Tanker truck

Abstract

To provide a tank lorry that can efficiently discharge liquified gas in a tank.SOLUTION: A first inclined part 62a and a third inclined part 62c extending in lateral direction, of second piping 62 for a delivery pipe 6 have slopes inclining downward, from an upstream side to a downstream side, so that a vehicle body inclines in a lateral direction with respect to a horizontal direction, which enables liquified gas to be easily fed to each of a pair of pressurizing evaporators 7a and 7b, even in an inclined state where one of the pressurizing evaporators 7a and 7b is lifted up. Therefore, it is possible to return sufficient quantities of vaporized gas from each of the pair of pressurizing evaporators 7a and 7b into a tank 5, which enables liquified gas in the tank 5 to be efficiently discharged.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a tank truck, and more particularly to a tank truck that can efficiently discharge liquefied gas from a tank. [Background technology]

[0002] A known technology is to send liquefied gas from a tank to a pressurized evaporator, and then use the pressure of the gas generated by evaporating the liquefied gas to expel the liquefied gas from the tank to the outside. For example, Patent Document 1 describes a technology in which pressurized evaporators are provided on both sides of the vehicle in the width direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-193690 A (e.g., paragraph 0028, Figures 1 and 2) Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of the conventional technology described above, when pressure evaporators are provided on both sides in the vehicle width direction, if the vehicle body tilts in the vehicle width direction relative to the horizontal, one of the pressure evaporators will be raised. When liquefied gas in the tank is sent to the pressure evaporator in this state, liquefied gas is easily sent to the other pressure evaporator, but not enough liquefied gas is sent to the raised pressure evaporator. As a result, the amount of vaporized gas returned from the pressure evaporator to the tank becomes insufficient, resulting in the problem of inefficient discharge of liquefied gas from the tank.

[0005] The present invention has been made to solve the above-mentioned problems, and has as its object to provide a tank truck that can efficiently discharge liquefied gas from a tank. [Means for solving the problem]

[0006] In order to achieve this object, the tank truck of the present invention comprises a tank, a chassis frame supporting the tank, a pair of pressurized evaporators disposed on both sides of the chassis frame in the vehicle width direction, for vaporizing the liquefied gas in the tank and returning it to the tank, and for pressurizing the inside of the tank, and an inlet of the pair of pressurized evaporators. The entrance is provided facing the center of the vehicle width. and a delivery pipe that connects the tank and delivers the liquefied gas in the tank to each of the pair of pressurized evaporators, and a portion of the delivery pipe that extends in the vehicle width direction has a gradient that slopes downward from the upstream side to the downstream side. The delivery pipe includes a first pipe extending downward from the rear of the tank, and a second pipe branching from a lower end of the first pipe in the vehicle width direction and connected to the inlets of the pair of pressurized evaporators, the connection position of the first pipe and the second pipe being set at positions spaced apart in the front-rear direction from the connection position of the second pipe and the inlets of the pressurized evaporators, the second pipe being composed of a pair of first inclined portions extending from the lower end of the first pipe to both sides in the vehicle width direction, a pair of second inclined portions extending in the front-rear direction from outer ends of the pair of first inclined portions, and a pair of third inclined portions extending outward in the vehicle width direction from the front-rear direction ends of the pair of second inclined portions and connected to the inlets of the pressurized evaporators, and having a gradient that slopes downward from the upstream side to the downstream side, and the connection portions of the first inclined portion, the second inclined portion, and the third inclined portion are curved. do. [Effects of the Invention]

[0007] According to the tank truck of claim 1, the portion of the delivery pipe extending in the vehicle width direction has a gradient that slopes downward from the upstream side to the downstream side, so even when the vehicle body is tilted in the vehicle width direction with respect to the horizontal direction and one of the pressurized evaporators is in a raised tilted state, liquefied gas can be easily delivered to the raised pressurized evaporator. Therefore, a sufficient amount of vaporized gas can be returned from each of the pair of pressurized evaporators to the tank, which has the effect of efficiently discharging the liquefied gas in the tank.

[0008] Furthermore, according to the tank truck described in claim 1, the delivery pipe comprises a first pipe extending downward from the rear of the tank, and a second pipe branching from the lower end of the first pipe in the vehicle width direction and connected to each of the pair of pressurized evaporators, so that liquefied gas can be delivered to each of the pair of pressurized evaporators through a single first pipe.

