JP2016070488A - Fault diagnosis system of control valve in hydraulic circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily specify a broken control valve, in a case where a control valve is broken, even in a hydraulic circuit in which many control valves are provided.SOLUTION: A fault diagnosis system includes fault diagnosis means 44 setting a plurality of test patterns in which two ore more control valves among a plurality of control valves are combined as a diagnosis object, and performing fault diagnosis with each test pattern as a unit on the basis of detection values of discharge pressures of first and second hydraulic pump 1, 2. The fault diagnosis system collates control valves with each other contained in a test pattern in which presence/absence of fault is diagnosed by the fault diagnosis means 44, and specifies a broken control valve.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technical field of a control valve failure diagnosis system in a hydraulic circuit of a work machine such as a construction machine.

Generally, a hydraulic circuit of a work machine such as a construction machine is provided with various control valves for controlling the operation of various hydraulic actuators such as a working hydraulic cylinder and a traveling hydraulic motor. If this occurs, prompt action such as repair or replacement is required. However, for example, if a malfunction occurs in the hydraulic circuit, such as insufficient output of the hydraulic actuator, a decrease in circuit pressure, or an unstable pump pressure, there are multiple control valves that can cause the malfunction. In order to specify whether or not the problem has been resolved by exchanging control valves that may be a factor, it takes time and effort. In particular, in construction machines, as metering valves for controlling the supply and discharge flow rate of hydraulic oil to the hydraulic actuator, first and second meter-in valves that respectively control the supply flow rate to a pair of ports provided in the hydraulic actuator. And four independent metering valves, a first meter-out valve and a second meter-out valve for controlling the discharge flow rate from the pair of ports, respectively, and finely controlling these four metering valves individually by electronic control. In addition, a hydraulic actuator that can efficiently control a hydraulic actuator is known (for example, see Patent Document 1). However, in a hydraulic circuit in which such an independent metering valve is employed, one hydraulic actuator is used. Requires four metering valves, pump confluence and pump pressure regulator Since there are valves and circuits other than the purpose of directly controlling the hydraulic actuator, such as a valve for the purpose, it has a complicated configuration. Therefore, if a malfunction occurs in the hydraulic circuit, the cause of the malfunction There are many control valves that can be used, and it is necessary to have a sufficient knowledge about the circuit configuration to identify which one of these control valves is malfunctioning, and it takes a lot of time and effort. was there.
On the other hand, as a fault diagnosis device for a control valve in a hydraulic circuit of a work machine, conventionally, a control means for outputting a control signal to a control valve is a fault that causes a normal control mode for performing a normal control operation and a specific fault diagnosis operation. It is configured to be exchangeable with the diagnosis mode, and is configured to determine whether or not there is a failure in the control valve based on the discharge pressure of the hydraulic pump when the control valve is operated for failure diagnosis in the failure diagnosis mode. Techniques have been proposed (for example, see Patent Document 2).

JP 10-311301 A JP 2000-46015 A

  However, the failure diagnosis device of Patent Document 2 is configured to determine a control valve to be diagnosed and perform failure diagnosis individually on the control valve. For this reason, if there are multiple control valves that can cause the failure in the hydraulic circuit in which the failure has occurred, failure diagnosis for all these control valves must be performed individually, which still takes time and effort. The failure of one control valve may affect the failure diagnosis of other normal control valves, and there is a possibility that accurate failure diagnosis cannot be performed. This is the problem to be solved by the present invention. is there.

The present invention was created in view of the above-described circumstances to solve these problems. The invention of claim 1 is operated by a hydraulic pump and hydraulic oil discharged from the hydraulic pump. In a hydraulic circuit of a work machine having a hydraulic actuator for controlling and a plurality of control valves for controlling the direction, flow rate or pressure of the hydraulic oil discharged from the hydraulic pump, the failure of the plurality of control valves is diagnosed In order to provide a failure diagnosis system, a plurality of test patterns in which two or more control valves among a plurality of control valves are subjected to diagnosis are set, and a failure diagnosis in units of each test pattern is hydraulically performed. Provide a failure diagnosis means based on the detected value of the discharge pressure of the pump, and a test pattern in which the presence or absence of a failure is diagnosed by the failure diagnosis means A fault diagnosis system of the control valve in the hydraulic circuit, characterized in that so as to identify the control valve failed in the match between Murrell control valve.
According to a second aspect of the present invention, in the first aspect, the failure diagnosing means outputs a diagnostic control signal set in accordance with each test pattern to the control valve to bring the control valve into a diagnostic control state. A fault diagnosis system for a control valve in a hydraulic circuit, wherein a fault diagnosis is performed by comparing a detection value of a discharge pressure of a hydraulic pump when the valve is in a diagnostic control state with a preset discharge pressure standard value. is there.
The invention of claim 3 is characterized in that, in claim 1 or 2, the failure diagnosis means is connected to a monitor device disposed in a cab of the work machine, and performs failure diagnosis based on an operation of the monitor device. This is a fault diagnosis system for a control valve in a hydraulic circuit.
A fourth aspect of the present invention provides the hydraulic actuator according to any one of the first to third aspects, wherein the hydraulic actuator includes a pair of ports as inlets and outlets of hydraulic oil for operating the hydraulic actuator, and controls a supply / discharge flow rate to the hydraulic actuator. The metering valve for controlling the flow rate is an electronically controlled first meter-in valve that controls the supply flow rate to one port of the hydraulic actuator, and an electronically controlled type of metering valve that controls the discharge flow rate from one port of the hydraulic actuator. One meter-out valve, an electronically controlled second meter-in valve that controls the supply flow rate to the other port of the hydraulic actuator, and an electronically controlled second meter that controls the discharge flow rate from the other port of the hydraulic actuator Of the control valve in the hydraulic circuit, characterized by being configured using an out valve. It is a disability diagnosis system.

