Suction vehicle

Abstract

To provide a suction vehicle capable of preventing damage to a lock piece caused by operation of an opening / closing cylinder that opens and closes a tail gate of the suction vehicle.SOLUTION: A suction vehicle detects, by a lever proximity switch 80, a position of a lock operation lever 62 of a gate lock mechanism 70 comprising a lock piece 71 for securing a tail gate 7 to a tank flange of a rear opening of a tank body 6. Provided that the position of the lock operation lever 62 is within a predetermined operation prohibition range including the secured position, the suction vehicle prohibits an opening / closing cylinder from operating in a direction to open the tail gate 7. This enables avoiding a state in which rotational force in the direction to open the tail gate 7 acts on the lock piece 71 and so as to prevent damage of the lock piece 71.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a suction vehicle that sucks up wastewater, sludge, and the like. [Background technology]

[0002] Conventionally, there is known a suction vehicle that sucks up wastewater and sludge from sewers and gutters and collects them in a tank. As disclosed in Patent Document 1, this type of suction vehicle includes a hollow tank body, a tailgate that can open and close a rear opening of the tank body, and a lock piece that can fasten the tailgate to the opening edge of the rear opening.

[0003] An opening / closing cylinder (e.g., a hydraulic cylinder) is connected to the tailgate, and the rear opening can be opened and closed by the operation of the opening / closing cylinder. The locking piece is movable between a position where the tailgate is fastened to the edge of the rear opening and a position where the fastening is released. When the tailgate is fastened by the locking piece, the locking piece abuts against the gate flange of the tailgate in the closed state, thereby pressing the gate flange against the edge of the rear opening of the tank body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-67451 A [Patent Document 2] Patent No. 7214214 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, the opening and closing operation of the tailgate is performed by operating an opening and closing cylinder in response to a switch (or lever) operation by an operator, but if an operation to open the tailgate (open the rear opening by the tailgate) is performed when the lock piece is not in a position to release the fastening, the opening and closing cylinder operates and a rotational force in the opening direction of the tailgate acts on the lock piece, which may damage the lock piece. In particular, if the opening and closing cylinder is operated when only a part of the lock piece is in contact with the gate flange of the tailgate (hereinafter, this state will be referred to as a semi-fastened state), the rotational force acts concentratedly on a part of the lock piece (the part in contact with the gate flange), which increases the possibility of damaging the lock piece.

[0006] Patent Document 2 proposes a technology for prohibiting the opening of a tailgate. Patent Document 2 discloses that a human presence sensor is provided to detect the presence or absence of a person around the tailgate (called a hatch in Patent Document 2), and when a person is detected by the human presence sensor, the tailgate cannot be operated.

[0007] However, even in Patent Document 2, if a person is not detected by the human presence sensor and an operation is performed to open the tailgate when the locking piece is not in a position to release the fastening, there is a risk that the locking piece will be damaged by the operation of the opening / closing cylinder.

[0008] The present invention has been made in consideration of the above-mentioned points, and its object is to provide a suction car that can prevent damage to the locking piece caused by the operation of the opening and closing cylinder. [Means for solving the problem]

[0009] The solution of the present invention for achieving the above object is based on a suction vehicle including a tank body having a rear opening, a tailgate to which an opening / closing cylinder is connected and capable of opening and closing the rear opening in accordance with the operation of the opening / closing cylinder, and a locking means having a locking piece and movable between a fastening position where the locking piece fastens the tailgate to the edge of the rear opening and a fastening release position where the fastening is released. The suction vehicle is characterized by having a locking means detection unit that detects the position of the locking means, and being configured to prohibit operation of the opening / closing cylinder at least in the direction to open the tailgate when the tailgate is in a closed state, on the condition that the position of the locking means is within a predetermined operation prohibition range including the fastening position.

[0010] With this specification, when the tailgate is opened (the rear opening is opened) (for example, when an operation to open the tailgate is performed), if the position of the locking means is within a predetermined prohibited operation range that includes the fastening position where the locking piece fastens the tailgate to the opening edge of the rear opening of the tank body, the operation of the opening / closing cylinder in the direction to open the tailgate is prohibited, on that condition. This makes it possible to avoid a situation in which the rotational force in the opening direction of the tailgate acts on the locking piece, and to prevent damage to the locking piece.

[0011] In addition, the locking piece is adapted to abut against the gate flange of the tailgate and press the gate flange against the edge of the opening of the rear opening of the tank body, thereby fastening the tailgate to the edge of the opening of the rear opening, and the prohibited operation range is set as the range from the fastening position of the locking means to the position of the locking means where a predetermined distance is present between the outer edge of the locking piece and the outer edge of the gate flange when the locking piece is not abutting against the gate flange.

[0012] When the locking piece is moved from a position where it abuts against the gate flange of the tailgate (fastening position) to a position where it does not abut against the gate flange (unfastening position), it is possible to release the prohibition of the operation of the opening and closing cylinder at the position (position of the locking means) at which the locking piece no longer abuts against the gate flange. However, if the opening and closing cylinder is operated with the locking means in this position, the vibration caused by the operation may be transmitted to the locking means and the locking piece may abut against the gate flange. In this case, there is a concern that the rotation force in the opening direction of the tailgate caused by the operation of the opening and closing cylinder acts on the locking piece and the locking piece may be damaged. In view of this point, in this solution, the operation prohibition range (the range of the position of the locking means that prohibits the operation of the opening and closing cylinder) is set to a range up to the position of the locking means that has a predetermined interval between the outer edge of the locking piece and the outer edge of the gate flange (specifically, a position where the locking piece does not abut against the gate flange even if vibration is transmitted). This makes it difficult for the locking piece to abut against the gate flange even if it is subjected to the vibration, and the reliability of preventing damage to the locking piece can be improved.

