JP2001520335A - System for controlling multiple rotating and / or translating consumers independently of load pressure to maintain load - Google Patents

Abstract

(57) Abstract: Multiple rotational movements and / or translations of construction and / or machine tools with at least one pump to be controlled and at least one secondary pressure regulator including a spring-biased control piston. With a system that loads and controls the operating consumer independently of the load pressure, the functional separation between the signal generation, load holding and pressure compensation functions implemented in current systems is achieved by external discrete It should result in a structure that is optimized with reduced parts, low cost, suitable for assembly, and resistant to turbulence. This means that all the control members which generate signals in the upper housing part (78, 79) and compare the signals of the load detection signals, and the lower housing part (86) which is detachably connected to the upper housing part (78, 79). , 87) are provided with members (36, 73, 53, 75) that generate a load holding function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The invention relates to a plurality of rotary movements and / or a construction machine and / or work machine having at least one controlled pump and at least one secondary pressure regulator including a spring-biased control plunger. A system for controlling a translating consumer independent of load pressure to maintain load.

There are different arrangements of a signal generator and a signal transmitter for a control slider that operates according to the principle of flow distribution independent of load pressure using a secondary pressure regulator.

[0003] Currently known systems of flow distribution independent of load pressure have a functionally and spatially separating part of a secondary regulator which takes on the function of pressure compensation, a signal generating part, a signal transmitting part and a load holding function. . The functional and spatial separation of these functional units increases the number and cost of the individual components of the system and the costs of assembly and maintenance.

In a control slider based on the principle of flow distribution independent of load pressure (LUDV),
There are various possibilities for capturing and sending so-called load sensing (LS) signals. On the other hand, there is a possibility that this signal can be sent from the notification lead to the pump control by means of a system built into the expensive slider section. On the other hand, it is possible to incorporate another plunger with a relatively weak spring in the compensating plunger. These compensating plungers are configured to transmit a load sensing signal through the control aperture. The first described configuration is expensive, but the last two are sensitive with respect to signal output so that control edges do not always guarantee that the load sense signal is transmitted at the correct pressure when oil flow is low. . This controls the pump controller incorrectly, which again has a negative effect on the overall control, i.e. the drive of individual or multiple consumers.

[0005] DE 34 43 354 discloses a hydraulic installation in which, for example, a pump driven by a diesel engine is used and the pressurized medium is guided to the consumer by means of a distribution valve.
The speed control of the injection pump of a diesel engine is regulated by a pressure-regulating cylinder, on which the pressure generated in the control line acts to increase the speed of the internal combustion engine. This pressure is controlled in conjunction with one of the consumer acting dispensing valves and the pressure control valve so that a constant pressure is generated when operating the normal dispensing valve in the conduit. Operating the other dispensing valve for consumers, which works easily,
A special control edge acts. This creates a pressure in the conduit that increases in proportion to the movement of the control slider. As a result, the rotational speeds of the internal combustion engine and the pump are increased, and the consumer is adjusted to obtain just the required amount of pressurized medium. Thus, economical operation becomes possible.

[0006] US Pat. No. 2,892,312 discloses a hydraulic installation for a truck starter with a working cylinder for driving a number of working devices. These working cylinders are then supplied by a pump whose supply pressure is controlled independently of the load,
These working cylinders are each driven separately using a control slider and a control valve.

“Technik und Wissenschaft” (Technology and Science), Vol. 63, 1969, Linde Report on pages 6-8, Linde, Synchro and Control for Mobile Hydraulic Applications
e-Synchro-Control) (LSC) This system operates on the load detection principle. This significantly improves the simultaneous operation of the different functions of the hydraulic system with open circulation. The Linde Synchro Control (LSC) valve is a separate valve part. A suitable combination for different machines is achieved by incorporating the individual valve parts into the corresponding valve plates. These valve plates only include connection passages such as, for example, the inlet passage to the pump, the connection passage to and from the valve, the return conduit and the connection of the return to the tank. These valve parts are equipped with unique functional members. The valve itself is formed of a plunger-type structure, is spring-centered, has a closed intermediate position, and is hydraulically operated. The maximum stroke of the plunger is adjustable and the pressure drop at the control edge is kept constant, which means that the maximum oil flow through the valve is limited at the final abutment of the valve. The pressure regulator is located inside the valve plunger. A switching valve for the LS signal is inside the pressure regulator and moves with the pressure regulator in the plunger of the valve.

