Attractor Car

Abstract

This invention provides a suction vehicle that allows for easy pressure adjustment using the same control valve during both suction and pressurization, thereby reducing noise. [Solution] The suction vehicle 2 includes a receiver tank 5 for collecting the object to be collected, a water-sealed pump 25 for generating airflow by increasing or decreasing the pressure of the air inside the receiver tank 5, an intake / exhaust port 23a for releasing air to the outside air, a suction-side flow path switching valve installed in the piping between the receiver tank 5 and the water-sealed pump 25, and a discharge-side flow path switching valve installed in the piping between the water-sealed pump 25 and the intake / exhaust port 23a. A bypass pipeline 41 is provided connecting the piping from the pump discharge port 25b to the discharge-side flow path switching valve and the piping from the pump suction port 25a to the suction-side flow path switching valve, and a pressure regulating valve 42 is installed in the bypass pipeline 41.

Description

Technical Field

[0005] ,

[0001] The present invention relates to a suction vehicle.

Background Art

[0002] Conventionally, a suction vehicle equipped with a receiver tank for collecting a collection target and a vacuum pump for adjusting the pressure of air (air) inside the receiver tank to generate an air flow is known (see, for example, Patent Document 1). In this suction vehicle, a load release valve connected to the outside air (atmosphere) is provided in a path directly connected to the inside of the receiver tank, and the load release valve is operated according to the temperature of the air discharged from the blower.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention provides the following means for solving the above-mentioned problems. Specifically, the present invention provides a suction vehicle having a receiver tank for collecting a target material, a vacuum pump for generating an airflow by increasing or decreasing the pressure of the air inside the receiver tank, an exhaust port for releasing air to the outside air, a suction-side flow path switching valve disposed in the piping between the receiver tank and the vacuum pump, and a discharge-side flow path switching valve disposed in the piping between the vacuum pump and the exhaust port, wherein a bypass pipeline is provided connecting the piping from the pump discharge port to the discharge-side flow path switching valve and the piping from the pump suction port to the suction-side flow path switching valve, and a pressure regulating valve is provided in the bypass pipeline.

[0007] With the above configuration, the pressure (suction force, pressurized force) can be easily adjusted using the same pressure regulating valve during both suction and pressurization, foaming of the collected material during suction can be suppressed, and leakage of the collected material from unexpected locations can be prevented. Furthermore, when the pressure regulating valve is opened, the pump discharge port and pump suction port of the vacuum pump are bypassed by a bypass pipe, so that no opening is created that is exposed to the outside air (atmosphere), and noise when the pressure regulating valve is opened can be reduced.

[0008] In the suction vehicle with the above configuration, it is preferable that the discharge-side flow path switching valve and the suction-side flow path switching valve are the same four-way valve, and that the four-way valve is a solenoid valve that can switch the position of the valve body to one of three positions: suction, pressurization, or neutral by switching a switch.

[0009] With the above configuration, the position of the valve body of the four-way valve can be switched and controlled by a simple switch operation, thereby switching the mode of the suction device. Furthermore, while the position of the valve body of the four-way valve is switched and controlled by electromagnetic control of the four-way valve, the pressure can be maintained at a level that is less prone to foaming, etc., by adjusting the pressure regulating valve.

[0010] In the suction vehicle with the above configuration, it is preferable that the pressure regulating valve is a solenoid valve, a pressure sensor is installed between the receiver tank and the vacuum pump (including inside the receiver tank), and a control unit is electrically connected to the pressure regulating valve and the pressure sensor, and the control unit is configured to operate the pressure regulating valve based on the detection result of the pressure sensor.

[0011] With the above configuration, the pressure can be automatically maintained at a level that is less prone to foaming, etc., by electromagnetic control of the pressure regulating valve.

[0012] In the suction vehicle with the above configuration, it is preferable that the control unit is equipped with a setting unit capable of setting a pressure threshold for which the pressure regulating valve operates.

[0013] With the above configuration, it is possible to easily handle a wide variety of materials to be recovered. The operational intuition possessed by skilled operators is standardized in terms of two items: the material to be recovered and the pressure value. By setting thresholds according to the material to be recovered, the pressure regulating valve can be automatically controlled based on the detection results of the pressure sensor. [Effects of the Invention]

[0014] According to the suction vehicle of the present invention, the pressure can be easily adjusted using the same pressure regulating valve during both suction and pressurization, foaming of the collected material during suction can be suppressed, and leakage of the collected material from unexpected locations can be prevented. Furthermore, when the pressure regulating valve is opened, the pump discharge port and pump suction port of the vacuum pump are bypassed by a bypass pipeline, so that no opening is created that is exposed to the outside air, and noise when the pressure regulating valve is opened can be reduced. [Brief explanation of the drawing]

