JP5252307B2 - Leak detection mechanism and detection method for fluid pressure system - Google Patents

Description

  The present invention relates to a leak detection mechanism and a detection method of a fluid pressure system capable of detecting the leakage of air in a fluid pressure system including a fluid pressure device driven under an air supply action.

  2. Description of the Related Art Conventionally, for example, a fluid pressure cylinder having a piston that moves under the action of supplying a pressure fluid has been used as a means for conveying a workpiece or the like. In such a fluid pressure cylinder, a piston is movably provided in a cylinder chamber defined in a cylindrical cylinder, and alternately connected through a pipe to a set of ports provided in the vicinity of both ends of the cylinder. When the pressure fluid is supplied to the piston, the piston is linearly displaced along the cylinder (for example, see Patent Document 1).

  For example, in a factory or the like, a fluid pressure system that enables a plurality of workpieces to be conveyed by installing and driving a plurality of fluid pressure cylinders as described above is employed. The fluid pressure system includes a fluid pressure cylinder, a pressure fluid supply source that supplies pressure fluid to the fluid pressure cylinder, and a switching valve that switches a supply state of the pressure fluid from the pressure fluid supply source. The supply source, the fluid pressure cylinder, and the switching valve are each connected by piping.

JP-A-6-313410

  Generally, in the fluid pressure system as described above, leakage of the supplied pressure fluid occurs, and there is a demand for reducing running costs and saving energy by suppressing waste of the pressure fluid. .

  In addition, for example, it is assumed that a flow sensor is provided at a set of ports in the fluid pressure cylinder, and the leakage of the pressure fluid to the outside is detected by detecting the flow rate of the pressure fluid supplied to the fluid pressure cylinder. The However, when a flow sensor is provided, the flow sensor becomes a flow resistance of the pressure fluid introduced into the fluid pressure cylinder, and there is a concern that the flow rate may decrease.

  In order to avoid this decrease in the flow rate of the pressure fluid, it is conceivable to employ a flow sensor having a large diameter, but in that case, it becomes difficult to detect a leak at a small flow rate. That is, there is a problem that a slight leak cannot be confirmed in a flow sensor having a large diameter.

  The present invention has been made in consideration of the above-described problems, and can reliably detect air leakage without impeding the driving of the fluid pressure device, and can reduce running costs and save energy. It is an object of the present invention to provide a leak detection mechanism and detection method for a fluid pressure system that can perform the above-described operation.

In order to achieve the above object, the present invention includes a fluid supply source for supplying a fluid and a drive switching mechanism for switching a supply state of the fluid supplied from the fluid supply source to a fluid pressure device. In the fluid pressure system including the fluid pressure device having the moving body connected to the drive switching mechanism and driven under the fluid supply action,
Leakage detecting means connected between the fluid supply source and the drive switching mechanism via a pipe for detecting the amount of leakage of the fluid to the outside;
With
The leakage detection means includes a switching unit that switches a supply state of the fluid to the drive switching mechanism, a detection unit that is provided in parallel with the switching unit and detects the flow rate of the fluid,
It is characterized by comprising.

  According to the present invention, in the fluid pressure system, between the fluid supply source for supplying the fluid and the drive switching mechanism for switching the supply state of the fluid to be supplied to the fluid pressure device, to the outside of the fluid. A leakage detection means for detecting the amount of leakage of the fluid is provided. The leakage detection means is provided in parallel with the switching portion for switching the supply state of the fluid to the drive switching mechanism, and detects the flow rate of the fluid. It consists of a detector.

  Then, in the drive stop state in which the moving body of the fluid pressure device is stopped, the switching unit is switched, and the fluid that has been circulated from the fluid supply source to the drive switching mechanism through the switching unit is not circulated through the switching unit. It is made to circulate to the detection part side, and the flow volume of this fluid is detected.

  Therefore, when the fluid pressure device is in the drive stop state, it is possible to detect whether the fluid leaks to the outside from the fluid pressure system based on the flow rate of the fluid flowing through the detection unit. As a result, it is possible to reliably detect the leakage of the fluid without interfering with the operation of the fluid pressure device, and to confirm and prevent the leakage, thereby reducing the running cost of the fluid pressure system and saving energy. Can be achieved.

  Further, when the fluid pressure device is driven and fluid leakage is not detected, the fluid is directly circulated to the drive switching mechanism and the fluid pressure device via the detection unit without flowing the fluid to the detection unit. Therefore, pressure loss can be suppressed, and the fluid can be reliably circulated without reducing the flow rate of the fluid.

