Tank car

Abstract

To provide a tank vehicle capable of suppressing the generation of defective changeover of a valve body.SOLUTION: A tank vehicle includes: a tank; a piping; a direction selector valve 31 disposed in the piping, and having a valve body 46 and a valve drive part for rotating the valve body; driving means having an engagement part to be engaged with the valve drive part, and rotating the valve drive part due to the rotation of the engagement part; a sensor for detecting a rotation quantity of the engagement part; and a control part for controlling the rotation of the engagement part according to a detection result of the sensor. The valve drive part includes a drive shaft part 470 to be rotated by the engagement part, and a guide part 471 for guiding the drive shaft part to a position corresponding to a stop position of the valve body. The drive shaft part is engaged with the engagement part so that the engagement part idles at a prescribed angle from each of a plurality of stop positions to the drive shaft part when being rotated. The guide part includes a fitting part 472 moving with the rotation of the drive shaft part, and a fitting recess having a guide inclined surface for guiding the fitting part, and allowing the fitting part to be fitted to when the valve drive part is positioned in a stop position.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a tank vehicle such as a sprinkler truck or a tank truck. [Background technology]

[0002] A known tank car is the tank car described in Patent Document 1. The tank car includes a tank for storing a fluid, a plurality of pipes forming a circuit for drawing the fluid into the tank and discharging the fluid from the tank, and a directional switching valve having a valve body that connects the plurality of pipes, and the directional switching valve can switch between a state in which the fluid is drawn into the tank and a state in which the fluid is discharged from the tank by switching the position of the valve body.

[0003] The directional control valve is connected to a drive shaft coupled to the valve element and a rotating shaft provided in the reducer, and is configured so that the position of the valve element can be changed by rotating the rotating shaft. The amount of rotation of the rotating shaft is controlled by a control unit, and the amount of rotation (rotation angle) of the rotating shaft is detected by an angle sensor provided in the reducer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-123226 Summary of the Invention [Problem to be solved by the invention]

[0005] In tank cars such as those described above, there is a risk that the rotation angle detected by the rotating shaft may be shifted due to dimensional errors in the installation position of the angle sensor, and if the detected angle is shifted, the control unit may control the rotation amount at the shifted angle, which may result in poor switching of the valve body of the directional control valve.

[0006] Therefore, an object of the present invention is to provide a tank car that can suppress the occurrence of valve body switching failures. [Means for solving the problem]

[0007] The tank car of the present invention comprises a tank mounted on a vehicle body, piping for discharging liquid from the tank and for drawing liquid into the tank, a directional switching valve provided in the piping, the directional switching valve having a valve body and a valve drive unit for rotating the valve body, and switching the path of the piping as the valve body rotates, drive means having an engagement unit for engaging with the valve drive unit and generating a drive force for rotating the valve drive unit as the engagement unit rotates, a sensor for detecting the amount of rotation of the engagement unit, and a control unit for controlling the rotation of the engagement unit in accordance with the detection result of the sensor, the control unit being configured to drive and control the drive means to stop the valve body at a plurality of stop positions defined corresponding to each of the flow paths so that the paths in the piping become a plurality of different flow paths, and the valve drive unit comprises a drive shaft with which the engagement unit engages and which is rotated by the engagement unit, and a guide for guiding the drive shaft to a position corresponding to the stop position of the valve body and a fitting receiving portion, wherein the drive shaft portion engages with the engaging portion such that, when the engaging portion rotates in at least one of one and the other of the rotation directions, the engaging portion rotates freely by a predetermined angle from each of the plurality of stop positions relative to the drive shaft portion, and the guide portion is a fitting recess including a fitting portion and a guide inclined surface that is an inclined surface that guides the fitting portion, and the fitting recess can be fitted with the fitting portion when the valve drive portion is positioned at the stop position. the fitting portion is configured to move relative to the fitting recess as the drive shaft portion rotates, one of the fitting portion and the fitting receiving portion is fixed to the drive shaft portion and rotates coaxially with the drive shaft portion, and the other of the fitting portion and the fitting receiving portion is fixed so as not to rotate regardless of the rotation of the drive shaft portion, and the fitting portion comprises a fitting main body portion that fits into the fitting recess and a biasing portion that biases the fitting main body portion toward the fitting receiving portion.

[0008] With this configuration, the fitting main body is biased toward the fitting receiving portion by the biasing portion, so that when the fitting main body approaches the guide inclined surface, it is guided to move to the fitting recess, the drive shaft is guided to a position corresponding to the stop position of the valve body, and because the engagement portion is free to rotate relative to the drive shaft, even if there is a deviation in the angle at which the control portion rotates the engagement portion, the deviation can be absorbed by the free rotation and the drive shaft can be positioned at the stop position, thereby preventing the occurrence of valve body switching failures.

[0009] The guide inclined surfaces may be disposed on one side and the other side of the fitting recess in the direction of movement of the fitting main body.

