, a bias of a spring of the pressure control valve or a spring of the flow control valve, which counteracts a pressure of the second control port, adjustable via a clamped in the associated valve bore sleeve. This allows manufacturing tolerances and material fatigue of the spring can be corrected.

It is preferred if the sleeve is a tapered sleeve, in which a truncated cone is clamped. This solution is device-technically simple. Or the bias of the springs of the pressure control valve and the flow control valve can be adjusted in the classical manner via a screwed into the associated valve bore screw.

In a preferred embodiment of the pressure-flow control according to the invention, the pressure of the second control terminal counteracting spring of the pressure control valve is arranged in a spring chamber, which is relieved to the tank.

In a preferred embodiment of the pressure-flow control according to the invention, the pressure of the second control terminal counteracting spring of the flow control valve is arranged in a spring chamber which is connected to at least one powered by the variable displacement consumer via a load reporting.

In the following, various embodiments of the invention will be described in detail with reference to FIGS. Show it:

Figure 1 is a hydraulic circuit diagram of a pressure-flow control device according to the invention with a variable displacement pump;

FIG. 2 shows a perspective view of a first exemplary embodiment of a pressure-flow regulator according to the invention;

Figure 3 shows the first embodiment of a pressure-flow control according to the invention in the lateral section;

Figure 4 shows a second embodiment of a pressure-flow control according to the invention in the lateral section;

Figure 5 shows the second embodiment of a pressure-conveying flow regulator according to the invention in a view; and Figure 6 shows a third embodiment of a pressure-flow control according to the invention in the lateral section.

The circuit diagram of the pressure-flow regulator 3 of Figure 1 is particularly true for the embodiment shown in Figures 4 and 5 of the pressure-flow regulator with a throttle forming transverse bore 131. The circuit diagram of the pressure-flow regulator 3 according to Figure 1 also largely applies to the in Figures 2 and 3 shown embodiment and for the embodiment shown in Figure 6.

A pivoting angle of the variable displacement pump 5 can be changed via two adjusting cylinders 7 and 9. To reduce the swivel angle is supplied via the control pressure port A the actuating cylinder 7 via the pressure-flow regulator 3 pressure medium. Counteracts the other actuating cylinder 9, in which the pump pressure is present. To increase the pivoting angle of the adjusting cylinder 7 is connected via the pressure flow regulator 3 with tank, so that the adjusting 5 is adjusted in the direction of greater swing angle by the pressure force of the actuating cylinder 9 and the force of a spring 11. About the set in this way swivel angle of the pressure or the flow rate is controlled at a working line 13 of the variable 5.

Furthermore, the pressure-flow regulator 3 and the variable displacement pump 5 have a common tank connection T. In addition, the pressure-flow regulator 3 has a load-signaling connection LS, via which the highest working pressure of a plurality of consumers supplied by the variable-displacement pump 5 via the working line 13 is reported. If only one consumer is supplied, its working pressure is reported.

The pressure-flow regulator 3 has a pressure control valve 17 and a flow control valve 19. Both valves 17, 19 are designed as proportionally adjustable 3/2-way valves and each have an adjustable spring 14, 16 in the direction of the rest position shown in FIG respective valve piston of the valves 17, 19 acts. In these two rest positions of the actuating cylinder 7 is relieved via the control pressure port A, via the two valves 17, 19 and a tank line 21 to the tank T, so that the pivot angle of the variable 5 is set maximum. Also in Rieh tion of the illustrated rest position of the flow control valve 19 acts on the load message port LS applied pre-described control pressure.

On the valve piston of the valves 17, 19 also acts on the port P and the control pressure line 15, the pump pressure in the working line 13. Thus, when the force generated by the pending in the working line 13 pump pressure force is greater than the respective counterforce, the valve piston of Valves 17, 19 are set such that via the control pressure port P, the control pressure line 15 and the control pressure port A to the actuating cylinder 7 pressure medium supplied and thus the variable displacement pump 5 is pivoted back.

Both valves 71, 19 are shown in their respective rest positions where the respective valve pistons (see Figures 3, 4, and 6) are in their respective rest positions.

An output A _{D of} the pressure control valve 17 is connected via the flow control valve 19 to the control port A of the pressure-flow regulator 3 and the variable displacement 5.

In the illustrated rest position of the pressure control valve 17, the flow control valve 19 can produce the necessary connections. When the pressure control valve 17 begins to regulate, the flow control valve 19 is in the rest position, since the pressure at the load reporting port LS has approximated the pressure at the control port P (pump pressure). Then the pressure control valve can make the various connections.

