JP2019112801A - Work vehicle - Google Patents

Abstract

To provide a work vehicle capable of securely detecting abnormality in hydraulic pumps arranged on the work vehicle which is provided with the plurality of hydraulic pumps.SOLUTION: A work vehicle having a plurality of actuating parts comprises: a plurality of hydraulic actuators arranged corresponding to the plurality of actuating parts; a plurality of hydraulic pumps supplying hydraulic oil to at least one hydraulic actuator; a plurality of pressure sensors 51 to 53 detecting each of delivery pressures of the plurality of hydraulic pumps; an actuating condition determination part 54 determining actuating conditions created through combining the plurality of actuating parts; and an abnormality determination part 56 determining an abnormality occurrence in at least one hydraulic pump when a second relation, which is a relation of delivery pressures between the plurality of hydraulic pumps detected by the pressure sensors 51 to 53, is different from a first relation, which is a relation of preset delivery pressures between the plurality of hydraulic pumps corresponding to actuation conditions determined by the actuating condition determination part 54, as a comparison result of the first relation and the second relation.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a work vehicle having a plurality of operation units.

  In working vehicles such as backhoes and wheel loaders, a plurality of hydraulic actuators are driven by hydraulic fluid supplied by a plurality of hydraulic pumps to operate a plurality of operation units.

  Patent Document 1 below discloses a pump failure warning device for a hydraulic working machine such as a hydraulic shovel. The device of Patent Document 1 generates a warning corresponding to the first hydraulic pump when, for example, only the discharge pressure of the first hydraulic pump is lowered among the first and second hydraulic pumps that drive the hydraulic actuator. Patent Document 1 describes that when both the first and second hydraulic pumps are in a normal state, there is no large difference between the pump discharge pressures of the two.

Japanese Patent Application Publication No. 11-200423

  In Patent Document 1, failure of the hydraulic pump is detected on the premise that the discharge pressures of the first and second hydraulic pumps are equal if they are normal. However, the method of Patent Document 1 is applicable only when the hydraulic circuit including the first hydraulic pump and the hydraulic circuit including the second hydraulic pump are completely symmetrical, and a plurality of hydraulic pumps are circuits. Application to general work vehicles that drive complex hydraulic systems including merging is difficult. The discharge pressure of the hydraulic pump is influenced by, for example, the length and resistance of the flow path to the junction with the hydraulic oil discharged from another hydraulic pump, and further, the operating state of the operating unit, etc. When the discharge pressures of the hydraulic pumps are equal, not all the hydraulic pumps are in a normal state, and there is a possibility that a failure can not be detected.

  Then, in view of the above-mentioned subject, in the work vehicle provided with a plurality of hydraulic pumps, an object of the present invention is to provide a work vehicle which can detect abnormalities of these hydraulic pumps more certainly.

The work vehicle of the present invention is a work vehicle having a plurality of operation units, and
A plurality of hydraulic actuators provided corresponding to the plurality of operation units;
A plurality of hydraulic pumps for supplying hydraulic fluid to at least one hydraulic actuator of the plurality of hydraulic actuators;
A plurality of detection units for detecting the discharge pressure of each of the plurality of hydraulic pumps;
An operation state determination unit that determines an operation state by a combination of the plurality of operation units;
A first relationship which is a relationship of discharge pressure among the plurality of hydraulic pumps set in advance corresponding to the operating condition determined by the operating condition determination unit, and the plurality of hydraulic pumps detected by the detection unit Comparing with the second relationship which is the relationship of the discharge pressure between them, and when the second relationship is different from the first relationship, at least one hydraulic pump of the plurality of hydraulic pumps has an abnormality And an abnormality determination unit that determines that

  The present invention sets in advance the relationship of the discharge pressure between the plurality of hydraulic pumps according to the operating state, and at least one when the relationship of the discharge pressure among the plurality of hydraulic pumps actually detected differs from this. It is determined that an abnormality has occurred in one hydraulic pump. Therefore, even if the absolute values of the discharge pressures of the plurality of hydraulic pumps change independently depending on the operating state, it is possible to reliably detect an abnormality in the hydraulic pump. The discharge pressure relationship between the plurality of hydraulic pumps set in advance may be a simple magnitude relationship or may be expressed by a regression equation.

