MOBILE HYDRAULIC WORKING MACHINE COMPRISING EMERGENCY STOP VALVES, AND METHOD FOR CONTROLLING A MOBILE HYDRAULIC WORKING MACHINE

Abstract

A mobile hydraulic working machine includes an upper structure, a lower structure, a boom assembly with an arm, an attachment connected to the arm and a hydraulic system to move the boom assembly and the attachment. The hydraulic system includes at least one hydraulic pump and a valve block to regulate flow through at least one hydraulic line connecting a hydraulic consumer to the at least one hydraulic pump in order to actuate the hydraulic consumer. The at least one hydraulic line includes an emergency stop valve operable to close the hydraulic line in an emergency and located in the hydraulic line in a region of the boom assembly and/or in the upper structure on a flow side of the valve block remote from the at least one hydraulic pump.

Claims

1. A mobile hydraulic working machine, comprising: an upper structure; a lower structure; a boom assembly with an arm, an attachment connected to the arm, and a hydraulic system to move the boom assembly and the attachment; wherein the hydraulic system includes at least one hydraulic pump and a valve block to regulate flow through at least one hydraulic line connecting a hydraulic consumer to the at least one hydraulic pump to actuate the hydraulic consumer; the at least one hydraulic line is connected to at least one emergency stop valve structured to close the hydraulic line in an emergency, the at least one emergency stop valve being arranged in the hydraulic line in a region of the boom assembly and/or in the upper structure on a flow side of the valve block remote from the pump.

2. The mobile hydraulic working machine according to claim 1, wherein the at least one hydraulic line is in a protected region on an upper side of the arm or is defined by channels, and the emergency stop valve is located in the protected region.

3. The mobile hydraulic working machine according to claim 1, wherein the at least one hydraulic line is attached at a first attachment point to the hydraulic consumer and at a second attachment point to the boom assembly and defines a flexible hose bend between the first and second attachment points, the at least one emergency stop valve being provided in the region of the boom assembly outside the flexible hose bend.

4. The mobile hydraulic working machine according to claim 1, wherein the at least one emergency stop valve is an electronically controlled solenoid valve.

5. The mobile hydraulic working machine according to claim 4, wherein the at least one emergency stop valve is a 2-way valve and the hydraulic system includes at least one return line which connects the at least one emergency stop valve to a hydraulic oil tank from which the hydraulic system is fed by the hydraulic pump.

6. The mobile hydraulic working machine according to claim 1, wherein the mobile hydraulic working machine includes an emergency stop actuator which communicates with the at least one emergency stop valve and/or the valve block and is operable to close when the at least one emergency stop valve is actuated.

7. The mobile hydraulic working machine according to claim 6, wherein the emergency stop actuator is located in a driver's cab of the mobile hydraulic working machine.

8. The mobile hydraulic working machine according to claim 1, wherein the at least one hydraulic line is connected to at least one sensor to detect a leakage in the at least one hydraulic line, the at least one sensor being capable of communicating with the at least one emergency stop valve and/or the valve block.

9. The mobile hydraulic working machine according to claim 1, wherein the mobile hydraulic working machine is a long-boom excavator having a reach height in a range from about 15 m to about 40 m.

10. A method for controlling a mobile hydraulic working machine including an upper structure, a lower structure, a boom assembly with an arm, an attachment connected to the arm and a hydraulic system to move the boom assembly and the attachment, the hydraulic system including at least one hydraulic pump and a valve block, and at least one hydraulic line connecting a hydraulic consumer to the hydraulic pump, the valve block being connected to the at least one hydraulic line, the method comprising: detecting a leakage in the at least one hydraulic line between the hydraulic consumer and the valve block; and switching at least one emergency stop valve located in a region of the boom assembly and/or in the upper structure on a flow side of the valve block remote from the pump in the at least one hydraulic line to shut off the at least one hydraulic line.

11. The method according to claim 10, wherein the at least one emergency stop valve is a 2-way valve and the hydraulic system includes at least one return line, and the emergency stop valve connects the associated hydraulic line to the return line, which is connected to a hydraulic oil tank from which the hydraulic system is fed by the hydraulic pump.

12. The method according to claim 10, further comprising actuating the valve block and shutting off the at least one hydraulic line after a predetermined time delay.

13. The method according to claim 10, wherein the detecting includes sighting by an operator or by a sensor in the hydraulic line.