Figure 2 shows a first embodiment of a pressure flow control device 3 according to the invention, the housing is designed as a cartridge 1. This can be screwed space saving in a (not shown) variable.

On the outer circumference of the built-in cartridge 1, the control pressure port A and the tank port T are arranged, while the end face of the control pressure port P is provided. The latter serves to "signal" the pump pressure of the variable displacement pump 5 (not shown in FIG. 2), wherein each of the two valves 17, 19 has a bore of the Control pressure port P is assigned. The control pressure port A is used to adjust the pivot angle of the variable displacement pump 5 via the actuating cylinder 7, and the tank port T is connected to the tank (see Figure 1).

Adjacent to the control pressure port P is provided in the cartridge 1 a continuous transverse bore 2, which is explained with reference to Figure 3. For screwing the mounting cartridge 1 in the variable displacement pump a two-fold is provided, of which in Figure 1, only a planar portion 4a is shown.

Figure 3 shows the first embodiment of a pressure-flow control device 3 according to the invention in a sectional view. The pressure control valve 17 has a valve piston 6, and the flow control valve 19 has a valve piston 8. The valve piston 6, 8 are each biased by a flat spring plate 10, 12 of a respective spring 14, 16 (in Figure 3) to the left in their rest position shown , The movement of the valve piston 6, 8 (in Figure 3) to the left is limited by a stop pin 18 which is pressed into the continuous transverse bore 2.

About the voltage applied to the control pressure port P control pressure, the valve piston 6, 8 and the associated spring plate 10, 12 (in Figure 3) to the right in their switching positions proportionally displaced. This movement against the force of the springs 14, 16 is limited by respective cylindrical stop pins 20, 22 which are received parallel to a central axis 24 of the pressure-flow regulator 3 in the interior of the respective spring 14, 16.

The springs 14, 16 are each supported on a disc 26, 28, which are each supported via a spacer sleeve 30, 32 on a respective cone sleeve 34, 36. The two conical sleeves 34, 36 are fixed in the respective valve bore 38, 40 frictionally. For this purpose, the conical sleeves 34, 36 have frustoconical inner recesses into which corresponding truncated cones 42, 44 are pressed. The pressing was carried out during assembly of the pressure-flow regulator 3 by moving or pulling the truncated cones 42, 44 in the associated conical sleeves 34, 36 (in Figure 3) to the right. As a further connection of the flow control valve 19 of the load-indicating connection LS is provided. A spring chamber of the flow control valve 19 is connected via a transverse bore with the load-signaling connection LS, while a spring chamber of the pressure control valve 17 is connected via a formed between the valve piston 6 and the valve bore 40 fluid connection and a transverse bore portion with the tank port T.

Between the (in FIG. 3) right or outer end section of the installation cartridge 1 and the load-signaling connection LS, and between the load-signaling connection LS and the tank connection T, and between the tank connection T and the control pressure connection A, as well as between the control pressure connection A and the control pressure Final P is in each case a sealing ring 46 disposed on the outer circumference of the cartridge 1.

By the rest positions of the valve piston 6, 8 shown in Figure 3, connections between the control pressure ports A and P are shut off by a respective piston collar of the two valve pistons 6, 8, while the control pressure port A via two transverse bore sections and one between the valve piston 8 and the valve bore 38th formed pressure fluid connection and connected via two transverse bore sections with the tank port T and thus relieved to the tank. By pressurizing (the two holes) of the control pressure port P, the two valve pistons 6, 8 respectively against the force of the associated spring 14, 16 (in Figure 3) to the right, both valves 17, 19 a connection from the control pressure port P to the control pressure port A. on dear. Thus, the variable displacement pump 5 (cf., FIG. 1) is pivoted back so that its pressure and / or its delivery flow are reduced. The pressure regulating valve 17 has decision priority before the flow control valve 19.

FIG. 4 shows a second exemplary embodiment of a pressure-flow regulator 103 according to the invention in a lateral section. In the following, only the differences from the first exemplary embodiment according to FIG. 3 will be explained. Between the outer circumference of the installation cartridge 101 and the pressure medium connection formed between the valve bore 138 and the valve piston 8 of the flow control valve 119, a transverse bore 131 is provided, which due to its low throughput - messers represents a throttled connection between the pressure medium connection and the tank port T.

Spring plates 110, 112 are each formed integrally with a stop pin.