[0013] In addition, the locking means are arranged at multiple locations, and the locking means detection units are arranged at multiple locations corresponding to each of the locking means, and if the position of at least one of the locking means detected by each of the multiple locking means detection units is within the operation prohibited range, operation of the opening and closing cylinder is prohibited on that condition.

[0014] In other words, the operation of the opening and closing cylinder is not permitted unless all of the locking means disposed at multiple locations are in a position outside the prohibited operation range. This makes it possible to prevent damage to the locking pieces of each locking means when the locking means are disposed at multiple locations.

[0015] In addition, the system includes a support rod for maintaining the position of the tailgate in a position that opens the rear opening of the tank body, a support rod detection unit for detecting the position of the support rod, and a configuration that prohibits operation of the opening / closing cylinder at least in the direction of closing the tailgate (closing the rear opening), provided that the position of the support rod detected by the support rod detection unit is in a position that maintains the position of the tailgate.

[0016] When closing the tailgate (for example, when an operation to close the tailgate is performed), the position of the support bar is detected by the support bar detection unit. If the detected position of the support bar is in a position that maintains the tailgate in a position that opens the rear opening of the tank body, the operation of the opening / closing cylinder in the direction to close the tailgate is prohibited under this condition. This makes it possible to avoid a situation in which a rotational force in the closing direction of the tailgate acts on the support bar, and to prevent damage to the support bar.

[0017] In addition, the opening and closing cylinder is permitted to operate in both directions, that is, in the direction of opening and closing the tailgate, provided that the position of the locking means detected by the locking means detection unit is not within the prohibited operation range and the position of the support rod detected by the support rod detection unit is not in a position that maintains the posture of the tailgate in a position that opens the rear opening.On the other hand, the opening and closing cylinder is permitted to operate only in the direction of opening the tailgate, provided that the position of the locking means detected by the locking means detection unit is not within the prohibited operation range and the position of the support rod detected by the support rod detection unit is in a position that maintains the posture of the tailgate in a position that opens the rear opening.

[0018] As a result, when the position of the locking means is not within the prohibited operation range and the position of the support bar is not in a position that maintains the tailgate's position, the lock piece and the support bar will not be damaged even if the tailgate is opened or closed. Therefore, in this case, the opening and closing cylinder is permitted to operate in both directions, that is, in the direction to open and close the tailgate. On the other hand, when the position of the locking means is not within the prohibited operation range and the position of the support bar is in a position that maintains the tailgate's position, the lock piece will not be damaged even if the tailgate is opened, but the support bar may be damaged if the tailgate is closed. Therefore, in this case, the opening and closing cylinder is permitted to operate only in the direction to open the tailgate. In other words, the opening and closing cylinder is prohibited from operating in the direction to close the tailgate. These operations make it possible to prevent damage to the lock piece and the support bar without prohibiting the opening and closing cylinder more than necessary. Effect of the Invention

[0019] In the present invention, the operation of the opening / closing cylinder at least in the direction to open the tailgate is prohibited on the condition that the position of the locking means equipped with a locking piece for fastening the tailgate to the opening edge of the rear opening of the tank body is within a predetermined prohibited operation range including the fastening position. This makes it possible to avoid a situation in which the rotational force in the tailgate opening direction acts on the locking piece, and prevents damage to the locking piece. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a left side view showing the suction vehicle according to the embodiment of the present invention. [Diagram 2] 1 is a plan view showing a suction vehicle according to an embodiment of the present invention; [Diagram 3] FIG. 2 is a rear view showing the suction vehicle according to the embodiment of the present invention. [Figure 4] 1 is a left side view of the rear part of a suction vehicle according to an embodiment of the present invention, showing a state in which the tailgate of the suction vehicle is open. FIG. [Diagram 5]FIG. 2 is a schematic diagram showing a hydraulic circuit for operating the opening / closing cylinder and the tilting cylinder. [Figure 6] 6(a) is a rear view showing the gate lock mechanism in a first rotation position, FIG. 6(b) is a second rotation position, FIG. 6(c) is a third rotation position, and FIG. 6(d) is a fourth rotation position. [Figure 7] 7 is a view seen from the arrow VII in FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] 11A and 11B are diagrams for explaining permission and prohibition of tailgate operation according to the positions of the lock operation levers and the support rods. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] -Exterior description of the suction vehicle- FIG. 1 is a left side view showing a suction vehicle 2 according to an embodiment of the present invention, FIG. 2 is a plan view showing the suction vehicle 2, and FIG.

[0023] As shown in these figures, in the suction vehicle 2, a subframe 4 is installed on a chassis frame 3 of the vehicle, and a suction device 1 is mounted at the front of the subframe 4, and a receiver tank 5 for collecting the objects to be collected is mounted at the rear. The objects to be collected are, for example, sludge, earth and sand, waste liquid, etc. In the following explanation, the front-rear direction refers to the same direction as the front-rear direction of the suction vehicle 2 (the direction along the traveling direction), and the left-right direction refers to the left-right direction when the suction vehicle 2 is facing forward.

[0024] The receiver tank 5 includes a tank body 6 having a rear end opening, and a tailgate 7 for opening and closing the rear end opening. The tailgate 7 is pivotally supported at the upper rear end of the tank body 6 via a hinge pin 8. An opening / closing cylinder 9 is disposed between the tank body 6 and the tailgate 7. The tailgate 7 opens and closes the rear end opening of the tank body 6 by expanding and contracting the opening / closing cylinder 9. That is, the front end of the opening / closing cylinder 9 is pivotally supported at the side of the tank body 6, while the rear end (the tip of the piston rod) of the opening / closing cylinder 9 is pivotally supported at the side of the tailgate 7. When the opening / closing cylinder 9 is contracted as shown in FIG. 1, the tailgate 7 closes the rear end opening, while when the opening / closing cylinder 9 is extended as shown in FIG. 4 (a left side view of the rear of the suction vehicle 2 showing the state in which the tailgate 7 is open), the tailgate 7 rotates around the hinge pin 8 to open the rear end opening.