In the present invention, the detection unit repeatedly detects each discharge pressure of the plurality of hydraulic pumps.
The abnormality determination unit compares the first relationship with the second relationship every time the detection unit performs the detection, and when the second relationship is different from the first relationship by a predetermined number of times or more, It may be determined that an abnormality has occurred in one hydraulic pump.

  Since it is determined whether or not an abnormality has occurred after performing the abnormality determination of the hydraulic pump a plurality of times, it is possible to prevent an erroneous determination.

It is a left side view of a backhoe concerning this embodiment. It is a hydraulic circuit diagram of a backhoe. It is a hydraulic circuit figure at the time of boom operation. It is a hydraulic circuit diagram at the time of arm operation. It is a hydraulic circuit figure at the time of bucket operation. It is a hydraulic circuit diagram at the time of boom, an arm, and bucket combined work. It is a hydraulic circuit diagram at the time of driving | running | working. It is a functional block diagram which shows the structure of a pump abnormality detection system. It is a flowchart which shows the procedure of the pump abnormality detection method. It is a functional block diagram which shows the structure of the pump abnormality detection system which concerns on other embodiment. It is a flowchart which shows the procedure of the pump abnormality detection method which concerns on other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, a schematic structure of a backhoe 1 as an example of a work vehicle will be described with reference to FIG. However, the work vehicle is not limited to the backhoe 1, and may be another vehicle such as a wheel loader. The backhoe 1 includes a traveling device 2, a work device 3, and a turning device 4.

  The traveling device 2 is driven by receiving power from the engine 42 and causes the backhoe 1 to travel. The traveling device 2 includes a pair of left and right crawlers 21 and a pair of left and right traveling motors 22 and 22. The left and right traveling motors 22, 22 as hydraulic motors drive the left and right crawlers 21, 21, respectively, to allow the backhoe 1 to move forward and backward. Further, the traveling device 2 is provided with a blade 23 and a blade cylinder 24 for rotating the blade 23 in the vertical direction. The crawlers 21 and 21 and the blades 23 correspond to the operation units, respectively, and the travel motors 22 and 22 and the blade cylinders 24 correspond to the hydraulic actuators, respectively.

  The work device 3 is driven by receiving power from the engine 42, and performs digging work of soil and the like. The working device 3 includes a boom 31, an arm 32 and a bucket 33, and can independently perform drilling operations by driving them independently. The boom 31, the arm 32, and the bucket 33 correspond to the operation units, respectively.

  One end of the boom 31 is supported at the front of the pivoting device 4 and is pivoted by a telescopically movable boom cylinder 31 a. Further, the arm 32 is supported by the other end of the boom 31 at one end, and is rotated by the telescopically movable arm cylinder 32 a. One end of the bucket 33 is supported by the other end of the arm 32, and the bucket 33 is pivoted by a telescopically movable bucket cylinder 33a. The boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a correspond to hydraulic actuators, respectively.

  The turning device 4 turns the work device 3. In the turning device 4, a control unit 41, an engine 42, a turning stand 43, a turning motor 44, and the like are disposed. The swing motor 44, which is a hydraulic motor, drives the swing base 43 to cause the working device 3 to swing. The swivel base 43 corresponds to an operation unit, and the swivel motor 44 corresponds to a hydraulic actuator. Further, in the turning device 4, a first pump 11, a second pump 12, and a third pump 13 (not shown in FIG. 1) driven by the engine 42 are disposed.