[0015] [Figure 1] It is a side view showing a schematic configuration of a suction vehicle according to an embodiment of the present invention. [Figure 2] It is a plan view of the suction vehicle. [Figure 3] It is an air piping diagram of a suction device mounted on a suction vehicle, showing the flow of air during suction. [Figure 4] In the air piping diagram of FIG. 3, it is a diagram showing the flow of air during pressurization. [Figure 5] It is a diagram showing the stop position of the valve body of a four-way valve when switching to three modes: a suction mode, a pressurization mode, and a neutral mode. [Figure 6] It is a side view showing an operation panel installed on the suction vehicle. [Figure 7] It is a schematic diagram showing a part of the hydraulic circuit of the suction vehicle. [Figure 8] It is a schematic diagram showing a part of the sequence circuit of the suction vehicle. [Figure 9] It is a piping diagram of a suction device mounted on a suction vehicle according to another embodiment. [Figure 10] It is a side view showing the schematic configuration of the suction device of FIG. 9.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] FIG. 1 and FIG. 2 show a suction vehicle 2 according to an embodiment of the present invention. A suction device 1 is provided on a sub-frame 4 on a vehicle body 3 of this suction vehicle 2. Specifically, a receiver tank 5 for collecting objects to be collected such as sludge, earth and sand, waste liquid, etc. is mounted at the rear part of the sub-frame 4.

[0018] The receiver tank 5 has, for example, a tank body 5a in the shape of a circular cross-section container having an opening at the rear end, and a tailgate 5c for opening and closing this rear end opening. The tailgate 5c is pivotally supported, for example, at the upper rear end of the tank body 5a via a hinge pin 5b so as to be rotatable. An opening / closing cylinder 5d is provided between the tank body 5a and the tailgate 5c, and by expanding and contracting this opening / closing cylinder 5d, the tailgate 5c can open and close the rear end opening of the tank body 5a.

[0019] At the lower part of the tailgate 5c, a suction port 8 with an on-off valve serving as a suction port for the object to be recovered and a discharge port 9 with an on-off valve serving as a discharge port for the object to be recovered are provided. The receiver tank 5 is pivotally supported with respect to the sub-frame 4 via a tilting shaft 10 provided behind the sub-frame 4 so as to be tiltable. That is, a tilting cylinder 11 is provided between the sub-frame 4 and the receiver tank 5. By expanding and contracting this tilting cylinder 11, the receiver tank 5 is adapted to stand up and rotate or lie down and rotate around the tilting shaft 10.

[0020] On the sub-frame 4 between the receiver tank 5 and the driver's cab 13, a water-sealed pump 25 as a vacuum pump for increasing and decreasing the pressure of the air in the receiver tank 5 and generating a flow of air is provided. The water-sealed pump 25 is adapted to be rotationally driven by the driving force of an engine (not shown) connected via the drive shaft of the PTO of the suction vehicle 2. Piping connected to the water-sealed pump 25, various valves, an operation panel 15, etc. are arranged around the water-sealed pump 25.

[0021] As shown in Figures 3 and 4, the suction device 1 includes the receiver tank 5 as a primary catcher, secondary catchers 20 and tertiary catchers 21 consisting of cyclone-type dust collectors, a quaternary catcher 22 consisting of a gas-water separator and water tank, and the water-sealed pump 25 as described above. These devices are connected via receiver tank pressure / pressure piping 7, which is made of, for example, a metal round steel pipe. The receiver tank 5 is connected to the secondary catcher 20 by a first pipe 7a. The secondary catcher 20 is also connected to the tertiary catcher 21 by a second pipe 7b. In this embodiment, the tertiary catcher 21 and the quaternary catcher 22 are provided integrally.

[0022] The water-sealed pump 25, tertiary catcher 21, quaternary catcher 22, and integrated silencer 23 are connected to a four-way valve 24 via piping. Specifically, the water-sealed pump 25 has an inlet 25a and a discharge port 25b. The tertiary catcher 21 and the four-way valve 24 are connected by a third pipe 7c. The inlet 25a of the water-sealed pump 25 and the four-way valve 24 are connected by a fourth pipe 7d. The quaternary catcher 22 and the four-way valve 24 are connected by a fifth pipe 7e. The integrated silencer 23 and the four-way valve 24 are connected by a sixth pipe 7f. The upper end of the integrated silencer 23 is provided with an intake / exhaust port 23a that can communicate with the outside air (atmosphere), making it possible to release air to the outside air from the intake / exhaust port 23a or to take in outside air from the intake / exhaust port 23a. The discharge port 25b of the water-sealed pump 25 is connected to the fourth catcher 22 by the seventh pipe 7g. In this embodiment, the fourth pipe 7d connected to the suction port 25a of the water-sealed pump 25 and the seventh pipe 7g connected to the discharge port 25b are connected by a bypass pipe 41. In this case, the section of the fourth pipe 7d near the suction port 25a and the section of the seventh pipe 7g near the discharge port 25b are connected by the bypass pipe 41. A pressure regulating valve 42 is provided in the bypass pipe 41, and a hydraulic cylinder 43 (see Figure 7) that operates by hydraulic pressure is used as an actuator to change the opening degree of the pressure regulating valve 42 by switching the position of the valve body of the pressure regulating valve 42.