[0009] Since the connection position of the first pipe and the second pipe and the connection position of the second pipe and the inlet of the pressurized evaporator are set at positions separated in the longitudinal direction, a portion of the second pipe is formed to extend in the longitudinal direction. In contrast, in claim 1, since the second pipe has a downward slope from the upstream side to the downstream side, liquefied gas can be easily delivered to each of the pair of pressurized evaporators regardless of whether the vehicle body is tilted in the transverse direction or the longitudinal direction. This has the effect of enabling more efficient delivery of liquefied gas from the tank.

[0010] According to the tank truck of claim 1, the second pipe is composed of the first inclined portion, the second inclined portion, and the third inclined portion, and the connecting portion of each inclined portion is curved, so that when a load that expands or contracts the second pipe in the front-rear direction acts on the second pipe, the second pipe can be deformed to absorb the load, thereby having the effect of suppressing damage to the second pipe.

[0011] According to the tank truck of claim 2, in addition to the effects of the tank truck of claim 1, since the downward inclination of the delivery pipe is constant, the ease of flow of the liquefied gas can be made uniform over the entire length of the inclined portion of the delivery pipe. This makes it easier for the liquefied gas to be delivered to each of the pair of pressurized evaporators, and has the effect of enabling the liquefied gas in the tank to be discharged more efficiently.

[0012] Claim 3 According to the tank truck described above, 1 or 2In addition to the effects of the tank truck described in 1., the present invention provides the following effect: The delivery pipe that delivers the liquefied gas in the tank to the pressurized evaporator and the return pipe that returns the gas vaporized by the pressurized evaporator to the tank connect the tank and the pressurized evaporator. Therefore, for example, if the pressurized evaporator is configured to be fixed to the chassis frame, the routes of the delivery pipe and the return pipe must be set to match the shape of the chassis frame, etc.

[0013] In contrast, the claim 3 In the tank unit, a subframe is fixed to the tank unit, which integrates the tank, delivery pipe, pressurized evaporator, and return pipe, and the tank unit is mounted to the chassis frame via the subframe, so the routes of the delivery pipe and return pipe can be set without depending on the shape of the chassis frame. Furthermore, by positioning the connection position of the first pipe and the second pipe passing between a pair of chassis frames below the chassis frames, the route of the second pipe can be set without depending on the shape of the chassis frame. This has the effect of allowing the tank unit to be mounted to chassis frames of various shapes. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a side view of a tank truck according to an embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. 3 is a partially enlarged cross-sectional view of the tank truck taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a partially enlarged cross-sectional view of the tank truck showing a portion IV in FIG. 3 in an enlarged manner. [Figure 5] FIG. 4 is a partially enlarged cross-sectional view of the tank truck taken along line VV in FIG. 3. [Figure 6] FIG. 6 is a partially enlarged cross-sectional view of the tank truck taken along line VI-VI in FIG. 5. [Figure 7] 7 is a partially enlarged bottom view of the tank truck as seen in the direction of arrow VII in FIG. 6. [Figure 8] FIG. 10 is a partially enlarged cross-sectional view of a tank truck according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0015] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. First, the overall configuration of a tank truck 1 will be described with reference to Fig. 1. Fig. 1 is a side view of a tank truck 1 according to one embodiment of the present invention.

[0016] 1, the tank truck 1 is configured as a vehicle that transports liquefied gas (for example, LNG) and includes a plurality of wheels 2. The wheels 2 support a chassis frame 3 that forms the framework of the vehicle body.

[0017] The chassis frame 3 is a frame that extends in the front-to-rear direction of the vehicle body (left-to-right direction in FIG. 1 ), and a cab 30 configured as a driver's seat is disposed at the front end portion of the chassis frame 3. A tank 5 is supported (mounted) via a subframe 4 on the chassis frame 3, which is located rearward of the cab 30. Before the tank 5 is supported on the chassis frame 3 (before mounting), the subframe 4 is fixed to the tank 5 by welding or the like, and the tank 5 is mounted on the chassis frame 3 by fixing the subframe 4 to the chassis frame 3 with a fixture (not shown) or by welding.

[0018] Tank 5 is a cylindrical tank for carrying liquefied gas. A delivery pipe 6 is connected to the rear of tank 5, and a pressurized evaporator 7 is connected to tank 5 via delivery pipe 6. Pressurized evaporator 7 is a device that vaporizes the liquefied gas delivered from tank 5 through delivery pipe 6 to produce gas, and returns the gas to tank 5. The detailed configuration of delivery pipe 6 will be described later.

