Pressure-flow regulator

Abstract

Pressure flow regulator comprising a pressure control valve (17; 117) and a flow control valve (19; 119), a first control port (A), a tank port (T), and a housing, wherein the first control port (A) can be discharged to a tank from the flow control valve (19; 119) via a control edge (6c) of the pressure control valve (17; 117) which is open in a rest position of a valve piston (6) of the pressure control valve (17; 117), wherein the housing of the pressure flow regulator is designed as a cartridge (1) on the outer circumference of which the first control port (A) and the tank port (T) are arranged, while a second control port (P) is provided at the end face, wherein the first control port (A) is connected to the pressure control valve (17; 117) and to the flow control valve (19; 119) via a first straight channel (50), wherein the first channel (50) a valve bore (40; 140) of the pressure regulating valve (17; 117) and a valve bore (38;138) of the flow control valve (19; 119) intersects at approximately a right angle, wherein the valve piston (6) of the pressure control valve (17; 117) is received in the valve bore (40; 140) of the pressure control valve (17; 117), wherein the first channel (50) of the valve piston (6) is uninterruptible, and wherein the tank connection (T) is connected to the pressure control valve (17; 117) and to the flow control valve (19; 119) via a second straight channel (52), wherein the second channel (52) intersects the valve bore (40; 140) of the pressure control valve (17; 117) at approximately a right angle and intersects or opens into the valve bore (38; 138) of the flow control valve (19; 119) at approximately a right angle, wherein the second channel (52) narrower than a control collar (6a) of the valve piston (6) of the pressure regulating valve (17).

Description

[0001] The invention relates to a pressure-flow regulator according to the preamble of claim 1.

[0002] Pressure flow regulators have a pressure control valve and a flow control valve, each with a valve bore and a common first control port, through which a swivel angle of a variable displacement pump is controlled.

[0003] In the publication DE 101 36 416 A1 and in the prospectus of Sauer Danfoss 520L0519 Rev FN July 2009, pressure flow regulators are disclosed in which the pressure medium regulated by the flow control valve always passes through the pressure control valve to the first control port.

[0004] In publication DE 101 36 416 A1 and in publication DE 199 04 616 A1, a pressure flow regulator is shown in which the pressure control valve connects the first control port to a tank via a control edge of the flow control valve which is open in the rest position of the flow control valve.

[0005] In DE 102 19 850 B3 and DE 102 47 665 A1, pressure flow regulators are shown in which the first control connection to a tank can be relieved from the flow control valve via a control edge of the pressure control valve which is open in a rest position of the valve piston of the pressure control valve.

[0006] In all the above-mentioned printed materials, the swivel angle of a variable displacement pump is regulated via the pressure medium of the first control connection, which is regulated in this way.

[0007] A disadvantage of the aforementioned pressure-flow regulators is the effort required for the production of the channels.

[0008] In contrast, the invention is based on the objective of creating a pressure-flow regulator with reduced manufacturing effort.

[0009] This problem is solved by a pressure-flow regulator with the features of claim 1.

[0010] The pressure-flow regulator according to the invention comprises a pressure regulating valve, a flow-flow regulating valve, and a first control port. The first control port can be relieved from the flow-flow regulating valve to a tank via a control edge of the pressure regulating valve, which is open in the rest position of a valve piston of the pressure regulating valve. This reduces the manufacturing effort for the pressure-flow regulator, as the channels are less complex.

[0011] Further advantageous embodiments of the invention are described in the dependent patent claims.

[0012] In a particularly preferred application, the pressure-flow regulator is used to set the swivel angle of a variable displacement pump. For this purpose, the first control port can be connected to an actuating chamber of an actuating cylinder of the variable displacement pump, either directly or permanently.

[0013] The first control port is connected to the pressure regulating valve and the flow control valve via a first straight channel, the first channel intersecting a valve bore of the pressure regulating valve and a valve bore of the flow control valve at approximately right angles.

[0014] The valve piston is received in the valve bore of the pressure regulating valve, whereby the first channel cannot be interrupted by the valve piston.

[0015] It is preferred that the control collar of the pressure regulating valve's piston is narrower than the first channel, allowing flow around the control collar. This prevents the connection from the flow control valve to the first control port from being blocked by the pressure regulating valve's piston.

[0016] The pressure-flow regulator according to the invention has a tank connection which is connected to the pressure regulating valve and to the flow regulating valve via a second straight channel.

[0017] The second channel also intersects the valve bore of the pressure regulating valve at approximately a right angle. The second channel also intersects the valve bore of the flow control valve at approximately a right angle or opens into it.

