JP5459718B2 - Damage detection device for hydraulic rotating machine - Google Patents

Description

  The present invention relates to a damage detection apparatus for a hydraulic rotating machine.

  In order to identify a faulty part in a hydraulic pump, which is a hydraulic rotary machine, with a simple configuration, the internal pressure and discharge pressure of the hydraulic pump are detected, and the wear of sliding members inside the hydraulic pump is determined based on these detected values. There is a diagnostic device for a hydraulic pump for diagnosing a state (see, for example, Patent Document 1).

JP 2007-77804 A

  The above-described hydraulic pump diagnosis apparatus needs to operate the hydraulic pump in order to detect the discharge pressure of the hydraulic pump. This is because, for example, even if the sliding member inside the hydraulic pump is damaged at the time of stoppage, the operation for diagnosis of the hydraulic pump is required. There was a risk of further expansion.

  In addition, the detected values of the internal pressure and discharge pressure of the hydraulic pump when the hydraulic pump is operating constantly change dynamically, so even if a small change in the internal pressure of the hydraulic pump suggests small damage, for example, this is detected It was difficult to do. As a result, for example, there is a problem that the damage of the sliding member inside the hydraulic pump cannot be diagnosed unless the wear state or damage progresses to some extent.

  The present invention has been made based on the above-described matters, and its purpose is to detect a damage to a hydraulic rotary machine capable of detecting damage to a sliding member inside the hydraulic rotary machine without operating the hydraulic rotary machine. Is to provide.

  In order to achieve the above object, a first invention is a damage detection apparatus for a hydraulic rotating machine including at least two supply / discharge ports, the accumulator for accumulating hydraulic oil, and the hydraulic rotation A switching valve for switching communication or blocking of an oil passage connecting at least one supply / discharge port of the machine and the discharge side of the pressure accumulator; and a first pressure for measuring the port pressure of the supply / discharge port of the hydraulic rotating machine A pressure measuring means; a second pressure measuring means for measuring the internal pressure of the case of the hydraulic rotating machine; and a damage state detecting means for detecting a damaged state of a sliding member inside the hydraulic rotating machine. The detecting means includes a stop detecting means for detecting stop of the hydraulic rotating machine, a switching valve driving means for introducing hydraulic oil from the pressure accumulator to a supply / discharge port of the hydraulic rotating machine, and the first pressure measuring means. A predetermined function from the port pressure measured in A first calculation means for calculating and calculating a reference internal pressure value; and a second calculation means for comparing and calculating the reference internal pressure value calculated by the first calculation means and the case internal pressure value measured by the second pressure measurement means. Shall be provided.

  According to a second aspect of the present invention, in the first aspect of the present invention, the information processing device further includes a notifying unit for notifying a damaged state of the sliding member inside the hydraulic rotating machine detected by the damaged state detecting unit.

  Furthermore, a third invention is the first or second invention, wherein the hydraulic rotating machine is a variable capacity type having a variable capacity mechanism, and the displacement capacity of the hydraulic rotating machine is increased by the variable capacity mechanism. It is provided with a reverse rotation preventing means for minimizing.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the switching valve can communicate with all the supply / discharge ports of the hydraulic rotating machine and the pressure accumulator. .

  Further, in a fifth invention according to any one of the first to fourth inventions, the second pressure measuring means for measuring the internal pressure of the case of the hydraulic rotator drains the drain of the hydraulic rotator. A variable throttling mechanism is provided in the drain piping for connecting the port or the drain port and the tank.

  According to a sixth invention, in any one of the first to fourth inventions, the pressure accumulating device includes a pressure accumulating means for accumulating pressure energy of return oil from the hydraulic actuator.

  According to the present invention, the port pressure at the intake / exhaust port of the hydraulic rotary machine for the hydraulic oil supplied from the pressure accumulator to the hydraulic rotary machine and the pressure inside the case in the stopped state without operating the hydraulic rotary machine. By measuring, damage inside the hydraulic rotating machine can be detected safely and accurately.