[0019] Next, the mounting structure of the pressurized evaporator 7 will be described with reference to Figures 2 to 4. Figure 2 is a partially enlarged perspective view of the tank truck 1, Figure 3 is a partially enlarged cross-sectional view of the tank truck 1 taken along line III-III in Figure 2, and Figure 4 is a partially enlarged cross-sectional view of the tank truck 1 taken along line IV in Figure 3.

[0020] 2 and 3, side frames 40 are connected to the side surfaces of the subframe 4. The subframe 4 extends rearward beyond the tank 5, and in the following description, the portion of the subframe 4 that is connected to the tank 5 is referred to as a connecting portion 4a, and the portion that protrudes rearward beyond the tank 5 from the connecting portion 4a is referred to as a protruding portion 4b (see FIG. 3). Of the multiple side frames 40, the one connected to the connecting portion 4a will be referred to as a side frame 40a, and the one connected to the protruding portion 4b will be referred to as a side frame 40b.

[0021] The side frames 40a, 40b are frames with a C-shaped cross section (channel steel shape in this embodiment) that protrude outward in the left-right direction (vehicle width direction) beyond the tank 5. The pressurized evaporator 7 is fixed to the subframe 4 via these side frames 40a, 40b. That is, the pressurized evaporator 7 is connected to the chassis frame 3 via the side frames 40a, 40b and the subframe 4, but is not directly connected to the chassis frame 3. This structure prevents a load caused by the deformation from acting directly on the pressurized evaporator 7 from the chassis frame 3, even if the chassis frame 3 is deformed, for example, by vibrations while the tank truck 1 is traveling. Furthermore, since the subframe 4 is fixed to the cylindrical tank 5, it has a relatively high rigidity and is difficult to deform. Therefore, a load caused by deformation of the chassis frame 3 can be prevented from acting on the pressurized evaporator 7 via the subframe 4.

[0022] A plurality of side frames 40a, 40b (three in this embodiment) are provided at predetermined intervals in the front-rear direction, and the pressurized evaporator 7 is supported (fixed) on the undersides of the plurality of side frames 40a, 40b. As a result, even if the sub-frame 4 is deformed due to the above-described deformation of the chassis frame 3, the load caused by the deformation can be prevented from acting on the pressurized evaporator 7 via the side frames 40a, 40b. In other words, compared to when the pressurized evaporator 7 is fixed directly to the sub-frame 4, the load acting on the pressurized evaporator 7 when the chassis frame 3 is deformed can be reduced.

[0023] Here, the connecting portion 4a of the subframe 4 that is connected to the tank 5 is configured to have relatively high rigidity compared to the protruding portion 4b that protrudes rearward beyond the tank 5. Because the side frame 40a is connected to the connecting portion 4a with high rigidity, the pressurized evaporator 7 can be fixed using the connecting portion 4a of the subframe 4, which is relatively resistant to deformation. This prevents the load that occurs when the chassis frame 3 deforms from acting on the pressurized evaporator 7 via the subframe 4 and the side frame 40a. In this way, by reducing the load that acts on the pressurized evaporator 7 when the chassis frame 3 deforms, damage to the pressurized evaporator 7 can be prevented.

[0024] A connecting frame 41 for fixing the pressurized evaporator 7 is connected to the undersides of the side frames 40a, 40b. The connecting frame 41 is a frame with a C-shaped cross section (a channel steel shape in this embodiment) extending in the left-right direction, and a frame body 70 of the pressurized evaporator 7 is fixed to the underside of the connecting frame 41. The frame body 70 is a rectangular parallelepiped frame that forms the outer shell of the pressurized evaporator 7, and the inside of the frame body 70 houses the pipes of an inlet header 71, a serpentine pipe 72, and an outlet header 73, which will be described below.

[0025] The inlet header 71 is a pipe extending in the left-right direction at the front end portion of the frame 70, and the above-mentioned delivery pipe 6 is connected to the end portion of the inlet header 71 on the inner side in the left-right direction (towards the center of the vehicle width). Therefore, the liquefied gas in the tank 5 is introduced into the pressurized evaporator 7 through this inlet header 71. The connection port at the end portion on the inner side in the left-right direction of the inlet header 71, to which the delivery pipe 6 is connected, is the "inlet" of the pressurized evaporator 7.