[0018] Since the second channel is narrower than a control collar of the valve piston of the pressure regulating valve located there, the second channel can be blocked off by the control collar of the pressure regulating valve.

[0019] A preferred embodiment of the pressure-flow regulator according to the invention has a second control port which is connected to a working line of the variable displacement pump, so that pump pressure is present at the second control port. The second control port is connected to a respective end-face pressure chamber of the pressure regulating valve and the flow regulating valve, so that the pump pressure exerts a force in the opening direction on the two valve pistons.

[0020] In a further development not belonging to the invention, the second control connection is connected to the two pressure chambers via a third straight channel, wherein the third channel also intersects the valve bore of the pressure regulating valve and the valve bore of the flow control valve at approximately right angles.

[0021] Preferably, the second and third channels run parallel to the first channel. This reduces the manufacturing effort for the channels.

[0022] Preferably, the first channel and / or the second channel and / or the third channel is a bore. This allows the channels to be easily produced with a drill.

[0023] Preferably, the preload of a spring in the pressure regulating valve or a spring in the flow control valve, which opposes the pressure at the second control port, is adjustable via a sleeve clamped in the associated valve bore. This allows for the correction of manufacturing tolerances and spring fatigue.

[0024] It is preferred if the sleeve is a conical sleeve into which a truncated cone is clamped. This solution is simple from a tooling perspective.

[0025] Alternatively, the preload of the springs of the pressure regulating valve and the flow control valve can be adjusted in a classic way via an adjusting screw screwed into the associated valve bore.

[0026] In a preferred embodiment of the pressure flow regulator according to the invention, the spring of the pressure regulating valve, which opposes a pressure of the second control port, is arranged in a spring chamber which is relieved towards the tank.

[0027] In a preferred embodiment of the pressure-flow regulator according to the invention, the spring of the flow control valve, which opposes a pressure of the second control connection, is arranged in a spring chamber which is connected to at least one consumer supplied by the variable displacement pump via a load sensing connection.

[0028] The following section describes various embodiments of the invention in detail with reference to the figures. The figures show: Fig. 1 a hydraulic circuit diagram of a pressure-flow regulator according to the invention with a variable displacement pump; Fig. 2 a first embodiment of a pressure-flow regulator according to the invention in a perspective view; Fig. 3 the first embodiment of a pressure-flow regulator according to the invention in side section; Fig. 4 a second embodiment of a pressure-flow regulator according to the invention in side section; Fig. 5 the second embodiment of a pressure-flow regulator according to the invention in one view; and Fig. 6 an example of a pressure-flow regulator not belonging to the invention in a side section.

[0029] The circuit diagram of the pressure-flow regulator 3 according to Fig. 1 applies in particular to the one in the Fig. 4 and Fig. 5 shows an embodiment of the pressure-flow regulator with a transverse bore 131 forming a throttle. The circuit diagram of the pressure-flow regulator 3 according to Fig. 1 largely applies to the one in the Fig. 2 and Fig. 3 shown embodiment and for the one in Fig. 6. Example shown, not belonging to the invention.

[0030] The swivel angle of the variable displacement pump 5 can be changed via two actuators 7 and 9. To decrease the swivel angle, pressure medium is supplied to actuator 7 via the pressure-flow regulator 3 through the first control port A. This is counteracted by the second actuator 9, in which the pump pressure is present. To increase the swivel angle, actuator 7 is connected to the tank via the pressure-flow regulator 3, so that the pressure force of actuator 9 and the force of a spring 11 move the variable displacement pump 5 towards a larger swivel angle. The pressure or flow rate at a working line 13 of the variable displacement pump 5 is regulated by the swivel angle set in this way.

[0031] Furthermore, the pressure flow regulator 3 and the variable displacement pump 5 share a common tank connection T. The pressure flow regulator 3 also has a load sensing connection LS, through which the highest operating pressure of multiple consumers supplied by the variable displacement pump 5 via the working line 13 is reported. If only one consumer is supplied, its operating pressure is reported.

[0032] 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 has an adjustable spring 14, 16 which acts in the direction of the Fig. The control pressure shown in Figure 1 acts in the rest position of each valve piston of valves 17 and 19. In these two rest positions, the actuator cylinder 7 is relieved of pressure via the first control port A, via the two valves 17 and 19, and via a tank line 21 to tank T, so that the swivel angle of the variable displacement pump 5 is set to its maximum. The control pressure described above, applied to the load sensing port LS, also acts in the direction of the rest position of the flow control valve 19 shown.