The invention according to claim 1 can greatly reduce the time and labor required for fault diagnosis of the control valve, and does not require high knowledge about the circuit configuration, and can greatly contribute to improvement in maintainability.
According to the invention of claim 2, when the failure diagnosis of the test pattern is performed, the control valve automatically enters a diagnostic control state corresponding to each test pattern, and thus there is no knowledge of the circuit configuration. In addition, failure diagnosis can be performed easily and in a short time.
According to the third aspect of the present invention, it is possible to execute a failure diagnosis using a monitor device without requiring a separate operation device for failure diagnosis.
According to the invention of claim 4, the failure diagnosis system of the present invention is configured such that the metering valve includes four individual valves, a first meter-in valve, a first meter-out valve, and a second meter-out valve. It can be implemented in complex hydraulic circuits.

It is a hydraulic circuit diagram of a hydraulic excavator. It is a block diagram which shows the input / output of a controller. It is a table | surface figure which shows the diagnostic object of a test pattern and a pump test. FIG. 3 is a diagram showing an oil flow in a test pattern 1. It is a figure which shows the flow of the oil in the test pattern 2. FIG. It is a figure which shows the flow of the oil in the test pattern 3. FIG. It is a figure which shows the flow of the oil in the test pattern 4. FIG. It is a figure which shows the flow of the oil in the pump test 1. FIG. It is a figure which shows the flow of the oil in the pump test 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a hydraulic circuit of a hydraulic excavator (an example of a working machine of the present invention) in which the failure diagnosis system of the present invention is implemented. In the hydraulic circuit, 1 and 2 are variable displacement type first, Second hydraulic pump (in this embodiment, a swash plate type piston pump whose capacity changes depending on the swash plate angle), 3 is an oil tank, 4 to 9 are hydraulic oil discharged from the first and second hydraulic pumps 1 and 2 In this embodiment, a bucket cylinder 4, a boom cylinder 5, and a left traveling motor 6 are provided as hydraulic actuators mainly supplied with pressure oil from the first hydraulic pump 1. A right traveling motor 7, a turning motor 8, and a stick cylinder 9 are provided as hydraulic actuators mainly supplied with pressure oil from the second hydraulic pump 2.

Further, 10, 11 and 15 are bucket, boom and stick metering valves for controlling the supply and discharge flow rates of hydraulic oil to and from the bucket cylinder 4, boom cylinder 5 and stick cylinder 9, respectively. Each of the valves 10, 11, and 15 is configured using four independent electronically controlled valves. The bucket metering valve 10 will be described as an example. The bucket metering valve 10 is a first meter-in valve 10 </ b> A that controls the supply flow rate to the rod-side port 4 a serving as the inlet / outlet of the rod-side oil chamber of the bucket cylinder 4. A first meter-out valve 10B for controlling the discharge flow rate from the rod-side port 4a, and a second meter-in valve 10C for controlling the supply flow rate to the head-side port 4b serving as the inlet / outlet of the head-side oil chamber of the bucket cylinder 4 And a second meter-out valve 10D for controlling the discharge flow rate from the head side port 4b, and these first and second meter-in valves 10A, 10C, first and second meter-out valves. 10B and 10D are configured to operate in response to a control signal from a controller 16 described later. The rod side port 4a and the head side port 4b correspond to one port and the other port of the pair of ports provided in the hydraulic actuator of the present invention, and the boom cylinder 5 and the stick cylinder 9 are also buckets. Similar to the cylinder 4, a pair of ports 5 a, 5 b, 9 a, 9 b serving as hydraulic oil inlets and outlets are provided. Further, although description of the boom and stick metering valves 11 and 15 is omitted, the boom and stick metering valves 11 and 15 are also supplied from the controller 16 in the same manner as the bucket metering valve 10. The electronic control type first and second meter-in valves 11A, 11C, 15A, and 15C, and the first and second meter-out valves 11B, 11D, 15B, and 15D are operated based on the control signal.
Further, 12 and 13 are metering valves for left traveling and right traveling for controlling the supply and discharge flow rates of hydraulic oil to the left and right traveling motors 6 and 7, respectively. These metering valves 12 and 13 are for traveling. A pilot-actuated valve that is operated by a pilot pressure output from a pilot valve (not shown) based on the operation of the operation tool is used. Reference numeral 14 denotes a turning metering valve for controlling the supply and discharge flow rate of hydraulic oil to and from the turning motor 8. The turning metering valve 14 is not independently controlled by meter-in and meter-out. It is comprised using the electronically controlled valve | bulb which operate | moves by the control command from.

  Reference numerals 17 and 18 denote first and second discharge lines connected to the discharge sides of the first and second hydraulic pumps 1 and 2, respectively. In addition to being supplied to the valve 12, it is configured to be supplied to the bucket metering valve 10 and the boom metering valve 11 via a travel straight valve 27 at a first position X described later. On the other hand, the pressure oil in the second discharge line 18 is supplied to the turning metering valve 14 and the stick metering valve 15, and the right traveling metering valve via the traveling straight valve 27 at the first position X. 13 is configured to be supplied.

  Further, 19 and 20 are first and second relief oil passages that are branched from the first and second discharge lines 17 and 18 to reach the oil tank 3, respectively. 20 includes first and second main relief valves 21 and 22 for setting the circuit maximum pressure of the first and second discharge lines 17 and 18, respectively.