Set screws 141a, 141b are screwed into the valve holes 138, 140 via a respective hexagon socket and thus serve to adjust the respective bias of the springs 14, 16. The screws 141a, 141b are fixed with respective lock screws 133a, 133b, which are also in the respective Valve bore 138, 140 are screwed. The lock screws 133a, 133b each have a continuous hexagon socket, which is larger than the respective hexagon socket of the adjusting screws 141a, 141b.

Furthermore, in each valve bore 138, 140 a locking ring 137a, 137b used so that the screws 141a, 141b and their counter-bolts 133a, 133b are secured against falling out and in particular against pressurized falling out.

Finally, between the respective spring 14, 16 and the associated adjusting screw 141a, 141b, an intermediate piece with sealing ring 143a, 143b for sealing in particular the pressure chamber of the delivery flow control valve 119 which is acted upon by load-indicating pressure with respect to the environment.

FIG. 5 shows the second exemplary embodiment according to FIG. 4 in an end view. The two-flattened system consisting of the two parallel planar sections 104a, 104b offers the possibility of bringing a special tool (not shown) into abutment and screwing the installation cartridge 101 in or out. The stepped sizes, on the one hand, of the hexagon socket of the countersunk screws 133a, 133b and, on the other hand, of the adjusting screws 141a, 141b in the valve bores 138, 140 can be reached simultaneously.

FIG. 6 shows a third exemplary embodiment of a pressure-flow regulator 203 according to the invention in a lateral section. Its housing 201 is designed in flange construction. Accordingly, the two control connections A and P and the tank connection T are arranged on one side and (in FIG. 6) on the bottom of the housing 201. Of the Control port P is connected via a channel 248, the control port A via a channel 250 and the tank port T via a channel 252 to the pressure control valve 217 and to the flow control valve 219. The channels 248, 250 252 on the one hand cut the valve bore 240 of the pressure control valve 217 and on the other hand open into the valve bore 238 of the flow control valve 219. The three channels 248, 250, 252 are arranged parallel to one another and extend at right angles to the two valve bores 238, 240.

In the valve bore 238 of the flow control valve 219, a valve piston 208 and in the valve bore 240 of the pressure control valve 217, a valve piston 206 is arranged. Both valve pistons 206, 208 are acted upon (in FIG. 6) by the pump pressure of the control port P from the left via the channel 248 and via a fluid path formed in the respective valve piston 206, 208 and consisting of a continuous transverse bore and an axial blind bore. The valve piston 206 of the pressure control valve 217 is shown in its rest position (in Figure 6) left, while the valve piston 208 of the flow control valve 219 is shown in a control position. The valve piston 206 of the pressure control valve 217 is acted upon (in Figure 6) from the right via the spring plate 212 by the force of the spring 216, while the valve piston 208 of the flow control valve 219 (in Figure 6) from the right via the spring plate 210 by the force of spring 214th and is also acted upon by the control pressure of a load-signaling connection LS. This control pressure is in the spring chamber of the spring 214.

The spring chamber of the spring 216 of the pressure control valve 217 is continuously relieved via a longitudinal channel 254 and via the channel 252 to the tank port T of the pressure-flow regulator 203. The spring 214 is supported by a washer 226 on a set screw 241a, while the spring 216 is supported by a washer 228 on a set screw 241b. Both adjusting screws 241a, 241b are screwed into respective stop bushings 256, 258, which in turn are screwed into the housing 201 of the pressure flow regulator 203. The two stop bushes 256, 258 serve as stops for the respective associated spring plate 210, 212 and thus as a travel limit for the respectively associated valve piston 206, 208. The voltage applied to the spring plate 210 end portion of the valve piston 208 is formed as a guide collar, which has at least one flattening 208b to form a pressure medium connection.

The voltage applied to the spring plate 212 end portion of the valve piston 206 is formed to form a throttled pressure fluid connection as a neck 206b.

The two (in Figure 6) left end portions of the valve piston 206, 208 are formed as guide collars. Longitudinal channels are formed in the end sections, via which small radial bores of the valve pistons 206, 208 are connected to the respective end pressure chambers, as a result of which they are subjected to pump pressure.

The valve piston 206 of the pressure control valve 217 blocks in its rest position shown in Figure 6 a direct pressure medium connection from the control port A to the tank port T via its control collar 206a. Connections from the control port A to the flow control valve 219 via the channel 250 and the tank port T to the flow control valve 219 via the channel 252 are not shut off in the rest position of the valve piston 206 of the pressure control valve 217. In a (not shown) control position of the valve piston 206 of the pressure control valve 217, the connection from the tank port T to the flow control valve 219 is shut off, so that the control port A can not be relieved. Thus, the tilt angle of the variable displacement pump 5 and thus its flow can not be increased.