1 is a side sectional view of a hydraulic pump to which a first embodiment of a damage detection apparatus for a hydraulic rotating machine according to the present invention is applied. 1 is a hydraulic circuit diagram showing a hydraulic circuit of a first embodiment of a damage detection apparatus for a hydraulic rotating machine according to the present invention. It is a flowchart figure which shows the processing content of 1st Embodiment of the damage detection apparatus of the hydraulic rotary machine of this invention. It is a characteristic view which shows the relationship between the port pressure and case internal pressure in 1st Embodiment of the damage detection apparatus of the hydraulic rotating machine of this invention. It is a hydraulic circuit diagram which shows the hydraulic circuit of 2nd Embodiment of the damage detection apparatus of the hydraulic rotating machine of this invention. It is a hydraulic circuit diagram which shows the hydraulic circuit of 3rd Embodiment of the damage detection apparatus of the hydraulic rotating machine of this invention. It is a hydraulic circuit diagram which shows the hydraulic circuit of 4th Embodiment of the damage detection apparatus of the hydraulic rotating machine of this invention. It is a hydraulic circuit diagram which shows the hydraulic circuit of 5th Embodiment of the damage detection apparatus of the hydraulic rotating machine of this invention.

  Hereinafter, embodiments of a damage detection apparatus for a hydraulic rotating machine according to the present invention will be described with reference to the drawings.

  FIG. 1 is a side sectional view of a hydraulic pump to which a first embodiment of a damage detection apparatus for a hydraulic rotating machine according to the present invention is applied. FIG. 2 shows a first embodiment of the damage detection apparatus for a hydraulic rotating machine according to the present invention. 3 is a hydraulic circuit diagram showing the hydraulic circuit of the embodiment, FIG. 3 is a flowchart showing the processing contents of the first embodiment of the damage detection apparatus for a hydraulic rotating machine of the present invention, and FIG. 4 is a hydraulic rotation of the present invention. It is a characteristic view which shows the relationship between the port pressure and case internal pressure in 1st Embodiment of the damage detection apparatus of an apparatus.

  As shown in FIG. 1, a hydraulic pump 1 to which a first embodiment of a damage detection apparatus for a hydraulic rotating machine of the present invention is applied includes a case 2, a cover 3, bearings 4a and 4b, and a rotating shaft. 5, a rotor 6, a piston 8, a shoe 9, a swash plate 10, and a valve member 11.

The case 2 accommodates other components therein, and includes a suction port 12 that sucks hydraulic oil, a discharge port 13 that discharges hydraulic oil, and a drain port 15 that discharges hydraulic oil inside the case. It is closed by the cover 3.
The rotating shaft 5 is rotatably supported by a bearing 4 a fixed to the case 2 and a bearing 4 b fixed to the cover 3. The rotor 6 includes a plurality of cylinders 7 and is provided so as to be rotatable integrally with the rotary shaft 5. The piston 8 is inserted into each cylinder 7 of the rotor 6 and is provided so as to be capable of reciprocating movement. The piston 8 is provided with a shoe 9 in sliding contact with the swash plate 10 at an end portion on the protruding side. The swash plate 10 is supported by the case 2 so as to be tiltable, and is provided so that the end surface of the shoe 9 is in sliding contact with a circular orbit. The valve member 11 includes a communication port 14 that is in sliding contact with the end surface of the rotor 6 and that switches communication / blocking between the suction port 12 and the discharge port 13 and the cylinder 7, and is fixed to the case 2.

  FIG. 2 shows a hydraulic circuit of a first embodiment of the damage detection apparatus for a hydraulic rotating machine according to the present invention. In FIG. 2, the suction port 12 and the drain port 15 of the hydraulic pump 1 are connected to the tank 22 via a suction pipe 27 and a drain pipe 28, respectively. The discharge port 13 of the hydraulic pump 1 is connected to a control valve 23 that supplies hydraulic oil to each actuator (not shown) via a discharge pipe 26.