[0010] With this configuration, the drive shaft can be guided to a position corresponding to the stop position both when the fitting portion moves toward the fitting recess from one side and when the fitting portion moves toward the fitting recess from the other side. [Effects of the Invention]

[0011] According to the present invention, a tank car can be obtained that can suppress the occurrence of valve body switching failures. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a front view of a sprinkler truck according to a first embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 2 is a partial front cross-sectional view of the directional switching valve. [Figure 6] FIG. 2 is a partial cross-sectional side view of the directional switching valve. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. 2 is a partial cross-sectional plan view of the electric motor and the reducer. [Figure 11] FIG. 2 is a partial cross-sectional plan view showing a main part of the reduction mechanism. [Figure 12] FIG. [Figure 13] 5A and 5B are schematic diagrams showing the movement of the drive shaft portion. [Figure 14] 10A and 10B are schematic diagrams showing the movement of the guide portion. [Figure 15] 5A and 5B are schematic diagrams showing the movement of the drive shaft portion. DETAILED DESCRIPTION OF THE INVENTION

[0013] A tank car according to one embodiment of the present invention will be described below as a sprinkler car with reference to Figures 1 to 15. First, a first embodiment of the present invention will be described.

[0014] As shown in Figures 1 and 2, the body 1 of the sprinkler truck has a cab 2 located at the front, and a frame 3 located at the rear lower part of the cab 2. A tank 4 for storing water W (an example of a fluid) is located above the frame 3 via a support member 5. A partitioned priming chamber 6 is located at the lower front corner inside the tank 4. A full water sensor 11 is located above the tank 4 to detect when the tank 4 is full of water W.

[0015] Such a sprinkler truck is equipped with front sprinkler nozzles 9, 9 below the cab 2 and rear sprinkler nozzles 10, 10 located at the rear lower part of the frame 3 so that water W is discharged from the bottom of the cab 2 and the rear part of the frame 3. This makes it possible to sprinkle water on road surfaces and the like at construction sites. Furthermore, when the water W in the tank 4 is insufficient, the sprinkler truck is configured to suck water W into the tank 4 via a suction hose 13 from an external facility, such as a water storage tank 12.

[0016] That is, as shown in Figures 3 and 4, the sprinkler truck is equipped with piping (circuits) for spraying water W from the tank 4 and for suctioning water W into the tank 4. This piping is for discharging water W from the tank 4 and for suctioning water W into the tank 4, and includes tank piping 15, priming piping 16, junction piping 19, forward sprinkler piping 17, suction piping 18, direction switching circuit 20, discharge piping 21, and rearward sprinkler piping 22.

[0017] The tank piping 15 is disposed midway forward of the lower part of the tank 4. A forward sprinkler piping 17 is connected to the end of the tank piping 15, and a pair of gate valves (ball valves) 24, 24 are disposed at the end of the forward sprinkler piping 17. The forward sprinkler nozzles 9, 9 are disposed at the end of each gate valve 24, 24 via a sprinkler hose 24 a. In addition, a forward valve (solenoid valve) 25 is connected midway through the forward sprinkler piping 17.

[0018] The priming pipe 16 is arranged at the front end of the lower part of the tank 4, and the priming pipe 16 can communicate with the priming chamber 6 defined in the tank 4.

[0019] A priming valve (solenoid valve) 26 is connected to the tank 4 side of the priming pipe 16. In addition, a suction pipe 18 is connected to the end side of the priming pipe 16, and a suction port 27 is connected to the end of the suction pipe 18. A suction valve (solenoid valve) 28 is connected to the suction pipe 18. A suction hose 13 is detachably connected to the suction port 27. A strainer 29 is disposed at the end of the suction hose 13. The strainer 29 and a portion of the suction hose 13 can be immersed in the water tank 12.

[0020] The tank pipe 15 and the priming pipe 16 are connected by a junction pipe 19 that joins them together.

[0021] The junction pipe 19 and a forward pipe 30, which will be described later, are connected via a directional switching valve 31. Here, a description will be given of a direction switching circuit 20 including the directional switching valve 31. The direction switching circuit 20 includes the directional switching valve 31, a pump 32, and a relief valve 33.

[0022] The ports of the directional control valve 31 will be described. First, the directional control valve 31 is a four-way valve connected to a drive means. The drive means has an electric motor 34, a reducer 45, and an engaging portion (coupling 59). The reducer 45 and the coupling 59 will be described in detail later.

[0023] 5 and 6, this four-way valve has a ball 46 connected to an elbow pipe 46a housed inside a case 31A. The electric motor 34 and the reducer 45 are housed inside the tank-side operation unit F (see FIG. 1), and a rotating shaft 56 of the reducer, which outputs the power of the drive means, is connected via an engaging portion to a drive shaft 470 serving as a valve drive unit 47, which rotates the ball 46 of the directional switching valve 31.

[0024] Valve drive unit 47 includes drive shaft 470, which receives rotational force from an engagement portion that is part of the drive means and rotates ball 46 (valve element), and guide portion 471, which guides drive shaft 470 to a position corresponding to a stop position of ball 46, which will be described later. Drive shaft 470 in this embodiment is a rod-like body with a square cross section (see FIG. 13).