A control collar 208a of the flow control valve 219 has a length slightly larger than a bore diameter of the channel 250. Thus, the control collar 208a blocks in the control position shown, the connection from the control port A via the channel 250 on the one hand to the control port P and on the other hand to the tank port T.

Disclosed is a pressure-flow regulator with a pressure control valve and with a flow control valve and a first control port for adjusting a variable, wherein the flow control valve is relieved via a open in a rest position of a valve piston of the pressure control valve control edge of the pressure control valve, the control port to a tank.

Claims

claims

1. Pressure-flow regulator with a pressure control valve (17; 117; 217) and with a flow control valve (19; 119; 219) and with a first control connection (A), characterized in that the flow control valve (19; 119; 219) via a in a rest position of a valve piston (6; 206) of the pressure control valve (17; 117; 217) open control edge (6c; 206c) of the pressure control valve (17; 117; 217), the control port (A) is relieved to a tank.

2. Pressure-flow regulator according to claim 1, wherein the first control port (A) with a control chamber of an actuating cylinder (7) of a variable displacement pump (5) is connectable or connected.

3. Pressure-conveying flow regulator according to claim 1 or 2, wherein the first control port (A) via a first straight channel (50; 250) connected to the pressure control valve (17; 117; 217) and with the flow control valve (19; 119; 219) and wherein the first channel (50; 250) has a valve bore (40; 140; 240) of the pressure regulating valve (17; 117; 217) and a valve bore (38; 138; 238) of the flow control valve (19; 119; 219) approximately cuts at right angles.

4. Pressure-flow regulator according to claim 3, wherein in the valve bore (40;

140; 240) of the pressure regulating valve (17; 117; 217) of the valve piston (6; 206) of the pressure regulating valve (17; 117; 217), wherein of the valve piston (6; 206) the first channel (50; 250) is not interruptible ,

5. Pressure-flow regulator according to claim 3 or 4, wherein a control collar (6a) of the valve piston (6) of the pressure regulating valve (17; 117) is narrower than the first channel (50).

6. Pressure-flow regulator according to one of the preceding claims with

a tank port connected to the pressure regulating valve (17; 117; 217) via a second straight passage (52; 252) and to the flow control valve (19; 119; 219).

A pressure-conveying flow regulator according to claim 6, wherein the second passage (52; 252) approximately perpendicularly intersects the valve bore (40; 140; 240) of the pressure regulating valve (17; 117; 217) and the valve bore (38; 138; 238) of the Förderstrom- control valve (19, 119, 219) approximately at right angles intersects or flows into this.

8. Pressure-flow regulator according to claim 6 or 7, wherein the second channel (252) is narrower than a control collar (206a) of the valve piston (206) of the pressure regulating valve (217).

9. pressure-conveying flow governor according to one of claims 2 to 8 with a second control port (P) which is connected to a working line (13) of the variable displacement pump (5), and with a respective end-side pressure chamber of the pressure regulating valve (17; 217) and the flow control valve (19; 119; 219).

10. Pressure-flow regulator according to claim 9, wherein the second control port (P) via a third straight channel (248) is connected to the two pressure chambers, wherein the third channel, the valve bore (240) of the pressure control valve (217) and the valve bore (238). of the flow control valve (219) approximately at right angles intersects.

11. Pressure-flow regulator according to claim 10, wherein the second channel (252) and the third channel (248) parallel to the first channel (250) extend.

12. Pressure-flow regulator according to one of claims 9 to 11, wherein a

a pressure of the second control terminal (P) counteracting

Spring (14, 16) of the pressure regulating valve (17) or the flow control valve (19) via a in the associated valve bore (38, 40) clamped sleeve (34, 36) is adjustable.

13. Pressure-flow regulator according to one of claims 9 to 11, wherein a pressure of the second control terminal (P) counteracting

Spring (14, 16) of the pressure control valve (117) or the flow control valve (119) via an in the associated valve bore (138, 140) screwed adjusting screw (141 a, 141 b) is adjustable.

14. Pressure-flow regulator according to one of claims 9 to 13, wherein a pressure of the second control terminal (P) counteracting

Spring (16; 216) of the pressure control valve (17; 117; 217) is arranged in a spring chamber, which is relieved to the tank.

15. Pressure-flow regulator according to one of claims 9 to 14, wherein a pressure of the second control terminal (P) counteracting

The spring (14; 214) of the delivery flow control valve (19; 119; 219) is arranged in a spring chamber which is connected to at least one consumer supplied by the variable displacement pump (5) via a load reporting connection (LS).