[0008] A similar control system for controlling a number of consumers of a mobile hydraulic construction machine independently of the load pressure is known from EP 0 326 150. The control system has a pressure regulator including a spring-biased control plunger.

From DE 296 04 215, a load-holding or anti-torque valve is known in which components for generating the load-holding function and a control element are provided in the region of the control plunger.

An object of the present invention is to provide a signal generation function, a load holding function, and a pressure compensation function which are realized in a current system by reducing external individual parts so as to provide a low-cost, suitable for assembly and trouble-free structure. In optimizing the functional separation between

The object of the invention is to provide a system of the type mentioned at the outset according to the invention in which all control elements for generating a signal in the upper housing part and comparing the signal of the load detection signal;
The problem is solved by providing a lower housing portion detachably connected to the upper housing portion with a member for generating a load holding function.

By distributing each of the secondary pressure regulators into two housing parts respectively, in particular by incorporating the entire control element into an upper housing part which can be easily removed from the lower housing part, for example because it can be easily flanged. In addition, the system can be easily assembled at a remarkably low cost. In particular, reinforcement, modification or repair can be easily performed. By distributing all the functional components to the two housing parts in which they are arranged, these functional components are functionally and spatially combined, thereby achieving a considerable optimization compared to known systems. .

A system configured in this way is intended to control and regulate the speed of the consumer independently of the load pressure in moving construction and work machines, such as excavators, wheel bearings, levelers, etc. In this system, at least two consumers, for example one of the hydraulic cylinders, each perform an operating motion unaffected by a significant external load pressure and do not affect each other.

In this case, it is advantageous if the lower housing part is a component of the control valve.

[0015] Other advantageous configurations are disclosed in the remaining dependent claims.

In the system according to the present invention, a secondary pressure regulator having a load holding function is used. In this regulator, the signal for controlling the load pressure in the passage on the consumer side is not used for guiding to the pressure controller of the supply pump, contrary to the function of the conventional load compensator having the independent load holding function. Because of this, an unintentional load drop due to a leak in the pressure regulator of the supply pump or the pressure relief valve of the load sensing conduit without a load holding valve additionally located in the passage of the consumer. This is because This, in accordance with the present invention, signals the pressure controller of the feed pump and the compensator of each low-loaded consumer, a pressure signal that is generated and maintained by the pump itself and that the Reduced by supporting maximum pressure.

Hereinafter, the present invention will be exemplarily described in detail with reference to the drawings.

FIG. 1 shows a schematic structure of a control system according to the present invention as an example of a consumer. The secondary pressure regulator with load holding function is divided into two structural parts, an upper housing part 78 and a lower housing part 86. The lower housing part 86 is preferably a component of the control valves 7, 8, 9. That is, this forms a unified housing.

FIG. 2 schematically shows, by way of example, the structure of a control system for two translating consumers 16, 17 (hydraulic cylinders). The system has correspondingly two secondary pressure regulators, the housing of which respectively has two housing parts 78,
79 and 86,87. That is, the configuration of the second secondary pressure adjustment unit matches the configuration of the secondary pressure adjustment units 78 and 86 shown in FIG.

First, assuming that only one consumer 16 is operated, the concept of control and regulation is as follows. A pressure level occurs in the system which is greater than the inlet pressure signal of the pressure controller 2 of the pump 1 by a control difference Δp _LS preselectable by the pump 1. This pressure level occurs below the plunger bottom 37 of the first secondary pressure regulator 78, 86 when the inlet throttle 7 is opened.