  Further, 23 and 24 are first and second bypass oils branched from the first and second discharge lines 17 and 18 respectively to the oil tank 3 on the downstream side of the first and second relief oil passages 19 and 20. A first and second bypass oil passages 23 and 24 that perform flow rate control of the first and second bypass oil passages 23 and 24 based on a control signal from the controller 16. Bypass valves 25 and 26 are provided, respectively.

  Further, the traveling straight valve 27 is a two-position switching valve that switches between a first position X and a second position Y based on a control signal from the controller 16, and the traveling straight valve 27 is moved to the first position X. In the position, the pressure oil in the first discharge line 17 is supplied to the left travel metering valve 12, and the pressure oil in the second discharge line 18 is supplied to the right travel metering valve 13. In the state where it is located at the second position Y, the pressure oil in the first discharge line 17 is supplied to both the left and right traveling metering valves 12 and 13. When the straight travel valve 27 is located at the second position Y, the pressure oil in the second discharge line 18 is applied to the metering valves 10, 11, 14, and 15 for buckets, booms, swivels, and sticks. Is to be supplied.

  Furthermore, 28 is a merging oil passage that communicates the first discharge line 17 and the second discharge line 18, and a merging valve 29 that switches based on a control signal from the controller 16 is arranged in the merging oil passage 28. It is installed. The merging valve 29 is a three-position switching valve provided with a check valve 29a. When the merging valve 29 is located at the first position X, oil is supplied from the first discharge line 17 to the second discharge line 18 by the check valve 29a. The flow is allowed but the reverse flow is blocked, and in the state where it is located at the second position Y, the oil flow between the first and second discharge lines 17 and 18 is interrupted and is located at the third position Z. In this state, the first and second discharge lines 17 and 18 are configured to communicate with each other.

Further, 30 and 31 are first and second circulation oil passages for circulating the discharge oils of the first and second discharge lines 17 and 18 and returning them to the oil tank 3, respectively. First and second warm-up valves 32 and 33 for opening and closing the first and second circulation oil passages 30 and 31 based on a control signal from the controller 16 are disposed in the passages 30 and 31, respectively.
In the present embodiment, the first and second main relief valves 21 and 22, the first and second bypass valves 25 and 26, the traveling straight valve 27, the merging valve 29, and the first and second warm-up valves 32. , 33 correspond to the control valve of the present invention. And these control valves and the metering valves 10-15 mentioned above are arrange | positioned in the state put together as a control valve unit.

  On the other hand, the controller 16 is configured using a microcomputer or the like, and as shown in the block diagram of FIG. 2, a hydraulic actuator operation tool (for bucket, for boom, for left travel, for right travel, Operation tools 34 to 39, first and second hydraulic pumps 1 and 2 for detecting the operation direction and operation amount of an operation lever and an operation pedal (not shown, which are operation tools for turning and sticking, not shown). The first and second pressure sensors 41 and 42 for detecting the pressures of the first and second swash plate angle sensors 40a and 40b and the first and second discharge lines 17 and 18, respectively, for detecting the swash plate angle, respectively. Signals from the monitor device 43 and the like are input, and based on these input signals, the metering valves for the first and second hydraulic pumps 1 and 2, bucket, boom, swivel, and stick are used. 10, 11, 14, 15, first and second bypass valves 25 and 26, traveling straight valve 27, junction valve 29, first and second warm-up valves 32 and 33, monitor device 43, etc. In addition, it is configured to include a failure diagnosis means 44, a memory 46, and the like. Then, the controller 16 performs normal control for operating the hydraulic actuators 4 to 9 based on the operation of the hydraulic actuator operation tool, warm-up operation control for performing warm-up operation based on the operation of the monitor device 43, and failure diagnosis. Various controls such as failure diagnosis control for performing failure diagnosis by means 44 based on the operation of the monitor device 43 are executed. The monitor device 43 is disposed in a cab of a hydraulic excavator, and includes a display and operation keys (not shown), and is connected to the controller 16 so as to allow input / output.

  First, the normal control performed by the controller 16 will be described. The controller 16 receives operation signals for the hydraulic actuator operation tools from the bucket, boom, swivel, and stick operation detection means 34, 35, 38, and 39. In the case, the control signals are output to the operated hydraulic actuator metering valves 10, 11, 14, 15, and the corresponding hydraulic actuators (bucket cylinder 4, boom cylinder 5, swing motor 8, stick cylinder 9) are output. ) Is controlled. For example, when a bucket-out (bucket cylinder 4 contraction) operation signal is input from the operation detection means 34 of the bucket operation tool, the first meter-in valve 10A and the second meter-out valve of the bucket metering valve 10 are used. A control signal is output to 10D to control the supply flow rate to the rod side port 4a of the bucket cylinder 4 and the discharge flow rate from the head side port 4b.

  Further, in the normal control, the controller 16 receives the first and second hydraulic pumps 1 and 2 that are the hydraulic supply sources of the operated hydraulic actuators 4 to 9 when an operation signal of the hydraulic actuator operation tool is input. In order to adjust the discharge pressure of the first and second bypass oil passages 23 and 24, a control signal for adjusting the opening amount is output to the first and second bypass valves 25 and 26 in order to adjust the discharge pressure of the first and second bypass valves 25 and 26. Take control. The memory 46 of the controller 16 stores a map showing the relationship between the operation amount of the operation tool for the hydraulic actuator and the opening amounts of the first and second bypass valves 25, 26. Opening amount control of the first and second bypass valves 25 and 26 is performed. When the hydraulic actuator operating tool is not operated, the first and second bypass valves 25 and 26 are controlled to open the first and second bypass oil passages 23 and 24 with the maximum opening amount. Thus, the first and second hydraulic pumps 1 and 2 are configured to be in a low pressure state.