[0026] One ends of a plurality of serpentine pipes 72 arranged on the left and right sides are connected to the inlet header 71. The serpentine pipes 72 are pipes for evaporating and vaporizing liquefied gas, and are composed of straight pipes 72a extending in the front-rear direction and U-shaped pipes 72b (see FIG. 3) that connect the ends of the straight pipes 72a together.

[0027] The front ends and rear ends of a plurality of vertically arranged straight pipes 72a are connected by U-shaped pipes 71b to form a single serpentine pipe 72. That is, the serpentine pipe 72 is provided so as to snake multiple times from the lower end (one end) to the upper end (the other end) of the pressurized evaporator 7.

[0028] The other end of each of the multiple serpentine pipes 72 is connected to an outlet header 73. The outlet header 73 is a pipe that extends in the left-right direction, and one end of the return pipe 8 is connected to the left-right center of the upper surface of the outlet header 73. Although not shown in the figure, the other end of the return pipe 8 is connected to the tank 5 through an equipment room 9, which will be described later.

[0029] In the pressurized evaporator 7 configured as described above, the liquefied gas introduced from the inlet header 71 is vaporized by heat exchange with the outside air as it flows through the serpentine pipe 72, and the vaporized gas is returned to the tank 5 via the outlet header 73 and the return pipe 8. As the liquefied gas flows into the serpentine pipe 72 and the flow of that gas stops, the serpentine pipe 72 may expand and contract in the front-to-rear direction. To allow for this expansion and contraction, the straight pipe 72a of the serpentine pipe 72 is slidably supported by a support member 74. This support structure will be described below.

[0030] The support member 74 is a plate-like body extending in the left-right direction, and both left and right ends of the support member 74 are fixed to the frame body 70. The support member 74 has a plurality of through holes (not shown) formed in a row in the left-right direction, and the straight pipe 72a of the serpentine pipe 72 is slidably inserted into each of the plurality of through holes. This allows the serpentine pipe 72 to be supported by the support member 74 while allowing the serpentine pipe 72 (straight pipe 72a) to expand and contract. A plurality of support members 74 (six in this embodiment) are arranged in a row in the vertical direction, and the plurality of support members 74 are connected to each other by connecting rods 75 (see FIG. 4).

[0031] 4, the upper end portion of the connecting rod 75 is inserted into the through hole 41a of the connecting frame 41 and fixed to the connecting frame 41, and the support member 74 is fixed to the lower surfaces of the side frames 40a, 40b via the connecting rod 75 and the connecting frame 41. As a result, the support member 74 can be supported not only by the frame body 70 that supports both the left and right ends of the support member 74, but also by the side frames 40a, 40b, thereby preventing damage to the pressurized evaporator 7.

[0032] That is, the load from the serpentine pipe 72 as described above is applied to the connecting portion between the support member 74 and the frame 70 via the support member 74 due to vibrations during travel, etc. Therefore, for example, in a configuration in which only the upper surface of the frame 70 of the pressurized evaporator 7 is fixed to the side frames 40a, 40b (connecting frame 41), the load as described above tends to concentrate on one portion of the frame 70, making the pressurized evaporator 7 (frame 70) more susceptible to damage.

[0033] In contrast, in this embodiment, multiple support members 74 arranged vertically are integrated by a connecting rod 75, and the upper ends (connecting rods 75) of the integrated support members 74 are supported by the side frames 40a, 40b via the connecting frame 41. Therefore, the load acting on the frame 70 can be reduced compared to when only the upper surface of the frame 70 is fixed to the side frames 40a, 40b (connecting frame 41). Furthermore, because the connecting rods 75 connecting the multiple support members 74 are fixed to the side frames 40a, 40b via the connecting frame 41, the fixed portions of the connecting rods 75 (upper ends of the support members 74) can be reinforced by the side frames 40a, 40b and the connecting frame 41. Therefore, damage to the pressurized evaporator 7 (frame 70) can be suppressed.

[0034] In this way, the support members 74 are supported by being suspended from the side frames 40a, 40b, and as shown in FIG. 3 , of the multiple support members 74 lined up in the front and rear, the support member 74 suspended from the side frame 40a supports both end portions of the serpentine pipe 72 (i.e., the connection portions with the inlet header 71 and the outlet header 73). The side frame 40a is connected to the connecting portion 4a, which has a relatively high rigidity among the subframes 4. Therefore, by connecting the serpentine pipe 72 to the inlet header 71 and the outlet header 73 near this side frame 40a, it is possible to prevent a load due to deformation of the chassis frame 3 from acting on these connection portions (areas where liquid leakage may occur). This makes it possible to prevent liquid leakage from occurring at the connection portions between the serpentine pipe 72 and the inlet header 71 and the outlet header 73.