  In the control unit 41, a control seat 411 is disposed. A pair of work operation levers 412 and 412 are disposed on the left and right of the pilot seat 411, and a pair of travel levers 413 and 413 are disposed on the front. The operator controls the engine 42, each hydraulic actuator, etc. by sitting on the cockpit 411 and operating the work operation levers 412, 412, travel levers 413, 413, etc., and performs operations such as traveling, turning, work, etc. It can be carried out.

  Next, the configuration of the hydraulic circuit 10 according to the present embodiment will be described using FIG. In the hydraulic circuit 10, hydraulic oil discharged from the first pump 11, the second pump 12, and the third pump 13 driven by the engine 42 is supplied to the respective hydraulic actuators and driven.

  The hydraulic circuit 10 is connected to the right traveling motor 22 from the first pump 11 through the first junction 101 and the second junction 102, to the bucket cylinder 33a through the first junction 101, and to the first junction 101 and the like. The hydraulic fluid can be supplied to the boom cylinders 31a via the second joining portion 102, respectively.

  The hydraulic circuit 10 is formed so that hydraulic oil can be supplied from the second pump 12 to the left travel motor 22 and the arm cylinder 32 a through the third junction portion 103.

  The hydraulic circuit 10 is formed so as to be able to supply hydraulic fluid from the third pump 13 to the swing motor 44 and the blade cylinder 24 via the fourth junction portion 104, respectively. Further, the hydraulic circuit 10 supplies hydraulic fluid from the third pump 13 to the boom cylinder 31a via the check valve 105, to the arm cylinder 32a via the check valve 106, and to the bucket cylinder 33a via the check valve 107. It is formed as possible.

  FIG. 3A shows the hydraulic circuit 10 at the time of work using the boom 31. When the operator operates the work operation lever 412, the hydraulic fluid discharged from the first pump 11 and the third pump 13 is supplied to the boom cylinder 31a. Thereby, the boom cylinder 31a can expand and contract, and the boom 31 can be turned up and down. At this time, the hydraulic fluid in the boom piping 31b connected to the first pump 11 (corresponding to one hydraulic pump) and the boom cylinder 31a is discharged from the third pump 13 (corresponding to another hydraulic pump). The hydraulic oil is joined via the check valve 105. Therefore, at the time of work using only the boom 31, the discharge pressure P3 of the third pump 13 is higher than the discharge pressure P1 of the first pump 11.

  FIG. 3B shows the hydraulic circuit 10 during work using the arm 32. As shown in FIG. When the operator operates the work operation lever 412, the hydraulic fluid discharged from the second pump 12 and the third pump 13 is supplied to the arm cylinder 32a. Thereby, the arm cylinder 32a can expand and contract, and the arm 32 can be turned up and down. At this time, the hydraulic fluid in the arm pipe 32b connected to the second pump 12 (corresponding to one hydraulic pump) and the arm cylinder 32a is discharged from the third pump 13 (corresponding to the other hydraulic pump). The hydraulic fluid is joined via the check valve 106. Therefore, at the time of work using only the arm 32, the discharge pressure P3 of the third pump 13 is higher than the discharge pressure P2 of the second pump 12.

  FIG. 3C shows the hydraulic circuit 10 at the time of work using the bucket 33. When the operator operates the work operation lever 412, the hydraulic fluid discharged from the first pump 11 and the third pump 13 is supplied to the bucket cylinder 33a. Thereby, the bucket cylinder 33a can expand and contract, and the bucket 33 can be rotated up and down. At this time, the hydraulic fluid in the bucket piping 33b connected to the first pump 11 (corresponding to one hydraulic pump) and the bucket cylinder 33a is discharged from the third pump 13 (corresponding to the other hydraulic pump). The hydraulic oil is joined via the check valve 107. Therefore, at the time of work using only the bucket 33, the discharge pressure P3 of the third pump 13 is higher than the discharge pressure P1 of the first pump 11.