  Further, in normal control, the controller 16 operates when both the left and right traveling operation tools are operated to perform straight traveling, and any of the operation tools for bucket, boom, turning, and stick is operated. Then, a control signal is output to switch the traveling straight valve 27 to the second position Y. In this state, the oil discharged from the first hydraulic pump 1 is supplied to the left traveling motor 6 and the right traveling motor 7, while the oil discharged from the second hydraulic pump 2 is operated by the above-described operation tool bucket cylinder 4 and boom cylinder 5. In this way, the discharge flow rate of the first hydraulic pump 1 is distributed only by the left and right traveling motors 6 and 7 to both traveling motors 6 and 7. The supply flow rate can be made equal. When only the left and right traveling operation tools are operated, or when only the bucket, boom, turning, and stick operation tools are operated, the traveling straight valve 27 is set to the first position X. It is controlled to be located in

Further, in normal control, the controller 16 receives the hydraulic oil from the first hydraulic pump 1 and the second hydraulic pump when an operation signal of a hydraulic actuator (for example, the boom cylinder 5 and the stick cylinder 9) requiring a flow rate is input. A control signal is output to the merging valve 29 in order to join the hydraulic oil from 2 to the hydraulic actuator. In this case, the controller 16 obtains a required flow rate according to the operation amount of the hydraulic actuator operating tool, and controls the total flow rate of the hydraulic oil so that the required flow rate is supplied to the hydraulic actuator.
When the normal control is being executed, the monitor device 43 is configured to display various body information such as the engine coolant temperature, the hydraulic oil temperature, and the remaining amount of fuel on the display.

  Next, the warm-up control performed by the controller 16 will be described. The controller 16 displays “warm-up control” on the display of the monitor device 43 when conditions (warming oil temperature, outside air temperature, etc.) requiring warm-up are satisfied. A screen for confirming the necessity of “execution” is displayed. When the operator inputs an instruction to “warm up” based on the display on this screen, the controller 16 sends the first and second circulating oils to the first and second warm-up valves 32 and 33. A control signal is output so that it may be located in the open position which opens the paths 30 and 31. The first and second warm-up valves 32 and 33 are opened to automatically circulate the hydraulic oil of the first and second hydraulic pumps 1 and 2 to warm the hydraulic oil and the control valve unit. Has been. When the warm-up control is not being executed, the first and second warm-up valves 32 and 33 are controlled so as to be positioned at the closed positions where the first and second circulation oil passages 30 and 31 are closed.

  Next, failure diagnosis control performed by the controller 16 will be described. The failure diagnosis control is performed based on the operation of the monitor device 43. In the present embodiment, the monitor device 43 is operated only by a specific person such as a service person by inputting a password based on the operation of the operation key. The service mode in which the operation is allowed can be set in the service mode, and the operation of the failure diagnosis control can be performed in the service mode (hereinafter, the person who performs the operation of the failure diagnosis control, Called the diagnostic performer).

  Here, the memory 46 of the controller 16 stores data in which a plurality of test patterns for failure diagnosis are set. The test pattern includes two or more control valves among the control valves (first and second main relief valves 21 and 22, first and second bypass valves 25 and 26, travel straight valve 27, and merging valve 29). In the present embodiment, the first bypass valve 25, the first main relief valve 21, and the first warm-up valve 32 are set as the diagnosis targets, as shown in the table of FIG. Test pattern 1, test pattern 2, second bypass valve 26, second main relief valve 22 and second warm-up valve 33 to be diagnosed, first bypass valve 25, first main relief valve 21 and first warm-up valve Test pattern 3, the second bypass valve 26, the second main relief valve 22 and the first warm-up valve which are the diagnosis targets of the mechanical valve 32 and the second warm-up valve 33 Test pattern 4 to a a blanking 32 and the second warm-up valve 33 and the diagnostic target is set. Further, in the present embodiment, a pump test 1 for which the first hydraulic pump 1 is a diagnosis target and a pump test 2 for which the second hydraulic pump 2 is a diagnosis target are also set. The pump tests 1 and 2 with the first and second hydraulic pumps 1 and 2 as diagnosis targets are not included in the test pattern of the present invention. The test patterns 1 to 4 are set in advance in the present embodiment, and the data is stored in the memory 46 of the controller 16, but an arbitrary control valve is targeted for diagnosis using the monitor device 43. A configuration in which various test patterns can be set is also possible.

When performing a fault diagnosis of the control valve, first, when any one of the test patterns 1 to 4 is selected by a key operation of the monitor device 43, the signal is input to the controller 16 and each of the selected tests The failure diagnosis unit 44 executes failure diagnosis in units of patterns. In this case, the failure diagnosing means 44 outputs a diagnostic control signal set according to each test pattern to the control valve to put the control valve in the diagnostic control state, and the first and second hydraulic pumps 1, 2 , The discharge pressure is detected by the first and second pressure sensors 41 and 42, and the detected discharge pressure is compared as a preset discharge pressure standard value to perform failure diagnosis. Yes.
Note that when performing failure diagnosis of the test patterns 1 to 4, all the metering valves 10 to 15 are controlled to be closed, and although not shown, a turning brake device provided in a hydraulic circuit of a hydraulic excavator Is controlled to be in a brake state. Furthermore, while the failure diagnosis of the test pattern by the failure diagnosis means 44 is being executed, the first and second hydraulic pumps 1 and 2 detected by the first and second pressure sensors 41 and 42 are displayed on the display of the monitor device 43. 2 is displayed, and after the failure diagnosis of each test pattern is completed, the diagnosis result is displayed on the display.