[0035] On the other hand, since the side frame 40b is connected to the protruding portion 4b (which is not connected to the tank 5) and has lower rigidity than the connecting portion 4a, a load due to deformation such as twisting of the chassis frame 3 may act on the support member 74 (serpentine pipe 72) supported by this side frame 40b. In contrast, in this embodiment, as described above, the serpentine pipe 72 (straight pipe 72a) is supported in a slidable state on the support member 74, so even if a load due to deformation of the chassis frame acts on the support member 74 (serpentine pipe 72) via the side frame 40b, damage to the pressurized evaporator 7 due to the load can be suppressed.

[0036] In this embodiment, the protruding portion 4b is reinforced by a reinforcing frame 42 (see FIG. 5) or the like in order to reduce the influence of deformation of the chassis frame 3. This configuration will be described with reference to FIGS.

[0037] Fig. 5 is a partially enlarged cross-sectional view of the tank truck 1 taken along line VV in Fig. 3, and Fig. 6 is a partially enlarged cross-sectional view of the tank truck 1 taken along line VI-VI in Fig. 5. Note that Figs. 5 and 6 show only the essential parts of the tank truck 1, and omit the illustration of some of the configuration (for example, the structure of the pressurized evaporator 7).

[0038] 5 and 6, a pair of sub-frames 4 are provided at a predetermined interval in the left-right direction, and a pressurized evaporator 7 is fixed to each of the pair of sub-frames 4. In the following explanation, of the pair of pressurized evaporators 7, the one fixed to the left sub-frame 4 is referred to as pressurized evaporator 7a, and the one fixed to the right sub-frame 4 is referred to as pressurized evaporator 7b.

[0039] The pair of pressurized evaporators 7a, 7b are configured symmetrically. Therefore, for example, each component connected to the pressurized evaporator 7 (for example, the side frames 40a, 40b and the return pipe 8) is provided in each of the pair of pressurized evaporators 7a, 7b.

[0040] The protruding portions 4b of the pair of sub-frames 4 are connected to each other by a reinforcing frame 42. The reinforcing frame 42 is a frame that extends left and right and has a C-shaped cross section (in this embodiment, a channel steel shape), and the reinforcing frame 42 is disposed at a position that overlaps with each of the pair of left and right side frames 40b when viewed in the left-right direction (when viewed in the left-right direction in FIG. 5).

[0041] That is, the reinforcing frame 42 is disposed between the side frame 40b to which the left pressurized evaporator 7a is fixed and the side frame 40b to which the right pressurized evaporator 7b is fixed, thereby reinforcing the connecting portion between the protrusion 4b and the side frame 40b, which has a relatively low rigidity. This makes it possible to prevent deformation such as twisting of the subframe 4 (protrusion 4b) at this connecting portion, and therefore prevents the load caused by deformation of the chassis frame 3 from acting on the pressurized evaporator 7 via the subframe 4 and the side frame 40b.

[0042] Furthermore, assuming that a pair of left and right side frames 40b constitutes one set, a reinforcing frame 42 is disposed between each of the multiple sets (two sets in this embodiment) of side frames 40b lined up in the front-to-rear direction (see FIG. 7). That is, multiple reinforcing frames 42 (two in this embodiment) are provided lined up in the front-to-rear direction, thereby effectively reinforcing the pair of protrusions 4b. Note that, because the connecting portions 4a of the subframe 4 have relatively high rigidity, no reinforcing frame 42 is provided between the connecting portions 4a (between the pair of side frames 40a) (see FIG. 7).

[0043] An equipment room 9 is provided on the rear side of the tank 5 to cover the rear end of the tank 5, and this equipment room 9 also reinforces the protruding portion 4b of the sub-frame 4. Specifically, the equipment room 9 is formed in a box shape with an opening 90 (see Figure 5) on the rear side, and inside the equipment room 9 are provided operating devices and meters (neither of which is shown) that are operated during loading and unloading operations of liquefied gas. The left-right dimension of the floor plate 91 of the equipment room 9 is set to be larger than the distance between the pair of sub-frames 4, and the left and right ends of the floor plate 91 protrude laterally beyond the pair of sub-frames 4.