[0025] A tank pressurization / depressurization pipe 41 is connected to the upper part of the tank body 6 of the receiver tank 5, and the air in the receiver tank 5 can be sucked in and depressurized by operating the suction device 1, or conversely, air can be sent into the receiver tank 5 to pressurize it. A part of the tank pressurization / depressurization pipe 41 is made of a flexible material such as a flexible hose in order to accommodate the rotational movement of the receiver tank 5. In addition, a suction port 11 with an opening / closing valve that serves as a suction port for objects to be collected, and a discharge port 12 with an opening / closing valve that serves as a discharge port for objects to be collected are provided below the tailgate 7.

[0026] The receiver tank 5 is pivotally supported on the subframe 4 via a tilt pin 14 so as to be able to tilt freely, and a tilt cylinder 15 is disposed between the subframe 4 and the receiver tank 5. By extending and contracting this tilt cylinder 15, the receiver tank 5 rotates upright or down around the tilt pin 14.

[0027] When the suction vehicle 2 suctions and collects objects to be collected into the receiver tank 5, the air in the receiver tank 5 is reduced in pressure by operating the suction device 1, and the objects to be collected are sucked into the receiver tank 5 from the outside through a suction hose (not shown) connected to a suction port 11 equipped with an opening / closing valve.

[0028] On the other hand, when the suction vehicle 2 discharges the objects to be collected in the receiver tank 5 to a predetermined location (such as a sludge treatment plant), the air in the receiver tank 5 is pressurized and the objects to be collected in the receiver tank 5 are discharged to the outside through a discharge hose (not shown) connected to the discharge port 12 with an on-off valve. The objects to be collected in the receiver tank 5 can also be discharged by opening the tailgate 7 and rotating the receiver tank 5 upright.

[0029] In order to pressurize or depressurize the inside of the receiver tank 5 in this manner, various valves, pipes, and devices are mounted as the suction device 1 between the driver's cab 16 of the suction vehicle 2 and the receiver tank 5, such as an upstream catcher 44 connected to the receiver tank 5 via the tank pressurization / depressurization pipe 41 and the suction pipe 42, a catcher tank 60, and a blower 40 connected to the upstream catcher 44 via a pipe 47 for pressurizing and depressurizing the air in the receiver tank 5. As an example, the blower 40 is a roots type, and is driven by the driving force of an engine (not shown) of the suction vehicle 2. That is, the blower 40 is connected to a PTO (power take off) that takes out the driving force of the engine via a drive belt (not shown) or a propeller shaft 17. The configuration of the suction device 1 is not limited to this.

[0030] As shown in Fig. 1, the suction vehicle 2 is equipped with an operation panel 19 on which meters, switches, operating levers, etc. are concentrated. Operation levers for operating the opening / closing cylinder 9 and the tilting cylinder 15 are arranged on this operation panel 19. Operation of this operation lever performs a switching operation of the hydraulic circuit described below, and the opening / closing cylinder 9 is contracted or extended, and the tilting cylinder 15 is contracted or extended. In addition, a warning buzzer, warning lights, panel lights, tachometer lights, etc. are also arranged on this operation panel 19.

[0031] - Hydraulic circuit explanation - Next, the hydraulic circuit O for operating the opening / closing cylinders 9, 9 and the tilting cylinders 15, 15 will be described with reference to Fig. 5. As shown in Fig. 5, the hydraulic circuit O includes a hydraulic pump P as a hydraulic source, an oil reservoir T, and a hydraulic control valve unit M. The hydraulic pump P is connected to the PTO of the engine via a propeller shaft 17, and is configured such that as the engine speed increases, the pump speed increases and the discharge amount increases.

[0032] The hydraulic control valve unit M is disposed on the rear side of the operation panel 19, and is connected to the opening / closing cylinders 9, 9 and the tilting cylinders 15, 15 by hydraulic piping.

[0033] Specifically, the hydraulic control valve unit M includes, as an example, manual valves V1 and V2. These manual valves V1 and V2 are 6-port, 3-position manual directional control valves, and their positions can be switched by manual operation.

[0034] When the manual valve V1 is manually switched to a first communication position (left side position in the figure), it supplies hydraulic oil from the hydraulic pump P to the rod side oil chambers of each tilting cylinder 15, 15. Specifically, it supplies hydraulic oil to the rod side oil chambers of each tilting cylinder 15, 15 via a first piping system 15A. On the other hand, when the manual valve V1 is manually switched to a second communication position (right side position in the figure), it supplies hydraulic oil from the hydraulic pump P to the cap side oil chambers of each tilting cylinder 15, 15. Specifically, it supplies hydraulic oil to the cap side oil chambers of each tilting cylinder 15, 15 via a second piping system 15B.

[0035] When hydraulic oil from the manual valve V1 is supplied to the cap side oil chambers of the tilting cylinders 15, 15, the tilting cylinders 15, 15 extend to raise the receiver tank 5. On the other hand, when hydraulic oil from the manual valve V1 is supplied to the rod side oil chambers of the tilting cylinders 15, 15, the tilting cylinders 15, 15 contract to lay the receiver tank 5 down.

[0036] On the other hand, when the manual valve V2 is manually switched to the first communication position (left side position in the figure), it supplies hydraulic oil from the hydraulic pump P to the rod side oil chambers of each of the opening and closing cylinders 9, 9. Specifically, it supplies hydraulic oil to the rod side oil chambers of each of the opening and closing cylinders 9, 9 via the third piping system 9A. On the other hand, when the manual valve V2 is manually switched to the second communication position (right side position in the figure), it supplies hydraulic oil from the hydraulic pump P to the cap side oil chambers of each of the opening and closing cylinders 9, 9. Specifically, it supplies hydraulic oil to the cap side oil chambers of each of the opening and closing cylinders 9, 9 via the fourth piping system 9B.