  Furthermore, the switching unit is composed of a switching valve provided in a first passage connecting the fluid supply source and the drive switching mechanism, and the detection unit is a part of the first passage that is upstream and downstream of the switching unit. It is good to provide in the 2nd channel | path connected to.

  Furthermore, the switching unit may switch the communication state so that the fluid flows to the second passage when detecting the amount of fluid leakage.

  Furthermore, it is preferable to provide the same number of drive switching mechanisms and fluid pressure devices.

  The switching unit is a switching valve provided in a first passage connecting the fluid supply source and the drive switching mechanism, and the detection unit is provided in a second passage connected between the switching unit and the drive switching mechanism. Good.

  Furthermore, the switching unit is a switching valve provided in a first passage connecting the fluid supply source and the drive switching mechanism, and the detection unit is a first detection body provided on the downstream side of the switching unit in the first passage; It is good to comprise from the 2nd detection body provided in the said 2nd channel | path connected between the said switching part and the said drive switching mechanism.

The present invention further includes a fluid supply source for supplying fluid, and a drive switching mechanism for switching a supply state of the fluid supplied from the fluid supply source to the fluid pressure device, and the drive switching mechanism. In a fluid pressure system comprising a fluid pressure device having a moving body that is connected to the fluid and driven under the action of supplying the fluid, a leak detection method for detecting leakage of the fluid to the outside by a leak detection means,
After the drive of the fluid pressure device is stopped under the switching action by the drive switching mechanism, the fluid is detected by the switching portion of the leak detection means connected via a pipe between the fluid supply source and the drive switching mechanism. Switching the flow state of the flow of the fluid to the detection unit side capable of detecting the flow rate of the fluid,
Outputting the flow rate of the fluid detected by the detection unit to the control unit as a detection signal;
Determining whether or not the fluid leaks in the control unit based on the flow rate;
It is characterized by having.

  Furthermore, a warning signal may be output when the flow rate of the fluid detected by the detection unit exceeds a preset value set in advance by the control unit.

  According to the present invention, the following effects can be obtained.

  That is, a leakage detection means for detecting the amount of leakage of the fluid to the outside between a fluid supply source for supplying fluid and a drive switching mechanism for switching a supply state of the fluid supplied to a fluid pressure device And the leakage detection means comprises a switching unit that switches the supply state of the fluid to the drive switching mechanism, and a detection unit that is provided in parallel with the switching unit and detects the flow rate of the fluid, When the movement of the fluid pressure device is stopped, the switching unit is switched, and the fluid flowing from the fluid supply source to the drive switching mechanism through the switching unit is circulated to the detection unit side without flowing the switching unit. By detecting the flow rate of the fluid, it is possible to detect whether or not the fluid is leaking to the outside from the fluid pressure system based on the flow rate.

  As a result, it is possible to reliably detect the leakage of the fluid without interfering with the operation of the fluid pressure device, and to confirm and prevent the leakage, thereby reducing the running cost of the fluid pressure system and saving energy. Can be achieved.

1 is a schematic configuration diagram of a fluid pressure system having a leak detection mechanism according to an embodiment of the present invention. It is an enlarged block diagram which shows the detection part in the fluid pressure system of FIG. It is a time chart figure which shows the relationship between the flow volume of the pressure fluid detected by the flow sensor in the fluid pressure system of FIG. 1, the operation state of a switching valve, and a position detection sensor, and time. It is a characteristic curve figure which shows the relationship between the warning signal output when the leak of a pressure fluid is detected by the detection part of FIG. 2, and time. FIG. 5A is an enlarged configuration diagram showing a detection unit according to the first modification, and FIG. 5B is an enlarged configuration diagram showing a detection unit according to the second modification.

  A preferred embodiment of a leak detection mechanism and detection method for a fluid pressure system according to the present invention will be described in detail below with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates a fluid pressure system provided with a leak detection mechanism according to an embodiment of the present invention.