  The pressure accumulating device 25 is constituted by, for example, an accumulator or the like, and accumulates hydraulic oil, and enables the accumulated hydraulic oil to be discharged as necessary. The discharge side of the pressure accumulator 25 is connected to a discharge pipe 26 via a two-port two-position switching valve 24 that switches between communication / blocking of the oil passage. The discharge pipe 26 is provided with a pressure gauge 29 for measuring the port pressure of the hydraulic oil in the discharge port 13 of the hydraulic pump 1 and constitutes a first pressure measuring means. The drain pipe 28 is provided with a pressure gauge 30 for measuring the internal pressure of the case 2 of the hydraulic pump 1 and constitutes a second pressure measuring means. Further, output signals from the pressure gauge 29 and the pressure gauge 30 are input to the signal processing device 31. Further, the signal processing device 31 outputs a signal representing the diagnostic contents to a notification device 40 such as a driver's cab monitor.

Next, the operation of the first embodiment of the damage detection apparatus for a hydraulic rotating machine according to the present invention will be described with reference to FIGS.
First, an outline of the operation will be described. In a state in which the stop of the hydraulic pump 1 is detected by, for example, a stop detection means that determines from the number of revolutions, the control valve 23 is operated and the discharge pipe 26 is shut off. Next, the switching valve driving means switches the switching valve 24 to the communication position to guide the pressure oil stored in the pressure accumulating device 25 to the discharge pipe 26. As a result, a part of the pressure oil from the pressure accumulating device 25 flows into the case 2 through a gap of a sliding portion on a path connecting the discharge port 13 of the hydraulic pump 1 and the inside of the case 2.

  Here, the gap between the sliding portions in FIG. 1 is, for example, any one of the sliding portion between the rotor 6 and the valve member 11, the sliding portion between the rotor 6 and the piston 8, and the sliding portion between the shoe 9 and the swash plate 10. Or it is the clearance gap of all the sliding parts.

  If any sliding member on the path connecting the discharge port 13 of the hydraulic pump 1 and the inside of the case 2 is damaged due to wear, the cross-sectional area of the path connecting the discharge port 13 of the hydraulic pump 1 and the inside of the case 2 Becomes larger. The larger the cross-sectional area of this path, the more pressure oil flows from the discharge port 13 of the hydraulic pump 1 to the inside of the case 2, so that the internal pressure of the case 2 increases.

  In the present embodiment, the damage detection device for the hydraulic rotating machine is a sliding member of the hydraulic pump 1 that performs arithmetic processing by the signal processing device 31 based on the port pressure measured by the pressure gauges 29 and 30 and the internal pressure of the case 2. Judge wear.

  Next, processing contents and the like of the signal processing device 31 will be described with reference to FIGS.

  First, in step (S100) of FIG. 3, it is confirmed that the hydraulic pump 1 is stopped. Specifically, for example, the stop detection means determines the stop by taking in the rotational speed of the hydraulic pump 1 and comparing it with a predetermined rotational speed. The damage detection apparatus according to the present embodiment is characterized in that damage detection is performed in a state where the hydraulic pump 1 that is a hydraulic rotating machine is not in operation, and the stop of the hydraulic pump 1 is a precondition. If YES is determined in this step (S100), the process proceeds to step (S101). If NO is determined, the process is repeated until YES is determined.

  In step (S101), the port pressure P and the internal pressure Pd of the case 2 are measured. Specifically, the pressure oil stored in the pressure accumulator 25 by the switching valve driving means is introduced into the discharge port 13 of the hydraulic pump 1 and the inside of the case 2, and the port pressure P measured by the pressure gauge 29 and the pressure gauge 30. The output signal of the internal pressure Pd of case 2 is input to the signal processing device 31.

  In step (S102), fc (P) and fd (P) are calculated based on the port pressure P. Specifically, the signal processing device 31 calculates fc (P) and fd (P), which are functions having the port pressure P as a variable, as the first calculation means. FIG. 4 shows the characteristics. Here, the functions fc (P) and fd (P) indicate the respective reference internal pressure values corresponding to the port pressure value P.

  In step (S103), it is determined whether or not fc (P) calculated in step (S102) is larger than the internal pressure Pd of case 2 measured in step (S101). Specifically, the signal processing device 31 calculates a magnitude comparison between the reference internal pressure value calculated in step (S102) and the internal pressure value Pd of case 2 measured in step (S101) as the second calculation means.