When the introduction restrictor is opened, the pressure level at the inlet of the pressure controller 2 is changed to the load detection bypass valve 3.
Via drops in conduit 20 to the tank pressure level p _r.

Assuming simply that p _r ≒ 0, this means that when one of the illustrated inlet throttles 7, 10 starts to open, first a pressure level of the level of the control pressure difference of p = Δp _LS is assigned. Bottom 37,5 of each plunger of the next pressure regulator 78,86 or 79,87
Occurs under 4.

The discharge throttle unit 9 opens according to the advance of the phase at the time when the introduction throttle unit 7 starts to open. As a result, the pressure signal p _{L1 on} the consumer side is output from the discharge passage 22 of the secondary pressure adjusting sections 78 and 86.
And propagates through the passage 29, the switching valve 32, the passage 31, and the damping nozzle 30 to the spring-biased plunger head 27 of the secondary pressure adjusting portions 78, 86.

The consumer-side pressure signal p _L1 acting on the spring-biased plunger head 27 of the secondary pressure regulators 78, 86 holds the two-part control plungers 72, 73 in the valve seat 36. . Thus, the pressure is controlled from the passage on the consumer side to the introduction passage 3.
The leakage flow to 3 does not leak.

When the opening distance of the plunger of the main slider is increased, the phase of the phase is correspondingly advanced and the introduction throttle section 7 is also opened. As a result, first a pump pressure p _{P at} the level of the control pressure difference Δp _LS is generated on the working surface of the bottom 37 of the plunger. The plunger heads 27, 44 of the two-piece control plunger, the valve seats 36, 53 at the bottom of the plunger and the secondary pressure regulators 78, 86 and 79, 87, balance the surface.

The passage 24 controlled by the pump pressure, the introduction nozzle 21, the check valve 34 and the passage 25,
The pressure signal, which is limited to the consumer load pressure p _L1 via 4 and 20
To the pressure controller 2.

The pump 1 outputs an initial pressure p _P having a preselected control difference Δp _LS compared to the pressure input signal of the conduit 22.

When the pressure signal generated by the pump 1 after the introduction nozzle 21 in the passage 35 reaches the consumer pressure level p _L1 in the discharge passage 22 of the secondary pressure regulators 78, 86, the other check valve 33 Opens, which ensures that the pressure signal in the passage 35 does not exceed the value of the consumer pressure p _L1 . This ensures that the pressure signal generated by the pump 1 and supplied to the pressure controller 2 and the secondary pressure regulators 79, 87 of the pump 1 is limited by the level of the load pressure at that time.

The pressure input signal of the pump controller 2 is larger by a preselected control difference Δp _LS ,
Thus the load pressure signal pump output pressure Delta] p _LS only larger conduit 19 than p _L1 P _P control plunger of the two parts at the beginning to the secondary pressure regulator 78 and 86 of the motion 72,7
3 occurs below the plunger bottom 37, thereby increasing the sum of the load pressure p _L1 acting on the working surface of the plunger head 27 and the spring equivalent pressure p _F1 by the difference Δp _LS −p _F1 .

The valve seat 36 of the two-part control plungers 72, 73 of the secondary pressure regulators 78, 86
Is opened due to excessive pressure on the bottom surface 37 of the plunger. This gives the volume flow Q_V1Is introduced
It flows to the consumer pair 16 via the throttle 7, the open valve seat 36 and the discharge throttle 9.
The volume flow Q adjusted in this case_V1Is a variable opening cross section A of the introduction throttle section 7. _D1 And the pressure difference Δp generated thereon_LS-P_F1Is determined according to the following equation. That is, Q_V1= K ° A_D1° √ (Δp_LS-P_F1) At the same time, the pressure level p of the consumer occurring in the passage 35_L1Pump pressure signal limited to
Through the check valve 34, the passage 35 and the conduits 4 and 5,
, 87.