[0025] The guide portion 471 is fixed to the drive shaft portion 470 and includes a fitting portion 472 that rotates coaxially with the drive shaft portion 470 as the drive shaft portion 470 rotates, and a fitting receiving portion 473 into which the fitting portion 472 fits when the drive shaft portion 470 is positioned at a position corresponding to the stop position of the ball 46. The guide portion 471 of this embodiment is a so-called notch mechanism.

[0026] The fitting portion 472 includes a fitting base portion 474 fixed to the drive shaft portion 470, a spherical fitting main body portion 475 protruding from the fitting base portion 474 toward the ball 46, and a biasing portion 476 that connects the fitting main body portion 475 and the fitting base portion 474 and biases the fitting main body portion 475 toward the fitting receiving portion 473. The biasing portion 476 in this embodiment is made of an elastic body. That is, in this embodiment, when the fitting main body portion 475 is pressed from the fitting receiving portion 473 side toward the fitting base portion 474, it can move toward the fitting base portion 474 against the biasing force. Furthermore, the biasing portion 476 in this embodiment is made of a coil spring. Note that the biasing portion 476 is not limited to being made of a coil spring, but can be made of various elastic bodies such as a leaf spring or rubber.

[0027] As shown in FIG. 14 , the fitting receiving portion 473 is a portion configured not to rotate regardless of the rotation of the drive shaft portion 470. In this embodiment, the fitting receiving portion 473 is provided on the case 31A. The fitting receiving portion 473 also has a plurality of fitting recesses 477 into which the fitting portion 472 fits when the drive shaft portion 470 is positioned at a position corresponding to each stop position of the ball 46. In this embodiment, the fitting recesses 477 are provided at four locations spaced 90 degrees apart in the movement direction of the fitting portion 472. Specifically, the fitting receiving portion 473 includes the fitting recess 477 into which the fitting portion 472 can fit when the valve drive unit 47 is positioned at the stop position, and a guide inclined surface 478 that is provided in the fitting recess 477 and is an inclined surface that guides the fitting portion 472 to a predetermined position in the fitting recess 477. Specifically, the guide inclined surfaces 478 guide the fitting portion 472 to a position in the fitting recess 477 where the fitting portion 472 will be located when the valve drive unit 47 is located at the stop position. The fitting receiver 473 of this embodiment is a conical recess formed in the case 31A. That is, the fitting receiver 473 of this embodiment is provided with the guide inclined surfaces 478 on one and the other sides in the rotation direction of the fitting portion 472, and the fitting recess 477 into which the fitting portion 472 fits is formed by the two guide inclined surfaces 478. Furthermore, in this embodiment, the guide inclined surfaces 478 are arranged on one and the other sides of the fitting recess 477 in the movement direction of the fitting main body 475. When the fitting main body 475 approaches the fitting recess 477 as the drive shaft 470 rotates, the guide inclined surface 478 guides the fitting main body 475 to the fitting recess 477 by a predetermined angle, which is the rotation angle of the drive shaft 470. The fitting portion 472 guided by the guide inclined surface 478 is held at a fixed position by the fitting recess 477. In this embodiment, the fitting main body 475 comes into ring-like contact with the guide inclined surface 478, thereby holding the fitting portion 472 at a fixed position.

[0028] The junction pipe 19 is connected to port [a] of the directional switching valve 31. An inlet pipe 35 is connected to the inlet side of the pump 32 for water W, and an end of this inlet pipe 35 is connected to port [b] of the directional switching valve 31. An outlet pipe 37 is connected to the outlet side of the pump 32 for water W, and the outlet pipe 37 is connected to port [c] of the directional switching valve 31. The relief valve 33 is disposed on the junction pipe 19 side of the outlet pipe 37. The aforementioned forward pipe 30 is connected to port [d] of the directional switching valve 31, and an end of the forward pipe 30 is disposed at the connection point T between the forward sprinkler pipe 17 and the suction pipe 18 (see Figure 4).

[0029] 5, the orientation in which the ball 46 connects port [a] and port [c] is defined as 0°, with counterclockwise rotation being the forward rotation and clockwise rotation being the reverse rotation. Here, in the directional switching valve 31 of this embodiment, which has ports spaced 90° apart, the normal orientation is defined as 90° when connected to port [d], 180° when the lower part of case 31A and ball 46 face each other, and 270° when connected to port [b].

[0030] The pump 32 is driven by a pulley mechanism 36, which is connected to the engine (PTO) of the water truck. The above is the configuration of the direction switching circuit 20.

[0031] The water discharge pipe 21 is connected to the front pipe 30, and a water discharge port 38 is connected to the end of the water discharge pipe 21. A water discharge valve 39 is arranged on the water discharge pipe 21 on the water discharge port 38 side.

[0032] The rear sprinkler piping 22 is arranged behind the lower part of the frame 3 of the tank 4 (see Figure 1). Rear sprinkler nozzles 10, 10 connected to gate valves (ball valves) 40, 40 are arranged at the end of the rear sprinkler piping 22. A rear sprinkler valve 41 is arranged on the rear sprinkler piping 22 between the base end of the tank 4 and the rear sprinkler nozzles 10, 10.