  FIG. 3D shows the hydraulic circuit 10 at the time of work using the boom 31, the arm 32, and the bucket 33 simultaneously. When the operator operates the work operation lever 412, hydraulic fluid discharged from the first pump 11, the second pump 12, and the third pump 13 is supplied to the boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a. As a result, the boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33a can expand and contract to simultaneously rotate the boom 31, the arm 32, and the bucket 33. At this time, the hydraulic fluid discharged from the third pump 13 joins the hydraulic fluid in the boom piping 31b, and the hydraulic fluid discharged from the third pump 13 is hydraulic fluid to the hydraulic oil in the arm piping 32b. The hydraulic oil discharged from the third pump 13 merges with the hydraulic oil in the bucket piping 33b. Therefore, the discharge pressure P3 of the third pump 13 is higher than the discharge pressure P1 of the first pump 11 or the discharge pressure P2 of the second pump 12 whichever is lower.

  FIG. 3E shows the hydraulic circuit 10 when traveling. When the operator operates the travel lever 413, the hydraulic fluid discharged from the first pump 11 or the second pump 12 is supplied to the right travel motor 22 or the left travel motor 22. As a result, one or both of the right traveling motor 22 and the left traveling motor 22 can be rotated to move the backhoe 1 forward, backward, or turn left or right. At this time, since the hydraulic oil discharged from the third pump 13 does not join anywhere and returns to the tank, the discharge pressure P3 of the third pump 13 is the discharge pressure P1 of the first pump 11 and the discharge of the second pump 12 Lower than pressure P2.

  The pump abnormality detection system 5 of the present embodiment is provided in the work vehicle as described above, and FIG. 4 is a block diagram showing a configuration of the pump abnormality detection system 5. The pump abnormality detection system 5 includes first to third pressure sensors 51 to 53 (corresponding to a plurality of detection units), an operation state determination unit 54, a data storage unit 55, and an abnormality determination unit 56.

  The first pressure sensor 51 detects the discharge pressure P1 of the first pump 11. The second pressure sensor 52 detects the discharge pressure P2 of the second pump 12. The third pressure sensor 53 detects the discharge pressure P3 of the third pump 13.

  The operating state determination unit 54 determines an operating state by a combination of a plurality of operating units. The operating state includes the traveling state by the crawlers 21 and 21, the turning state by the turning table 43, and the working state by the boom 31, the arm 32, and the bucket 33. In the determination of the operation state, the operation state is determined using the operation states of the work operation lever 412, the travel lever 413, and other switches. For example, when it is desired to move the boom 31, the arm 32, and the bucket 33 simultaneously or independently, the left and right pair of operation operation levers 412 and 412 are operated to rotate in the left and right direction and in the front and back direction. By detecting the operation states of the work operation levers 412 and 412, it is possible to determine the current operation state (work state). Further, when it is desired to drive the left and right crawlers 21 and 21 to move the backhoe 1 forward and backward, the pair of travel levers 413 and 413 are rotated in the front and rear direction, so that the operation state of the travel levers 413 and 413 is detected. Thus, the current operation state (running state) can be determined.

  The data storage unit 55 corresponds to an operation state when each hydraulic pump is normally driven (at normal time), and a relationship (also referred to as a first relationship) between discharge pressures among a plurality of hydraulic pumps set in advance. The data of are stored. Specifically, in the case of the operation state using only the boom 31 as shown in FIG. 3A, the relationship of discharge pressure P3> discharge pressure P1 is stored. Similarly, in the operation state using only the arm 32 as shown in FIG. 3B, the discharge pressure P3> the discharge pressure P2; in the operation state using only the bucket 33 as shown in FIG. 3C, the discharge pressure P3 If the relationship of discharge pressure P1 and the operation state where boom 31, arm 32, and bucket 33 are simultaneously used as shown in FIG. 3D, the relationship of discharge pressure P3> discharge pressure P1 and discharge pressure P2 is stored. In the case of the operation state as shown in FIG. 3D, the discharge pressure P1> discharge pressure P2, the discharge pressure P3> discharge pressure P1, and the discharge pressure P1> discharge pressure P2, the discharge pressure P3> discharge pressure P2 The relationship between the pressure P1 and the discharge pressure P2 is stored. In the case of the traveling state as shown in FIG. 3E, the relationship of discharge pressure P1> discharge pressure P3 and discharge pressure P2> discharge pressure P3 is stored.