  As shown in FIG. 1, the fluid pressure system 10 includes a pressure fluid supply source (fluid supply source) 12 and a plurality of (for example, three) pressure fluids that are driven by the pressure fluid supplied from the pressure fluid supply source 12. Fluid pressure cylinders 14a-14c, piping 16 connecting the pressure fluid supply source 12 and the plurality of fluid pressure cylinders 14a-14c, respectively, between the pressure fluid supply source 12 and the fluid pressure cylinders 14a-14c A plurality of drive switching valves (drive switching mechanisms) 18a-18c that switch the supply state of the pressure fluid to the fluid pressure cylinders 14a-14c, the pressure fluid supply source 12, and the drive switching valves 18a-18c. A detection unit 20 provided between the detection unit 20 and the leakage of the pressure fluid supplied through the pipe 16 to the outside, and a flow rate detected by the detection unit 20 And a control unit 22 which is input as a detection signal.

  The number of drive switching valves 18a to 18c is set to be the same as the number of fluid pressure cylinders 14a to 14c.

  The fluid pressure cylinders 14 a to 14 c include a cylindrical cylinder body 24, a piston 26 movably provided inside the cylinder body 24, and a piston rod 28 connected to the piston 26, and the cylinder body One end portions of first and second pipes 34 and 36 (described later) are connected to first and second ports 30 and 32 provided on the side surfaces of 24, respectively.

  Then, when the pressure fluid is supplied from the pressure fluid supply source 12 through the first or second port 30 or 32, the piston 26 is pressed by the pressure fluid introduced into the cylinder body 24 and the axial direction of the cylinder body 24 ( Move in the direction of arrows C and D).

The piping 16 includes a supply piping (first passage ) 38 that connects the pressure fluid supply source 12 and the drive switching valves 18a to 18c, and the first ports 30 of the drive switching valves 18a to 18c and the fluid pressure cylinders 14a to 14c. Are provided in the middle of the supply pipe 38, the second pipe 36 for connecting the drive switching valves 18a to 18c and the second ports 32 of the fluid pressure cylinders 14a to 14c, respectively. And a bypass pipe (second passage) 40.

  The first and second pipes 34 and 36 are respectively provided with speed controllers 42 capable of adjusting the flow rate of the pressure fluid supplied to the fluid pressure cylinders 14a to 14c.

  Specifically, the supply pipe 38 has one end connected to the pressure fluid supply source 12 and the other end branched into three according to the quantity of the drive switching valves 18a to 18c. Connected to a supply port (described later). Further, a detection switching valve (switching unit) 52 constituting the detection unit 20 is connected to the supply pipe 38 in the middle, and the bypass is provided so as to bypass the upstream side and the downstream side of the detection switching valve 52. A pipe 40 is connected. The bypass pipe 40 is connected to a flow rate sensor (detection unit) 44 (described later) that can detect the flow rate of the pressure fluid flowing through the supply pipe 38.

  The first and second pipes 34 and 36 are provided in a plurality (for example, three) according to the numbers of the fluid pressure cylinders 14a to 14c and the drive switching valves 18a to 18c. One end side is connected to the first port 30 in each fluid pressure cylinder 14a to 14c, and the other end side is connected to a first connection port 48 (described later) of each drive switching valve 18a to 18c.

  On the other hand, the second pipe 36 has one end connected to the second port 32 and the other end connected to a second connection port 50 (described later) of the drive switching valves 18a to 18c.

  The drive switching valves 18a to 18c are, for example, electromagnetic valves that are driven by a control signal (current) from the control unit 22, and include a supply port 46 that is connected to the pressure fluid supply source 12 via the supply pipe 38, and the first It has the 1st connection port 48 to which the piping 34 is connected, and the 2nd connection port 50 to which the 2nd piping 36 is connected.

  When no control signal is input to the drive switching valves 18a to 18c (OFF), the supply port 46 and the first connection port 48 communicate with each other, and the pressure fluid from the pressure fluid supply source 12 is the first. On the other hand, when the control signal is input to the drive switching valves 18a to 18c (ON) while being supplied to the first ports 30 of the fluid pressure cylinders 14a to 14c through one pipe 34, the solenoid unit 58 is excited. The supply port 46 and the second connection port 50 are switched so as to communicate with each other, and the pressure fluid from the pressure fluid supply source 12 is supplied to the second ports 32 of the fluid pressure cylinders 14a to 14c through the second pipe 36. The Rukoto.

  That is, the drive switching valves 18a to 18c cause the first connection port 48 or the second connection port 50 and the supply port 46 to communicate with each other by a control signal, and the pressure fluid supplied from the pressure fluid supply source 12 is supplied to the fluid pressure cylinder 14a. Are distributed to either the first port 30 or the second port 32 of ˜14c.