[0037] When hydraulic oil from the manual valve V2 is supplied to the cap side oil chambers of the opening and closing cylinders 9, 9, the opening and closing cylinders 9, 9 extend, rotating the tailgate 7 to open the rear end opening. On the other hand, when hydraulic oil from the manual valve V2 is supplied to the rod side oil chambers of the opening and closing cylinders 9, 9, the opening and closing cylinders 9, 9 contract, rotating the tailgate 7 to close the rear end opening.

[0038] When both manual valves V1 and V2 are in the neutral position, the hydraulic oil flows back to the oil reservoir T.

[0039] Further, the piping systems 15A, 15B, 9A, and 9B are provided with known double pilot check valves CV1 and CV2.

[0040] Further, a first electromagnetic check valve CV10 is disposed in the second piping system 15B at a position closer to the hydraulic control valve unit M than the double pilot check valve CV1. This first electromagnetic check valve CV10 is a 4-port 2-position electromagnetic switching valve, and its position is switched by energizing a solenoid SOLe. That is, when the solenoid SOLe is excited by energization from a sequence circuit (not shown), it switches to the first communication position (upper position in the figure), restricting the return of hydraulic oil from the cap-side oil chambers of each tilting cylinder 15, 15 and restricting the receiver tank 5 from tipping over.

[0041] Additionally, in the fourth piping system 9B, a second electromagnetic check valve CV20 and a third electromagnetic check valve CV30 are disposed in series at a position closer to the hydraulic control valve unit M than the double pilot check valve CV2. These electromagnetic check valves CV20, CV30 are also 4-port 2-position electromagnetic change-over valves, and their positions are changed over by energizing solenoids SOLf, SOLg.

[0042] When the solenoid SOLf of the second electromagnetic check valve CV20 is excited by the passage of current from a sequence circuit (not shown), it switches to the first communicating position (upper position in the figure) to restrict the return of hydraulic oil from the cap side oil chamber of each opening / closing cylinder 9, 9, thereby restricting the rotation of the tailgate 7 in the closing direction.

[0043] Furthermore, when the solenoid SOLg of the third electromagnetic check valve CV30 is excited by energization from a sequence circuit (not shown), it switches to the first communicating position (upper position in the figure) to restrict the supply of hydraulic oil to the cap-side oil chambers of each opening / closing cylinder 9, 9, and restricts the rotation of the tailgate 7 in the opening direction. This restriction on the rotation of the tailgate 7 in the opening direction is a feature of this embodiment, and is intended to prevent damage to a lock piece 71 (see FIG. 3) described later. Details will be described later.

[0044] -Gate lock mechanism explanation- As shown in Fig. 3, the suction vehicle 2 according to this embodiment is provided with a pair of left and right gate lock mechanisms 70, 70 for fastening the tailgate 7 to the tank flange, which is the opening edge of the rear opening, when the tailgate 7 closes the rear opening. Since the configurations of the gate lock mechanisms 70, 70 are symmetrical, the gate lock mechanism 70 located on the left side of the vehicle body will be described below as a representative.

[0045] Fig. 6 is a rear view showing the gate lock mechanism 70. In Fig. 6, the tank body 6 and the tailgate 7 are shown in imaginary lines. Figs. 6(a) to 6(d) show the lock pieces 71 constituting the gate lock mechanism 70 in different rotation positions. Specific rotation positions will be described later. Fig. 7 is a view seen from the arrow VII in Fig. 6(a). Fig. 8 is a cross-sectional view taken along the line VIII-VIII in Fig. 6(a).

[0046] As shown in Figures 7 and 8, the gate lock mechanism 70 includes a lock piece 71 and a lever holding member 72 that is provided on the tank body 6 facing the lock piece 71 and that rotatably supports the lock piece 71 and a lock operating lever 62 described later.

[0047] The lever holding member 72 includes an abutment plate 6b welded to the tank flange 6a, which is the opening edge of the rear opening, and a curved mounting portion 6c welded to the abutment plate 6b and welded to the underside of the tank body 6. A lever side plate 6d having the same shape as the abutment plate 6b is disposed at a position of the lever holding member 72 facing the abutment plate 6b. The abutment plate 6b, the mounting portion 6c, and the lever side plate 6d are connected by a pair of side plates 6e, 6e that face each other (facing each other in a direction perpendicular to the paper in Figs. 7 and 8). As shown in Fig. 8, a pipe-shaped boss portion 6g having a first through hole 6f is welded to the abutment plate 6b. A second through hole 6h is formed in the lever side plate 6d concentrically with the first through hole 6f. A connecting shaft 61 is inserted through the first through hole 6f and the second through hole 6h. The large diameter portion 61a at the tip portion (the portion on the right side in FIG. 8) of the connecting shaft 61 is inserted into the first through hole 6f, and the lock piece 71 is connected to the tip portion in a rotatable manner. A screw portion 61b is provided in the middle portion of the connecting shaft 61, and a male screw is machined in the screw portion 61b. A through hole 61d perpendicular to the axial direction is formed in the small diameter portion 61c at the base end portion (the portion on the left side in FIG. 8) of the connecting shaft 61. A lock operation lever 62 for rotating the lock piece 71 is inserted into the small diameter portion 61c, and a split pin (not shown) is inserted into the through hole 61d, so that the lock operation lever 62 is connected to the connecting shaft 61 in a rotatable manner. The lock operation lever 62, the connecting shaft 61, and the lock piece 71 constitute the locking means (the locking means that can move between a fastening position where the lock piece fastens the tailgate to the opening edge portion of the rear opening and a fastening release position where the fastening is released) in the present invention.