[0023] When the suction device 1 sucks and collects the material to be collected into the receiver tank 5, the reduced pressure and airflow within the receiver tank 5 draw the material into the receiver tank 5 from the outside through a suction hose (not shown) connected to the suction port 8. On the other hand, when the suction device 1 discharges the material to be collected from the receiver tank 5 to, for example, a sludge treatment plant, the air inside the receiver tank 5 is pressurized, and the material to be collected from the receiver tank 5 is discharged to the outside through a discharge hose (not shown) connected to the discharge port 9. It is also possible to discharge the material to be collected from the receiver tank 5 by opening the tailgate 5c and rotating the receiver tank 5 upright.

[0024] As shown in Figure 1, the operation panel 15 is installed on one side of the suction vehicle 2 in the left-right direction. In this embodiment, the operation panel 15 is provided on the left side of the suction vehicle 2. As shown in Figure 6, the operation panel 15 is equipped with a control device (control unit) PLC that controls the operation of the four-way valve 24, water-sealed pump 25, pressure regulating valve 42, etc. in the suction device 1. The operation panel 15 is provided with operation switches (mode switching switches) for switching the switching state of the four-way valve 24 to one of three modes: suction state (suction mode), neutral state (neutral mode), and pressurized state (pressurized mode). These switches include a suction mode button 15a, a neutral mode button 15b, and a pressurized mode button 15c. An accelerator knob 15d is also provided for adjusting the rotation speed of the water-sealed pump 25. Furthermore, the suction mode button 15a is equipped with a suction indicator lamp 40a that indicates that the four-way valve 24 is controlled to be in suction mode. Furthermore, the pressurizing mode button 15c is equipped with a pressurizing indicator lamp 40c that shows that the four-way valve 24 is switched to pressurizing mode. The control device PLC may be installed in the operator's cab 13.

[0025] Furthermore, the control panel 15 is equipped with an operating lever 27 for operating the opening / closing cylinder 5d and the tilting cylinder 11. By operating the operating lever 27, the opening / closing cylinder 5d is retracted or extended, and the tilting cylinder 11 is retracted or extended. In this embodiment, it is possible to operate both the opening / closing cylinder 5d and the tilting cylinder 11 with a single operating lever 27. The operating lever 27 can be operated, for example, in the left-right and up-down directions around the position shown in the figure. For example, when the operating lever 27 is operated upward, the receiver tank 5 is raised (dump raised) by the extension of the tilting cylinder 11. When the operating lever 27 is operated downward, the receiver tank 5 is lowered (dump lowered) by the retraction of the tilting cylinder 11. Also, when the operating lever 27 is operated to the right, the tailgate 5c is opened (gate opened) by the extension of the opening / closing cylinder 5d. When the operating lever 27 is operated to the left, the tailgate 5c is closed (gate closed) by the contraction of the opening / closing cylinder 5d. Alternatively, the operation of the opening / closing cylinder 5d and the operation of the tilting cylinder 11 may be performed using separate operating tools.

[0026] The four-way valve 24 is provided in the suction device 1 to switch the flow of air generated by the water-sealed pump 25. Specifically, the four-way valve 24 is used to switch between three modes: a suction mode in which the receiver tank 5 is made negatively pressurized and the material to be recovered is sucked into the receiver tank 5; a pressurizing mode in which the receiver tank 5 is pressurized and the material to be recovered is discharged outside the receiver tank 5; and a neutral mode in which the water-sealed pump 25 is driven but the receiver tank 5 is not pressurized or depressurized. Figures 3 and 4 show the operating state of the suction device 1 according to this embodiment. Figure 5 is a perspective view showing the position of the valve body 28 of the four-way valve 24 during suction (upper left figure), neutral (center figure), and pressurizing (upper right figure). Each port 24a to 24d of the four-way valve 24 shown in Figure 5 corresponds to each port 24a to 24d of the four-way valve 24 shown in Figures 3 and 4.

[0027] Figure 3 shows the airflow of the suction device 1 during suction (suction operation). As shown in Figures 3 and 5, during suction, ports 24a and 24b of the four-way valve 24 are connected, and ports 24c and 24d are connected. Ports 24a and 24b are separated from ports 24c and 24d by a valve body 28. As a result, air flows simultaneously from port 24a to port 24b and from port 24d to port 24c. Consequently, the air sucked from the receiver tank 5 passes through the secondary catcher 20 and tertiary catcher 21, through the four-way valve 24, through the ejector 30, and is sucked by the water-sealed pump 25, and then passes through the four-way valve 24 again via the quaternary catcher 22 and is exhausted from the intake / exhaust port 23a of the integrated silencer 23.

[0028] Figure 4 shows the airflow during pressurization (pressurized operation) of the suction device 1. As shown in Figures 4 and 5, during pressurization, the position of the valve body 28 of the four-way valve 24 is switched, connecting port 24a and port 24d, and port 24b and port 24c. Ports 24a and 24d are separated from ports 24b and 24c by the valve body 28. As a result, air flows simultaneously from port 24a to port 24d, and from port 24b to port 24c. As a result, the air drawn in from the intake and exhaust port 23a of the integrated silencer 23 passes through the four-way valve 24, is drawn into the water-sealed pump 25, passes through the quaternary catcher 22, passes through the four-way valve 24 again, and pressurizes the receiver tank 5 through the tertiary catcher 21 and the secondary catcher 20.