When operating the second consumer 17 at the load pressure p _L2 , the following three situations differ.

[0032] Case 1: First Consumption body 16 to be operated has a load pressure p _L2 larger load supply member 17 that will be operated in the following pressure p _L1 having a (p _L1> p _L2).

Operating the consumer 16 results in a load pressure signal p _L1 in the pressure reporting conduit 5 of the secondary pressure regulator 79,87. This signal is transmitted to the operating surface 4 of the two-part control plungers 74 and 75 through the passage 42, the switching valve 49 and the passage 48 and the damping nozzle 47.
4, thus ensuring that the valve seat 53 of the two-part control plungers 74, 75 is closed. When operating the consumer 17, the discharge throttle 12 is first opened, whereby the load pressure p _L2 acts on the switching valve 49 via the passage 46. However, the switching valve 4
The higher load pressure p _L1 of the upper chamber 9 is greater than the load pressure p _L2 and acts on the two-part control plungers 74, 75. Therefore, the inlet restrictor 10 having the surface A _D2
, The differential pressure drop Δp _LS −p _F2 acts, and the volume flow Q _V2 to the consumer 17 is calculated as follows. Q _V1 = K ° A _D2 ° √ (Δp _LS −p _F2 ) The pump pressure signal p _P = p _L1 acting on the bottom 54 of the plunger and the consumer passage 39
The differential pressure drop p _L1 -p _L2 between the load pressures p _L2 occurring in the control plunger 7
It drops at the control edge 85 of 4,75.

[0034] Case II: First Consumption body 16 to be operated have the same load pressure p _L1 and consumption body 17 which is operated in the following with the load pressure _{p L2 (p L1 = p L2} ).

By operating the consumer 16, the pressure reporting conduit 5 of the secondary pressure regulators 79, 87
A load pressure signal p _L1 is generated therein, which acts via the passage 42, the switching valve 49, the passage 48 and the damping nozzle 47 on the operating surface of the head 44 of the control piston. And the valve seat 53 of the two-part control plungers 74 and 75 is securely closed.

By operating the consumer 17, first, the discharge throttle unit 12 is opened. As a result, the load pressure p _L2 acts on the lower chamber of the switching valve 49 via the passage 46. Since the load pressure p _L2 is equal to the load pressure p _L1 , the switching valve 49 occupies the neutral position. Thus, the load pressure p _L1 = p _L2 acts on the head 44 of the two-part control plungers 74 and 75 via the passage 48. In this case, the differential pressure drop Δp _LS −p _F2 acts in this case via the inlet throttle section 10. Therefore, the volume flow Q _V2 to the consumer 17 is calculated as follows. That is, Q _V2 = K ° A _D2 ° √ (Δp _LS −p _F2 ) Since the load pressure level p _L1 = p _L2 is the same for both consumers 16 and 17, the valve seat 5
3, the pressure difference does not decrease.

Case III: The first operated consumer 16 has a smaller load pressure p _L1 than the next operated consumer 17 with a load pressure p _L2

Operating the consumer 16 results in a load pressure p _L1 in the pressure reporting conduit 5 of the secondary pressure regulators 79, 87. This pressure is applied to the passage 42, the switching valve 49 and the passage 48.
Act on the operating surface of the control plunger head 44 via As a result, the valve seat 53 of the two-part control plungers 74 and 75 is securely closed.

When operating the main slider plunger 11 of the consumer 17, the discharge throttle section 12 is first opened, whereby the load pressure p _L2 is applied to the lower chamber of the switching valve 49 via the passage 46. Since it is assumed that p _L1 <p _L2 holds, the load pressure p _L2 is strong in the lower chamber of the switching valve 49 and is applied to the head 44 of the two-part control plungers 74 and 75 via the passage 48 and the damping nozzle 47. Works. When the main slider plunger 11 of the consumer 17 is further switched, the inlet throttle section 10 having the cross-sectional area A _D2 is opened. This allows
The pressure potential p _L1 + Δp _LS supplied from the pump 1 acts below the plunger bottom 54 of the two-part control plungers 74, 75 of the pressure regulators 79, 87. Since the sum of the load pressure p _L2 acting on the plunger head 44 and the equivalent pressure p _F2 of the spring is greater than the pressure signal p _L1 + Δp _LS acting on the plunger bottom 54 by the pump 1, the two-part control plunger 74. , 75 are initially closed.