  Next, the diagnostic control performed by the failure diagnosis means 44 will be specifically described for each of the test patterns 1 to 4. First, in the test pattern 1 in which the first bypass valve 25, the first main relief valve 21, and the first warm-up valve 32 are diagnosed, the merging valve 29 connects the first discharge line 17 and the second discharge line 18. It controls so that it may be located in the 2nd position Y to interrupt | block. The traveling straight valve 27 is supplied with pressure oil from the first discharge line 17 via the left traveling metering valve 12 and the traveling straight valve 27 to the bucket metering valves 10 and 11 and the boom metering valves 10 and 11. Control is performed so that the pressure oil in the discharge line 18 is located at the first position X supplied to the metering valve 13 for right travel via the swiveling and stick metering valves 14 and 15 and the travel straight valve 27. The first bypass valve 25 is controlled to close the first bypass oil passage 23, and the second bypass valve 26 is controlled to open the second bypass oil passage 24 with the maximum opening amount. The first and second warm-up valves 32 and 33 are controlled so as to be positioned at the closed positions where the first and second circulation oil passages 30 and 31 are closed. In this way, the first hydraulic pump 1 is driven at the minimum flow rate with each control valve in the diagnostic control state of the test pattern 1. In this state, as shown in FIG. 4, the discharge oil from the first hydraulic pump 1 reaches the merging valve 29 at the second position Y from the first discharge line 17 via the travel straight valve 27 and at the closed position. In this state, the pressure in the first discharge line 17 input from the first pressure sensor 41 is set to the preset pressure (mainly set in the first main relief valve 21). It corresponds to the discharge pressure standard value of the invention. When the pressure in the first discharge line 17 is equal to or higher than the set pressure of the first main relief valve 21, it is determined that there is no failure in the test pattern 1 (no failure in all control valves that are diagnosed by the test pattern 1). When the pressure of the first discharge line 17 is lower than the set pressure of the first main relief valve 21, it is determined that there is a failure in the test pattern 1 (the test pattern 1 has a failure in at least one control valve to be diagnosed). . Further, the determination result is displayed on the display of the monitor device 43.

  In the test pattern 2 in which the second bypass valve 26, the second main relief valve 22, and the second warm-up valve 33 are diagnosed, the merging valve 29 is connected from the first discharge line 17 to the second discharge line 18. Control is performed so as to be in a first position X that allows oil flow but prevents reverse flow. The traveling straight valve 27 is supplied with pressure oil from the first discharge line 17 via the left traveling metering valve 12 and the traveling straight valve 27 to the bucket metering valves 10 and 11 and the boom metering valves 10 and 11. Control is performed so that the pressure oil in the discharge line 18 is located at the first position X supplied to the metering valve 13 for right travel via the swiveling and stick metering valves 14 and 15 and the travel straight valve 27. The first bypass valve 25 is controlled to open the first bypass oil passage 23 with the maximum opening amount, and the second bypass valve 26 is controlled to close the second bypass oil passage 24. The first and second warm-up valves 32 and 33 are controlled so as to be positioned at the closed positions where the first and second circulation oil passages 30 and 31 are closed. In this way, the second hydraulic pump 2 is driven at the minimum flow rate in a state where each control valve is in the diagnostic control state of the test pattern 2. In this state, as shown in FIG. 5, the discharge oil from the second hydraulic pump 2 reaches the merging valve 29 at the first position X from the second discharge line 18 and reaches the second warm-up valve 33 at the closed position. In this state, the pressure of the second discharge line 18 input from the second pressure sensor 42 is set to the preset pressure of the second main relief valve 22 (corresponding to the discharge pressure standard value of the present invention). Compare with). If the pressure in the second discharge line 18 is equal to or higher than the set pressure of the second main relief valve 22, it is determined that there is no failure in the test pattern 2 (no failure in all control valves that are diagnosed by the test pattern 2). When the pressure of the second discharge line 18 is lower than the set pressure of the second main relief valve 22, it is determined that there is a failure in the test pattern 2 (the test pattern 2 has a failure in at least one control valve to be diagnosed). . Further, the determination result is displayed on the display of the monitor device 43.

  In the test pattern 3 in which the first bypass valve 25, the first main relief valve 21, the first warm-up valve 32, and the second warm-up valve 33 are diagnosed, the merging valve 29 is connected to the first and second discharge lines. It controls so that it may be located in the 3rd position Z which communicates 17 and 18 and joins each other. The traveling straight valve 27 is supplied with pressure oil from the first discharge line 17 via the left traveling metering valve 12 and the traveling straight valve 27 to the bucket metering valves 10 and 11 and the boom metering valves 10 and 11. Control is performed so that the pressure oil in the discharge line 18 is located at the first position X supplied to the metering valve 13 for right travel via the swiveling and stick metering valves 14 and 15 and the travel straight valve 27. The first bypass valve 25 is controlled to close the first bypass oil passage 23, and the second bypass valve 26 is controlled to open the second bypass oil passage 24 with the maximum opening amount. The first and second warm-up valves 32 and 33 are controlled so as to be positioned at the closed positions where the first and second circulation oil passages 30 and 31 are closed. In this way, the first hydraulic pump 1 is driven at the minimum flow rate in a state where each control valve is in the diagnostic control state of the test pattern 3. In this state, as shown in FIG. 6, the discharge oil from the first hydraulic pump 1 reaches the first warm-up valve 32 in the closed position from the first discharge line 17 via the travel straight valve 27 and the third warm-up valve 32. It flows so as to reach the second warm-up valve 33 in the closed position via the merge valve 29 at the position Z. In this state, the pressure of the first discharge line 17 input from the first pressure sensor 41 is set in advance. This is compared with the set pressure of the first main relief valve 21 (corresponding to the discharge pressure standard value of the present invention). When the pressure in the first discharge line 17 is equal to or higher than the set pressure of the first main relief valve 21, it is determined that there is no failure in the test pattern 3 (no failure in all the control valves that are diagnosed by the test pattern 3). When the pressure of the pressure of the first discharge line 17 is lower than the set pressure of the first main relief valve 21, there is a failure in the test pattern 3 (the test pattern 3 has a failure in at least one control valve to be diagnosed). to decide. Further, the determination result is displayed on the display of the monitor device 43.