  In step (S103), if fc (P) is larger than the internal pressure value Pd of case 2, YES is determined, and the process proceeds to step (S105). If the internal pressure value Pd of case 2 is equal to or smaller than NO, it is determined NO. Go to).

  In step (S104), it is determined whether or not fd (P) calculated in step (S102) is larger than the internal pressure Pd of case 2 measured in step (S101). Specifically, the signal processing device 31 calculates a magnitude comparison between the reference internal pressure value calculated in step (S102) and the internal pressure value Pd of case 2 measured in step (S101) as the second calculation means.

  If it is determined in step (S104) that fd (P) is greater than the internal pressure Pd of case 2, the process proceeds to step (S106), and if it is equal to or smaller than the internal pressure Pd of case 2, the process proceeds to step (S107). move on.

  Step (S105) is a case where fc (P) is larger than the internal pressure Pd of case 2. In this case, as shown in FIG. 4, the signal processing device 31 determines that the sliding member of the hydraulic pump 1 is normal, and outputs a normal wear state to the notification device 40. The notification device 40 notifies that the wear state is normal.

  Step (S106) is a case where fd (P) is larger than the internal pressure Pd of case 2. In this case, as shown in FIG. 4, the signal processing device 31 determines that there is a small damage on the sliding member of the hydraulic pump 1, and outputs to the notification device 40 that the wear state is a caution state. The notification device 40 notifies that the wear state requires attention.

  Step (S107) is a case where fd (P) is equal to or smaller than the internal pressure Pd of case 2. In this case, the signal processing device 31 determines that the sliding member of the hydraulic pump 1 is largely damaged as shown in FIG. 4 and outputs to the notification device 40 that the wear state is a warning state. The notification device 40 notifies that the wear state requires caution.

  According to the first embodiment of the damage detection device for a hydraulic rotating machine of the present invention described above, the pressure accumulating device 25 changes to the hydraulic pump 1 in a stopped state without operating the hydraulic pump 1 that is the hydraulic rotating machine. By measuring the port pressure P of the intake / exhaust port in the hydraulic pump 1 of the supplied pressure oil and the pressure Pd inside the case 2, damage inside the hydraulic pump 1 can be detected safely and accurately.

  In addition, according to the first embodiment of the damage detection device for a hydraulic rotating machine of the present invention described above, the hydraulic pump 1 which is the hydraulic rotating machine is stopped due to wear of the sliding member of the hydraulic pump 1. Since damage can be detected, it can be detected safely without enlarging the damage.

  Furthermore, according to the first embodiment of the damage detection device for a hydraulic rotating machine of the present invention described above, damage due to wear of the sliding member of the hydraulic pump 1 is caused by static pressure stored in the pressure accumulator 25. In order to detect, the internal pressure of case 2 can be measured statically and damage can be detected accurately.

  Further, according to the first embodiment of the damage detection device for a hydraulic rotating machine of the present invention described above, the notification device 40 notifies the driver of damage inside the hydraulic pump 1, for example. Can be prevented.

  In addition, as an aspect of the alerting | reporting apparatus 40, although the example which alert | reports a diagnostic content to an operator etc. with the monitor etc. of the cab was demonstrated, it is not restricted to this. For example, diagnosis content data may be transmitted and notified to a host computer of a base station that manages a machine such as a manufacturer or a user. Further, the notification is not limited to the purpose of alerting, but may be intended to accumulate information, for example.

Hereinafter, a second embodiment of a damage detection apparatus for a hydraulic rotating machine according to the present invention will be described with reference to the drawings. FIG. 5 is a hydraulic circuit diagram showing a hydraulic circuit according to a second embodiment of the damage detection apparatus for a hydraulic rotating machine of the present invention. In FIG. 5, the same reference numerals as those shown in FIGS. 1 to 4 are the same parts, and detailed description thereof is omitted.
The present embodiment is different from the first embodiment described above in that the hydraulic pump 1 that is a hydraulic rotating machine is a variable displacement type and a variable displacement mechanism 32 is provided. Other components and the like are the same as those in the first embodiment. In the first embodiment, the switching valve 24 is switched to the communication state, and the pressure oil stored in the pressure accumulator 25 is guided from the discharge pipe 26 to the discharge port 13 of the hydraulic pump 1. There is a risk of reverse rotation. Therefore, in the present embodiment, reverse rotation preventing means is provided.