[0033] As shown in Fig. 7, a control unit 48 is connected to the tank side operation unit F and the cab operation unit, and valves other than the relief valve 33, the gate valves 24, 24, the gate valves 40, 40, and the discharge valve 39 are controlled by the control unit 48. In addition, the directional switching valve 31 is configured such that the ball 46 is driven by the electric motor 34 being controlled by the control unit 48, and ports [a] to [d] communicate with the piping via the ball 46.

[0034] The structure of the aforementioned reducer 45 will be described with reference to Figures 8 to 12. As shown in Figures 8 and 9, the reducer 45 includes a metal housing 49, and as shown in Figures 10 and 11, a reduction mechanism 50 housed in the housing 49.

[0035] As shown in Figure 10, the reduction gear mechanism 50 connected to the output shaft 34a of the electric motor 34 first performs primary reduction by a worm gear mechanism 52 including an input shaft 52a connected to the output shaft 34a of the electric motor 34 to reduce the motor output, and then performs secondary reduction by a gear train 54 connected to a worm wheel 53 on the output side of the worm gear mechanism 52, i.e., as shown in Figure 11. A rotating shaft 56 rotates integrally with an output gear 55 of the gear train 54, and a portion of the rotating shaft 56 extends outside the housing 49. The rotating shaft 56 corresponds to the output shaft of the reducer 45.

[0036] As shown in Fig. 11, a portion of the rotary shaft 56 that extends outside the housing 49 is referred to as an extension 57. As shown in Fig. 12, a primary gear 58 is fitted into the extension 57. Furthermore, a drive shaft 470 for driving the ball 46 of the directional control valve 31 is disposed approximately coaxially with the rotary shaft 56. The extension (extension shaft) 57 and the drive shaft 470 are connected by an Oldham coupling 59 serving as an engaging part.

[0037] The coupling 59 is of a recess-and-protrusion type, and circumferentially engages the drive shaft portion 470 of the ball 46 with the rotating shaft 56 (extension portion 57) of the reducer 45. That is, the coupling 59 is configured so that a drive shaft portion side portion 60 that engages with the drive shaft portion 470 of the ball 46 and a reducer portion side portion 61 that is fitted onto the rotating shaft 56 of the reducer 45 can be engaged with each other in the circumferential direction. The drive shaft portion side portion 60 and the reducer portion side portion 61 have multiple convex portions arranged side by side at intervals in the circumferential direction, and the spaces between the convex portions are concave portions. Note that in the coupling 59, the drive shaft portion side portion 60 may spin freely relative to the reducer portion side portion 61, but this free rotation of the coupling 59 does not contribute to the effect of this embodiment.

[0038] The drive shaft side portion 60 and the reducer side portion 61 are connected by fitting the convex portion of one into the concave portion of the other. As a result, the convex portion of the drive shaft side portion 60 and the convex portion of the reducer side portion 61 are adjacent to each other in the circumferential direction and engage with each other. In this coupling 59, the drive shaft side portion 60 rotates back and forth in the circumferential direction as the reducer side portion 61 rotates.

[0039] As shown in Figure 13, the drive shaft side portion 60 and the drive shaft portion 470 are connected by a recess-projection fit. Specifically, the drive shaft side portion 60 is cylindrical and has a fitting hole 601, which is a square hole, inside. The fitting hole 601 is configured so that the drive shaft portion 470 can be inserted therein, and the drive shaft side portion 60 and the drive shaft portion 470 are connected by inserting the drive shaft portion 470 into the fitting hole 601. In this embodiment, the drive shaft portion 470 and the fitting hole 601 have similar shapes. Furthermore, the fitting hole 601 is formed so that the internal space is larger than that of the drive shaft portion 470, and when the drive shaft portion 470 is inserted therein, a gap S is formed between the drive shaft portion 470 and the fitting hole 601. The gap S between the drive shaft 470 and the fitting hole 601 is a gap S that allows the fitting hole 601 to rotate freely relative to the drive shaft 470 by a predetermined angle. That is, in this embodiment, the drive shaft 470 engages with the coupling 59 so that, when engaged with the coupling 59, the coupling 59 rotates freely relative to the drive shaft 470 based on a predetermined angle. Note that "free rotation" refers to the rotation of the coupling 59 relative to the drive shaft 470, and refers to a state in which only the coupling 59 rotates and no rotational force is transmitted to the drive shaft 470. The angle at which the drive shaft 470 can rotate freely relative to the fitting hole 601 is configured to be smaller than the angle at which the guide inclined surface 478 of the guide portion 471 can guide the fitting main body 475 into the fitting recess 477. Note that in FIGS. 13 and 15, the angle at which the drive shaft 470 rotates freely relative to the coupling 59 is exaggerated for clarity.

[0040] Returning to FIG. 12, on the outside of the housing 49, a A mounting member B is placed on the mounting member B. A boss portion 63 is arranged on the outer surface of the mounting member B, and a bushing 64 is arranged at the axis of the boss portion 63. The bushing 64 is fixed by a bolt 62 so that it does not come off from the boss portion 63 in the axial direction. A secondary gear 65 that meshes with the primary gear 58 is fitted into the bushing 64. A positioning element 66 is fitted onto the portion of the bushing 64 that protrudes from the secondary gear 65, and the positioning element 66 rotates together with the secondary gear 65.