  Further, in the test pattern 4 in which the second bypass valve 26, the second main relief valve 22, the first warm-up valve 32, and the second warm-up valve 33 are diagnosed, the merging valve 29 has the first and second discharges. Control is performed so as to be positioned at a third position Z where the lines 17 and 18 are communicated with each other and merge with each other. The traveling straight valve 27 is supplied with pressure oil from the first discharge line 17 via the left traveling metering valve 12 and the traveling straight valve 27 to the bucket metering valves 10 and 11 and the boom metering valves 10 and 11. Control is performed so that the pressure oil in the discharge line 18 is located at the first position X supplied to the metering valve 13 for right travel via the swiveling and stick metering valves 14 and 15 and the travel straight valve 27. The first bypass valve 25 is controlled to open the first bypass oil passage 23 with the maximum opening amount, and the second bypass valve 26 is controlled to close the second bypass oil passage 24. The first and second warm-up valves 32 and 33 are controlled so as to be positioned at the closed positions where the first and second circulation oil passages 30 and 31 are closed. In this way, the second hydraulic pump 2 is driven at the minimum flow rate with each control valve in the diagnostic control state of the test pattern 4. In this state, as shown in FIG. 7, the discharge oil from the second hydraulic pump 2 reaches the second warm-up valve 33 in the closed position from the second discharge line 18 and also passes through the merging valve 29 in the third position Z. In this state, the pressure of the second discharge line 18 input from the second pressure sensor 42 is set to the preset second main relief valve 22. To the set pressure (corresponding to the discharge pressure standard value of the present invention). If the pressure in the second discharge line 18 is equal to or higher than the set pressure of the second main relief valve 22, it is determined that there is no failure in the test pattern 4 (no failure in all control valves to be diagnosed by the test pattern 4). When the pressure of the second discharge line 18 is lower than the set pressure of the second main relief valve 22, it is determined that there is a failure in the test pattern 4 (the test pattern 4 has a failure in at least one control valve to be diagnosed). . Further, the determination result is displayed on the display of the monitor device 43.

Thus, the failure diagnosis of the test patterns 1 to 4 is executed by the failure diagnosis means 44, and the diagnosis result is displayed on the display of the monitor device 43. In this case, for example, as shown in the table of FIG. Further, the control valve to be diagnosed for each test pattern 1 to 4 and the diagnosis result (presence of failure) can be displayed together. Then, the diagnosis executor collates the control valves included in the test pattern in which the presence or absence of the failure is diagnosed, and identifies the failed control valve. In this case, if there is a control valve included in the test pattern diagnosed as having a failure and a control valve included in the test pattern diagnosed as having no failure but included in the failure and not included in the failure The control valve is identified as a failed valve. For example, when the test pattern 1 has no failure and the test pattern 3 has a failure, the only control valve that is included in the test pattern 3 but not included in the test pattern 1 is the second warm-up valve 33. Then, it is specified that the second warm-up valve 33 has failed. Further, when the test pattern 2 has no failure and the test pattern 4 has a failure, the first warm-up valve 32 is the only control valve included in the test pattern 4 but not included in the test pattern 2. Then, it is specified that the first warm-up valve 32 has failed.
Further, if there is a common control valve among the control valves included in the plurality of test patterns diagnosed as having a failure, the control valve is identified as a control valve having a high possibility of failure. For example, when both test pattern 1 and test pattern 2 are faulty, if there are not a plurality of control valves that are out of control valves included in these test patterns 1 and 2, the test patterns 1 and 2 are common to these test patterns 1 and 2. It can be specified that the second warm-up valve 33 is a failure valve. However, in this case, since a plurality of control valves may have failed, the second warm-up valve 33 is specified as a control valve that has a high possibility of failure.
Furthermore, the specification of the failed valve is not limited to the case where only the failed valve is specified, and includes the case where at least one of the narrowed down control valves is failed. For example, when test pattern 1 and test pattern 3 are faulty and test pattern 2 and test pattern 4 are diagnosed as having no fault, they are included in test patterns 1 and 3 but not in test patterns 2 and 4. Since the control valves that are not included are the first bypass valve 25 and the first main release valve 21, it is specified that at least one of the first bypass valve 25 and the first main release valve 21 has failed.
For control valves that are identified as having a high possibility of failure, or for control valves that are narrowed down as having at least one failure, failure diagnosis is performed separately.

  Next, the diagnosis control performed by the failure diagnosis means 44 in the failure diagnosis of the pump tests 1 and 2 will be described. When performing the failure diagnosis of the pump tests 1 and 2, the cases of the test patterns 1 to 4 described above are used. Similarly, all the metering valves 10 to 15 are controlled to be closed, and the turning brake device is controlled to be in a brake state.