[0048] Fastening nuts 63, 63 as fastening members are screwed onto the threaded portion 61b of the connecting shaft 61. Washers 64a, 64b are provided on both sides of the fastening nuts 63, 63. A compression coil spring 66 is disposed in a compressed state between the washer 64b and the lever side plate 6d. As a result, the washer 64b and the fastening nuts 63, 63 are pressed against the boss portion 6g via the washer 64a, so that the lock piece 71 and the lock operation lever 62 do not wobble.

[0049] A tapered surface 71a is formed at a corner of the inner surface side (lock operation lever 62 side) of the lock piece 71. This tapered surface 71a is brought into contact with a spacer 73a protruding from a gate flange 73, which is the outer peripheral edge of the tailgate 7, and the gate flange 73 is sandwiched between the tank flange 6a and the lock piece 71, thereby fastening the tailgate 7 to the tank flange 6a. That is, the lock piece 71 presses the gate flange 73 toward the tank flange 6a, compressing the packing 73b on the inner surface of the gate flange 73, so that the tailgate 7 seals the tank body 6.

[0050] As shown in Fig. 6, the gate lock mechanism 70 is provided with a lever holding mechanism 65 that holds the lock operation lever 62 in a closed position (the fastening position shown in Fig. 6(a)) or an open position (the release position shown in Fig. 6(d)). Although details are omitted, this lever holding mechanism 65 is provided with a stopper 65a that restricts the lock operation lever 62 from rotating beyond the closed position (rotating counterclockwise in Fig. 6(a)), a holding pin 65b that is biased toward the lock piece 71 by a built-in tension coil spring (not shown) and has a knob, and a holding through hole 65c into which the holding pin 65b is inserted when the lock operation lever 62 is in the open position.

[0051] The operation of the gate lock mechanism 70 will be described as follows: as shown in Figures 6(a), 7 and 8, when the tank body 6 is sealed by the tailgate 7, the retaining pin 65b of the lever retaining mechanism 65 is pulled, the lock operating lever 62 is released from the closed position (the position shown in Figure 6(a)), and rotated until it drops into the retaining through-hole 65c (see Figure 6(d)), and held in the open position. This releases the lock between the lock piece 71 and the tailgate 7, making it possible to open the tailgate 7. When the operating lever on the operation panel 19 is operated in this state, the opening / closing cylinder 9 extends, causing the tailgate 7 to rotate in the opening direction.

[0052] On the other hand, when closing the tailgate 7, first, the opening / closing cylinder 9 is contracted to rotate the tailgate 7 in the closing direction. In this state, the retaining pin 65b is pulled to release the retention, and the lock operation lever 62 is rotated from the open position (the position shown in FIG. 6(d)), the retaining pin 65b is dropped into the lower end of the lever side plate 6d, and the lock operation lever 62 is sandwiched and locked between the stopper 65a and the retaining pin 65b, and the lock piece 71 is held in the closed position (the position shown in FIG. 6(a)).

[0053] As a result, the tailgate 7 is tightened toward the tank flange 6a and the packing 73b is compressed, so that the tailgate 7 reliably covers the rear opening, preventing the wastewater and sludge in the tank body 6 from leaking out.

[0054] -Configuration for detecting the rotation position of the lock operation lever- 6 and 7, in the suction vehicle 2 according to this embodiment, the gate lock mechanism 70 is provided with a lever proximity switch 80 as a locking means detector for detecting the rotational position of the lock operating lever 62 (detecting the rotational position of the lock piece 71 by detecting the rotational position of this lock operating lever 62). Specifically, a switch support bracket 81 is attached to the side plate 6e of the lever holding member 72, and the lever proximity switch 80 is supported by this switch support bracket 81.

[0055] As shown in Figure 7, the switch support bracket 81 includes a support plate portion 81a supported by the side plate 6e, a first extension portion 81b extending diagonally upward from the lower end of the support plate portion 81a (toward the front side of the paper in Figure 7), a cover portion 81c extending diagonally downward from the outer end of the first extension portion 81b, and an intermediate plate portion 81d (see Figure 6(a)) extending diagonally downward from a midpoint in the extension direction of the first extension portion 81b so as to be parallel to the cover portion 81c.

[0056] The lever proximity switch 80 is disposed in the space between the cover portion 81c and the intermediate plate portion 81d, and is supported on the intermediate plate portion 81d by means of screws or the like. The position of the lever proximity switch 80 is set to a position facing the lock operating lever 62 when the lock operating lever 62 is in the open position (the position shown in FIG. 6(d)). The lever proximity switch 80 is also connected to a sequence circuit (not shown) via a signal line 82 (see FIG. 7).

[0057] When the lock operating lever 62 is in the open position or in the vicinity of the open position, the lever proximity switch 80 detects the lock operating lever 62 and outputs a signal. This turns on the relay contact of the sequence circuit. In this embodiment, when the relay contact is OFF, as described above, the solenoid SOLg of the third electromagnetic check valve CV30 is excited, and the rotation of the tailgate 7 in the opening direction is restricted. In other words, the solenoid SOLg is excited to restrict the supply of hydraulic oil to the cap-side oil chambers of the opening / closing cylinders 9, 9, and to restrict the rotation of the tailgate 7 in the opening direction. When the relay contact of the sequence circuit is ON, the solenoid SOLg of the third electromagnetic check valve CV30 is not excited, and the rotation of the tailgate 7 in the opening direction is permitted. That is, by operating the operating lever for operating the opening / closing cylinders 9, 9 (particularly, by operating to extend the opening / closing cylinders 9, 9), hydraulic oil is supplied to the cap-side oil chamber of each of the opening / closing cylinders 9, 9, and the opening / closing cylinders 9, 9 perform an extending operation to rotate in the opening direction of the tailgate 7. Note that when the lever proximity switch 80 detects the lock operating lever 62, the relay contact is turned OFF to permit rotation in the opening direction of the tailgate 7, and when the lever proximity switch 80 does not detect the lock operating lever 62, the relay contact may be turned ON to prohibit rotation in the opening direction of the tailgate 7.