  As shown in FIGS. 1 and 2, the detection unit 20 functions as a leakage detection mechanism (leakage detection means) capable of detecting leakage of pressurized fluid to the outside in the fluid pressure system 10, and is provided in the middle of the supply pipe 38. A detection switching valve 52 that switches the communication state between the supply pipe 38 and the bypass pipe 40, and a flow rate sensor that is provided in the bypass pipe 40 and that can detect the flow rate of the pressure fluid flowing through the bypass pipe 40. 44.

  Similar to the drive switching valves 18 a to 18 c, the detection switching valve 52 is composed of, for example, an electromagnetic valve that is driven by a control signal (current) from the control unit 22, and is connected to the pressure fluid supply source 12 via the supply pipe 38. Connected to the drive switching valves 18a to 18c, and a discharge port 56 for discharging the pressure fluid.

  Further, the detection switching valve 52 is formed therein, and the flow passage cross-sectional area E1 of the flow passage through which the pressure fluid flows is set larger than the flow passage cross-sectional area E2 of the flow rate sensor 44 (E1> E2).

  The flow sensor 44 is electrically connected to the control unit 22 via a lead wire, and outputs the detected flow rate value of the pressure fluid to the control unit 22 as a detection signal. In addition, the thing of the performance (size) according to the leakage amount H (flow rate) of the pressure fluid to detect is selected for the flow sensor 44.

  The control unit 22 detects leakage of the pressure fluid in the fluid pressure system 10 including the fluid pressure cylinders 14 a to 14 c based on the flow rate value detected by the detection unit 20, and the drive switching valves 18 a to 18 c and the detection switching valve. A control signal is output to 52 to perform switching control.

  The fluid pressure system 10 provided with the leak detection mechanism according to the embodiment of the present invention is basically configured as described above. Next, refer to FIGS. While explaining.

  Here, as shown in FIG. 1, the state in which the piston 26 of the fluid pressure cylinders 14 a to 14 c has moved to the second port 32 side (arrow D direction) will be described as an initial position, and the piston 26 The case of moving toward the first port 30 side (arrow C direction) is called forward, and the case of moving toward the second port 32 side (arrow D direction) is called backward.

  In this initial position, the drive switching valves 18a to 18c are in a non-energized state (OFF), the pressure fluid supply source 12 and the first port 30 communicate with each other through the drive switching valves 18a to 18c, and the pressure fluid is in the first port. The piston 26 is introduced into the cylinder body 24 through 30 and is moved by pressing the piston 26 toward the second port 32 (in the direction of arrow D), and the piston 26 is stopped at the initial position (stopped state).

  On the other hand, the detection switching valve 52 constituting the detection unit 20 is also in a non-energized state (OFF), and the upstream side and the downstream side of the supply pipe 38 communicate with each other via the detection switching valve 52, and the pressure Fluid is supplied from the pressure fluid supply source 12 to the drive switching valves 18a to 18c, respectively. In this case, a part of the pressure fluid flowing through the supply pipe 38 flows to the bypass pipe 40.

  As shown in FIG. 1 and FIG. 3, first, a control signal is inputted to each solenoid part 58 of the drive switching valves 18a to 18c and energized (refer to F1 in FIG. 3) to supply under the excitation action. The port 46 and the second connection port 50 communicate with each other, and pressure fluid is supplied from the pressure fluid supply source 12 to the second ports 32 of the fluid pressure cylinders 14a to 14c through the drive switching valves 18a to 18c, respectively. In this case, the first port 30 is opened to the atmosphere via the drive switching valves 18a to 18c.

  The piston 26 is pushed forward by the pressure fluid introduced from the second port 32 into the cylinder body 24 toward the first port 30 (in the direction of arrow C), and the cylinder body pressed by the piston 26. The air in 24 is discharged from the first port 30 to the drive switching valves 18 a to 18 c through the first pipe 34. It is detected by a position detection sensor S1 (not shown) provided at the other end of the cylinder body 24 that the piston 26 has advanced by a predetermined distance along the cylinder body 24 to reach the displacement end position. The control signal is output to the control unit 22 (see F3 in FIG. 3).

  That is, it is confirmed by the position detection sensor S1 that the piston 26 has reached the displacement end position and has stopped.