  In FIG. 5, the variable displacement hydraulic pump 1 includes a variable displacement mechanism 32. The variable capacity mechanism 32 is controlled by a command signal from a control device (not shown) or the like, but is also controlled by a command from the signal processing device 31 in the present embodiment.

First, the occurrence of reverse rotation of the hydraulic pump 1 described above will be described.
When the switching valve 24 is switched and the pressure oil of the pressure accumulating device 25 is guided to the discharge port 13 of the hydraulic pump 1, torque T shown in the equation (1) is generated on the rotating shaft 5 of the hydraulic pump 1 by the motor action.

  Here, Vg is the displacement volume, ΔP is the differential pressure between the pressure at the discharge port 13 and the pressure at the suction port 12, and η is the torque efficiency.

  The torque efficiency η is determined by the configuration of the device and is treated as a constant unique to the device here. On the other hand, since the suction port 12 is connected to the tank 22, ΔP is equal to the port pressure of the discharge port 13 when the port pressure of the suction port 12 is ignored. When the torque efficiency η is a constant and ΔP is the port pressure of the discharge port 13, the torque T generated in the rotating shaft 5 of the hydraulic pump 1 is determined by the port pressure of the discharge port 13 of the hydraulic pump 1 and the displacement volume Vg.

  That is, if the displacement volume Vg is small, the torque T is also small. Therefore, before the changeover valve 24 is switched and the pressure oil of the pressure accumulator 25 is guided to the discharge port 13 of the hydraulic pump 1, the displacement volume Vg of the hydraulic pump 1 is minimized by the variable capacity mechanism 32. The torque T generated in the rotary shaft 5 of the hydraulic pump 1 can be minimized by introducing the pressure oil.

  If the torque T generated on the rotary shaft 5 of the hydraulic pump 1 by the pressure oil of the pressure accumulator 25 is made smaller than the torque required to rotate the rotary shaft 5 of the hydraulic pump 1, the rotary shaft 5 of the hydraulic pump 1 rotates in the reverse direction. Can be prevented.

  Therefore, in this embodiment, the reverse rotation prevention means is provided, the control valve 23 is operated, the discharge pipe 26 is shut off, the switching valve 24 is switched to the communication state, and the pressure stored in the pressure accumulator 25 is stored. Before guiding the oil to the discharge port 13 of the hydraulic pump 1, a displacement volume Vg minimum command is output from the signal processing device 31 to the variable displacement mechanism 32.

  According to the second embodiment of the damage detection device for a hydraulic rotating machine of the present invention described above, the same effect as that of the first embodiment described above can be obtained, and the hydraulic pressure can be increased by the variable capacity mechanism 32. By minimizing the displacement of the hydraulic pump 1 that is a rotating machine, the torque generated in the rotating shaft 5 of the hydraulic pump 1 by the pressure oil from the pressure accumulating device 25 is minimized, and the rotating shaft 5 of the hydraulic pump 1 rotates in reverse. Can be prevented.

Hereinafter, a third embodiment of a damage detection apparatus for a hydraulic rotating machine according to the present invention will be described with reference to the drawings. FIG. 6 is a hydraulic circuit diagram showing a hydraulic circuit according to a third embodiment of the damage detection apparatus for a hydraulic rotating machine of the present invention. In FIG. 6, the same reference numerals as those shown in FIGS. 1 to 5 are the same parts, and detailed description thereof is omitted.
In the second embodiment, the reverse rotation preventing means for preventing the rotating shaft of the hydraulic rotating machine from rotating in reverse by the variable capacity mechanism 32 has been described. However, in the present embodiment, the hydraulic rotating machine is similarly described. Another embodiment for preventing reverse rotation of the rotation shaft will be described. Therefore, other constituent equipment other than the constituent equipment mentioned below is the same as that of the second embodiment.

