JP7531987B2 - Suction vehicle - Google Patents

Description

The present invention relates to a suction vehicle.

Conventionally, a suction vehicle is known that has a receiver tank (hopper) and a suction device mounted on a chassis (traveling body). Such a suction vehicle is equipped with a dust collector that purifies the dirty air flowing from inside the receiver tank, a blower that sets the inside of the receiver tank to a vacuum state, a silencer that serves as a water tank that removes dust and silences the air flowing through the blower, an exhaust pipe that is connected to the silencer and exhausts the air introduced into the silencer to the outside, a four-way valve that is commonly interposed between the dust collector and the blower and between the silencer and the exhaust pipe 34 and switches between four flow paths by rotating the valve body while sliding against the inner surface of the valve housing, and a cleaning means that cleans off any deposits that have adhered to the sliding surface of the four-way valve (see, for example, Patent Document 1).

JP 2004-33859 A

Among the suction vehicles mentioned above, there are ones that can be switched between three modes: suction mode, pressure mode, and neutral mode. However, conventional suction vehicles required the operation of a heavy operating lever to switch between modes, which could not be said to be easy to use.

The present invention was made in consideration of the above-mentioned circumstances, and aims to improve safety and ease of use in a suction vehicle equipped with a four-way valve that switches between three modes: suction mode, pressure mode, and neutral mode.

The present invention provides a means for solving the above-mentioned problems as follows: That is, the present invention is a suction vehicle comprising a receiver tank for storing objects to be sucked, a suction device having a suction mode for creating a negative pressure inside the receiver tank and sucking the objects to be sucked into the receiver tank, a control device for controlling the suction device, and an operation panel for operating the suction device, the suction device comprising an air pipe connecting an outside air port and the receiver tank, a vacuum pump interposed in the air pipe, a four-way valve interposed in the air pipe and for switching between three modes: the suction mode, a pressurization mode for pressurizing the inside of the receiver tank to discharge the objects to be sucked out of the receiver tank, and a neutral mode for driving the vacuum pump but not pressurizing or depressurizing the receiver tank, and an air drive mechanism for operating a valve element of the four-way valve, the air drive mechanism being an air piping provided in the four-way valve. the control panel is provided with an operation switch for controlling the solenoid valve to be switched to one of the three modes by the control device, the operation switch being provided corresponding to each of the three modes, and the control device is configured to disable operation of the operation switch for the pressurization mode when the operation switch for the suction mode is operated, and to disable operation of the operation switch for the suction mode when the operation switch for the pressurization mode is operated.

With the above configuration, an operator simply operates the operation switch on the control panel, and the control device automatically switches the solenoid valve to one of three modes: suction mode, pressurization mode, or neutral mode. This provides superior operability compared to a case in which an operator manually operates a heavy control lever to switch the position of the valve body of the four-way valve to one of the three modes.

With this configuration, three independent operation switches corresponding to the three modes are provided on the operation panel, so the operator can operate the desired operation switch without hesitation to switch modes, resulting in excellent operability. In addition, a suction indicator lamp is provided on the operation switch for the suction mode, and a pressurization indicator lamp is provided on the operation switch for the pressurization mode, and by lighting the suction indicator lamp in response to the suction mode and the pressurization indicator lamp in response to the pressurization mode, the operator can operate the operation switches with even greater confidence.

With this configuration, when the mode switch button for the suction mode is operated to perform suction work by operating the mode switch button for the suction mode, even if the mode switch button for the pressurized mode is operated by mistake, the valve element of the four-way valve will not switch to the pressurized mode. Similarly, when the mode switch button for the suction mode is operated to perform discharge work by operating the mode switch button for the pressurized mode, the valve element of the four-way valve will not switch to the suction mode. This prevents the direction of the air flowing through the air piping from suddenly changing during work, which would place an abnormal load on the entire suction device. As a result, the suction device will not be damaged due to the operator accidentally operating the mode switch button during work, and safety is excellent.

Preferably, the solenoid valve is set so that the valve element switches to a position corresponding to the neutral mode when no control signal is input from the control device.

According to this configuration, under normal circumstances, a control signal is sent from the control device to the solenoid valve to switch the valve element of the four-way valve to a position corresponding to each of the three modes: suction mode, pressurization mode, and neutral mode. However, if a problem occurs in which the control signal cannot be input to the solenoid valve due to a broken signal line, for example, the valve element of the four-way valve can be switched to a position corresponding to neutral mode. As a result, if such a problem occurs during suction work in suction mode, for example, the valve element of the four-way valve will not become fixed in a position corresponding to suction mode or suddenly switch to a position corresponding to pressurization mode, and no abnormal load will be placed on the suction device, making it safe.