  The abnormality determination unit 56 is a relationship between the first relationship corresponding to the current operation state stored in the data storage unit 55 and the discharge pressures P1 to P3 detected by the first to third pressure sensors 51 to 53. A relationship comparison unit 56a that compares the second relationship is provided. The abnormality determination unit 56 determines that an abnormality has occurred in at least one hydraulic pump among the first to third pumps 11 to 13 when the second relationship is different from the first relationship in comparison by the relationship comparison unit 56a. Do. For example, in the case of the operation state using the boom 31, the arm 32, and the bucket 33 simultaneously, if an abnormality occurs in the third pump 13, the discharge pressure P3 of the third pump 13 is the discharge of the first pump 11. The pressure P1 is lower than the discharge pressure P2 of the second pump 12, and the hydraulic fluid in the boom piping 31b, the hydraulic fluid in the arm piping 32b, and the hydraulic fluid in the bucket piping 33b are discharged from the third pump 13 Hydraulic oil can not join. That is, assuming that the third pump 13 has an abnormality, the relationship among the discharge pressures P1 to P3 detected by the first to third pressure sensors 51 to 53 is: discharge pressure P3 <discharge pressure P1, discharge pressure It becomes a relation (second relation) called P2. Therefore, the abnormality determination unit 56 detects the first relationship (discharge pressure P3> discharge pressure P1 or discharge pressure P3> discharge pressure P2) in the normal state and the second to third pressure sensors 51 to 53 detected. When the relationship (discharge pressure P3 <discharge pressure P1 and discharge pressure P3 <discharge pressure P2) is compared, the second relationship is different from the first relationship, so it is determined that the third pump 13 has an abnormality. be able to.

  Next, a pump abnormality detection method using the above-described pump abnormality detection system 5 will be described. FIG. 5 is a flowchart showing the procedure of the pump abnormality detection method.

  In the pump abnormality detection method, first, the discharge pressure P1 of the first pump 11 is detected by the first pressure sensor 51, the discharge pressure P2 of the second pump 12 is detected by the second pressure sensor 52, and the third pressure sensor 53 is used. The discharge pressure P3 of the third pump 13 is detected (step S1).

  Next, the current operation state is determined using the operation states of the work operation lever 412, the travel lever 413, and other switches (step S2).

  Next, data of a first relationship which is a relationship between the discharge pressures P1 to P3 at normal time corresponding to the current operation state is acquired from the data storage unit 55 (step S3).

  Then, the first relationship is compared with the second relationship which is the relationship between the discharge pressures P1 to P3 among the first to third pumps 11 to 13 detected by the first to third pressure sensors 51 to 53, It is determined whether the second relationship is different from the first relationship (step S4).

  If the second relationship is different from the first relationship, it is determined that an abnormality has occurred in at least one hydraulic pump of the first to third pumps 11 to 13 (step S5). On the other hand, when the second relationship is the same as the first relationship, the process returns to step S1 and the discharge pressures P1 to P3 are detected again.