By opening the inlet throttle 10, the pump pressure p _L1 + Δp _LS is further introduced into the pump controller 2 via the nozzle 38, the check valve 51 and the load notification conduits 42 and 5, based on which the pump The controller acts on the pressure rise of the pump outlet pressure p _{P in} the conduit 19.

The pressure in the conduit 51 and the load notification conduit 42 reaches the load pressure level p _L2 at the maximum. This will open the check valve 40, thereby connecting to the consumer passage 46 or 39 which conducts the load.

Thus, the pressure level at the pump outlet 19 rises to p _L2 + Δp _LS .

The load pressure signal p _L2 is also transmitted via the load notification conduit 5 to the secondary pressure regulator 7 of the consumer 16.
8, 87. Since it is assumed that p _L2 > p _L1 , the load signal p _L2 is also controlled via the passage 25, the switching valve 32, the passage 31, and the damping nozzle 30 by the two components of the secondary pressure regulator 78. Acts on the plunger head 27 of the plungers 72,73.

The pump 1 rises on the operating surface of the bottom 37 of the plunger of the secondary pressure adjusting sections 78 and 86.
The applied pressure signal acts. As a result, a constant pressure drop .DELTA.
p_LS-P_F1Occurs. Pump pressure signal p acting on plunger bottom 37_P= P _L2 And the load pressure p in the consumer passage 22_L1Differential pressure drop p_L2-P_L1Is a two-part control
It decreases at the control edge 36 of the lancers 72,73.

Further, the illustrated secondary pressure regulators 78, 86 and 79, 87 include all functions of generating signals and comparing signals in addition to the load holding function. This eliminates the need for an external logic element such as a check valve or a switching valve.

The valve seat function incorporated in the two-part control plunger 72, 73 or 74, 75 realizes the mobile hydraulic construction and the load holding function often required in working machines without additional external parts. I do.

FIG. 3 shows an exemplary configuration of the individual secondary pressure regulators 78, 86, which includes substantially the following components. That is, it includes a two-part control plunger 72, 73 that includes a plunger bottom 37 and a plunger head 27. In that case, a spring 28 is provided in the area of the head 27 of the plunger. Via an inlet nozzle plate 21, a check valve 34 and a passage 25, a pump pressure signal, not shown, is further introduced into the pump pressure controller. Other passages 26, 29, 31 are provided in the region of the housing head of the illustrated secondary pressure regulators 78, 86. The pressure signal generated by the pump is applied to the discharge passage 2 of the secondary pressure regulator 78 behind the inlet nozzle plate 21 of the passage 35.
When the consumer pressure level p _L1 of 2 or 29 is reached, the other check valve 23 opens, thereby ensuring that the pressure signal in the passage 35 does not exceed the value of the consumer pressure p _L1 . The switching valve is labeled 32, the valve seats of the two-part control plungers 72, 73 are labeled 36, and the control edges of the control plungers 72, 73 are labeled 84.

FIG. 4 shows an exemplary configuration with two secondary pressure regulators 78, 86 and 79, 87 with two consumers 16, 17.

FIG. 5 shows, based on a graph, the opening characteristics of the discharge throttle unit with respect to the inlet throttle unit. In this case, the phase shift is also shown according to the presented parameter.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a secondary pressure adjusting unit incorporating a load holding function,

FIG. 2 is a schematic control scheme for two translating consumers;

FIG. 3 shows an embodiment of a secondary pressure regulator incorporating a load holding function,

FIG. 4 shows an embodiment of a control system with two translating consumers,

FIG. 5 shows an opening characteristic of a discharge throttle unit with respect to an inlet throttle unit.