[0041] An angle sensor (rotary encoder) 67 is disposed outside the positioning element 66, and the angle sensor 67 detects the rotation angle of the positioning element 66 which rotates together with the secondary gear 65. That is, the reducer 45 is provided with an angle sensor 67 (angle detection means) which detects the rotation angle of the rotating shaft 56, and the rotation angle of the rotating shaft 56 is detected by the angle sensor 67 and input to the control unit 48.

[0042] Furthermore, the angle sensor 67 has an output signal line connected to an input terminal of the control unit 48 , and the positioning element 66 is connected to the input side of the angle sensor 67 .

[0043] The sprinkler truck is operated by an operator using a tank-side operating unit F (see FIG. 1) located at the front upper part of the frame 3. An example of the flow of water W in the sprinkler truck will be shown below.

[0044] In this embodiment, at least an automatic priming mode switch S1 and a water intake mode switch S2 are arranged on the tank-side operation unit F. When the automatic priming mode switch S1 is operated by an operator, the water intake hose 13 immersed in the water tank 12 is operated to prepare for water intake, that is, to send water W from the priming chamber 6 to the water intake hose 13. When the water intake mode switch S2 is operated by an operator, water W is filled into the tank 4 via the water intake hose 13, and the full water sensor 11 indicates that the tank 4 is full.

[0045] Furthermore, the discharge operation from the front sprinkler nozzles 9,9 and the rear sprinkler nozzles 10,10 is performed by a cab operation unit, which is located in the cab 2 (for example, on the dashboard). In this case, a front sprinkler switch is provided for turning on and off the discharge from the front sprinkler nozzles 9,9, and a rear sprinkler switch is provided for turning on and off the discharge from the rear sprinkler nozzles 10,10.

[0046] The sprinkler operation of the sprinkler truck having the above configuration is performed as follows: Assume that the tank 4 is full of water W or nearly full, the engine (PTO) is running, the operator opens the gate valves 24, 24, and the front sprinkler switch in the cab operation unit located in the cab 2 is turned on.

[0047] In this case, the control unit 48 closes the priming valve 26, the suction valve 28, and the rear sprinkler valve 41, opens the front valve 25, rotates the ball 46 of the directional control valve 31 to the sprinkler position, opens (connects) the tank piping 15, the junction piping 19, the front piping 30, and the front sprinkler piping 17, and water W is ejected from the front sprinkler nozzles 9, 9 of the sprinkler truck.

[0048] At this time, the control unit 48 outputs a drive signal to the drive means, i.e., the electric motor 34, to open from port [a] to port [d], thereby driving the rotary shaft 56 of the reducer 45. As a result, the coupling 59 is engaged in the circumferential direction.

[0049] Furthermore, when the forward sprinkling switch of the operator's cab operation unit is turned OFF, the control unit 48 closes the front valve 25, and the water W from the forward sprinkling nozzles 9,9 is stopped.

[0050] The pump 32 may also discharge water W from the discharge pipe 21 by water force. In this case, the control unit 48 closes the priming valve 26, the suction valve 28, and the rear sprinkler valve 41, closes the front valve 25, rotates the ball 46 of the directional switching valve 31 to the water discharge position, opens (communicates) the tank pipe 15, the junction pipe 19, the front pipe 30, the inlet pipe 35, and the outlet pipe 37, and discharges the water W from the discharge pipe 21 of the sprinkler truck.

[0051] At this time, the control unit 48 outputs a drive signal to the electric motor 34 to open from port [a] to port [b] and from port [c] to port [d], thereby driving the rotating shaft 56 of the reducer 45. As a result, the coupling 59 is engaged in the circumferential direction.

[0052] When the rear sprinkler switch on the cab operating unit located in the cab 2 is turned ON, the operator opens the gate valves 40, 40, and the control unit 48 opens the rear sprinkler valve 41, causing water W to be discharged from the rear sprinkler nozzles 10, 10 under its own weight. When the rear sprinkler switch is turned OFF, the control unit 48 closes the rear sprinkler valve 41, stopping the water W being discharged under its own weight from the rear sprinkler nozzles 10, 10. It is possible that both the front sprinkler switch and the rear sprinkler switch are turned ON.

[0053] Now, consider a case where there is a shortage of water W in tank 4. In this case, in order to fill tank 4 with water W, the sprinkler truck is parked near water tank 12 and the tip of water suction hose 13 (strainer 29) is immersed in water tank 12. The engine remains running.

[0054] Then, the operator turns ON the automatic priming mode switch S1 of the tank-side operation unit F. This causes the control unit 48 to open the priming valve 26 and drive the electric motor 34 to circumferentially engage the reducer-side portion 61 of the reducer 45 with the drive shaft-side portion 60, rotating the ball 46 of the directional control valve 31 to a position where it opens from port [a] to port [d]. This connects the junction pipe 19 and the front pipe 30. The other valves that are closed by the control unit 48 are the rear sprinkler valve 41 and the front valve 25.