14. The method according to claim 10, wherein the mobile hydraulic construction machine includes an emergency stop actuator communicating with the at least one emergency stop valve and/or the valve block, the method further comprising: manually actuating the emergency stop device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 shows a spatial representation of a mobile hydraulic construction machine according to an example embodiment of the present disclosure.

[0026] FIG. 2 shows a top view of the mobile hydraulic construction machine from FIG. 1.

[0027] FIG. 3 shows a schematic representation of an example embodiment of a hydraulic system of an attachment of the mobile hydraulic construction machine from FIG. 1.

[0028] FIG. 4 shows a schematic representation of a further example embodiment of a hydraulic system of an attachment according to the present disclosure.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0029] FIG. 1 shows a mobile hydraulic construction machine 1 according to an example embodiment of the present invention as a long-arm boom excavator with a lower structure 2, which is connected to an upper structure 4 via a slewing mechanism 3 that can rotate about a slewing axis S. The slewing mechanism 3 enables a controlled slewing movement between the upper structure 4 and the lower structure 2 about the slewing axis S. In general, a distinction can be made between mobile excavators and crawler excavators. On the one hand, the lower structure 2 can have tires in a chassis and is referred to as a mobile excavator, whereby mobile excavators are only used in the weight class up to 25 t, and on the other hand the lower structure 2 can have tracks, so that crawler excavators are referred to, which are used in all weight classes. Mobile and crawler excavators are to be distinguished as self-propelled land vehicles from other types of excavators such as floating excavators. In the present example embodiment, the long arm excavator 1 is realized as a crawler excavator, which is in a weight class between about 25 t and about 400 t typical for demolition work, for example. The upper structure 4 includes a driver's cab 5 at its end in the direction of travel F (straight ahead) and a counterweight 6 opposite the driver's cab 5. FIGS. 1 and 2 show a three-part boom assembly 7, which is attached to the upper structure 4 next to or behind the driver's cab 5. The boom assembly 7 includes three links 8, 9, 10 arranged one behind the other. A first portion 8, called the boom, a second portion 9, called the intermediate boom, and a third portion furthest from the upper structure, called the arm 10, whereby two consecutive members are pivotably mounted to each other by bolts, for example. The boom assembly 7 further comprises a boom cylinder 11, which can move the first link 8, and an intermediate boom cylinder 12, which can move the second link 9 of the boom assembly 7. Furthermore, an arm cylinder 22 is provided which can be driven to move the arm 10. An attachment 14 is attached to the free end of the arm 10, through which an arm head bolt 13 passes. This connection can preferably be made by a quick coupler, for example. The attachment 14 and the quick coupler can also be pivoted about the pivot axis defined by the arm head bolt 13. In this example embodiment, the attachment 14 is a gripping tool, but all hydraulic attachments such as shears can be used.