[0058] 6(a) (hereinafter referred to as the first rotation position), the lock operating lever 62 is in a fastening position in which the lock piece 71 presses the gate flange 73 toward the tank flange 6a, and in this case, since the lock operating lever 62 is in a position away from the lever proximity switch 80, the lever proximity switch 80 does not detect the lock operating lever 62 and no signal is output from the lever proximity switch 80. In other words, the tailgate 7 is restricted from rotating in the opening direction.

[0059] 6(b) (hereinafter referred to as the second rotation position), this is the point in time when the lock operating lever 62 is released from contact with the gate flange 73, but even in this state, the lock operating lever 62 is relatively far from the lever proximity switch 80, so the lever proximity switch 80 does not detect the lock operating lever 62 and no signal is output from the lever proximity switch 80. In other words, even in this state, rotation of the tailgate 7 in the opening direction is still restricted.

[0060] When the lock operating lever 62 is further rotated toward the open position and reaches the rotation position shown in FIG. 6(c) (hereinafter referred to as the third rotation position), at this time, the lock piece 71 has been rotated toward the open position by a predetermined angle from the time when the state of contacting the gate flange 73 was released (there is a predetermined gap between the outer edge of the lock piece 71 and the outer edge of the gate flange 73), and in this state, the lever proximity switch 80 detects the lock operating lever 62 and outputs a signal. That is, rotation in the opening direction of the tailgate 7 is permitted (when the operating lever for extending the opening and closing cylinders 9, 9 is operated, the opening and closing cylinders 9, 9 are extended to rotate the tailgate 7 in the opening direction). For this reason, the range from the first rotation position to the third rotation position (the range immediately before the third rotation position is reached) corresponds to the operation prohibited range (the predetermined operation prohibited range in which the position of the locking means includes the fastening position) as the rotation range of the lock operating lever 62 in the present invention.

[0061] 6(d) (hereinafter referred to as the fourth rotation position), the lock operating lever 62 is in a position facing the lever proximity switch 80, so that the lever proximity switch 80 detects the lock operating lever 62 and outputs a signal. In other words, rotation in the opening direction of the tailgate 7 is permitted (when the operating lever for extending the opening / closing cylinders 9, 9 is operated, the opening / closing cylinders 9, 9 extend and the tailgate 7 is rotated in the opening direction).

[0062] In this way, within the rotation range from the first rotation position to the third rotation position (the rotation position just before reaching the third rotation position), no signal is output from the lever proximity switch 80, whereas when the third rotation position is reached, a signal is output from the lever proximity switch 80, and a signal is output from this third rotation position to the fourth rotation position, thereby allowing rotation of the tailgate 7 in the opening direction.

[0063] As described above, in this embodiment, the operation of the opening / closing cylinder 9 in the direction to open the tailgate 7 is prohibited under the condition that the lever proximity switch 80 does not detect the lock operation lever 62, that is, the rotation position of the lock operation lever 62 is in the range from the first rotation position (the rotation position shown in FIG. 6(a)) to the third rotation position (the rotation position shown in FIG. 6(c)). Specifically, since no signal is output from the lever proximity switch 80, the solenoid SOLg (see FIG. 5) of the third electromagnetic check valve CV30 is excited by the energization from a sequence circuit (not shown) and is switched to the first communication position, thereby restricting the supply of hydraulic oil to the cap-side oil chambers of each opening / closing cylinder 9, 9, and restricting the rotation of the tailgate 7 in the opening direction. As a result, the rotation of the tailgate 7 in the opening direction is restricted in the state where the lock piece 71 is in contact with the gate flange 73 and in the state where the lock piece 71 may be in contact with the gate flange 73 due to the transmission of vibration to the gate lock mechanism 70. This makes it possible to avoid a situation in which a rotational force in the opening direction of the tailgate 7 acts on the lock piece 71, and therefore damage to the lock piece 71 can be prevented.

[0064] -Explanation of the tailgate support mechanism- The suction vehicle 2 according to this embodiment is provided with a tailgate support mechanism 90 for maintaining the position of the tailgate 7 in a position that opens the rear opening of the tank body 6. The tailgate support mechanism 90 will be described below.

[0065] 1 and 4, the tailgate support mechanism 90 is disposed below the opening / closing cylinder 9 on the side of the tank body 6. The tailgate support mechanism 90 includes a switch unit 91 equipped with a support rod proximity switch 92, which is a support rod detection unit, and a support rod 93, as shown in an enlarged view in FIG.

[0066] The switch unit 91 includes a base member 94 attached to a side surface of the tank body 6, a first L-shaped bracket 95 attached to the upper surface of the base member 94, a second L-shaped bracket 96 attached to the upper surface of the first bracket 95, and a support rod proximity switch 92 supported by the second bracket 96. The support rod proximity switch 92 outputs a signal when an object (in this embodiment, a protruding piece 93a of a support rod 93 described later) is located outside in the vehicle width direction.