[0029] Furthermore, when neutral, the valve body 28 of the four-way valve 24 remains stationary in an intermediate position between the suction and pressurization positions described above. The position of the valve body 28 of the four-way valve 24 is changed by an actuator integrally attached to the four-way valve 24. In this embodiment, a hydraulic cylinder 29 (see Figure 7), which is operated by hydraulic pressure, is used as the actuator to switch the position of the valve body 28 of the four-way valve 24.

[0030] Next, with reference to Figure 7, the hydraulic circuit for operating the hydraulic cylinder 29 that switches the position of the valve body 28 of the four-way valve 24 described above, and the hydraulic cylinder 43 that changes the opening degree of the pressure regulating valve 42 of the bypass pipeline 41 in the suction vehicle 2 will be described. As shown in Figure 7, the hydraulic circuit includes a hydraulic pump P as a hydraulic power source, an oil reservoir T, an electromagnetic control valve V1 for controlling the hydraulic cylinder 43, and an electromagnetic control valve V2 for controlling the hydraulic cylinder 29. The hydraulic pump P is connected to the PTO described above, and the driving force of an engine (not shown) is transmitted via the PTO. When the engine speed increases, the rotational speed of the hydraulic pump P increases and the discharge volume increases.

[0031] As an example, electromagnetic control valves V1 and V2 are both electromagnetic directional control valves with 6 ports and 3 positions. When solenoid SOLa is energized, electromagnetic control valve V1 switches to the first communication position (upper position in the diagram) and supplies hydraulic fluid from hydraulic pump P to the rod-side oil chamber of hydraulic cylinder 43, while when solenoid SOLb is energized, it switches to the second communication position (lower position in the diagram) and supplies hydraulic fluid to the head-side oil chamber.

[0032] When hydraulic fluid is supplied to the head-side oil chamber from the electromagnetic control valve V1, the hydraulic cylinder 43 extends, and the pressure regulating valve 42 operates, increasing its opening degree. Conversely, when hydraulic fluid is supplied to the rod-side oil chamber, the hydraulic cylinder 43 retracts, and the pressure regulating valve 42 operates, decreasing its opening degree. The opening degree of the pressure regulating valve 42 can be adjusted steplessly between a fully closed state and a fully open state. Furthermore, when neither solenoid SOLa nor SOLb is energized, the electromagnetic control valve V1 returns to the neutral position (center position in the diagram).

[0033] When solenoid SOLc is energized, the electromagnetic control valve V2 switches to the first communication position (lower position in the diagram) and supplies hydraulic fluid from the hydraulic pump P to the rod-side oil chamber of the hydraulic cylinder 29. When solenoid SOLd is energized, it switches to the second communication position (upper position in the diagram) and supplies hydraulic fluid to the head-side oil chamber.

[0034] When hydraulic fluid is supplied to the head-side oil chamber from the electromagnetic control valve V2, the hydraulic cylinder 29 extends, and the valve body 28 of the four-way valve 24 switches to the suction position shown in Figures 3 and 5. On the other hand, when hydraulic fluid is supplied to the rod-side oil chamber, the hydraulic cylinder 29 retracts, and the valve body 28 of the four-way valve 24 switches to the pressurized position shown in Figures 4 and 5. Furthermore, when neither solenoid SOLc nor SOLd is energized, the electromagnetic control valve V1 returns to the neutral position (center position in the figure), and the valve body 28 of the four-way valve 24 switches to the neutral position shown in Figure 5. To prevent unexpected operation, when neither solenoid SOLc nor SOLd is energized, the previous position may be maintained, and operation of the neutral mode button 15b may be required to return to the neutral position.

[0035] When both electromagnetic control valves V1 and V2 are in the neutral position, the hydraulic fluid returns to the oil reservoir T. In the hydraulic circuit, symbol V3 is a check valve, and symbol V4 is a relief valve for setting the upper limit of the discharge pressure of the hydraulic pump P.

[0036] Next, the control device PLC (Programmable Logic Controller) that outputs control signals to the electromagnetic control valves V1 and V2 provided in the hydraulic circuit described above in the suction vehicle 2, and its input / output state will be explained with reference to Figure 8. As shown in Figure 8, power to the control device PLC is supplied by the battery BT shown in the upper left of Figure 8. A power supply line K2 is connected between this battery BT and the ground line K1 on the right side of Figure 8, extending left and right along the top of Figure 8. The key switch SWK, PTO switch SWP, relay coil CR1, etc. of the suction vehicle 2 are interposed in this power supply line K2.