[0055] Priming pipe 16 is arranged in priming chamber 6, which is partitioned within tank 4, and water W in priming chamber 6 flows out from junction pipe 19, front pipe 30, and suction pipe 18, and flows into suction hose 13. In other words, to store water W in tank 4, water W in priming chamber 6 is used to prime the priming path by allowing it to fall naturally. Furthermore, the standby time for water W to flow into suction hose 13 is set by control unit 48 for a predetermined time (e.g., 20 seconds). This completes the automatic priming mode.

[0056] When the automatic priming mode ends and the operator turns on the suction mode switch S2, the control unit 48 transitions to the suction mode. In the suction mode, the pump 32 of the direction switching circuit 20 is used. To achieve this, the control unit 48 drives the electric motor 34, circumferentially engaging the reducer side portion 61 of the reducer 45 with the drive shaft side portion 60, and rotates the ball 46 of the directional switching valve 31 to the ports [d] and [b]. The control unit 48 also rotates the ball 46 to a position where the ball 46 opens from the port [d] to the port [b] and from the port [c] to the port [a]. This connects the suction pipe 18, the forward pipe 30, and the inlet pipe 35, and also connects the outlet pipe 37, the junction pipe 19, and the priming pipe 16. Water W from the water storage tank 12 is transferred from the priming chamber 6 to the tank 4.

[0057] When pump 32 is driven, water W from water tank 12 flows into suction hose 13. In the automatic priming mode, suction hose 13 is sufficiently filled with water W from priming chamber 6 as priming water, so water W from water tank 12 can be easily sucked into tank 4. Tank 4 is equipped with full water sensor 11, which can detect when the tank is full.

[0058] As described above, the water W in the sprinkler truck flows through ports [a], [b], [c], and [d] by rotating the ball 46 of the directional switching valve 31 of the directional switching circuit 20 to form a piping route that corresponds to the manner in which the water W is to flow, but it is difficult to directly measure the rotation angle of the ball 46 of the directional switching valve 31.

[0059] Therefore, the ball 46 is driven via a driving member such as the reducer 45 or the coupling 59, and the control unit 48 detects the amount of rotation of the positioning element 66. That is, in this embodiment, the angle sensor 67 detects the amount of rotation of the positioning element 66, thereby making it possible to detect the amount of rotation of the engaging portion connected to the positioning element 66.

[0060] Next, the rotation of the engagement portion and drive shaft portion 470 will be described with reference to Figures 13 to 15. Here, Figures 13(a) to 13(d) and Figures 14(a) to 14(d) each show the state of the drive shaft portion 470 and the guide portion 471 at the same time. In Figure 14, in order to show the state of the guide portion 471 in a simplified manner, the fitting main body portion 475 is depicted as moving linearly, but in reality, the fitting main body portion 475 moves in an arc, and the fitting receiving portions 473 are arranged at intervals in the circumferential direction of the arc.

[0061] First, a case where insufficient rotation occurs in the drive shaft 470 will be described. As shown in Figure 13(a), rotation of the rotary shaft 56 rotates the coupling 59 serving as the engaging part, causing the fitting hole 601 of the drive shaft side part 60 of the coupling 59 to rotate. Here, a gap S is formed between the fitting hole 601 and the drive shaft 470, so initially only the fitting hole 601 rotates freely. In other words, due to the gap S, only the fitting hole 601 rotates, and the rotational force of the fitting hole 601 is not transmitted to the drive shaft 470, so the drive shaft 470 does not rotate.

[0062] 13(b), when the fitting hole portion 601 rotates by the amount of the gap S, the drive shaft portion 470 comes into contact with the fitting hole portion 601. After the drive shaft portion 470 comes into contact with the fitting hole portion 601, the drive shaft portion 470 also rotates in accordance with the rotation of the fitting hole portion 601.

[0063] As shown in FIGS. 14(a) and 14(b), the fitting main body 475 moves in accordance with the rotation of the drive shaft 470. Specifically, as shown in FIG. 14(a), when the drive shaft side portion 60 is rotating freely relative to the drive shaft 470, the fitting main body 475 remains fitted in the fitting recess 477 and does not move. Furthermore, as shown in FIG. 14(b), when the drive shaft 470 comes into contact with the fitting hole 601 and begins to rotate, the fitting main body 475 also begins to move. When the fitting main body 475 moves, it first disengages from the fitting recess 477. Specifically, as the drive shaft 470 moves in the movement direction, the fitting main body 475 moves along the guide inclined surface 478 and is pushed up toward the fitting base 474 against the biasing force of the biasing portion 476, thereby disengaging the fitting recess 477 from the fitting main body 475. The disengaged fitting main body 475 moves in the movement direction in accordance with the rotation of the drive shaft 470. In this embodiment, the fitting main body 475 slides on the surface of the case 31A.