Preferably, the air drive mechanism has a manual valve interposed between the four-way valve and the solenoid valve in the drive air piping, and is configured so that the valve body can be switched to a position corresponding to each of the three modes by operating the manual valve.

According to this configuration, the four-way valve can be switched to one of the three modes by operating the manual valve, so even if a problem occurs such as a broken signal line that makes it impossible to input a control signal to the solenoid valve and the valve element of the four-way valve is temporarily fixed in a position corresponding to the currently used mode, the manual valve can be operated to switch to a position corresponding to a different mode. This allows on-site work to be continued manually even if such a problem occurs, resulting in excellent workability.

Preferably, the vacuum pump is driven by power extracted from the vehicle drive source using a PTO, and the PTO is connected and disconnected by turning a PTO switch on and off, and the control device is configured to switch to the neutral mode when the PTO switch is turned from off to on.

With this configuration, when the PTO switch is turned from OFF to ON to start the vacuum pump at the start of work, it is always controlled to switch to neutral mode once. This means that even if the valve of the four-way valve is in suction mode or pressurization mode for some reason while the vehicle is running, it will switch to neutral mode at the start of work. As a result, it is possible to prevent operation in a mode unintended by the operator when the PTO switch is turned ON, providing excellent safety.

Preferably, the air tank is used for the operating system when the vehicle is running, and a PTO-linked valve that opens and closes in conjunction with the on/off of the PTO switch is provided between the air tank and the solenoid valve in the drive air piping.

This configuration ensures safety by preventing any effect on the operating system while the vehicle is running, even if the driving air in the driving air piping leaks out from the air actuator of the four-way valve or a nearby part for some reason while the vehicle is running.

The present invention improves workability and safety in a suction vehicle equipped with a four-way valve that switches between three modes: suction mode, pressure mode, and neutral mode.

1 is a side view showing a schematic configuration of a suction vehicle according to an embodiment of the present invention. FIG. 2 is a plan view of the suction vehicle of FIG. 1; FIG. 2 is an air piping diagram of the suction device mounted on the suction vehicle of FIG. 1 , showing the flow of air during suction. FIG. 4 is a diagram showing the flow of air when pressurized in the air piping diagram of FIG. 3 . 11A and 11B are diagrams showing the stopping positions of the valve body of the four-way valve when switching between three modes: a suction mode, a pressurization mode, and a neutral mode. 10A and 10B are diagrams for explaining the operation of an actuator of a four-way valve. This is an air piping diagram around the four-way valve. 1 is a flow chart showing three operation modes: aspiration mode, pressure mode, and neutral mode. FIG. 4 is a diagram showing an operation panel.

The following describes an embodiment of the present invention with reference to the drawings.

Figures 1 and 2 show a suction vehicle 2 according to an embodiment of the present invention. A receiver tank 5 and a suction device 1 for creating negative pressure inside the receiver tank 5 and sucking the object to be suctioned into the receiver tank 5 are provided on a subframe 4 on a chassis 3 of the suction vehicle 2. Specifically, the receiver tank 5 is mounted on the rear of the subframe 4, and contains the object to be suctioned, such as sludge, soil, waste liquid, etc.

The receiver tank 5 has, for example, a tank body 5a in the shape of a circular container with a rear opening, and a tailgate 5c that opens and closes this rear opening. The tailgate 5c is pivotally supported, for example, via a hinge pin 5b at the upper rear end of the tank body 5a. An opening/closing cylinder 5d is provided between the tank body 5a and the tailgate 5c, and by extending and retracting this opening/closing cylinder 5d, the tailgate 5c can open and close the rear opening of the tank body 5a.

At the bottom of the tailgate 5c, there is a suction port 8 with an on-off valve that serves as a suction port for objects to be sucked in, and a discharge port 9 with an on-off valve that serves as a discharge port for objects to be sucked in. The receiver tank 5 is supported so as to be tiltable relative to the subframe 4 via a tilt shaft 10 provided at the rear of the subframe 4. That is, a tilt cylinder 11 is provided between the subframe 4 and the receiver tank 5. By expanding and contracting this tilt cylinder 11, the receiver tank 5 can be rotated upright or down around the tilt shaft 10.