  In FIG. 6, the pressure accumulator 25 is connected to a discharge pipe 26 and a suction pipe 27 via a 4-port 2-position type switching valve 24 </ b> A that switches between communication / blocking of an oil passage. Similarly, a discharge pipe 26 is connected to the control valve 23 via a switching valve 24A for switching between communication / blocking of the oil passage. Further, a check valve 33 is provided on a path on the tank 22 side of the suction pipe 27 so that the pressure oil from the pressure accumulator 25 does not flow into the tank 22.

Next, the operation of the third embodiment of the damage detection apparatus for a hydraulic rotating machine according to the present invention will be described with reference to FIG.
In a state where the hydraulic pump 1 is stopped, the switching valve 24A is switched to the communication position to guide the pressure oil stored in the pressure accumulating device 25 to the discharge pipe 26 and the suction pipe 27. As a result, the pressure oil from the pressure accumulator 25 is guided to the discharge port 13 and the suction port 12 of the hydraulic pump 1. A part of the pressure oil from the pressure accumulator 25 flows into the case 2 through a gap of a sliding portion on a path connecting the suction port 12 of the hydraulic pump 1 and the inside of the case 2.

  If the sliding member on the path connecting the suction port 12 of the hydraulic pump 1 and the inside of the case 2 is damaged due to wear, the cross-sectional area of the path connecting the suction port 12 of the hydraulic pump 1 and the inside of the case 2 becomes large. The larger the cross-sectional area of this path, the more pressure oil flows from the suction port 12 of the hydraulic pump 1 to the inside of the case 2, so that the internal pressure of the case 2 increases. Further, since the pressure at the discharge port 13 and the pressure at the suction port 12 are equal, ΔP in the equation (Equation 1) in the second embodiment is substantially zero. For this reason, the torque generated in the rotating shaft 5 of the hydraulic pump 1 due to the inflow of the pressure oil from the pressure accumulating device 25 becomes substantially zero.

  Therefore, in the present embodiment, it is not necessary to provide the reverse rotation preventing means as in the second embodiment.

According to the third embodiment of the damage detection apparatus for a hydraulic rotating machine of the present invention described above, the same effects as those of the first embodiment described above can be obtained, and the following functions and effects can be obtained.
(1) By introducing the pressure oil of the pressure accumulator 25 to all the supply / discharge ports 12 and 13 of the hydraulic pump 1 which is a hydraulic rotary machine, all the supply / discharge ports 12 and 13 of the hydraulic pump 1 and the inside of the case 2 It is possible to detect damage due to wear of the sliding member on the path connecting the two.
(2) By introducing the pressure oil of the pressure accumulator 25 to all the supply / discharge ports 12 and 13 of the hydraulic pump 1 which is a hydraulic rotary machine, the torque of the rotary shaft 5 of the hydraulic pump 1 is offset, and the hydraulic pump 1 It is possible to prevent the rotation shaft 5 from rotating in the reverse direction.

Hereinafter, a fourth embodiment of the damage detection apparatus for a hydraulic rotating machine according to the present invention will be described with reference to the drawings. FIG. 7 is a hydraulic circuit diagram showing a hydraulic circuit according to a fourth embodiment of the damage detection apparatus for a hydraulic rotating machine of the present invention. In FIG. 7, the same reference numerals as those shown in FIG. 1 to FIG.
In the fourth embodiment, the internal pressure adjusting means of the case 2 of the hydraulic rotating machine is further provided in the third embodiment. Therefore, other constituent equipment other than the constituent equipment mentioned below is the same as that of the third embodiment.

  In FIG. 7, a drain pipe 28 that connects the drain port 15 of the hydraulic pump 1 and the tank 22 is provided with a variable throttle mechanism 34 that can change the cross-sectional area of the oil passage on the path.