  Next, a control signal is output from the control unit 22, and the control signal is input to the solenoid unit 58 of the detection switching valve 52 constituting the detection unit 20, thereby driving the detection switching valve 52. Thus, the communication state of the supply pipe 38 is switched to the non-communication state. As a result, the pressure fluid supplied from the pressure fluid supply source 12 is supplied from the supply pipe 38 to the drive switching valves 18a to 18c via the bypass pipe 40, respectively.

  Then, as shown in FIG. 3, after a preset set time T has elapsed, the flow rate of the pressure fluid flowing through the bypass pipe 40 is detected by the flow rate sensor 44, and the detection result is output as an output signal to the control unit. 22 to confirm the change in the flow rate.

  When pressure fluid is leaking from the fluid pressure cylinders 14a to 14c, the piping and the drive switching valves 18a to 18c constituting the fluid pressure system 10, the flow rate increases due to leakage of the pressure fluid to the outside. Therefore, the flow rate of the pressure fluid detected by the flow rate sensor 44 increases accordingly, and is output as a detection signal to the control unit 22 (see F5 in FIG. 3). Thereby, it is confirmed in the control part 22 that the leak of the pressure fluid has generate | occur | produced based on this detection signal.

  In this case, as shown in FIG. 4, when the pressurized fluid leaks from the fluid pressure system 10 to the outside, the flow rate that becomes the leakage limit is set in the control unit 22 in advance as an allowable flow rate value G (for example, 1000 cc / min). When the flow rate (leakage amount H) detected by the flow rate sensor 44 reaches the allowable flow rate value G (G = H), for example, a warning signal is output from the control unit 22 to the display unit 60. And display.

  Further, a warning buzzer or the like (not shown) may be provided instead of the display unit 60 so that the operator can recognize by sound that the pressure fluid leakage amount H (flow rate) has exceeded the allowable flow rate value G. .

  As described above, after confirming that the leakage amount H of the pressurized fluid in the fluid pressure system 10 exceeds the allowable flow rate value G (H ≧ G) by the display unit 60, the warning buzzer, or the like, Leakage sites in the fluid pressure cylinders 14a to 14c, pipes and drive switching valves 18a to 18c constituting the fluid pressure system 10 are confirmed, and maintenance of components is performed.

  In addition, when there is no leakage of pressurized fluid from the fluid pressure system 10 to the outside, the flow rate of the pressurized fluid detected by the flow rate sensor 44 does not change, and changes at a substantially constant value ( (See F6 in FIG. 3).

  Then, after confirming the leakage of the pressure fluid for a predetermined time T2, the control signal output to the detection switching valve 52 is stopped, and the detection switching valve 52 is in a non-energized state (see F2 in FIG. 3). By doing so, the pressure fluid is again switched to the state of being supplied to the drive switching valves 18a to 18c through the supply pipe 38 (see F1 in FIG. 3).

  On the other hand, by stopping the input of the control signal to the drive switching valves 18a to 18c and making it in a non-energized state (OFF), the solenoid unit 58 becomes in a non-excited state, and accordingly, the supply port is under the elastic action of the spring 62 And the first connection port 48 are switched to communicate with each other. The pressure fluid is supplied from the pressure fluid supply source 12 to the first ports 30 of the fluid pressure cylinders 14a to 14c through the drive switching valves 18a to 18c, respectively, and the second port 32 is connected to the drive switching valves 18a to 18c. Through the atmosphere.

  As a result, the piston 26 is pushed back toward the second port 32 (in the direction of arrow D) by the pressure fluid introduced from the first port 30 into the cylinder body 24, and the cylinder pushed by the piston 26 is retracted. Air in the main body 24 is discharged from the second port 32 to the drive switching valves 18a to 18c through the second pipe 36. It is detected by a position detection sensor S2 (not shown) provided at one end of the cylinder body 24 that the piston 26 has moved backward by a predetermined distance along the cylinder body 24 and reached the initial position. It is output as a control signal (ON). That is, it is confirmed by the position detection sensor S2 that the piston 26 reaches the initial position again and is stopped (see F4 in FIG. 3).

  Next, a control signal is output from the control unit 22, the control signal is input to the solenoid unit 58 of the detection switching valve 52 constituting the detection unit 20, and the detection switching valve 52 is driven to supply piping 38. The communication state is switched to a non-communication state (see F2 in FIG. 3). Thereby, the pressure fluid supplied from the pressure fluid supply source 12 is supplied from the supply pipe 38 to the drive switching valves 18a to 18c via the bypass pipe 40, respectively.