As will be described in more detail later, when the suction device 1 sucks in and stores the object to be sucked into the receiver tank 5, the reduced pressure and air flow in the receiver tank 5 causes the object to be sucked in from the outside through a suction hose (not shown) connected to the suction port 8 and into the receiver tank 5. On the other hand, when the suction device 1 discharges the object to be sucked in from the receiver tank 5 to, for example, a sludge treatment plant, the air in the receiver tank 5 is pressurized and the object to be sucked in 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 object to be sucked in from the receiver tank 5 by opening the tailgate 5c and rotating the receiver tank 5 upright.

A water-sealed pump 25 is provided on the subframe 4 between the cab 13 and the receiver tank 5 as a vacuum pump for pressurizing and depressurizing the air in the receiver tank 5 to generate an air flow. Although not shown in detail, the water-sealed pump 25 is rotated by the driving force of an engine (not shown) connected via a drive shaft of the PTO (power take-off) of the suction vehicle 2. Around the water-sealed pump 25, piping connected to the water-sealed pump 25, various valves, an operation panel 15, etc. are arranged.

Next, the air-switching four-way valve (hereinafter simply referred to as the "four-way valve") 24 will be described. Figures 3 and 4 are diagrams showing the operating state of the four-way valve 24 according to this embodiment. The four-way valve 24 is used to switch between three modes: a suction mode in which the receiver tank 5 is negatively pressurized and the object to be sucked is sucked into the receiver tank 5; a pressure mode in which the receiver tank 5 is pressurized and the object to be sucked is discharged out of the receiver tank 5; and a neutral mode in which the water seal pump 25 is driven but the receiver tank 5 is not pressurized or depressurized.

Figure 3 is a diagram showing the flow of air during suction through the four-way valve 24. Referring to Figure 3, during suction, air is sucked from the receiver tank 5 through the secondary catcher 20 and tertiary catcher 21, which are cyclone-type dust collectors, the four-way valve 24, and the ejector 30, where it is sucked by the water seal pump 25, which is a vacuum pump, and passes through the four-way valve 24 again via the quaternary catcher 22, before being exhausted from the integrated silencer 23. These devices are interconnected through piping 7 (7a to 7g).

On the other hand, Figure 4 shows the air flow when the four-way valve 24 is pressurized. Referring to Figure 4, when pressurizing, the air sucked from the integrated silencer 23 passes through the four-way valve 24, whose valve body 28 has been switched from the position during suction, is sucked into the water seal pump 25, passes through the quaternary catcher 22, passes through the four-way valve 24 again, and passes through the tertiary catcher 21 and secondary catcher 20 to pressurize the receiver tank 5.

Next, the structure of the four-way valve 24 will be described. Figure 5 is a perspective view showing the positions of the valve body 28 of the four-way valve 24 during suction (upper left figure), neutral (center figure), and pressurization (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. Referring to Figure 5, during suction, port 24a is connected to port 24b, and port 24c is connected to port 24d. The valve body 28 separates ports 24a and 24b from ports 24c and 24d. This allows air to flow simultaneously from port 24a to port 24b, and from port 24d to port 24c.

On the other hand, when pressurizing, as shown in FIG. 4, ports 24a and 24d are connected, and ports 24b and 24c are connected. Ports 24a and 24d are separated from ports 24b and 24c by a valve body 28. This allows air to flow simultaneously from port 24a to port 24d and from port 24b to port 24c. Also, when neutral, the valve body 28 stops at a position halfway between the above-mentioned suction and pressurization. The position of the valve body 28 can be changed by connecting compressed air to a specified port provided on an actuator (air actuator) attached integrally to the four-way valve 24.

Next, the actuator for operating the four-way valve 24 as described above will be described. Figure 6 is a schematic diagram for explaining the operation of the actuator. Figure 6(A) is a diagram showing the pressurized state, Figure 6(B) is a diagram showing the state moving from the pressurized state toward the neutral position, Figure 6(C) is a diagram showing the neutral state, and Figure 6(D) is a diagram showing the suction state.

Referring to Figures 6(A) to (D), the actuator integrally attached to the four-way valve 24 is entirely surrounded by a casing 31 and includes a central chamber 32, and a left chamber 33 and a right chamber 34 separated by partitions 38a, 38b on the left and right sides of the central chamber 32. The casing 31 includes an upper casing 31a, a lower casing 31b, a left casing 31c, and a right casing 31d.