[0033] The pump pressure in the working line 13 acts on the valve pistons of valves 17, 19 via port P and control pressure line 15. Thus, when the force generated by the pump pressure in the working line 13 is greater than the respective counterforce, the valve pistons of valves 17, 19 are adjusted such that pressure medium is supplied to the actuating cylinder 7 via the second control port P, the control pressure line 15 and the first control port A, and thus the variable displacement pump 5 is pivoted back.

[0034] Both valves 71,19 are shown in their respective rest positions, in which the corresponding valve pistons (cf. Fig. 3, Fig. 4, and Fig. 6) are in their respective resting positions.

[0035] An output A0 of the pressure control valve 17 is connected via the flow control valve 19 to the first control connection A of the pressure flow regulator 3 or the variable displacement pump 5.

[0036] In the rest position of the pressure control valve 17 shown, the flow control valve 19 can establish the necessary connections. When the pressure control valve 17 begins to regulate, the flow control valve 19 is in its rest position, because the pressure at the load sensing port LS has approached the pressure at the second control port P (pump pressure). The pressure control valve 17 can then establish the various connections.

[0037] Fig. Figure 2 shows a first embodiment of a pressure-flow regulator 3 according to the invention, the housing of which is designed as a built-in cartridge 1. This can be screwed into a variable displacement pump (not shown) in a space-saving manner.

[0038] According to the invention, the first control connection A and the tank connection T are arranged on the outer circumference of the cartridge 1, while the second control connection P is provided at the end face. The latter serves to "signal" the pump pressure of the (in Fig. 2 variable displacement pump 5 (not shown), wherein each of the two valves 17, 19 is assigned a bore of the second control port P. The first control port A serves to adjust the swivel angle of the variable displacement pump 5 via the actuating cylinder 7, and the tank port T is connected to the tank (see figure). Fig. 1).

[0039] Adjacent to the second control connection P, a continuous transverse bore 2 is provided in the mounting cartridge 1, which, with reference to Fig. 3 is explained. A double flat is provided for screwing the installation cartridge 1 into the variable displacement pump, of which in Fig. 1 only one area section 4a is shown.

[0040] Fig. Figure 3 shows the first embodiment of a pressure-flow regulator 3 according to the invention in a sectional view. The pressure regulating valve 17 has a valve piston 6, and the flow control valve 19 has a valve piston 8. The valve pistons 6, 8 are each actuated by a spring 14, 16 (in a flat spring plate 10, 12) via a spring plate 10, 12. Fig. 3) biased to the left into their shown rest position. The movement of the valve pistons 6, 8 (in Fig. 3) to the left is limited by a stop pin 18 which is pressed into the continuous transverse bore 2.

[0041] The control pressure applied to the second control port P actuates the valve pistons 6, 8 and the associated spring plates 10, 12 (in Fig. 3) can be moved proportionally to the right into their switching positions. This movement against the force of the springs 14, 16 is limited by respective cylindrical stop pins 20, 22, which are located parallel to a central axis 24 of the pressure-flow regulator 3 inside the respective spring 14, 16.

[0042] The springs 14, 16 are each supported on a disc 26, 28, which in turn are supported via a spacer sleeve 30, 32 on a respective conical sleeve 34, 36. The two conical sleeves 34, 36 are frictionally fixed in the respective valve bore 38, 40. For this purpose, the conical sleeves 34, 36 have frustoconical inner recesses into which corresponding frustocones 42, 44 are pressed. The pressing in was carried out during the assembly of the pressure-flow regulator 3 by sliding or pulling the frustocones 42, 44 in the associated conical sleeves 34, 36 (in Fig. 3) to the right.

[0043] The load sensing port LS is provided as a further connection for the flow control valve 19. A spring chamber of the flow control valve 19 is connected to the load sensing port LS via a transverse bore, while a spring chamber of the pressure control valve 17 is connected to the tank connection T via a pressure medium connection formed between the valve piston 6 and the valve bore 40 and via a transverse bore section.

[0044] Between the (in Fig. 3) A sealing ring 46 is arranged on the outer circumference of the installation cartridge 1 in each of the right or outer end section of the installation cartridge 1 and the load signaling connection LS, as well as between the load signaling connection LS and the tank connection T, as well as between the tank connection T and the first control connection A, as well as between the first control connection A and the second control connection P.