  Then, after a preset time T3 has elapsed, the flow rate of the pressure fluid flowing through the bypass pipe 40 is detected by the flow rate sensor 44, and the detection result is output to the control unit 22 as an output signal. Check for changes. The confirmation of leakage of the pressure fluid based on the change in the flow rate of the pressure fluid is the same as that performed at the displacement end positions of the fluid pressure cylinders 14a to 14c described above, and a detailed description thereof will be omitted.

  As described above, in the present embodiment, in the fluid pressure system 10, the pressure fluid supply source 12 and the drive switching valves 18a to 18c that switch the supply state of the pressure fluid to the fluid pressure cylinders 14a to 14c are described above. A detection unit 20 capable of detecting leakage of the pressure fluid from the fluid pressure system 10 to the outside is provided, and the piston 26 constituting the fluid pressure cylinders 14a to 14c is in a stopped state in an initial position or a displacement end position. The leakage check of the pressure fluid of the fluid pressure system 10 including the pressure cylinders 14a to 14c can be performed. Therefore, the operation of the fluid pressure cylinders 14a to 14c is not hindered, and the leakage of the pressure fluid can be reliably detected, and the running cost of the fluid pressure system 10 is reduced by checking and preventing the leakage. It is possible to save energy.

  Further, when the pressure fluid leakage is not detected, the fluid pressure cylinders 14a to 14c are driven because the pressure fluid is circulated through the detection switching valve 52 having a flow passage cross-sectional area larger than that of the flow rate sensor 44. The pressure loss can be minimized. As a result, since the supply pressure of the pressure fluid can be set low, for example, it is possible to suppress power consumption when a compressor is used for the pressure fluid supply source 12.

  Further, in the fluid pressure cylinders 14a to 14c having the plurality of fluid pressure cylinders 14a to 14c, the detection unit 20 may be provided only in the supply pipe 38 that supplies the fluid pressure to the fluid pressure cylinders 14a to 14c. The equipment cost of the fluid pressure system 10 can be kept low, and the installation space can be reduced.

  Furthermore, by regularly checking the leakage amount H of the pressure fluid by the detection unit 20, it becomes possible to grasp the change with time of the fluid pressure system 10, and the optimum fluid pressure system 10 based on the leakage amount H is obtained. It is possible to perform maintenance work on

  Furthermore, in the fluid pressure system 10 composed of a plurality of fluid pressure cylinders 14a to 14c, it is also possible to check leakage detection separately when the fluid pressure cylinders 14a to 14c are stopped. Even when the pressure fluid leaks from any one of the plurality of fluid pressure cylinders 14a to 14c, it can be reliably detected and confirmed.

  Further, the detection unit 20 includes a flow rate sensor 44, and the failure diagnosis of the fluid pressure system 10 including the fluid pressure cylinders 14a to 14c is detected by detecting leakage of the pressure fluid from the fluid pressure cylinders 14a to 14c and the piping. For example, it is possible to externally output the replacement timing of the fluid pressure cylinders 14a to 14c to the display unit 60 or the like.

  Furthermore, when the leakage amount H of the pressure fluid exceeds a preset allowable flow rate value G, a warning is output from the control unit 22 to the display unit 60 or the like, so that the leakage of the pressure fluid is reliably and quickly performed. It becomes possible to confirm and deal with it.

  In the present embodiment, the detection switching valve 52 has been described as being a solenoid valve that is switched under energization. However, the present invention is not limited to this. For example, the operator manually switches the switching valve 52. Possible manual switching valves may be used.

  The detection unit 20 is not limited to the above-described configuration. For example, the detection switching valve 72 provided in the middle of the supply pipe 38 is connected to the supply port like the detection unit 70 shown in FIG. 5A. 74 and the first and second connection ports 76 and 78, and the first connection port 76 and the drive switching valves 18 a to 18 c are connected to the second connection port 78. The flow sensor 44 may be provided in the middle of the bypass pipe 80.

  Further, as in the detection unit 90 shown in FIG. 5B, a first flow sensor (first detection body) 92 is provided in the bypass pipe 80 on the downstream side of the detection switching valve 72 and connected to the first connection port 76. In addition, a second flow rate sensor (second detection body) 94 different from the first flow rate sensor 92 may be provided in the supply pipe 38. In this case, the second flow rate sensor 94 has a larger flow path cross-sectional area than the first flow rate sensor 92.