The central chamber 32 is provided with a rotating shaft 35 with a pinion in the center, and a pair of left and right pistons 36, 37 with racks that are arranged 180 degrees apart and engage with the pinion of the rotating shaft 35. The valve body 28 shown in Figure 5 is held in a predetermined position by this rotating shaft 35.

Referring to FIG. 6(A), partition plates 36a, 37a that separate the central chamber 32 are provided at the ends of the pair of left and right pistons 36, 37 with racks that do not engage with the rotating shaft 35. When the rotating shaft 35 rotates, the partition plates 36a, 37a connected to the pair of pinion-equipped pistons 36, 37 move left and right, changing the volume of the central chamber 32.

In addition, protrusions 36b, 37b with flat portions at their tips are provided in the center of partition plates 36a, 37a, and the flat portions at the tips of protrusions 36b, 37b abut against partition walls 38a, 38b.

On the other hand, the left side chamber 33 is provided with a partition plate 33a for dividing the left side chamber 33 into two, and the partition plate 33a has a support shaft 33b in its vertical center for supporting the partition plate 33a and moving it in the left-right direction, and the support shaft 33b supports the partition plate 33a in its horizontal center. The end of the support shaft 33b on the partition wall 38a side can pass through a through hole provided in the center of the partition wall 38a and abut against the protrusion 36b of the partition plate 36a. In addition, the end of the support shaft 33b opposite the partition wall 38a extends through a through hole provided in the center of the left casing 31c that defines the left side chamber 33.

The right side chamber 34 also has a similar configuration, and is provided with a partition plate 34a and a support shaft 34b to divide the right side chamber 34 into two. The support shaft 34b can abut against the protrusion 37b of the partition plate 37a through a through hole provided in the center of the partition wall 38b, and the end of the support shaft 34b opposite the partition wall 38b extends through a through hole provided in the center of the right casing 31d that defines the right side chamber 34.

Next, the mechanism (air drive mechanism) that operates the valve body 28 of the four-way valve 24 will be described. To allow the drive air to flow from the air tank 41 (see FIG. 7) to operate the valve body 28 of the four-way valve 24, an A port is provided in the center of the lower casing 31b of the central chamber 32, a B port is provided at the upper end of the upper casing 31a between the piston 36 and the bulkhead 38a of the central chamber 32 and between the piston 37 and the bulkhead 38b, and a C port is provided in the lower casing 31b between the partition plate 33a of the left chamber 33 and the wall of the left casing 31c, and between the partition plate 34a of the right chamber 34 and the wall of the right casing 31d.

First, as shown in Figure 6 (A), in a pressurized state, pressurized air is introduced into the central chamber 32 through port A, which rotates the rotating shaft 35 counterclockwise, and the partition plates 36a, 37a connected to the left and right pistons 36, 37 move until they come into contact with the bulkheads 38a, 38b, maximizing the volume of the central chamber 32. At this time, the space between the partition plates 36a, 37a connected to the left and right pistons 36, 37 and the left and right bulkheads 38a, 38b is minimized, and the air that was in this space is released through port B.

In addition, as the partition plates 36a and 37a move, the support shafts 33b and 34b against which the protrusions 36b and 37b are in contact are pushed to the left and right, respectively, and the partition plates 33a and 34a provided on the support shafts 33b and 34b are pushed against the ends of the left chamber 33 and the right chamber 34, respectively, and the air in the pushed space is released through the C port.

To move from this state to the neutral state, as shown in Figure 6 (B), the air is removed from port A from the pressurized state, leaving the central chamber 32 free, and air is introduced into port C, causing the rotating shaft 35 to rotate clockwise, and the pistons 36 and 37 in the central chamber 32 are pushed from both sides and stop in the neutral position.

After this, air is again pumped into port A to maintain the neutral state shown in Figure 6 (C).

Next, when moving from this neutral state to the suction state, air is drawn out from port A while air is introduced from port B, the rotating shaft 35 rotates clockwise, the partitions 36a and 37a move toward the rotating shaft 35, the volume of the space between the bulkheads 38a and 38b and the partitions 36a and 37a increases, and the volume of the central chamber 32 sandwiched between the partitions 36a and 37a becomes minimum. At this time, the partitions 33a and 34a of the left and right chambers 33 and 34 are maintained in their original positions (Figure 6 (D)).

When transitioning from the suction state in Figure 6 (D) to the neutral state in Figure 6 (C), air is drawn out from port B and introduced from port A.