──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D003 AA00 AB05 BB03 CA02 DA02 DB02 3H089 AA74 BB27 CC01 CC12 DA03 DB33 EE13 EE14 GG02 JJ01

Claims (10)

[Claims] Construction machines having at least one pump to be controlled and at least one secondary pressure regulator including a spring-biased control plunger and / or
Alternatively, in a system for maintaining a load by controlling a plurality of rotating and / or translating consumers of a work machine independently of the load pressure, the upper housing part (7
8, 79), all the control members for generating signals and comparing the signals of the load detection signals,
Lower housing part (removably connected to upper housing part (78, 79)
86, 87) and members (36, 73, 53, 75) for generating a load holding function. 2. The lower housing part (86, 87) comprises a component (7,
8. The system according to claim 1, wherein the system is 8, 9, or 10, 11, 12). 3. A two-part control plunger (72, 73 or 74, 75) is provided with a lower part plunger (72, 73 or 74, 75) to ensure the function of load holding and pressure regulation.
73, 75) is formed by a conical seat valve (36, 53) associated with a throttle valve (84, 85) and its upper part plunger (72, 74) introduced into the substantially upper housing part (78, 79). 3. The system according to claim 1 or 2, characterized in that there are no other members such as passages, check valves, switching valves or throttle valves. 4. The pressure signal required for pump operation and internal pressure balance is determined by the arrangement incorporated in the upper housing part (78, 79) of the secondary pressure regulator and by the restrictor (21 or 38), Valves (23, 34 or 40, 51), switching valves (
32 or 49) and in particular the external LS bypass valve (3) is designed accordingly and the pressure between the control restrictor (7 or 10) and the control edge (84, 85) of the control plunger (73 or 75). 4. The system according to claim 1, 2 or 3, wherein the system can be generated from a signal. 5. A conical seat valve (36, 53) incorporated in the lower part (73 or 75) of the two-part control plunger (72, 73 or 74, 75) is provided for the load holding function. This seat valve is provided with the operating surface (27, 44) of the control plunger.
) By the load pressure signal on the consumer side of the passage (22 or 39) acting on the spring (2).
5. The system according to claim 3, wherein the discharge throttle (9 or 12) opens and closes under the force of (8, 45). 6. A pump (6) incorporated in each housing of the secondary pressure adjusting section.
The connection paths (24, 41) from 1) to the load notification conduits (25, 42) supplying the pump controller (2) are connected in the direction from the connection paths (24, 41) to the load notification (25, 42). 6. A non-return valve (34, 51) having a portion and blocking a backflow from the load notification conduit (25) to the connection passage (24) is provided.
The system according to paragraph. 7. A pressure signal introduced into a load notification conduit (25, 42) is passed through a passage (22).
Or 39) to limit the level of each consumer load pressure (p _L1,2 ) to direct the load during the bypass from the connecting passage (24,41) to the load notification conduit (25,42). The check valve (23, 40) connected to the stop valve (22, 39) is arranged, and a throttle (21, 38) serving as a throttle section is provided. System. 8. A control plunger (72, 73 or 74, 75) for supplying a pressure to a pressure chamber of a spring-biased control plunger (27, 44).
8. The system according to claim 1, further comprising a damping nozzle or a throttle check valve (30, 47) for controlling the opening and closing speed of (1). 9. The discharge throttle portion (9, 12) of the main slider shaft (8, 11) has a certain phase advance compared with the attached inlet throttle portion (7, 10). 9. The system according to claim 1, wherein the opening is closed earlier or later than the inlet throttle. 10. The opening characteristic of the discharge throttle portion (9, 12) is determined by the main slider shaft (8, 11).
10. The system according to any one of claims 1 to 9, wherein the system has a waveform that can be specified in advance as compared with the introduction restricting section (7, 10).