[0044] The floor panel 91 of the equipment room 9 extends rearward from the rear surface of the tank 5 (see Figure 6), and the rear end portion of the floor panel 91 extends to the side frame 40b located furthest rearward among the multiple side frames 40b.

[0045] The floor panel 91 of the equipment compartment 9 is fixed to the upper surface of the protruding portion 4b of the subframe 4 by welding or the like, so that the protruding portion 4b, which has a relatively low rigidity, can be reinforced by the floor panel 91 of the equipment compartment 9. This makes it possible to prevent deformation such as twisting of the subframe 4 (protruding portion 4b) at the connection portion between the protruding portion 4b and the side frame 40b, and therefore prevents the load caused by deformation of the chassis frame 3 from acting on the pressurized evaporator 7 via the subframe 4 and the side frame 40b. Furthermore, in addition to its function of storing equipment, the equipment compartment 9 can also have the function of reinforcing the protruding portion 4b.

[0046] The floor plate 91 of the equipment room 9 is also fixed to a plurality of reinforcing frames 42 (see FIG. 6) arranged in the front and rear by welding, etc. This also makes it possible to more effectively reinforce the protruding portion 4b, which has a relatively low rigidity.

[0047] As described above, the tank 5 and the pressurized evaporator 7 are connected by the delivery pipe 6 that delivers the liquefied gas in the tank 5 to the pressurized evaporator 7 and the return pipe 8 (see FIG. 3 ) that returns the gas vaporized by the pressurized evaporator 7 to the tank 5. Therefore, for example, if the pressurized evaporator 7 is configured to be fixed to the chassis frame 3, the routes of the delivery pipe 6 and the return pipe 8 must be set to match the shape of the chassis frame 3.

[0048] That is, the distance between the left and right opposing chassis frames 3 and the dimension in the left and right direction (width dimension) of the chassis frame 3 itself may differ depending on the type of vehicle that forms the base of the tank truck 1. Therefore, in a configuration in which the pressurized evaporator 7 is fixed to the chassis frame 3 (vehicle body side), the relative position between the tank 5 and the pressurized evaporator 7 changes depending on the type of vehicle (shape of the chassis frame 3), so it is necessary to change the routes of the delivery pipe 6 and the return pipe 8 depending on the type of vehicle. Also, it becomes necessary to process the chassis frame 3 in order to fix the pressurized evaporator 7.

[0049] In contrast to this, in this embodiment, the subframe 4, tank 5, delivery pipe 6, pressurized evaporator 7, and return pipe 8 are integrated into a tank unit, and the subframe 4 of the tank unit is fixed to the chassis frame 3, thereby mounting the tank unit to the chassis frame 3. In other words, since the pressurized evaporator 7 is fixed not to the vehicle body but to the tank unit side mounted to the vehicle body, the routes of the delivery pipe 6 and return pipe 8 connecting the tank 5 and pressurized evaporator 7 can be set without depending on the shape of the chassis frame 3. Furthermore, there is no need to process the chassis frame 3 in order to mount the pressurized evaporator 7. Therefore, the tank unit can be mounted to chassis frames 3 of various shapes (various vehicle models).

[0050] Next, a detailed configuration of the delivery pipe 6 will be described with reference to Fig. 5 to Fig. 7. Fig. 7 is a partially enlarged bottom view of the tank truck 1 as seen in the direction of arrow VII in Fig. 6.

[0051] 5 and 6, the delivery pipe 6 includes a first pipe 60 connected to the rear surface of the tank 5. In FIG. 6, the joint at the connection portion between the tank 5 and the first pipe 60 is hatched to omit the illustration of the inside.

[0052] The first piping 60 is composed of a horizontal section 60a extending rearward from the rear surface of the tank 5, and a hanging section 60b hanging downward from the rear end of the horizontal section 60a. Note that the horizontal section 60a extends horizontally when the tank truck 1 is stopped on a horizontal road surface (hereinafter referred to as "the stopped state of the tank truck 1"), but the horizontal section 60a may be configured to be inclined downward toward the rear end (downstream side) of the horizontal section 60a.

[0053] A pair of second pipes 62 branching out to the left and right are connected to the lower end of hanging portion 60b via a T-shaped joint 61. The pair of left and right second pipes 62 are configured symmetrically to each other.