[0067] A support plate 97 is attached across the base member 94 and the first bracket 95, and the support bar 93 is supported by the support plate 97 so as to be rotatable around a horizontal axis. As shown in FIG. 4, the length of the support bar 93 is approximately equal to the distance (distance in a direction perpendicular to the longitudinal direction of the opening and closing cylinder 9) between the position of the pivot shaft 97a of the support plate 97 and the bottom surface of the opening and closing cylinder 9 when the tailgate 7 is in a pivot position in which the tailgate 7 opens the rear end opening by extending the opening and closing cylinder 9. As a result, when the tailgate 7 is not in the open position as shown in FIG. 1, the support bar 93 is in a horizontal position (hereinafter referred to as a stored position) in which it is pivoted toward the rear side of the vehicle, whereas when the tailgate 7 is in the open position as shown in FIG. 4, when the support bar 93 is pivoted toward the front side of the vehicle to an upright position, the upper end of the support bar 93 is engaged with the bottom surface of the opening and closing cylinder 9 to support the opening and closing cylinder 9 and prevent the tailgate 7 from pivoting in the closing direction. The position of the support bar 93 is changed manually by an operator.

[0068] A protruding piece 93a is provided on a part of the outer surface of the support rod 93 so as to face the support rod proximity switch 92 when the support rod 93 is in the upright position shown in FIG.

[0069] In this embodiment, when the support rod 93 is in an upright position and the protruding piece 93a is in a position facing the support rod proximity switch 92, the support rod proximity switch 92 detects the protruding piece 93a and outputs a signal. This turns on the relay contact of the sequence circuit. In this embodiment, when the relay contact is turned on, the solenoid SOLf of the second electromagnetic check valve CV20 is excited, and the rotation of the tailgate 7 to close is restricted. In other words, the solenoid SOLf is excited to restrict the discharge of hydraulic oil from the cap-side oil chambers of the opening / closing cylinders 9, 9, and to restrict the rotation of the tailgate 7 in the closing direction. This makes it possible to avoid a situation in which the rotation force of the tailgate 7 in the closing direction acts on the support rod 93, and to prevent damage to the support rod 93.

[0070] When the support rod proximity switch 92 does not detect the protruding piece 93a and the relay contact of the sequence circuit is OFF, the solenoid SOLf of the second electromagnetic check valve CV20 is not excited, and the tailgate 7 is permitted to rotate in the closing direction. In other words, by operating the operating lever for actuating the opening and closing cylinders 9, 9 (particularly, by operating the opening and closing cylinders 9, 9 to contract), hydraulic oil is discharged from the cap-side oil chamber of each opening and closing cylinder 9, 9, and the opening and closing cylinders 9, 9 contract to rotate the tailgate 7 in the closing direction.

[0071] -Explanation of permitted and prohibited operations of opening and closing cylinders- Fig. 9 is a diagram for explaining permission and prohibition of tailgate operation according to the position of the lock operating lever 62 and the position of the support rod 93. "Open" for each lock operating lever in Fig. 9 represents a state in which the lock operating lever 62 is in the range from the third rotation position (the rotation position shown in Fig. 6(c)) to the fourth rotation position (the rotation position shown in Fig. 6(d)). Also, "Closed" for each lock operating lever represents a state in which the lock operating lever 62 is in the range from the first rotation position (the rotation position shown in Fig. 6(a)) to the third rotation position (the rotation position shown in Fig. 6(c)).

[0072] 9 indicates that the lever proximity switch 80 is detecting the lock operation lever 62. A blank space for each lever proximity switch indicates that the lever proximity switch 80 is not detecting the lock operation lever 62.

[0073] In addition, the "energized" relay / third check valve in Figure 9 indicates that the solenoid SOLg of the third electromagnetic check valve CV30 is energized, and the blank relay / third check valve column indicates that the solenoid SOLg of the third electromagnetic check valve CV30 is not energized.

[0074] 9 indicates that the solenoid SOLg is not energized, allowing the flow of hydraulic oil through the third electromagnetic check valve CV30, while the "Shut" state of the third check valve indicates that the solenoid SOLg is energized, preventing the flow of hydraulic oil through the third electromagnetic check valve CV30.

[0075] 9 indicates that the support rod 93 is in a stored position. Also, the support rod 93 is in a set position, indicating that the support rod 93 is in an upright position and maintains the position of the tailgate 7 in the open position.

[0076] 9 indicates that the support rod proximity switch 92 is detecting the support rod 93 (detecting the protruding piece 93a of the support rod 93). A blank support rod proximity switch column indicates that the support rod proximity switch 92 is not detecting the support rod 93.

[0077] 9 indicates that the solenoid SOLf is not energized, allowing the flow of hydraulic oil through the second electromagnetic check valve CV20, while the "Shut" state of the second check valve indicates that the solenoid SOLf is energized, preventing the flow of hydraulic oil through the second electromagnetic check valve CV20.

[0078] 9 indicates that the opening operation of the tailgate 7 by extending the opening / closing cylinder 9 and the closing operation of the tailgate 7 by retracting the opening / closing cylinder 9 are both permitted. The tailgate operation "can be opened / cannot be closed" indicates that the opening operation of the tailgate 7 by extending the opening / closing cylinder 9 is permitted, but the closing operation of the tailgate 7 by retracting the opening / closing cylinder 9 is not permitted (prohibited). The tailgate operation "stopped" indicates that the opening operation of the tailgate 7 by extending the opening / closing cylinder 9 and the closing operation of the tailgate 7 by retracting the opening / closing cylinder 9 are both not permitted (prohibited).

[0079] 9, when each lock operation lever 62 is in the "open" position (a state in which each lock operation lever 62 is in the range from the third rotation position to the fourth rotation position) and the support rod 93 is in the "stored" position (the support rod 93 is in the stored position), the operation of the tailgate 7 is "openable" and both the opening operation of the tailgate 7 by the extension of the opening / closing cylinder 9 and the closing operation of the tailgate 7 by the contraction of the opening / closing cylinder 9 are permitted. In other words, since the lock piece 71 and the support rod 93 are not damaged regardless of whether the tailgate 7 is opened or closed, operation of the opening / closing cylinder 9 in both directions, that is, in the opening and closing directions, is permitted.