[0045] Through the in Fig. In the 3 shown rest positions of the valve pistons 6, 8, connections between the control pressure ports A and P are closed off by a respective piston collar of the two valve pistons 6, 8, while the first control port A is connected to the tank port T via two transverse bore sections and via a pressure medium connection formed between the valve piston 8 and the valve bore 38 and via two transverse bore sections, and is thus relieved to the tank. By pressurizing (the two bores) the second control port P, the two valve pistons 6, 8 are each closed against the force of the associated spring 14, 16 (in Fig. 3) Displaceable to the right, whereby both valves 17, 19 control a connection from the second control port P to the first control port A. This makes the variable displacement pump 5 (see Fig. 1) pivoted back, so that their pressure and / or flow rate are reduced. The pressure control valve 17 has decision priority over the flow control valve 19.

[0046] Fig. Figure 4 shows a second embodiment of a pressure-flow regulator 103 according to the invention in a side section. Only the differences from the first embodiment according to the invention are discussed below. Fig. 3 explained: A transverse bore 131 is provided 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, which, due to its small diameter, represents a throttled connection between the pressure medium connection and the tank connection T.

[0047] Spring plates 110, 112 are each formed in one piece with a stop pin.

[0048] Adjusting screws 141a and 141b are screwed into the valve bores 138 and 140 via a respective internal hexagon socket and thus serve to adjust the respective preload of the springs 14 and 16. The adjusting screws 141a and 141b are secured by respective lock screws 133a and 133b, which are also screwed into the respective valve bores 138 and 140. The lock screws 133a and 133b each have a continuous internal hexagon socket that is larger than the respective internal hexagon socket of the adjusting screws 141a and 141b.

[0049] Furthermore, a retaining ring 137a, 137b is inserted into each valve bore 138, 140, so that the adjusting screws 141a, 141b and their locking screws 133a, 133b are secured against falling out and in particular against falling out under pressure.

[0050] Finally, between the respective spring 14, 16 and the associated adjusting screw 141a, 141b there is an intermediate piece with sealing ring 143a, 143b for sealing in particular the pressure chamber of the flow control valve 119, which is subjected to load signal pressure, against the environment.

[0051] Fig. 5 shows the second embodiment according to Fig. 4 in a front view. The double-flat section, consisting of the two parallel flat sections 104a, 104b, allows for the insertion of a special tool (not shown) and the screwing in or out of the cartridge 101. The stepped sizes of the internal hexagon of the locking screws 133a, 133b and the adjusting screws 141a, 141b in the valve bores 138, 140 are simultaneously accessible.

[0052] Fig. Figure 6 shows a side section of a pressure-flow regulator 203 not belonging to the invention. Its housing 201 is of flanged design. Accordingly, the two control connections A and P and the tank connection T are single-sided and (in Fig. 6) located at the bottom of the housing 201. The second control port P is connected to the pressure regulating valve 217 and the flow control valve 219 via a channel 248, the first control port A via a channel 250, and the tank port T via a channel 252. Channels 248, 250, and 252 intersect the valve bore 240 of the pressure regulating valve 217 and open into the valve bore 238 of the flow control valve 219. The three channels 248, 250, and 252 are arranged parallel to each other and run perpendicular to the two valve bores 238 and 240.

[0053] A valve piston 208 is arranged in the valve bore 238 of the flow control valve 219, and a valve piston 206 is arranged in the valve bore 240 of the pressure control valve 217. Both valve pistons 206 and 208 are (in Fig. 6) from the left via channel 248 and via a fluid path formed in the respective valve piston 206, 208 and consisting of a through transverse bore and an axial blind bore, is acted upon by the pump pressure of the second control port P. The valve piston 206 of the pressure regulating valve 217 is in its rest position (in Fig. 6) shown on the 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 (in Fig. 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 Fig. 6) from the right via the spring plate 210 is acted upon by the force of the spring 214 and, in addition, by the control pressure of a load sensing connection LS. This control pressure is present in the spring chamber of the spring 214.

[0054] The spring chamber of the spring 216 of the pressure regulating valve 217 is continuously relieved to the tank connection T of the pressure flow regulator 203 via a longitudinal channel 254 and via channel 252. The spring 214 is supported by a washer 226 on an adjusting screw 241a, while the spring 216 is supported by a washer 228 on an adjusting 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 bushings 256, 258 serve as stops for the respective associated spring retainers 210, 212 and thus as travel limits for the respective associated valve pistons 206, 208.

[0055] The end section of the valve piston 208, which rests against the spring plate 210, is designed as a guide collar, which has at least one flattening 208b to form a pressure medium connection.

[0056] The end section of the valve piston 206, which rests against the spring plate 212, is designed as a neck 206b to form a throttled pressure medium connection.