Next, the drive air pipe 60 for introducing and discharging drive air to the above-mentioned A to C ports will be described. FIG. 7 is a diagram showing the four-way valve 24 and the drive air pipe 60 for driving it. Referring to FIG. 7, the drive air pipe 60 is used to supply drive air from the air tank 41 to the four-way valve 24. The air tank 41 is also used for braking when the vehicle is running. In the drive air pipe 60, from the side closest to the upstream air tank 41, a protection valve 42, a three-way ball valve 43, a PTO interlocking valve 49, and a check valve 45 are interposed.

The air tank 41 supplies pressurized air at, for example, 0.7 MPa. The protection valve 42 stops the supply of air when the air pressure in the drive air piping 60 drops abnormally, so as not to affect the brake operation of the chassis 3. The three-way ball valve 43 can be manually switched to supply air from the air tank 41 to the body side (suction device 1 side) regardless of whether the PTO switch is on or off.

The PTO interlocking valve 49 is opened and closed in conjunction with the on/off of the PTO switch, and when the PTO switch is turned on, it supplies drive air from the air tank 41. An external communication pipe 50 that communicates with the outside of the vehicle is connected to this PTO interlocking valve 49. When the PTO switch is turned from on to off, the pressurized air remaining between the PTO interlocking valve 49 and the check valve 45 is released to the outside through the external communication pipe 50.

A four-way valve switching valve unit 51 is provided in the driving air pipe 60 via a check valve 45 that prevents air from flowing back toward the air tank 41. The four-way valve 24 is connected downstream of this four-way valve switching valve unit 51. The four-way valve switching valve unit 51 is switched and controlled by the control device 6 based on pressing any of the suction mode button 15a, neutral mode button 15b, and pressurization mode button 15c provided on the operation panel 15 shown in FIG. 9.

The four-way valve 24 can be supplied with pressurized air from the air tank 41. When any of the suction mode button 15a, neutral mode button 15b, or pressurization mode button 15c on the operation panel 15 (see FIG. 9) is pressed, pressurized air is supplied from the air tank 41 to the four-way valve 24, and the four-way valve 24 is switched by the pressure of this pressurized air. Air solenoid valves 30a to 30c are used for this switching.

The introduction and exhaust of driving air to ports A through C to switch the valve element 28 of the four-way valve 24 to one of the three modes is basically performed by air solenoid valves 30a through 30c, but this can also be done by manual valves 16a through 16c interposed between the four-way valve 24 and the air solenoid valves 30a through 30c.

As described above, the air drive mechanism includes an actuator (air actuator) provided in the four-way valve 24, a drive air pipe 60 that connects the actuator to the air tank 41 and supplies drive air to the actuator, and a number of air solenoid valves (electromagnetic valves) 30a-30c that are interposed in the drive air pipe 60 and that switch the position of the valve body 28 of the four-way valve 24 to one of three modes, pressurization mode, neutral mode, and suction mode, under the control of the control device 6.

Next, the operation of the suction device 1 configured as above will be described. FIG. 8 is a flow chart showing three operation modes: suction mode, pressurization mode, and neutral mode. Referring to FIG. 8, with the suction vehicle 2 stopped, operation is started by turning on the PTO switch provided in the driver's cab 13 (YES in step S11, steps will be omitted below). The PTO interlocking valve 49 is switched from closed to open (S12), and the four-way valve 24 is controlled to switch to neutral mode (S13). The operation of the pressurization mode button 15c and the operation of the suction mode button 15a are enabled (S14), and the water seal pump (vacuum pump) 25 rotates while the engine is idling (S15).

When the suction mode button 15a is operated (YES in S16), the suction indicator lamp 40a (see FIG. 9) turns on (S17), operation of the pressure mode button 15c is disabled (S18), and the four-way valve 24 is controlled to switch to the suction mode (S19).

Next, the rotation speed of the water seal pump 25 is increased by operating the accelerator knob 15d (S20), and the suction operation is performed. During the suction operation, the system waits until the neutral mode button 15b is pressed. When the neutral mode button 15b is pressed (YES in S21), the four-way valve 24 is controlled to switch to neutral mode (S22). The suction indicator lamp 40a goes out (S23), and the operation of the pressure mode button 15c and the suction mode button 15a becomes valid (S24). The neutral mode button 15b is pressed to temporarily stop the suction operation, but it is also pressed when the suction operation is ended. When the suction operation is ended, the neutral mode button 15b is pressed, and then the rotation speed of the water seal pump 25 is decreased by operating the accelerator knob 15d (S25). Then, the system proceeds to S26.