[0037] Furthermore, the upstream end of the power supply line K3 is connected so as to branch off from the power supply line K2 between the key switch SWK and the battery BT, and power is supplied to the signal power supply unit (not shown) of the control device PLC via this power supply line K3. In other words, the contact cr1 of the relay coil CR1 is interposed on the upstream side (closer to the battery BT) of the power supply line K3, and when the relay coil CR1 is turned on, the contact cr1 closes and power is supplied to the power supply line K3.

[0038] This power supply line K3 is always energized while the suction device 1 is in operation, and a stop switch SW1 of the control device PLC is interposed thereto. When the power supply is cut off by this stop switch SW1, the operation of the control device PLC stops, and thus the operation of the suction device 1 stops.

[0039] Furthermore, as shown on the left side of Figure 8, the upstream ends of multiple branch lines are connected to branch off from the energized line K3 downstream of the aforementioned contact cr1 (farther from the battery BT), and switches LS1 to LS5 are interposed in each of these branch lines. Based on the signals from these switches LS1 to LS5, the operating state of the suction device 1 is detected. Examples of switches LS1 to LS5, which detect the operating state of the suction device 1 include a mode switching switch that controls the position of the valve body 28 of the four-way valve 24, a proximity sensor that detects the position of the valve body 28 of the four-way valve 24 and the position of the hydraulic cylinder 29, a pressure sensor that detects the pressure inside the receiver tank 5, and a load cell that detects the weight of the recovered object in the receiver tank 5. The mode switching switches are the suction mode button 15a, the neutral mode button 15b, and the pressurizing mode button 15c provided on the operation panel 15 described above. The pressure sensor is installed between the receiver tank 5 and the water-sealed pump 25 (including inside the receiver tank 5), for example, in the secondary catcher 20, tertiary catcher 21, etc. The load cell is installed between the receiver tank 5 and the subframe 4, for example. Note that these switches and sensors are just examples, and the operating status of the suction device 1 may be detected using other detection means.

[0040] As described above, various switches LS1 to LS5 are connected to the input side, while solenoids SOLa to SOLd for electromagnetic control valves V1 and V2 are connected to the output side (right side of Figure 8) of the control device PLC. The control device PLC is programmed to output to the corresponding solenoids SOLa to SOLd in order to operate hydraulic cylinders 29, 43, etc., according to a preset procedure based on the signals input from switches SW1 and LS1 to LS5.

[0041] For example, when the suction device 1 is activated, both the key switch SWK and the PTO switch SWP on the power line K2 are closed, and the relay coil CR1 is energized. As a result, the contact cr1 of the relay coil CR1 is closed, and when energized by the power line K3, the control device PLC becomes operational and outputs control signals to the solenoids SOLa~SOLd as appropriate.

[0042] Upon receiving this control signal, the solenoids SOLa~SOLd are energized, and the positions of the electromagnetic control valves V1 and V2 are switched as appropriate, thereby supplying operating hydraulic pressure to the hydraulic cylinders 29 and 43. As a result, the hydraulic cylinders 29 and 43 operate, respectively, to control the switching of the position of the valve body 28 of the four-way valve 24 and to control the change in the opening degree of the pressure regulating valve 42 of the bypass pipeline 41, as described above.

[0043] In this embodiment, there is a suction-side flow path switching valve installed in the piping between the receiver tank 5 and the water-sealed pump 25, and a discharge-side flow path switching valve installed in the piping between the water-sealed pump 25 and the intake / exhaust port 23a. A bypass pipeline 41 is provided connecting the piping from the discharge port 25b of the water-sealed pump 25 to the discharge-side flow path switching valve and the piping from the suction port 25a of the water-sealed pump 25 to the suction-side flow path switching valve, and a pressure regulating valve 42 is installed in the bypass pipeline 41. This point will be explained with reference to Figures 1 to 4.

[0044] The suction device 1 is equipped with a four-way valve 24, which functions as both a suction-side flow path switching valve and a discharge-side flow path switching valve. When the suction device 1 is performing suction, the valve body 28 of the four-way valve 24 is switched to the position shown in Figures 3 and 5. The four-way valve 24 is installed in the piping 7a, 7b, 7c, and 7d between the receiver tank 5 and the suction port 25a of the water-sealed pump 25, specifically between the third piping 7c and the fourth piping 7d. In addition, the four-way valve 24 is installed in the piping 7g, 7e, and 7f between the discharge port 25b and the intake / exhaust port 23a of the water-sealed pump 25, specifically between the fifth piping 7e and the sixth piping 7f.

[0045] On the other hand, when the suction device 1 is pressurized, the valve body 28 of the four-way valve 24 is switched to the position shown in Figures 4 and 5. The four-way valve 24 is installed in the piping 7a, 7b, 7c, 7e, and 7g between the receiver tank 5 and the discharge port 25b of the water-sealed pump 25. Specifically, the four-way valve 24 is installed between the third piping 7c and the fifth piping 7e. In addition, the four-way valve 24 is installed in the piping 7d and 7f between the suction port 25a and the intake / exhaust port 23a of the water-sealed pump 25. Specifically, the four-way valve 24 is installed between the fourth piping 7d and the sixth piping 7f.