[0064] As shown in FIG. 13(c), when the fitting hole 601 rotates a predetermined angle (e.g., 90 degrees), the angle sensor 67 detects the predetermined rotation of the rotary shaft 56. The control unit 48 determines that the drive shaft 470 is positioned corresponding to the stop position of the ball 46, and stops the drive of the drive means (rotation of the electric motor 34), thereby stopping the rotation of the fitting hole 601. However, at this point, the drive shaft 470 has not rotated 90 degrees and has not yet fully reached the stop position. In other words, in this state, the ball 46 is not positioned at the actual stop position. In other words, the angle by which the drive shaft 470 rotates freely relative to the fitting hole 601 at the time the rotation of the fitting hole 601 stops is less than the predetermined angle by the amount of rotation. Furthermore, if there is a deviation in the detection by the angle sensor 67, a further deviation will occur. 14(c), since the angle of the guide inclined surface 478 is smaller than the angle at which the fitting main body portion 475 is guided into the fitting recess 477, when the rotation of the fitting hole portion 601 stops, the fitting main body portion 475 is not completely fitted into the fitting recess 477 and is positioned so as to abut only on one of the guide inclined surfaces 478. As shown in FIG. 14(d), when the fitting main body portion 475 is positioned on the guide inclined surface 478, the fitting main body portion 475 is urged toward the fitting receiving portion 473 by the urging portion 476, and the fitting main body portion 475 moves along the guide inclined surface 478 to the fitting recess 477. In other words, the urging force of the urging portion 476 is converted by the guide inclined surface 478 into a force in the rotation direction of the fitting portion 472, and the fitting main body portion 475 moves along the guide inclined surface 478 to the fitting recess 477. 13(d), as fitting main body 475 moves, drive shaft 470 to which fitting portion 472 is fixed also rotates and moves to a position corresponding to the stop position of ball 46. Therefore, when fitting hole 601 rotates the biasing main body until it is positioned on guide inclined surface 478, drive shaft 470 moves to a position corresponding to the stop position of ball 46. Therefore, even if there is some deviation in the rotation angle of fitting hole 601, drive shaft 470 stops at a position corresponding to the stop position of ball 46, so ball 46 can be positioned at the stop position.

[0065] 15(a) to 15(c), a case will be described where control unit 48 rotates fitting hole portion 601 too much. First, control unit 48 rotates fitting hole portion 601 by a predetermined angle (for example, 90 degrees) from the state of FIG. 15(a) to the state of FIG. 15(b), and drive shaft portion 470 is positioned at a position corresponding to the stop position of ball 46. Here, fitting main body portion 475 is fitted into fitting recess 477, so that drive shaft portion 470 is restricted in its rotation by fitting portion 472, and drive shaft portion 470 does not rotate any further. Here, even if there is a deviation in the rotation angle of the rotation shaft 56 detected by the angle sensor 67 and the control unit 48 rotates the rotation shaft 56 beyond a predetermined angle (for example, 90 degrees), as shown in Figure 15(c), the fitting hole 601 rotates in a state where the rotation of the drive shaft 470 is restricted, and therefore the fitting hole 601 rotates freely relative to the drive shaft 470. Therefore, even if the control unit 48 rotates the fitting hole 601 too much, the drive shaft 470 stops at a position corresponding to the stop position of the ball 46, and therefore the ball 46 can be located at the stop position.

[0066] As described above, since fitting main body 475 is biased toward fitting receiver 473 by biasing portion 476, fitting main body 475 is guided to move to fitting recess 477 when it approaches guide inclined surface 478, and drive shaft 470 is guided to a position corresponding to the stop position of the valve disc, and the engagement portion can rotate freely relative to drive shaft 470. Therefore, even if there is a deviation in the amount of rotation of the rotation shaft detected by angle sensor 67 and a deviation in the angle at which control unit 48 rotates the engagement portion, the deviation can be absorbed by the idle rotation, and drive shaft 470 can be positioned at the stop position. Therefore, it is possible to prevent switching failure of ball 46 (valve disc) from occurring.

[0067] The above describes an embodiment of the present invention using an example, but the present invention is not limited to the above embodiment, and various modifications can be made within the scope that does not deviate from the gist of the present invention.

[0068] For example, the case where the fitting portion 472 is fixed to the drive shaft portion 470 has been described, but the present invention is not limited to this case, and the fitting receiving portion 473 may be configured to be fixed to the drive shaft portion 470.

[0069] Furthermore, the directional control valve 31 has been described as a four-way valve, but it is not limited to this and can also be configured as a three-way valve or a five-way valve.

[0070] Furthermore, although the case where the engaging portion is the coupling 59 has been described, the present invention is not limited to this case. For example, the rotating shaft 56 (the output shaft of the reducer 45) may be configured as the fitting hole portion 601 serving as the engaging portion, and the rotating shaft 56 may be configured to directly engage with the drive shaft portion 470.

[0071] In addition, the case where the drive shaft portion 470 is a rod-shaped shaft, the engagement portion has a cylindrical portion with a hole into which the drive shaft portion 470 can fit, and the drive shaft portion 470 is inserted into the hole in the engagement portion has been described, but this is not limited to such a case, and the engagement portion may have a rod-shaped shaft and the drive shaft portion 470 may be cylindrical.

[0072] Furthermore, although the fitting receiving portion 473 has been described as being formed on the case 31A, it is not limited to this case and may be provided somewhere other than the case 31A as long as it does not rotate when the drive shaft portion 470 rotates.