[0030] The mobile hydraulic construction machine 1 includes a hydraulic system that drives the boom cylinder 11 and the intermediate boom cylinder 12 as well as the arm cylinder 22 by using hydraulic oil. The hydraulic oil flow and the associated movements are preferably controlled and monitored by a main valve block of the hydraulic system, not shown, located in the upper structure 4. The main valve block includes valves that regulate a supply quantity of hydraulic oil to one of the hydraulic cylinders. Furthermore, the main valve block is operable to control a hydraulic slewing drive of the slewing mechanism 3 and a hydraulic travel drive for the tracks of the lower structure 2. An additional valve block 15, a hydraulic oil tank 16 and a hydraulic pump 17 also belong to the hydraulic system are located in the upper structure 4. The hydraulic pump 17 supplies the hydraulic oil of the hydraulic system and is connected to the main valve block and the additional valve block 15 via a hydraulic connection. Several pumps can be used in the hydraulic system if the performance of one pump is not sufficient for the required application or if the system is to be designed redundantly. The additional valve block 15 controls and regulates a hydraulic oil flow to the attachment 14. Hydraulic lines 18 lead from the additional valve block 15 to the attachment 14. FIG. 1 shows only one hydraulic line 18, but depending on the attachment used and the type of construction machine, there may be several or at least two hydraulic lines 18. The type of attachment 14 and the movement that it can perform define the number of hydraulic lines 18 (used and connected). The hydraulic line 18 is provided in the area of bolt 19 of the boom assembly 7, between the upper structure 4 and the first link 8, and between the first link 8 and the second link 9 and between the second link 9 and the arm 10, by flexible hose lines arranged in a bend, also called boom hose bends 20. A flexible hose bend 21 is also preferably provided between a first attachment point on the attachment 14 and a second attachment point on the handle 10. The flexible boom hose bends 20 and the flexible hose bend 21 make it possible for the individual links of the boom assembly 7 to pivot about the longitudinal axis of the bolt 19 without the hydraulic line 18 being interrupted or ruptured. The hose bend 21 and the boom hose bends 20 are provided for each additional hydraulic line 18 (not shown). The portions of the hydraulic line 18 that extend centrally along the links of the boom assembly 7 away from the swivel axles or the bolt 19 are preferably rigid metal tubes. The ends of the metal tubes are each connected to a flexible hose line to define the hydraulic line 18. The metal tubes provide a protected area in which the hydraulic line 18 is protected from external damage. In the hydraulic line 18 shown, there are two emergency stop valves 23, 24 between the additional valve block 15 and the attachment 14. The emergency stop valves 23, 24 of the at least two hydraulic lines 18 are divided into first emergency stop valves 23 and second emergency stop valves 24 and are shown schematically as a rectangle in FIG. 1. The first emergency stop valve 23 and the second emergency stop valve 24 can close the corresponding hydraulic line 18 at the respective position. This can ensure that the emergency stop valve 23, 24 located on the side near the additional valve block of an occurring oil leakage reduces or prevents the hydraulic oil located between this emergency stop valve 23, 24 and the hydraulic pump 17 or the hydraulic oil tank 16 in the hydraulic lines 18 from escaping. The first emergency stop valve 23 is located in the upper structure 4 on the flow side of the additional valve block 15 remote from the pump. The second emergency stop valve 24 is located in the hydraulic line 18 in the area of the arm 10 outside the hose bend 21. A position that is directly upstream or downstream of the flexible hose line in the area of the arm head bolt 13 in the direction of flow is particularly preferred, as shown in FIG. 1. Experience has shown that the hose lines often leak in the area of the arm head bolt 13. The position of the second emergency stop valve 24 described above makes it possible to maintain the maximum possible amount of hydraulic oil in the hydraulic lines 18 in the event of such a leakage. If an oil leakage occurs in the hose bend 21, closing the second emergency stop valve 24 allows the oil in the hydraulic line 18 between the second emergency stop valve 24 and additional valve block 15 to remain in the hydraulic lines 18 and prevents it from escaping. It is conceivable to use further emergency stop valves which, for example, protect the boom hose bends 20 of the second link 9 against leakage. At least one emergency stop valve 23, 24 is required per hydraulic line 18. Even the first emergency stop valve 23 prevents the majority of the hydraulic oil from escaping in the event of a leakage in the flexible hose line in the area of the arm head bolt 13. The emergency stop valves 23, 24 differ from conventional pipe rupture safety devices, which are now installed as standard in mobile hydraulic construction machines. The pipe rupture safety valves, which are not shown, are installed on the attachment 14 and prevent uncontrolled movements of the attachment 14 in the event of pipe ruptures in order to protect operating personnel and construction site personnel. They maintain the pressure of the hydraulic oil in the attachment 14 or the working chambers of the hydraulic cylinders installed in it and allow the attachment 14 to remain in a fixed position. The emergency stop valves 23, 24 interrupt the hydraulic system at at least one point towards the additional valve block 15. The hydraulic oil in the hydraulic line between the break point and the emergency stop valve 23, 24 escapes. However, the emergency stop valve 23,24 prevents large quantities of hydraulic oil from escaping and thus contributes to environmental protection during demolition work. The emergency stop valves can also be provided in hydraulic lines connected to other hydraulic consumers. The hydraulic consumer can, for example, be the boom cylinder 11, the intermediate boom cylinder 12 and/or the arm cylinder.

[0031] FIG. 3 shows a portion of a hydraulic system, which is only shown schematically and is used to control the movement of the attachment 14. The hydraulic valves of the additional valve block 15 are electrically pilot-controlled to move the attachment 14, which is not shown in the figure. The hydraulic pump 17 supplies the additional valve block 15 with the oil pressure required to control the attachment 14 or its hydraulic cylinder. The additional valve block 15 regulates the volume flow of the hydraulic oil through the four hydraulic lines 18 shown as an example and can therefore control the movement of the attachment 14. There is a first emergency stop valve 23 and a second emergency stop valve 24 per hydraulic line 18. The first emergency stop valves 23 and the second emergency stop valves 24 are each located in two different sections of the hydraulic line 18. The hose bends 20 closest to the additional valve block and the flexible hose bends 21 in the area of the arm head bolt 13 are shown.