[0046] As described above, the four-way valve 24 is a solenoid valve that can switch the position of the valve body 28 to one of the three positions of suction, pressurization, and neutral, as shown in Figures 3 to 5, based on the operation of a switch on the control panel 15. In other words, the position of the valve body 28 of the four-way valve 24 is controlled to switch based on the operation of one of the suction mode button 15a, neutral mode button 15b, or pressurization mode button 15c on the control panel 15.

[0047] According to this embodiment, the fourth pipe 7d connected to the suction port 25a of the water-sealed pump 25 and the seventh pipe 7g connected to the discharge port 25b are connected by a bypass pipe 41, and a pressure regulating valve 42 is provided in the bypass pipe 41. Therefore, the pressure (suction force, pressurized force) can be easily adjusted using the same pressure regulating valve 42 during both suction and pressurization, which suppresses foaming of the collected material during suction and prevents leakage of the collected material from unexpected locations. Furthermore, when the pressure regulating valve 42 is opened, the discharge port 25b and suction port 25a of the water-sealed pump 25 are bypassed by the bypass pipe 41, so that no opening is created that is exposed to the outside air (atmosphere), and noise when the pressure regulating valve 42 is opened can be suppressed.

[0048] Furthermore, the four-way valve 24 has the functions of both a suction-side flow path switching valve and a discharge-side flow path switching valve. The four-way valve 24 is a solenoid valve that can switch the position of the valve body 28 to one of three positions: suction, pressurization, or neutral, by operating the suction mode button 15a, neutral mode button 15b, and pressurization mode button 15c on the operation panel 15. This allows the suction device 1 to be switched modes by simply switching and controlling the position of the valve body 28 of the four-way valve 24. In addition, while switching and controlling the position of the valve body 28 of the four-way valve 24 by electromagnetic control of the four-way valve 24, the pressure can be maintained to prevent foaming and other issues by adjusting the pressure regulating valve 42.

[0049] Furthermore, the pressure regulating valve 42 is a solenoid valve, and a pressure sensor is installed between the receiver tank 5 and the water-sealed pump 25. The pressure regulating valve 42 and the pressure sensor are electrically connected to the control device PLC. In this case, it is preferable that the control device PLC operates the pressure regulating valve 42 based on the detection result of the pressure sensor. It is also preferable that the control device PLC is equipped with a setting unit that can set a threshold pressure for which the pressure regulating valve 42 operates. This allows the pressure to be automatically maintained at a level that is less likely to cause foaming, etc., through electromagnetic control of the pressure regulating valve 42. In addition, it is possible to easily handle a variety of materials to be recovered, and the operational sense possessed by a skilled worker can be standardized in terms of two items: the material to be recovered and the pressure value. By setting a threshold (pressure value) according to the material to be recovered, the pressure regulating valve 42 can be automatically controlled based on the detection result of the pressure sensor, and suction work can be performed in the optimal state for each material to be recovered. Furthermore, by accumulating data (location information, temperature, humidity, atmospheric pressure, etc.) for each material to be recovered, the control of the pressure regulating valve 42 for each material to be recovered can be made to be closer to the control when a skilled worker manually operates it. Furthermore, not only in suction operations but also in discharge operations, by setting target discharge values ​​for each type of material to be recovered, the system can automatically perform the discharge of a specified amount based on detection results from load cells, etc.

[0050] The embodiments disclosed herein are illustrative in all respects and are not intended to be restrictive. The technical scope of the present invention is not construed solely by the embodiments described above, but is defined by the claims. Furthermore, the technical scope of the present invention includes all modifications within the meaning and scope of equivalence to the claims.

[0051] In the above embodiment, a water-sealed pump 25 was used as the vacuum pump, but other types may be used, for example, a multi-stage Roots blower may be used.

[0052] In the above embodiment, the opening degree of the pressure regulating valve 42 is continuously adjustable between a fully closed state and a fully open state. However, the invention is not limited to this, and the pressure regulating valve 42 may be switched between two states: a fully closed state and a fully open state. Alternatively, the opening degree of the pressure regulating valve 42 may be adjusted by an electric motor, or an operating lever or the like may be attached to allow manual adjustment of the opening degree of the pressure regulating valve 42. Furthermore, in the above embodiment, the position of the valve body 28 of the four-way valve 24 is changed by a hydraulic cylinder 29. However, the invention is not limited to this, and the position of the valve body 28 of the four-way valve 24 may be changed by an electric motor, an air cylinder, or the like.

[0053] In the above embodiment, the case in which the suction device 1 is equipped with a four-way valve 24 was described, but the present invention can also be applied to suction devices that are not equipped with a four-way valve 24. In other words, in the above embodiment, the discharge-side flow path switching valve and the suction-side flow path switching valve were the same four-way valve 24, but as shown in Figures 9 and 10, for example, the discharge-side flow path switching valve and the suction-side flow path switching valve may be provided separately. In this case as well, the same effect as when using the four-way valve 24 described above can be obtained by connecting the piping connected to the pump suction port of the vacuum pump and the piping connected to the pump discharge port with a bypass pipe and providing a pressure regulating valve in the bypass pipe.