[0057] The two (in Fig. 6) The left end sections of the valve pistons 206, 208 are designed as guide flanges. Longitudinal channels are formed in the end sections, through which small radial bores of the valve pistons 206, 208 are connected to the respective end-face pressure chambers, thereby pressurizing these chambers with pump pressure.

[0058] The valve piston 206 of the pressure regulating valve 217 blocks in its Fig.In the rest position shown in Figure 6, a direct pressure medium connection runs from the first control port A to the tank port T via its control collar 206a. Connections from the first control port A to the flow control valve 219 via channel 250 and from the tank port T to the flow control valve 219 via channel 252 are not closed 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 closed, so that the first control port A cannot be relieved. Therefore, the swivel angle of the variable displacement pump 5, and thus its flow rate, cannot be increased further.

[0059] A control collar 208a of the flow control valve 219 has a length that is slightly greater than the bore diameter of the channel 250. Thus, in the control position shown, the control collar 208a blocks the connection from the first control port A via the channel 250 on the one hand to the second control port P and on the other hand to the tank port T.

[0060] A pressure flow regulator is disclosed, comprising a pressure control valve and a flow control valve, and a first control port for adjusting a variable displacement pump, wherein the first control port can be relieved from the flow control valve to a tank via a control edge of the pressure control valve which is open in a rest position of a valve piston of the pressure control valve.

Claims

[1] Pressure flow regulator comprising a pressure control valve (17; 117) and a flow control valve (19; 119), a first control port (A), a tank port (T), and a housing, wherein the first control port (A) can be discharged to a tank from the flow control valve (19; 119) via a control edge (6c) of the pressure control valve (17; 117) which is open in a rest position of a valve piston (6) of the pressure control valve (17; 117), wherein the housing of the pressure flow regulator is designed as a cartridge (1) on the outer circumference of which the first control port (A) and the tank port (T) are arranged, while a second control port (P) is provided at the end face, wherein the first control port (A) is connected to the pressure control valve (17; 117) and to the flow control valve (19; 119) via a first straight channel (50). is, wherein the first channel (50) is a valve bore (40; 140) of the pressure regulating valve (17; 117) and a valve bore (38;138) of the flow control valve (19; 119) intersects at approximately a right angle, wherein the valve piston (6) of the pressure control valve (17; 117) is received in the valve bore (40; 140) of the pressure control valve (17; 117), wherein the first channel (50) of the valve piston (6) is uninterruptible, and wherein the tank connection (T) is connected to the pressure control valve (17; 117) and to the flow control valve (19; 119) via a second straight channel (52), wherein the second channel (52) intersects the valve bore (40; 140) of the pressure control valve (17; 117) at approximately a right angle and intersects or opens into the valve bore (38; 138) of the flow control valve (19; 119) at approximately a right angle, wherein the second channel (52) narrower than a control collar (6a) of the valve piston (6) of the pressure regulating valve (17). [2] Pressure flow regulator according to claim 1, wherein the first control connection (A) is connectable to or connected with an actuating chamber of an actuating cylinder (7) of a variable displacement pump (5). [3] Pressure flow regulator according to claim 1 or 2, wherein a control collar (6a) of the valve piston (6) of the pressure regulating valve (17; 117) is narrower than the first channel (50). [4] Pressure flow regulator according to one of claims 1 to 3, wherein the second control port (P) is connected to a working line (13) of the variable displacement pump (5) and to a respective end-face pressure chamber of the pressure control valve (17; 117; 217) and the flow control valve (19; 119; 219). [5] Pressure flow regulator according to claim 4, wherein a spring (14, 16) of the pressure control valve (17) or the flow control valve (19) which opposes a pressure of the second control port (P) is adjustable via a sleeve (34; 36) clamped in the associated valve bore (38, 40). [6] Pressure flow regulator according to claim 4, wherein a spring (14, 16) of the pressure control valve (117) or the flow control valve (119) which opposes a pressure of the second control port (P) is adjustable via an adjusting screw (141a, 141b) screwed into the associated valve bore (138, 140). [7] Pressure flow regulator according to one of claims 4 to 6, wherein a spring (16) of the pressure regulating valve (17; 117) which opposes a pressure of the second control port (P) is arranged in a spring chamber which is relieved to the tank. [8] Pressure flow regulator according to one of claims 4 to 7, wherein a spring (14) of the flow control valve (19; 119) which opposes a pressure of the second control port (P) is arranged in a spring chamber which is connected to at least one consumer supplied by the variable displacement pump (5) via a load sensing port (LS).

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