  First, the pump test 1 for diagnosing the first hydraulic pump 1 will be described. In the pump test 1, the merging valve 29 communicates the first and second discharge lines 17 and 18 and joins each other. Control is performed so that it is located at position Z. The traveling straight valve 27 is supplied with pressure oil from the first discharge line 17 via the left traveling metering valve 12 and the traveling straight valve 27 to the bucket metering valves 10 and 11 and the boom metering valves 10 and 11. Control is performed so that the pressure oil in the discharge line 18 is located at the first position X supplied to the metering valve 13 for right travel via the swiveling and stick metering valves 14 and 15 and the travel straight valve 27. The first and second bypass valves 25 and 26 are controlled to open the first and second bypass oil passages 23 and 24 with the maximum opening amount. The first and second warm-up valves 32 and 33 are controlled so as to be positioned at the open position where the first and second circulation oil passages 30 and 31 are opened. In this way, the first hydraulic pump 1 is driven at the minimum flow rate in a state where each control valve is in the diagnostic control state of the pump test. In this state, as shown in FIG. 8, the discharge oil from the first hydraulic pump 1 flows into the oil tank 3 via the first bypass oil passage 23. In this state, the flow rate of the first hydraulic pump 1 is reduced. Change 10% from minimum flow rate. Then, the swash plate angle command value for the first hydraulic pump 1 at this time is compared with the detected value of the first swash plate angle sensor 40a, and the swash plate angle displacement of the first hydraulic pump 1 corresponds to the command value. It is diagnosed whether or not the operation is accurately performed, thereby determining whether or not the first hydraulic pump 1 has failed and displaying it on the display of the monitor device 43.

Further, in the pump test 2 in which the second hydraulic pump 2 is a diagnosis target, the merging valve 29, the traveling straight valve 27, the first and second bypass valves 25 and 26, the first and second warm-up valves 32 and 33 are Control is performed so as to be in the same diagnostic control state as the pump test 1 described above, and in this state, the second hydraulic pump 2 is driven at the minimum flow rate. In this state, as shown in FIG. 9, the oil discharged from the second hydraulic pump 2 flows into the oil tank 3 via the second bypass oil passage 24. In this state, the flow rate of the second hydraulic pump 2 is reduced. Change 10% from minimum flow rate. Then, the swash plate angle command value for the second hydraulic pump 2 at this time is compared with the detection value of the second swash plate angle sensor 40b, and the swash plate angle displacement of the second hydraulic pump 2 corresponds to the command value. It is diagnosed whether or not the operation is accurately performed, thereby determining whether or not the second hydraulic pump 2 has failed and displaying it on the display of the monitor device 43.
The first and second hydraulic pumps 1 and 2 are not included in the test pattern diagnosis target of the present invention. However, in the present embodiment, the failure diagnosis means 44 includes the first and second hydraulic pumps 1 and 2. The pump tests 1 and 2 with 2 as the diagnosis target are also executed. Thus, the failure diagnosis of the hydraulic equipment not included in the test pattern diagnosis target according to the present invention is performed as the diagnosis target according to the present invention. It can also be performed in combination with the control valve failure diagnosis.

  In the embodiment configured as described, the hydraulic circuit of the excavator includes hydraulic pumps 1 and 2 (in the present embodiment, the first hydraulic pump 1 and the second hydraulic pump 2), and the hydraulic pumps 1 and 2 Hydraulic actuators 4 to 9 (in this embodiment, bucket cylinder 4, boom cylinder 5, left traveling motor 6, right traveling motor 7, turning motor 8 and stick cylinder 9) that are actuated by hydraulic oil discharged from the hydraulic fluid, and hydraulic pressure A plurality of control valves for controlling the flow direction, flow rate or pressure of the hydraulic oil discharged from the pumps 1 and 2 (in the present embodiment, the first and second main relief valves 21, 22, first, first Two bypass valves 25 and 26, a traveling straight valve 27, a merging valve 29, first and second warm-up valves 32 and 33), and the failure of these control valves is diagnosed. In providing the failure diagnosis system, a plurality of test patterns (in this embodiment, test patterns 1 to 4) in which two or more control valves among a plurality of control valves are variously combined as a diagnosis target are set, Failure diagnosis means 44 for performing failure diagnosis in units of each test pattern based on the detected value of the discharge pressure of the hydraulic pumps 1 and 2 is provided, and is included in the test pattern diagnosed by the failure diagnosis means 44 for the presence or absence of a failure. The control valve which failed is identified by collating the control valves.

  Thus, when performing failure diagnosis of a control valve, failure diagnosis is performed in units of test patterns in which two or more control valves are combined as a diagnosis target. Diagnosis can significantly reduce time and labor compared with the case of individually diagnosing the control valve. In addition, since the failure valve is identified by comparing the control valves included in the test pattern in which the presence or absence of failure is diagnosed, it can be easily performed without a high level of knowledge about the circuit configuration. It can greatly contribute to improvement.

  Further, in this device, the failure diagnosis means 44 outputs a diagnostic control signal set in accordance with each test pattern to the control valve to place the control valve in the diagnostic control state, while placing the control valve in the diagnostic control state. When the fault diagnosis of the test pattern is performed, control is performed because the detection value of the discharge pressure of the hydraulic pumps 1 and 2 is compared with a preset discharge pressure standard value. The valve automatically enters the diagnostic control state corresponding to each test pattern, so that the person performing the failure diagnosis does not need to put the control valve in the diagnostic control state according to the test pattern by itself. Even without knowledge, the test pattern can be easily diagnosed in a short time.