[0054] In the above embodiment, the secondary catcher 20 and the tertiary catcher 21 are separate components, but they may also be integrated into a single unit, in which case the second piping 7b can be omitted. Alternatively, the secondary catcher 20 may be omitted entirely.

[0055] The suction device 100 shown in Figures 9 and 10 will now be described. Figure 9 is a piping diagram of the suction device 100 mounted on a suction vehicle according to another embodiment, and Figure 10 is a side view showing the schematic configuration of the suction device 100. As shown in Figures 9 and 10, the suction device 100 is equipped with a receiver tank 105, an upstream catcher (upstream dust collector) 123, a blower 125, a silencer 128, a downstream catcher (downstream dust collector) 131, a catcher tank 135, etc., and these are connected via various types of piping.

[0056] The receiver tank 105 is connected to a receiver tank pressure / depressurization pipe 107 for supplying or drawing air when pressurizing or depressurizing the air inside the receiver tank 105. The receiver tank pressure / depressurization pipe 107 branches into a suction pipe 121 and a pressurizing pipe 122 at an intermediate point. In other words, the receiver tank pressure / depressurization pipe 107 is a common pipe for a suction pipe connected to the receiver tank 105 and the suction side of the blower 125, and a pressurizing pipe connected to the receiver tank 105 and the discharge side of the blower 125. In this case, the suction pipe consists of the receiver tank pressure / depressurization pipe 107, the suction pipe 121, and a pipe 124 connected to the suction port 125a of the blower 125, while the pressurizing pipe consists of the receiver tank pressure / depressurization pipe 107, the pressurizing pipe 122, and a portion of a pipe 127 connected to the discharge port 125b of the blower 125.

[0057] A manually operated valve (first switching valve) V11 for opening and closing the pipeline is installed midway through the suction piping 121. In other words, valve V11 is located in the suction piping which is connected to the receiver tank 105 and to the suction side of the blower 125. By operating the operating lever LV1 located on the side of the suction device 100 (left side of the vehicle), the open and closed state of valve V11 can be switched. A manually operated valve (second switching valve) V12 for opening and closing the pipeline is installed midway through the pressurizing piping 122. In other words, valve V12 is located in the pressurizing piping which is connected to the receiver tank 105 and to the discharge side of the blower 125. By operating the operating lever LV2 located on the side of the suction device 100 (left side of the vehicle), the open and closed state of valve V12 can be switched.

[0058] Blower 125 is configured as a wet Roots blower in which cooling water is sealed inside the blower casing. In this embodiment, blower 125 is configured as a two-stage blower comprising a first-stage blower 125A and a second-stage blower 125B. The first-stage blower 125A and the second-stage blower 125B are configured in which a pair of three-lobe rotors are housed inside the blower casing.

[0059] When the blower 125 is driven, during suction, air is drawn in from the suction port 125a of the first-stage blower 125A, and the compressed air is discharged from the discharge port 125e. The air discharged from the discharge port 125e of the first-stage blower 125A is drawn in through the piping 133 from the suction port 125f of the second-stage blower 125B, and the compressed air is discharged from the discharge port 125b into the piping 127. On the other hand, during pressurization, a portion of the air discharged from the discharge port 125e of the first-stage blower 125A is discharged to the outside through the check valve 128e via the piping 129, and the remaining air is drawn in from the suction port 125f of the second-stage blower 125B and discharged from the discharge port 125b into the piping 127. In this way, a portion of the air discharged from the outlet 125e of the first-stage blower 125A is discharged into the piping 129 without passing through the second-stage blower 125B. In other words, the check valve 128e provided on the discharge side of the first-stage blower 125A distributes the air discharged from the first-stage blower 125A to the second-stage blower 125B and the piping 129.

[0060] The suction pipe 121 is connected at its downstream end to the suction port 123a of the upstream catcher 123. The discharge port 123b of the upstream catcher 123 is connected via pipe 124 to the suction port 125a of the blower 125 (first-stage blower 125A). The discharge port 125b of the blower 125 (second-stage blower 125B) is connected via pipe 127 to the first air inlet 128c of the silencer 128. A portion of pipe 127 is the pressurizing pipe mentioned above and is connected to the pressurizing pipe 122.

[0061] A manually operated valve V13 for opening and closing the pipeline is installed at an intermediate position in the piping 127, other than the pressurizing piping mentioned above. Specifically, valve V13 is located in the piping 127 between the connection point with the pressurizing piping 122 and the first air inlet 128c of the silencer 128. In other words, valve V13 is installed in the piping that branches off from the pressurizing piping mentioned above and is connected to the outside air (atmosphere). The valve V13 can be switched between open and closed states by operating the operating lever LV3 located on the side of the suction device 100 (left side of the vehicle). A relief pipe 132 is connected to bypass valve V13. A relief valve V15 is provided at an intermediate position in this relief pipe 132 to protect against abnormal pressure from the discharge pressure of the blower 125. Furthermore, the piping 127 connecting the discharge port 125b of the blower 125 and the first air inlet 128c of the silencer 128 is located on the right side of the vehicle, and the valve V13 interposed in this piping 127 is also located on the right side of the vehicle. The operating lever LV3, which is located on the left side of the vehicle and is used to operate the valve V13, is connected to the valve V13 by an operating rod that extends in the left-right direction of the vehicle.