Next, the operation of the fourth embodiment of the damage detection apparatus for a hydraulic rotating machine according to the present invention will be described with reference to FIG.
In a state where the hydraulic pump 1 is stopped, the switching valve 24A is switched to the communication position to guide the pressure oil stored in the pressure accumulating device 25 to the discharge pipe 26 and the suction pipe 27. As a result, the pressure oil from the pressure accumulating device 25 flows into the inside of the case 2 through the clearance of the sliding portion on the path connecting the discharge port 13 and the suction port 12 of the hydraulic pump 1 and the inside of the case, and the inside of the case 2 To the tank 22 through the drain pipe 28. Here, when the variable throttle mechanism 34 is not provided, the pressure from the pressure accumulating device 25 that has flowed into the case through the clearance of the sliding portion on the path connecting the discharge port 13 and the suction port 12 and the inside of the case 2. Since the pressure oil flows from the drain port 15 to the tank 22 as it is, the internal pressure of the case 2 may become a low value.

  For this reason, for example, when the internal pressure of the case 2 is below the measurable range of the pressure gauge 30 installed in the drain pipe 28, there arises a problem that the internal pressure of the case 2 cannot be detected. Therefore, in the present embodiment, the variable throttle mechanism 34 is provided on the path of the drain pipe 28, and the pressure loss in the drain pipe 28 can be adjusted by adjusting the throttle amount. When the throttle amount of the variable throttle mechanism 34 is increased, the pressure loss of the drain pipe 28 increases, and the internal pressure of the case 2 can be set within a pressure range that can be accurately measured by the pressure gauge 30.

  Specifically, the optimum aperture amount characteristic and set value of the variable aperture mechanism 34 are determined in advance at a factory or the like. Normally, the variable aperture mechanism 34 is operated without being throttled. Before the port pressure and the internal pressure of the case 2 are measured, the variable throttle mechanism 34 is adjusted to the predetermined throttle amount described above, and the port pressure and the internal pressure of the case 2 after the throttle amount is adjusted are measured. As a result, these pressures can be accurately measured, and the accuracy of pressure measurement is improved, so that damage to the sliding member can be detected with high accuracy.

  Further, since the internal pressure of the case 2 can be increased even when the port pressure is low, there is no need to increase the port pressure applied to the supply / discharge ports 12 and 13 of the hydraulic pump 1.

According to the fourth embodiment of the damage detection device for a hydraulic rotating machine of the present invention described above, the same effects as those of the first embodiment described above can be obtained, and the following functions and effects can be obtained.
(1) The internal pressure of the case 2 of the hydraulic pump 1 can be accurately measured by adjusting the internal pressure of the case 2 of the hydraulic pump 1 that is a hydraulic rotary machine by the variable throttle mechanism 34.
(2) Since the internal pressure of the case 2 can be increased even if the pressure applied to the supply / discharge ports 12 and 13 of the hydraulic pump 1 which is a hydraulic rotating machine is small, the pressure applied to the supply / discharge ports 12 and 13 is kept low. It is possible to safely detect damage due to wear of the hydraulic pump 1.

Hereinafter, a fifth embodiment of the damage detection apparatus for a hydraulic rotating machine according to the present invention will be described with reference to the drawings. FIG. 8 is a hydraulic circuit diagram showing a hydraulic circuit of a fifth embodiment of the damage detection apparatus for a hydraulic rotating machine according to the present invention. In FIG. 8, the same reference numerals as those shown in FIG. 1 to FIG.
In the fifth embodiment, pressure accumulating means for accumulating pressure in the pressure accumulating device 25 in the fourth embodiment is further provided. Therefore, other constituent equipment other than the constituent equipment mentioned below is the same as that of the fourth embodiment.

  In FIG. 8, the damage detection apparatus for a hydraulic rotating machine according to the present invention includes, in addition to the equipment constituting the fourth embodiment, an actuator 35 that is connected to a control valve 23 by a conduit and is driven and controlled, And a pressure accumulator control valve 36 which is provided in a pipe line connecting the control valve 35 and the control valve 23 and supplies the pressure oil discharged from the actuator 35 to the pressure accumulator 25.

  In this embodiment, for example, when a force is applied to the driven member driven by the actuator 35 from the outside, the pressure oil is forcibly discharged from the actuator 35 by the force from the outside. The pressure accumulator control valve 36 controls the pressure accumulation of the pressure accumulator 25 by controlling supply of the pressure oil discharged from the actuator 35 to the pressure accumulator 25.