[Other embodiments]
In the said embodiment, whenever the detection by the 1st-3rd pressure sensor 51-53 is performed, the abnormality of the 1st-3rd pump 11-13 is determined. However, the first to third pressure sensors 51 to 53 repeatedly detect the discharge pressures P1 to P3 of the first to third pumps 11 to 13, and the abnormality determination unit 56 detects the first to third pressure sensors 51 to 53. The first relationship and the second relationship are compared each time detection is performed, and when the second relationship is different from the first relationship more than a predetermined number of times (two or more), an abnormality occurs in at least one hydraulic pump It may be determined that

  FIG. 6 is a block diagram showing the configuration of a pump abnormality detection system 5 according to another embodiment. In this embodiment, as shown in FIG. 6, the abnormality determination unit 56 further includes an abnormality degree calculation unit 56b.

  FIG. 7 is a flowchart showing the procedure of a pump abnormality detection method according to another embodiment. Steps S1 to S4 are the same as those in the above-described embodiment. If the second relation is different from the first relation in the comparison by the relation comparing part 56a, the abnormality degree calculating part 56b increases the abnormality degree count value by +1 (step S6). Here, the abnormality degree count value is the number of times that the second relation is different from the first relation. On the other hand, if the second relation is the same as the first relation in the comparison by the relation comparison unit 56a, the process returns to step S1 and the discharge pressures P1 to P3 are detected again.

  The abnormality determination unit 56 determines whether the abnormality degree count value is equal to or more than a predetermined number of times (step S7). When the abnormality degree count value is equal to or more than a predetermined number, it is determined that an abnormality has occurred in at least one hydraulic pump among the first to third pumps 11 to 13 (step S8). On the other hand, when the abnormality degree count value is smaller than the predetermined number, the process returns to step S1, and the discharge pressures P1 to P3 are detected again.

  As mentioned above, although embodiment of this invention was described based on drawing, it should be thought that a specific structure is not limited to these embodiment. The scope of the present invention is indicated not only by the description of the embodiments described above but also by the claims, and further includes all modifications within the meaning and scope equivalent to the claims.

Reference Signs List 1 backhoe 3 working device 5 pump abnormality detection system 31 boom 31a boom cylinder 32 arm 32a arm cylinder 33 bucket 33a bucket cylinder 42 engine 51 first pressure sensor 52 second pressure sensor 53 third pressure sensor 54 operation state determination unit 56 abnormality determination Part 56a Relational comparison part 56b Abnormality degree calculation part

Claims (3)

A work vehicle having a plurality of operation units,
A plurality of hydraulic actuators provided corresponding to the plurality of operation units;
A plurality of hydraulic pumps for supplying hydraulic fluid to at least one hydraulic actuator of the plurality of hydraulic actuators;
A plurality of detection units for detecting the discharge pressure of each of the plurality of hydraulic pumps;
An operation state determination unit that determines an operation state by a combination of the plurality of operation units;
A first relationship which is a relationship of discharge pressure among the plurality of hydraulic pumps set in advance corresponding to the operating condition determined by the operating condition determination unit, and the plurality of hydraulic pumps detected by the detection unit Comparing with the second relationship which is the relationship of the discharge pressure between them, and when the second relationship is different from the first relationship, at least one hydraulic pump of the plurality of hydraulic pumps has an abnormality And an abnormality determination unit that determines that the work vehicle is a work vehicle. The detection unit repeatedly detects each discharge pressure of the plurality of hydraulic pumps,
The abnormality determination unit compares the first relationship with the second relationship every time the detection unit performs the detection, and when the second relationship is different from the first relationship by a predetermined number of times or more, The work vehicle according to claim 1, wherein it is determined that an abnormality has occurred in one hydraulic pump. The operating state determined by the operating state determination unit is different from the one hydraulic pump in hydraulic oil of a pipe connected to one hydraulic pump of the plurality of hydraulic pumps and the one hydraulic actuator. The hydraulic fluid discharged from the hydraulic pump is combined to supply the hydraulic fluid to the one hydraulic actuator.
The work vehicle according to claim 1 or 2, wherein the first relationship corresponding to the operation state is a relationship in which the discharge pressure of the other hydraulic pump is higher than the discharge pressure of the one hydraulic pump.

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