[0032] On the one hand, the first emergency stop valves 23 are arranged in the upper structure 4, in an upper structure section of the respective hydraulic line 18, which is located on the flow side of the additional valve block 15 remote from the pump, and on the other hand, the second emergency stop valves 24 are arranged in a boom assembly section of the respective hydraulic line 18, which is located outside the upper structure 4 and in the area of the arm 10 outside the flexible hose bends 21, as already described above. The emergency stop valves 23, 24 are open during regular operation of the mobile hydraulic construction machine 1 so that the hydraulic oil can flow unhindered through the emergency stop valves 23, 24. The emergency stop valves 23, 24 are controlled by an emergency stop actuator 25. When the emergency stop actuator 25 is actuated, the hydraulic lines 18 are closed by the emergency stop valves 23, 24 and the hydraulic oil flow is stopped. The emergency stop device 25 communicates electronically with the additional valve block 15 and switches the emergency stop valves 23, 24.

[0033] After a leakage has been detected in one of the hydraulic lines 18 between the attachment 14 and the additional valve block 15, the emergency stop valves 23, 24 are switched and the hydraulic lines 18 are shut off. FIG. 3 shows the closed state of the emergency stop valves 23, 24, which is achieved by actuating the emergency stop actuator 25.

[0034] In an example embodiment, the emergency stop valves 23,24 are electronically controlled solenoid valves.

[0035] In an example embodiment, the leakage is detected by the operating personnel and the operating personnel then actuates the emergency stop actuator 25 and the emergency stop valves 23, 24 are switched and shut off the hydraulic lines 18. The detection can also be carried out by a sensor which is assigned to the hydraulic lines 18 and the emergency stop actuator 25 can then be actuated automatically.

[0036] In an example embodiment, the additional valve block 15 is first actuated by the emergency stop actuator 25 and the additional valve block 15 shuts off the at least two hydraulic lines 18. The emergency stop valves 23, 24 are then switched and the hydraulic lines 18 are closed with a predeterminable time delay.

[0037] FIG. 4 shows a further example embodiment of a portion of the hydraulic system largely analogous to FIG. 3. In this case, the attachment 14 is hydraulically pilot-controlled by a low-pressure line. The boom hose bends 20 and the hose bends 21 have not been shown. The differences are explained below. In the example embodiment shown in FIG. 4, the first emergency stop valves 23 in the upper structure section of the hydraulic lines 18 are realized by 2-way valves 26, which can be connected to the hydraulic oil tank 16 of the hydraulic system via a return line 27. In regular operation, the second emergency stop valves 24, which in one example embodiment are electronically controlled solenoid valves, are open in the boom assembly section and the 2-way valves 26 in the upper structure section are in a first switching position, which allows hydraulic oil to flow from the additional valve block 15 via the hydraulic line 18 to the attachment 14.

[0038] After an oil leakage has been detected by operating personnel or a sensor, the second emergency stop valves 24 in the boom assembly section of the hydraulic lines 18 are switched and closed by actuating the emergency stop actuator 25 and the 2-way valves 26 switch to a second switching position shown, in which hydraulic oil flows from the additional valve block 15 via the return line 27 into the hydraulic oil tank 16.

[0039] It is conceivable to use more than two emergency stop valves 23, 24 per hydraulic line 18.

[0040] In both versions of the hydraulic systems, one electrically and one hydraulically pilot-controlled, the detection of an oil leakage can be carried out by operating personnel or a sensor. The emergency stop actuator 25 can, for example, be provided as an actuation button in the driver's cab 5 or on the boom assembly 7 or be accessible via a controller of the mobile hydraulic construction machine 1, which includes the necessary operating elements to control the mobile hydraulic construction machine 1. By actuating the emergency stop actuator 25, the emergency stop valves 23, 24 are switched and the hydraulic oil flow is stopped. By actuating the emergency stop actuator 25 again, the emergency stop valves 23, 24 can be switched back and the hydraulic lines 18 to the attachment 14 can be opened again. The emergency stop valves 23, 24 are switched back when the oil leakage in the hydraulic lines 18 has been rectified. If the leakage is detected by a sensor, it is conceivable that an alarm is issued, whereupon the operating personnel can actuate the emergency stop actuator 25. However, it is also possible that the emergency stop valves 23, 24 and/or the additional valve block 15 are automatically activated by the sensor that detects a pressure drop. In a further example embodiment, it is intended to use emergency stop valves which close automatically in the event of a pressure drop in the hydraulic line 18.

[0041] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.