  In addition, the failure diagnosis means 44 is connected to a monitor device 43 disposed in the cab of the hydraulic excavator and can perform failure diagnosis based on the operation of the monitor device 43. Failure diagnosis can be performed using the monitor device 43 without requiring a separate device.

  The metering valves 10, 11, 15 for controlling the supply / discharge flow rates for the bucket cylinder 4, the boom cylinder 5, and the stick cylinder 9 among the hydraulic actuators 4 to 9 are hydraulic actuators 4, 5, 9 (bucket cylinders). 4, boom cylinder 5 and stick cylinder 9) of electronically controlled first meter-in valves 10A, 11A, and 15A for controlling the supply flow rate to one port 4a, 5a, and 9a, and hydraulic actuators 4, 5, and 9 Electronically controlled first meter-out valves 10B, 11B, 15B for controlling the discharge flow rate from one port 4a, 5a, 9a and supply to the other ports 4b, 5b, 9b of the hydraulic actuators 4, 5, 9 Electronically controlled second meter-in valves 10C, 11C, 15C for controlling the flow rate, and hydraulic actuators The second meter-out valves 10D, 11D, and 15D are electronically controlled to control the discharge flow rate from the other ports 4b, 5b, and 9b. 4b, 5a, 5b, 9a, 9b is controlled by separate meter-in and meter-out valves, and the hydraulic circuit is complicated. In addition to the metering valves 10, 11, 15 Many control valves are provided for controlling the flow direction, flow rate and pressure of the hydraulic oil. The present invention is particularly useful because even a hydraulic circuit having such a large number of control valves can easily identify a failed control valve in a short time.

Of course, the present invention is not limited to the above-described embodiment, and the test pattern can be set as appropriate in addition to the test patterns 1 to 4 described above. Various settings can be made according to a control valve or the like arranged in the hydraulic circuit.
In the above embodiment, the metering valve for controlling the supply / discharge flow rate to the hydraulic actuator is not included in the test pattern, but the metering valve is included in the test pattern as one of the control valves. You can also. In the above-described embodiment, as a failure diagnosis procedure, first, failure determination of a control valve other than the metering valve is performed by failure diagnosis based on a test pattern, and when it is determined by this failure determination that there is no failure in the control valve. The failure of the metering valve is diagnosed.
Further, in the above embodiment, the diagnosis executor is configured to identify the failed control valve by using the table as shown in FIG. 3. For example, the diagnosis result of the presence or absence of failure of each test pattern Alternatively, a flowchart or the like that can identify a failed valve may be created in advance, and the failed valve may be identified based on the flowchart. Furthermore, the controller can be provided with a fault valve specifying means having a function of specifying a control valve that has failed by collating the control valves included in the test pattern diagnosed by the fault diagnosis means. In this case, the failure valve specified by the controller can be displayed on the display of the monitor device, for example.

  The present invention can be used when diagnosing a malfunction of a control valve in a hydraulic circuit of a work machine such as a construction machine.

1, 2 First, second hydraulic pumps 4-9 Hydraulic actuators 10-15 Metering valves 10A, 11A, 15A First meter-in valves 10B, 11B, 15B First meter-out valves 10C, 11C, 15C Second meter-in Valves 10D, 11D, and 15D Second meter-out valve 16 Controllers 21 and 22 First and second main relief valves 25 and 26 First and second bypass valves 27 Travel straight valve 29 Merge valves 32 and 33 First and second warm Machine valve 43 monitoring device 44 fault diagnosis means

Claims (4)

  A work comprising a hydraulic pump, a hydraulic actuator that operates with hydraulic oil discharged from the hydraulic pump, and a plurality of control valves for controlling the direction, flow rate, or pressure of the hydraulic oil discharged from the hydraulic pump In providing a failure diagnosis system for diagnosing a failure of the plurality of control valves in a hydraulic circuit of a machine, a plurality of test patterns obtained by various combinations of two or more control valves among the plurality of control valves as diagnosis targets are provided. A failure diagnosis means for performing a failure diagnosis in units of each test pattern based on the detected value of the discharge pressure of the hydraulic pump is provided, and is included in the test pattern in which the presence or absence of a failure is diagnosed by the failure diagnosis means The control valve in the hydraulic circuit is characterized in that the control valve is identified by collating the control valves. Department of fault diagnosis system.   In Claim 1, the failure diagnosis means outputs a diagnostic control signal set in accordance with each test pattern to the control valve to place the control valve in the diagnostic control state, while placing the control valve in the diagnostic control state. A failure diagnosis system for a control valve in a hydraulic circuit, wherein a failure diagnosis is performed by comparing a detected value of a discharge pressure of a hydraulic pump with a discharge pressure standard value set in advance.   3. The control valve in the hydraulic circuit according to claim 1, wherein the failure diagnosis means is connected to a monitor device disposed in a cab of the work machine and executes failure diagnosis based on an operation of the monitor device. Fault diagnosis system.   The hydraulic actuator according to any one of claims 1 to 3, wherein the hydraulic actuator includes a pair of ports as an inlet / outlet of hydraulic oil that operates the hydraulic actuator, and a metering valve for controlling a supply / discharge flow rate to the hydraulic actuator includes: An electronically controlled first meter-in valve that controls the supply flow rate to one port of the hydraulic actuator, an electronically controlled first meter-out valve that controls the discharge flow rate from one port of the hydraulic actuator, and hydraulic pressure Consists of an electronically controlled second meter-in valve that controls the supply flow rate to the other port of the actuator and an electronically controlled second meter-out valve that controls the discharge flow rate from the other port of the hydraulic actuator A fault diagnosis system for a control valve in a hydraulic circuit.

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