[0080] On the other hand, when each lock operation lever 62 is in the "open" position and the support rod 93 is in the "set" position (the support rod 93 is in an upright position and the tailgate 7 is maintained in the open position), the tailgate 7 is in the "openable / unclosable" position, and the opening operation of the tailgate 7 by the extension of the opening / closing cylinder 9 is permitted, but the closing operation of the tailgate 7 by the contraction of the opening / closing cylinder 9 is not permitted (prohibited). In other words, the lock piece 71 will not be damaged even if the tailgate 7 is opened, but the support rod 93 may be damaged if the tailgate 7 is closed. Therefore, the opening / closing cylinder 9 is permitted to operate only in the direction to open the tailgate 7. In other words, the opening / closing cylinder 9 is prohibited from operating in the direction to close the tailgate 7.

[0081] Furthermore, when either of the conditions that at least one of the lock operating levers 62 is "closed (including half-open)" or the support rod 93 is "set (support rod 93 is in an upright position)" is met, the operation of the tailgate 7 is "stopped," and both the opening operation of the tailgate 7 by the extension of the opening / closing cylinder 9 and the closing operation of the tailgate 7 by the contraction of the opening / closing cylinder 9 are prohibited.

[0082] -Effects of the embodiment- As described above, in this embodiment, when the position of the lock operating lever 62 detected by the lever proximity switch 80 is within a predetermined prohibited operation range that includes the fastening position where the lock piece 71 fastens the tailgate 7 to the tank flange 6a of the tank body 6, operation of the opening / closing cylinder 9 in the direction to open the tailgate 7 is prohibited on that condition. This makes it possible to avoid a situation in which a rotational force in the opening direction of the tailgate 7 acts on the lock piece 71, and to prevent damage to the lock piece 71.

[0083] -Other embodiments- The present invention is not limited to the above-described embodiment, and all modifications and applications within the scope of the claims and equivalents thereto are possible.

[0084] For example, in the above embodiment, the present invention has been described as being applied to a suction vehicle 2 equipped with a lock piece 71 for fastening the tailgate 7 to the tank flange 6a of the tank body 6, and a support rod 93 for maintaining the position of the tailgate 7 in a position that opens the rear opening of the tank body 6. However, the present invention is not limited to this, and can also be applied to a suction vehicle 2 that does not have a support rod 93.

[0085] In the above embodiment, the lock piece 71 rotates between a fastening position where the tailgate 7 is fastened to the tank flange 6a and an unfastening position where the tailgate 7 is released from the fastening. However, the present invention is not limited to this, and the lock piece may slide between the fastening position and the unfastening position. [Industrial Applicability]

[0086] The present invention is applicable to a suction vehicle equipped with a lock piece for fastening a tailgate to the opening edge of the rear opening of the tank body. [Explanation of symbols]

[0087] 2 Suction car 6 Tank body 6a Tank flange (opening edge) 62 Lock operation lever (locking means) 7. Tailgate 71 Lock piece (locking means) 73 Gate flange 80 Lever proximity switch (locking means detection section) 9 Opening and closing cylinder 92 Support rod proximity switch (support rod detection part) 93 Support rod

Claims

1. A suction vehicle comprising: a tank body having a rear opening; a tailgate connected to an opening / closing cylinder capable of opening and closing the rear opening in accordance with the operation of the opening / closing cylinder; and a locking means having a locking piece and movable between a fastening position where the locking piece fastens the tailgate to an opening edge of the rear opening and a fastening release position where the fastening is released, a locking means detection unit that detects the position of the locking means; This suction vehicle is characterized in that, when the tailgate is in a closed state, the operation of the opening / closing cylinder in at least the direction of opening the tailgate is prohibited, provided that the position of the locking means is within a predetermined operation prohibition range that includes the fastening position.

2. The suction vehicle according to claim 1, the lock piece abuts against a gate flange of the tailgate to press the gate flange against an opening edge of the rear opening of the tank body, thereby fastening the tailgate to the opening edge of the rear opening, The suction vehicle is characterized in that the operation prohibited range is set as a range from the fastening position of the locking means to a position of the locking means at which a predetermined distance is left between the outer edge of the locking piece and the outer edge of the gate flange when the locking piece is not in contact with the gate flange.

3. The suction vehicle according to claim 1 or 2, The locking means is disposed at a plurality of locations, The locking means detection unit is provided at a plurality of locations corresponding to each of the locking means, A suction vehicle characterized in that, when the position of at least one of the locking means detected by each of the multiple locking means detection units is within the operation prohibited range, operation of the opening and closing cylinder is prohibited under that condition.

4. The suction vehicle according to claim 1 or 2, a support rod for maintaining the tailgate in a position that opens the rear opening of the tank body; A support rod detection unit that detects the position of the support rod; This suction vehicle is characterized in that it is configured to prohibit operation of the opening / closing cylinder at least in the direction of closing the tailgate, provided that the position of the support rod detected by the support rod detection unit is in a position that maintains the posture of the tailgate.

5. The suction vehicle according to claim 4, On the condition that the position of the locking means detected by the locking means detection unit is not within the operation prohibited range and the position of the support rod detected by the support rod detection unit is not in a position that maintains the attitude of the tailgate in a position that opens the rear opening, the opening / closing cylinder is permitted to operate in both directions, that is, in the direction of opening and closing the tailgate; A suction vehicle characterized in that it is configured to allow operation of the opening / closing cylinder only in the direction of opening the tailgate, provided that the position of the locking means detected by the locking means detection unit is not within the operation prohibited range and the position of the support rod detected by the support rod detection unit is in a position that maintains the attitude of the tailgate in a position that opens the rear opening.

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