[0062] The air outlet 128f of the silencer 128 is connected to the suction port 131a of the downstream catcher 131 via the piping 130. The discharge port 131b, located on the upper surface of the downstream catcher 131, is open to the outside air (atmosphere).

[0063] A pipe 134 is connected to a point along the pipe 124 that is connected to the suction port 125a of the blower 125 (first-stage blower 125A). A suction port 137a is connected to the upstream end of pipe 134, and this suction port 137a is connected to an outside air intake section 137 for taking in outside air (atmosphere). A manually operated valve V14 for opening and closing the pipeline is interposed in the middle of pipe 134. Valve V14 allows the suction port 125a of the blower 125 to be connected to the outside air. In other words, valve V14 is installed in the pipe that branches off from the middle of the aforementioned suction piping and is connected to the outside air side. By operating the operating lever LV4 located on the side of the suction device 100 (left side of the vehicle), the open state and the closed state of valve V14 can be switched.

[0064] Furthermore, the upstream end of the pressurized piping 122 is located at an intermediate position in piping 127 connected to the discharge port 125b of the blower 125 (second-stage blower 125B), specifically between valve V13 and the discharge port 125b of the blower 125. In the pressurized piping 122, an outside air connection piping 122a is connected to a position closer to the receiver tank 105 than the aforementioned valve V12, and an outside air release valve V16 is provided in this outside air connection piping 122a, which allows the inside of the receiver tank 105 to be connected to the outside air. The outside air release valve V16 is provided in the path between the receiver tank 105 and valve V12, and allows the inside of the receiver tank 105 to be connected to (communicated with) the outside air. The outside air release valve V16 is configured to be able to open and close its valve body by actuator drive, and is configured as an electrically operated butterfly valve that opens and closes its valve body by the rotational power of an electric motor M1, for example. The outside air release valve V16 is normally held in a closed position (closed state) that isolates the receiver tank 105 from the outside air. However, in the event of an abnormality, such as an abnormal temperature in the blower 125, it can be switched to an open position (open state) that connects the receiver tank 105 to the outside air by the drive of the electric motor M1.

[0065] In the suction device 100 with the above configuration, the outlet 131b is an exhaust port that releases air to the outside air, valve V14 is a suction-side flow path switching valve installed in the piping between the receiver tank 105 and the blower 125, and valve V13 is a discharge-side flow path switching valve installed in the piping between the blower 125 and the outlet 131b. Furthermore, piping 124 connected to the suction port 125a of the blower 125 and piping 127 connected to the discharge port 125b of the blower 125 are connected by a bypass pipe 141 (shown as a dashed line in Figure 9). A pressure regulating valve 142 is provided in the bypass pipe 141, and the opening degree of the pressure regulating valve 142 is changed by an actuator such as a hydraulic cylinder. [Explanation of Symbols]

[0066] 1 Suction device 2 Suction car 5 Receiver Tank 23a Intake and exhaust port 24. Four-way valves (discharge side flow path switching valve, suction side flow path switching valve) 25. Water-sealed pump (vacuum pump) 25a Suction port (pump suction port) 25b Discharge port (pump discharge port) 41 Bypass pipeline 42 Pressure regulating valve

Claims

1. A receiver tank for collecting the materials to be collected, A vacuum pump that generates an airflow by increasing or decreasing the pressure of the air inside the receiver tank, An exhaust vent that releases air into the outside air, A suction-side flow path switching valve is installed in the piping between the receiver tank and the vacuum pump, A suction vehicle having a discharge side flow path switching valve disposed in the piping between the vacuum pump and the exhaust port, It is equipped with a bypass pipeline connecting the piping from the pump discharge port to the discharge-side flow path switching valve and the piping from the pump suction port to the suction-side flow path switching valve. A suction vehicle characterized in that a pressure regulating valve is provided in the bypass pipeline.

2. In the suction vehicle according to claim 1, The discharge-side flow path switching valve and the suction-side flow path switching valve are the same four-way valve. The suction vehicle is characterized in that the four-way valve is a solenoid valve that can switch the position of the valve body to one of three positions: suction, pressurization, or neutral by operating a switch.

3. In the suction vehicle according to claim 1 or 2, The pressure regulating valve is a solenoid valve, A pressure sensor is installed between the receiver tank and the vacuum pump. The system includes a control unit electrically connected to the pressure regulating valve and the pressure sensor, The suction vehicle is characterized in that the control unit is configured to operate the pressure regulating valve based on the detection result of the pressure sensor.

4. In the suction vehicle according to claim 3, The suction vehicle is characterized in that the control unit is provided with a setting unit capable of setting a pressure threshold for which the pressure regulating valve operates.

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