[0073] Furthermore, although the case where the guide inclined surface 478 is provided on one side and the other side of the fitting recess 477 in the movement direction of the fitting main body 475 has been described, the present invention is not limited to this case, and when the rotation direction of the drive shaft 470 is fixed to one direction, the guide inclined surface 478 may be provided on only one side. In such a configuration, it is preferable that the side where the guide inclined surface 478 is not provided is configured so as not to hinder the movement of the fitting main body 475.

[0074] Furthermore, although the fitting receiving portion 473 has been described as being a conical recess, it is not limited to this shape and can also be configured, for example, to have a guide inclined surface which is a flat inclined surface and a fitting recess which is a spherical recess.

[0075] Furthermore, although the fitting main body 475 has been described as being spherical, the shape is not limited to this and various shapes can be adopted, such as a pointed shape or a bullet-shaped shape with a rounded tip.

[0076] In addition, in the embodiment of the present invention, the valve drive portion 47 of the ball 46 and the rotating shaft 56 of the reducer 45 are connected by an Oldham coupling 59. The reducer 45 can also be configured to be removable via the coupling 59. The engaging portion can also be configured to slide axially or radially to drive the valve body (ball 46).

[0077] If the directional control valve 31 and the reducer 45 are detachable, the directional control valve 31 can be attached to the tank car. The reducer 45 can be removed while it is still installed. Therefore, if a problem occurs with the electric motor 34 or the reducer 45, the directional control valve 31 can be operated manually.

[0078] In the above configuration, an example in which the drive means has a reducer has been shown, but a direct drive electric motor without a reducer may be used, with an engaging portion provided on the motor output shaft 34a. Also, the reducer of the drive means has been described as reducer 45 that performs primary reduction with worm gear mechanism 52 and secondary reduction with gear train 54 connected to worm wheel 53 on the output side of worm gear mechanism 52. However, although not shown, it may also be a reducer that performs tertiary reduction.

[0079] Furthermore, the present invention does not have to be a water truck, but may be a tank truck having a tank for transporting oil or chemicals. [Explanation of symbols]

[0080] 1...car body, 2...operator's cab, 4...tank, 6...priming chamber, 15...tank piping, 16...priming piping, 17...front sprinkler piping, 18...suction piping, 19...junction piping, 20...direction switching circuit, 22...rear sprinkler piping, 30...front piping, 31...directional switching valve, 32...pump, 34...electric motor (driving means), 34a...output shaft, 35...inlet piping, 37...outlet piping, 45...reduction gear (driving means), 46...ball, 47...valve drive portion, 470...drive shaft portion, 471...guide portion, 472...fitting portion, 473...fitting receiving portion, 474...fitting base, 475...fitting Main body portion, 476... biasing portion, 477... fitting recess, 478... guide inclined surface, 48... control portion, 50... reduction mechanism, 52... worm gear mechanism, 53... worm wheel, 54... gear train, 55... output gear, 56... rotating shaft, 58... primary gear, 59... coupling (engagement portion / driving means), 60... drive shaft portion side, 601... fitting hole portion, 61... reducer side portion, 65... secondary gear, 66... positioning element, 67... angle sensor (rotary encoder), W... water, F... tank side operation portion, B... mounting member, S... gap

Claims

1. A tank that can be mounted on the vehicle body, a pipe for discharging the liquid in the tank and for drawing the liquid into the tank; a directional switching valve provided in the piping, the directional switching valve having a valve body and a valve drive unit that rotates the valve body, and the rotation of the valve body switches the path of the piping; a driving means having an engaging portion that engages with the valve driving portion, the engaging portion rotating to generate a driving force that rotates the valve driving portion; a sensor for detecting the amount of rotation of the engagement portion; a control unit that controls the rotation of the engagement unit in accordance with the detection result of the sensor, the control unit is configured to drive and control the drive means to stop the valve element at a plurality of stop positions defined corresponding to the respective flow paths so that the paths in the piping become a plurality of different flow paths, the valve drive portion includes a drive shaft portion that engages with the engagement portion and is rotated by the engagement portion, and a guide portion that guides the drive shaft portion to a position corresponding to a stop position of the valve body, the drive shaft engages with the engaging portion such that, when the engaging portion rotates in at least one of one and the other of the rotation directions, the engaging portion rotates freely by a predetermined angle from each of the plurality of stop positions relative to the drive shaft, the guide portion includes a fitting receiving portion including a fitting recess including a guide inclined surface that is an inclined surface that guides the fitting portion, the fitting recess into which the fitting portion can be fitted when the valve driving portion is positioned at the stop position, the fitting portion is configured to move relative to the fitting recess in accordance with the rotation of the drive shaft portion, one of the fitting portion and the fitting receiving portion is fixed to the drive shaft portion and rotates coaxially with the drive shaft portion; the other of the fitting portion and the fitting receiving portion is fixed so as not to rotate regardless of rotation of the drive shaft portion, The fitting portion of the tank car includes a fitting main body portion that fits into the fitting recess, and a biasing portion that biases the fitting main body portion toward the fitting receiving portion.

2. 2. The tank car according to claim 1, wherein the guide inclined surfaces are arranged on one side and the other side of the fitting recess in a direction in which the fitting main body moves relative to the fitting recess as the drive shaft portion rotates.

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