[0054] The second piping 62 is formed to slope downward from the joint 61 (upstream side) to the inlet header 71 (downstream side) of the pressurized evaporators 7a, 7b. More specifically, when viewed in the front-rear direction, the second piping 62 is composed of a first inclined portion 62a extending outward in the left-right direction from the joint 61, a second inclined portion 62b extending forward from an outer left-right end of the first inclined portion 62a, and a third inclined portion 62c extending outward in the left-right direction from a front end of the second inclined portion 62b. In the following description, when the first to third inclined portions 62a to 62c are referred to collectively, they will be abbreviated as "individual inclined portions."

[0055] When the tank truck 1 is stopped, each inclined portion has a downward gradient (a gradient of 9° in this embodiment) from the upstream side to the downstream side relative to the horizontal direction. That is, because the first inclined portion 62a and the third inclined portion 62c extending in the left-right direction are each inclined downward, even when the vehicle body is tilted left-right relative to the horizontal direction, the first inclined portion 62a and the third inclined portion 62c can maintain their downward inclination relative to the horizontal direction. Therefore, even when the tank truck 1 is tilted relative to the horizontal direction and one of the pair of pressurized evaporators 7a, 7b is raised, liquefied gas can be easily delivered to the raised pressurized evaporator 7a, 7b. Therefore, a sufficient amount of vaporized gas can be returned from each of the pair of pressurized evaporators 7a, 7b to the tank 5, allowing the liquefied gas in the tank 5 to be efficiently discharged.

[0056] Furthermore, in addition to the first inclined portion 62a and the third inclined portion 62c, the second inclined portion 62b extending in the front-rear direction is also inclined downward, i.e., the entire second piping 62 is inclined downward, so that the liquefied gas can be easily delivered to each of the pair of pressurized evaporators 7a, 7b regardless of whether the vehicle body is inclined left-right or front-rear. Therefore, the liquefied gas in the tank 5 can be discharged more efficiently.

[0057] Furthermore, as described above, the shape of the chassis frame 3 may differ depending on the vehicle model, but because the connection position between the hanging portion 60b of the first pipe 60 and the first inclined portion 62a of the second pipe 62 is located below the chassis frame 3, the path of the second pipe 62 can be set without depending on the shape of the chassis frame 3. Therefore, the tank unit, in which the subframe 4, tank 5, delivery pipe 6, pressurized evaporator 7, and return pipe 8 are integrated, can be mounted on chassis frames 3 of various shapes (various vehicle models).

[0058] Here, the gradient of the road surface on which the tank truck 1 performs loading and unloading operations is generally 1 to 2 degrees. Therefore, the gradient of each inclined portion is preferably set to 3 degrees or more, and in this embodiment, it is set to 9 degrees. This allows each inclined portion to maintain a downward inclination with respect to the horizontal when the tank truck 1 is stopped on a general road surface, so that liquefied gas can be reliably delivered to each of the pair of pressurized evaporators 7a, 7b.

[0059] Furthermore, since the gradient of the downward inclination of the second piping 62 is set to a constant angle throughout the entire second piping 62 (each inclined portion), the ease of flow of the liquefied gas can be made uniform throughout the entire length of the second piping 62. This makes it easier for the liquefied gas to be delivered to each of the pair of pressurized evaporators 7a, 7b. Note that the outer ends in the left and right directions of the third inclined portion 62c of the second piping 62 are connected to the inlet header 71 via the joint 63, and the "entire" second piping 62 refers to the piping portion from the edge of the opening of the joint 61 to the edge of the opening of the joint 63.

[0060] 7, the connecting portions of the first inclined portion 62a, the second inclined portion 62b, and the third inclined portion 62c of the second pipe 62 are gently curved. That is, the second pipe 62 is formed in a substantially S-shape that connects the joints 61, 63 that are arranged at positions separated in the front-rear direction.

[0061] As a result, even if expansion and contraction of the second pipe 62 occurs as liquefied gas flows into and stops flowing into the second pipe 62, the curved portion of the second pipe 62 can be deformed to follow the expansion and contraction. Furthermore, even if a load that causes expansion and contraction similar to that described above acts on the second pipe 62 due to vibrations during travel or the like, the second pipe 62 can be deformed to absorb the load. Therefore, damage to the second pipe 62 can be suppressed.

[0062] The present invention has been described above based on the above embodiment, but the present invention is not limited to the above form in any way, and it can be easily inferred that various modifications and improvements are possible within the scope that does not deviate from the spirit of the present invention.