According to the fifth embodiment of the damage detection device for a hydraulic rotating machine of the present invention described above, the same effects as those of the first embodiment described above can be obtained, and the following functions and effects can be obtained.
(1) The pressure oil discharged from the actuator 35 is controlled by the pressure accumulator control valve 36 and accumulated in the pressure accumulator 25, whereby the energy of the pressure oil discharged from the actuator 35 is detected for damage to the hydraulic rotating machine. Can be reused as energy.

  In the above-described embodiment of the present invention, the damage detection apparatus related to hydraulic equipment has been described, but the present invention is not limited to this. For example, the present invention can be applied to a device using other hydraulic pressure such as water pressure.

  Moreover, in embodiment of this invention mentioned above, although the pump which converts a rotational motion into a hydraulic pressure was demonstrated, it does not restrict to this. For example, the present invention can be applied to other hydraulic rotating machines such as a motor that converts hydraulic pressure into rotational motion.

DESCRIPTION OF SYMBOLS 1 Hydraulic pump 2 Case 3 Cover 4 Bearing 5 Rotating shaft 6 Rotor 8 Piston 9 Shoe 10 Swash plate 11 Valve member 12 Intake port 13 Discharge port 15 Drain port 22 Tank 23 Control valve 24 Switching valve 25 Accumulator 29 Pressure gauge 30 Pressure gauge 31 Signal processor 32 Variable capacity mechanism 33 Check valve 34 Variable throttle mechanism 35 Actuator 36 Pressure accumulator control valve

Claims (6)

A damage detection device for a hydraulic rotating machine comprising at least two or more supply / discharge ports, an accumulator for accumulating hydraulic fluid, at least one supply / exhaust port of the hydraulic rotating machine, and an accumulator A switching valve that switches between communication and cutoff of the oil passage connecting the discharge side, first pressure measuring means for measuring the port pressure of the supply / discharge port of the hydraulic rotating machine, and measuring the internal pressure of the case of the hydraulic rotating machine Second pressure measuring means, and a damage state detecting means for detecting a damage state of the sliding member inside the hydraulic rotating machine,
The damage state detecting means includes a stop detecting means for detecting stop of the hydraulic rotating machine, a switching valve driving means for introducing hydraulic oil from the pressure accumulator to a supply / discharge port of the hydraulic rotating machine, and the first A first calculation unit that calculates a reference internal pressure value by calculating a predetermined function from the port pressure measured by the pressure measurement unit, and the reference internal pressure value calculated by the first calculation unit and the second pressure measurement unit. A damage detecting device for a hydraulic rotating machine, comprising: a second calculating means for comparing and calculating the case internal pressure value. The damage detection apparatus for a hydraulic rotating machine according to claim 1,
A damage detection apparatus for a hydraulic rotating machine, further comprising: an informing means for notifying a damaged state of a sliding member inside the hydraulic rotating machine detected by the damaged state detecting means. In the damage detection apparatus of the hydraulic rotating machine according to claim 1 or 2,
The hydraulic rotating machine is a variable capacity type equipped with a variable capacity mechanism,
A damage detection apparatus for a hydraulic rotary machine, comprising reverse rotation prevention means for minimizing a displacement volume of the hydraulic rotary machine by the variable capacity mechanism. In the damage detection apparatus of the hydraulic rotating machine according to any one of claims 1 to 3,
The changeover valve enables communication between all the supply / discharge ports of the hydraulic rotary machine and the pressure accumulator. In the damage detection apparatus of the hydraulic rotating machine according to any one of claims 1 to 4,
The second pressure measuring means for measuring a case internal pressure of the hydraulic rotating machine includes a variable throttle mechanism in a drain port for discharging the drain of the hydraulic rotating machine or a drain pipe for connecting the drain port and a tank. Damage detection device for hydraulic rotating machine characterized by In the damage detection apparatus of the hydraulic rotating machine according to any one of claims 1 to 4,
The pressure accumulating device comprises pressure accumulating means for accumulating pressure energy of return oil from a hydraulic actuator.

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