  Therefore, when the pressure fluid flows through the supply pipe 38 under the switching action of the detection switching valve 72 and the fluid pressure cylinders 14a to 14c are driven, the second flow rate sensor 94 does not become channel resistance, and the fluid The pressure cylinders 14a to 14c can be suitably driven, and the flow rate of the pressure fluid flowing through the supply pipe 38 can be detected.

  That is, by making the above-described detection units 20, 70, 90 into replaceable modules, it is possible to replace them as needed.

  In addition, the leak detection mechanism and leak detection method of the fluid pressure system according to the present invention are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Fluid pressure system 12 ... Pressure fluid supply sources 14a-14c ... Fluid pressure cylinder 16 ... Piping 18a-18c ... Drive switching valve 20, 70, 90 ... Detection part 22 ... Control part 26 ... Piston 30 ... 1st port 32 ... 2nd port 34 ... 1st piping 36 ... 2nd piping 38 ... Supply piping 40, 80 ... Bypass piping 44 ... Flow rate sensor 52, 72 ... Switching valve for detection 92 ... 1st flow rate sensor 94 ... 2nd flow rate sensor

Claims (9)

A fluid supply source for supplying a fluid; and a drive switching mechanism for switching a supply state of the fluid supplied from the fluid supply source to a fluid pressure device, connected to the drive switching mechanism, In a fluid pressure system comprising the fluid pressure device having a moving body driven under supply action,
Leakage detecting means connected between the fluid supply source and the drive switching mechanism via a pipe for detecting the amount of leakage of the fluid to the outside;
With
The leakage detection means includes a switching unit that switches the supply state of the fluid to the drive switching mechanism, a detection unit that is provided on the downstream side of the switching unit and detects the flow rate of the fluid,
Tona is, the switching section leak detection system of the hydraulic system, characterized in that a three-port switching valve provided in the first passage for connecting the drive switching mechanism and the fluid source. The leak detection mechanism according to claim 1,
The fluid pressure system leakage detection mechanism according to claim 1, wherein a cross-sectional area of the flow path through which the fluid flows in the switching unit is set larger than a cross-sectional area of the flow path in the detection unit. In the leak detection mechanism according to claim 1 or 2,
Prior Symbol detector, leak detection system of the hydraulic system, characterized in that provided in the second passage connected to the portion of the first passage on the upstream side and downstream side of the switching unit. The leak detection mechanism according to claim 3,
The fluid pressure system leakage detection mechanism according to claim 1, wherein the switching unit switches the communication state so that the fluid flows to the second passage when the fluid leakage amount is detected. In the leak detection mechanism according to any one of claims 1 to 4,
A fluid pressure system leakage detection mechanism, wherein the drive switching mechanism and the fluid pressure device are provided in the same number. The leak detection mechanism according to claim 1,
Before Symbol detection unit, the switching unit and leak detection system of the hydraulic system, characterized in that provided in the second passage connected between said drive switching mechanism. The leak detection mechanism according to claim 1,
Before Symbol detection unit, said a first detection member provided on the downstream side of the switching unit in the first path, the switching unit and the second detection provided in the second passage connected between said drive switching mechanism A leak detection mechanism for a fluid pressure system, characterized by comprising a body. A fluid supply source for supplying a fluid; and a drive switching mechanism for switching a supply state of the fluid supplied from the fluid supply source to a fluid pressure device, connected to the drive switching mechanism, In a fluid pressure system including a fluid pressure device having a moving body driven under a supply action, a leak detection method for detecting leakage of the fluid to the outside by a leak detection means,
After the drive of the fluid pressure device is stopped under the switching action by the drive switching mechanism, the fluid is detected by the switching portion of the leak detection means connected via a pipe between the fluid supply source and the drive switching mechanism. A flow state of the fluid, and the flow of the fluid to a detection portion side provided on the downstream side of the switching portion composed of a three-port switching valve and capable of detecting the flow rate of the fluid;
Outputting the flow rate of the fluid detected by the detection unit to the control unit as a detection signal;
Determining whether or not the fluid leaks in the control unit based on the flow rate;
A fluid pressure system leak detection method comprising: The method of claim 8, wherein
A fluid pressure system leak detection method, comprising: outputting a warning signal when a flow rate of the fluid detected by the detection unit exceeds a preset value preset by the control unit.

Images