On the other hand, in S16, if the suction mode button 15a is not operated but the pressure mode button 15c is operated (NO in S16, YES in S28), the pressure indicator lamp 40c turns on (S29), operation of the suction mode button 15a is disabled (S30), the four-way valve 24 is controlled to switch to the pressure mode (S31), and the process proceeds to S20.

Next, the speed of the water seal pump 25 is increased by operating the accelerator knob 15d (S20), and the discharge operation is performed. Thereafter, the system waits until the neutral mode button 15b is pressed. When the neutral mode button 15b is pressed (YES in S21), control is performed to switch the four-way valve 24 to neutral mode (S22). The pressurization indicator lamp 40c turns off (S23), and operation of the pressurization mode button 15c and operation of the suction mode button 15a become valid (S24). To end the discharge operation, after the neutral mode button 15b is pressed, the speed of the water seal pump 25 is reduced by operating the accelerator knob 15d (S25). Then, the system proceeds to S26.

On the other hand, if neither the suction mode button 15a nor the pressure mode button 15c is operated (NO in S16, NO in S28), proceed to S26.

In S26, it is determined whether the PTO switch is off. If the PTO switch is off (YES in S26), the PTO interlocking valve 49 transitions from open to closed (S27) and the process ends. If the PTO switch is not off in S26 (NO in S26), the process returns to S16.

Next, the operation panel 15 will be described. FIG. 9 is a diagram showing the operation panel (operation panel) 15. Referring to FIG. 9, the operation panel 15 is equipped with a control device 6 that controls the suction device 1 according to this embodiment. This control device 6 may be provided in the driver's cab 13. In addition, as shown in FIG. 5, a suction mode button 15a, a neutral mode button 15b, and a pressurization mode button 15c are provided as operation switches for switching and controlling a plurality of air solenoid valves 30a to 30c to switch the valve body 28 of the four-way valve 24 to one of three modes, namely, a suction state (suction mode), a neutral state (neutral mode), and a pressurization state (pressurization mode). Furthermore, the suction mode button 15a is provided with a suction indicator lamp 40a that indicates that the four-way valve 24 is being switched to the suction mode. In addition, the pressurization mode button 15c is provided with a pressurization indicator lamp 40c that indicates that the four-way valve 24 is being switched to the pressurization mode.

According to this embodiment, the operator simply operates the operation switches (suction mode button 15a, neutral mode button 15b, and pressurization mode button 15c) on the operation panel 15, and the control device 6 simultaneously switches multiple solenoid valves (air solenoid valves 30a-30c) to automatically control the operation to one of three modes: suction mode, pressurization mode, or neutral mode. This provides superior operability compared to a case in which an operator manually operates a heavy operating lever to switch the position of the valve body 28 of the four-way valve 24 to one of the three modes.

In addition, the operation switches (suction mode button 15a, neutral mode button 15b, and pressure mode button 15c) are provided corresponding to each of the three modes: suction mode, pressure mode, and neutral mode, and three types of independent operation switches corresponding to each of the three modes are provided on the operation panel 15. This allows the operator to easily switch modes by operating the desired operation switch, resulting in excellent operability.

Furthermore, the suction mode button 15c is configured to be disabled when the suction mode button 15a is operated, while the suction mode button 15a is disabled when the suction mode button 15c is operated. Therefore, even if the pressure mode button 15c is operated by mistake while the suction mode button 15a is being operated to perform suction work, the valve body 28 of the four-way valve 24 will not be switched to the pressure mode. Similarly, even if the suction mode button 15a is operated by mistake while the suction mode button 15c is being operated to perform discharge work, the valve body 28 of the four-way valve 24 will not be switched to the suction mode. This makes it possible to prevent the direction of the air flowing through the air piping from suddenly changing during work, causing an abnormal load to be placed on the entire suction device 1. As a result, the suction device 1 will not be damaged due to the operator mistakenly operating the operation switch (suction mode button 15a, pressure mode button 15c) during work, and safety is excellent.

The air solenoid valves 30a to 30c are set so that the valve body 28 of the four-way valve 24 is switched to a position corresponding to the neutral mode when no control signal is input from the control device 6. Normally, the control device 6 sends a control signal to the air solenoid valves 30a to 30c to switch the valve body 28 of the four-way valve 24 to a position corresponding to each of the three modes, suction mode, pressurization mode, and neutral mode. However, when a trouble occurs such that a control signal cannot be input to the air solenoid valves 30a to 30c due to a signal line break or the like, the valve body 28 of the four-way valve 24 can be switched to a position corresponding to the neutral mode. As a result, when the trouble occurs during suction work in the suction mode, for example, the valve body 28 of the four-way valve 24 is not fixed to a position corresponding to the suction mode or suddenly switched to a position corresponding to the pressurization mode, and no abnormal load is applied to the suction device 1, making it safe.

The air drive mechanism that operates the valve body 28 of the four-way valve 24 has manual valves 16a to 16c that are interposed between the four-way valve 24 and the air solenoid valves 30a to 30c in the drive air piping 60, and is configured so that the valve body 28 can be switched to a position corresponding to each of the three modes by operating the manual valves 16a to 16c. With this configuration, the four-way valve 24 can be switched to one of the three modes by operating the manual valves 16a to 16c, so even after a trouble occurs in which a control signal cannot be input to the air solenoid valves 30a to 30c due to a broken signal line, etc., and the valve body 28 of the four-way valve 24 is once fixed to a position corresponding to the currently used mode, the manual valves 16a to 16c can be operated to switch to a position corresponding to a different mode. This allows work at the site to be continued manually even if the trouble occurs, resulting in excellent workability.

The water seal pump 25, which is a vacuum pump, is driven by power extracted from the vehicle drive source using the PTO, and is configured so that the PTO is connected and disconnected by turning the PTO switch on and off, and the control device 6 is configured to control the switch to neutral mode when the PTO switch is turned from off to on. With this configuration, when the PTO switch is turned from off to on to drive the water seal pump 25 at the start of work, the switch is always controlled to switch to neutral mode once. As a result, even if the valve body 28 of the four-way valve 24 is in a position corresponding to the suction mode or the pressurization mode due to some factor while the vehicle is running, the switch to neutral mode is made at the start of work. As a result, it is possible to prevent operation in a mode unintended by the operator when the PTO switch is turned on, and safety is excellent.

The air tank 41 is used for the operating system when the vehicle is running, and a PTO-linked valve 49 that opens and closes in conjunction with the on/off of the PTO switch is provided between the air tank 41 and the air solenoid valves 30a-30c in the drive air piping 60. With this configuration, even if drive air leaks from the air actuator of the four-way valve 24 or a nearby area for some reason while the vehicle is running, it is safe and does not affect the operating system when the vehicle is running.

In addition, if the PTO interlocking valve 49 breaks and stops working, the three-way ball valve 43 can be used to supply and stop air, making it easy to use.

In the above embodiment, a water seal pump 25 is used as the vacuum pump, but the invention is not limited to this. It may be a roots blower type, or it may be a type that creates a vacuum inside the receiver tank 5 and then sucks out all at once.

The control device 6 in the above embodiment may be configured with a CPU, or may be configured as a relay control circuit without a CPU.

The present invention can be used in a suction vehicle equipped with a four-way valve for switching between three modes: suction mode, pressurization mode, and neutral mode, and an air drive mechanism for operating the valve body of the four-way valve.

1 Suction device 2 Suction vehicle 5 Receiver tank 6 Control device 15 Operation panel (operation panel)
15a Suction mode button (operation switch)
15b Center mode button (operation switch)
15c Pressure mode button (operation switch)
24 Four-way valve 25 Water seal pump (vacuum pump)
28 Valve body 30a to 30c Air solenoid valve (electromagnetic valve)
60 Drive air piping

Claims (5)

A receiver tank for containing the object to be sucked;
a suction device having a suction mode for creating a negative pressure in the receiver tank and sucking the object to be suctioned into the receiver tank;
A control device for controlling the suction device;
An operation panel for operating the suction device,
The suction device is a suction vehicle including an air pipe connecting an outside air port and the receiver tank, a vacuum pump disposed in the air pipe, a four-way valve disposed in the air pipe for switching between three modes: the suction mode, a pressurization mode in which the inside of the receiver tank is pressurized to discharge the object to be suctioned out of the receiver tank, and a neutral mode in which the vacuum pump is driven but the receiver tank is not pressurized or depressurized, and an air drive mechanism for operating a valve body of the four-way valve,
the air drive mechanism includes an air actuator provided in the four-way valve, a drive air pipe connecting the air actuator and an air tank to supply drive air to the air actuator, and a solenoid valve interposed in the drive air pipe and controlled by the control device to switch the position of the valve element of the four-way valve to one of the three modes;
The operation panel is provided with an operation switch for controlling the solenoid valve to be switched to one of the three modes by the control device ,
The operation switch is provided corresponding to each of the three modes,
The control device is configured to disable operation of the operation switch for the pressurized mode when the operation switch for the suction mode is operated, and to disable operation of the operation switch for the suction mode when the operation switch for the pressurized mode is operated. A receiver tank for containing the object to be sucked;
a suction device having a suction mode for creating a negative pressure in the receiver tank and sucking the object to be suctioned into the receiver tank;
A control device for controlling the suction device;
An operation panel for operating the suction device,
The suction device is a suction vehicle including an air pipe connecting an outside air port and the receiver tank, a vacuum pump disposed in the air pipe, a four-way valve disposed in the air pipe for switching between three modes: the suction mode, a pressurization mode in which the inside of the receiver tank is pressurized to discharge the object to be suctioned out of the receiver tank, and a neutral mode in which the vacuum pump is driven but the receiver tank is not pressurized or depressurized, and an air drive mechanism for operating a valve body of the four-way valve,
the air drive mechanism includes an air actuator provided in the four-way valve, a drive air pipe connecting the air actuator and an air tank to supply drive air to the air actuator, and a solenoid valve interposed in the drive air pipe and controlled by the control device to switch the position of the valve element of the four-way valve to one of the three modes;
The operation panel is provided with an operation switch for controlling the solenoid valve to be switched to one of the three modes by the control device,
The solenoid valve is set so that the valve element is switched to a position corresponding to the neutral mode when no control signal is input from the control device. A receiver tank for containing the object to be sucked;
a suction device having a suction mode for creating a negative pressure in the receiver tank and sucking the object to be suctioned into the receiver tank;
A control device for controlling the suction device;
An operation panel for operating the suction device,
The suction device is a suction vehicle including an air pipe connecting an outside air port and the receiver tank, a vacuum pump disposed in the air pipe, a four-way valve disposed in the air pipe for switching between three modes: the suction mode, a pressurization mode in which the inside of the receiver tank is pressurized to discharge the object to be suctioned out of the receiver tank, and a neutral mode in which the vacuum pump is driven but the receiver tank is not pressurized or depressurized, and an air drive mechanism for operating a valve body of the four-way valve,
the air drive mechanism includes an air actuator provided in the four-way valve, a drive air pipe connecting the air actuator and an air tank to supply drive air to the air actuator, a solenoid valve provided in the drive air pipe and configured to switch a position of the valve element of the four-way valve to one of the three modes under the control of the control device, and a manual valve provided in the drive air pipe between the four-way valve and the solenoid valve,
The operation panel is provided with an operation switch for controlling the solenoid valve to be switched to one of the three modes by the control device,
The suction vehicle is characterized in that the air drive mechanism is configured so that the valve body can be switched to positions corresponding to each of the three modes by operating the manual valve. A receiver tank for containing the object to be sucked;
a suction device having a suction mode for creating a negative pressure in the receiver tank and sucking the object to be suctioned into the receiver tank;
A control device for controlling the suction device;
An operation panel for operating the suction device,
The suction device is a suction vehicle including an air pipe connecting an outside air port and the receiver tank, a vacuum pump disposed in the air pipe, a four-way valve disposed in the air pipe for switching between three modes: the suction mode, a pressurization mode in which the inside of the receiver tank is pressurized to discharge the object to be suctioned out of the receiver tank, and a neutral mode in which the vacuum pump is driven but the receiver tank is not pressurized or depressurized, and an air drive mechanism for operating a valve body of the four-way valve,
the air drive mechanism includes an air actuator provided in the four-way valve, a drive air pipe connecting the air actuator and an air tank to supply drive air to the air actuator, and a solenoid valve interposed in the drive air pipe and controlled by the control device to switch the position of the valve element of the four-way valve to one of the three modes;
The operation panel is provided with an operation switch for controlling the solenoid valve to be switched to one of the three modes by the control device,
The vacuum pump is driven by power extracted from a vehicle drive source using a PTO, and the PTO is connected and disconnected by turning on and off a PTO switch,
The suction vehicle is characterized in that the control device is configured to control the switching to the neutral mode when the PTO switch is turned from off to on. 5. The suction vehicle according to claim 4, wherein the air tank is used for an operating system when the vehicle is traveling, and a PTO-linked valve that is opened and closed in conjunction with turning on and off of the PTO switch is provided in the drive air piping between the air tank and the solenoid valve.

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