[0063] In the above embodiment, a case has been described in which a pair of pressurized evaporators 7a, 7b are fixed to the subframe 4 via the side frames 40a, 40b. However, for example, the pressurized evaporator 7 may be directly fixed to the subframe 4. Alternatively, the pressurized evaporator 7 may be fixed to only one of the connecting portion 4a or the protruding portion 4b of the subframe 4 via the side frames 40a, 40b. Alternatively, one or three or more pressurized evaporators 7 may be fixed to the subframe 4.

[0064] Here, a modified example in which one pressurized evaporator 7 is fixed to the subframe 4 will be described with reference to Fig. 8, but the same parts as in the above embodiment are given the same reference numerals and detailed description will be omitted. Fig. 8 is a partially enlarged cross-sectional view of the tank truck 1 in the modified example. Note that Fig. 8 is a cross-sectional view taken at a position corresponding to line VV in Fig. 3. Also, in Fig. 8, to simplify the drawing, the serpentine pipe 72 (see Fig. 2 or 3) connecting the inlet header 71 and the outlet header 73 is not shown.

[0065] As shown in Fig. 8, in the tank truck 1 of the modified example, one pressurized evaporator 7 is fixed so as to be suspended from a pair of left and right side frames 40a, 40b (see Fig. 2 or 3 for the side frame 40a) and a reinforcing frame 42. As in the above embodiment, the inlet header 71 extends to both the left and right sides from the downstream end of the third inclined portion 62c of the second piping 62 (via joints 63). The inlet header 71 is connected to an outlet header 73 via a serpentine pipe 72 (not shown) (see Fig. 2 or 3).

[0066] The outlet header 73 is a pipe extending to the left and right above the inlet header 71. A pair of outlet headers 73 are provided on the left and right sides of the hanging portion 60b of the first pipe 60, and the pair of outlet headers 73 are connected to the tank 5 via the return pipe 8.

[0067] In the tank truck 1 of this modified example, the pressurized evaporator 7 is also fixed to the sub-frame 4 via the side frames 40a, 40b and the reinforcing frame 42. That is, the pressurized evaporator 7 is connected to the chassis frame 3 via the side frames 40a, 40b, the reinforcing frame 42, and the sub-frame 4, and is not directly connected to the chassis frame 3. This structure prevents the load caused by the deformation from acting directly on the pressurized evaporator 7 from the chassis frame 3, even if the chassis frame 3 is deformed, such as twisted, due to vibrations or the like while the tank truck 1 is traveling.

[0068] In the above embodiment, the configuration has been described in which the protruding portion 4b of the sub-frame 4 is reinforced by the reinforcing frame 42 and the equipment chamber 9, but the reinforcing frame 42 and the equipment chamber 9 may be omitted.

[0069] In the above embodiment, the case where the upper end portion of the support member 74 is fixed to the side frames 40a, 40b via the connecting rod 75 and the connecting frame 41 has been described, but the upper end portion of the support member 74 may be fixed directly (or via the connecting rod 75) to the side frames 40a, 40b. Also, the support member 74 may be fixed to the frame body 70 only at its left and right ends.

[0070] In the above embodiment, the case where the inclined portion with a constant gradient is provided in the second pipe 62 of the delivery pipe 6 has been described, but the delivery pipe 6 may be configured so that the entire delivery pipe 6 is inclined downward when the tank truck 1 is stopped, or so that a part (for example, the second inclined portion 62b) or the entire second pipe 62 extends horizontally. Also, the gradient of the downward gradient may be changed in a partial region of the delivery pipe 6 (second pipe 62).

[0071] In the above embodiment, the case where the second pipe 62 from the first pipe 60 of the delivery pipe 6 branches to the left and right and is connected to a pair of pressurized evaporators 7a, 7b, i.e., the case where the liquefied gas is delivered to the pair of pressurized evaporators 7a, 7b through the common delivery pipe 6, has been described. However, a configuration in which a delivery pipe for delivering the liquefied gas is provided separately for each of the pressurized evaporators 7a, 7b may also be used.

[0072] In the above embodiment, a case has been described in which the connection position between the first pipe 60 and the second pipe 62 and the connection position between the second pipe 62 and the inlet header 71 of the pressurized evaporator 7 are set at positions separated from each other in the front and rear, but such connection positions may also be configured so as not to be separated from each other in the front and rear.In this configuration, the second pipe 62 may be configured with only an inclined portion corresponding to the above-mentioned first inclined portion 62a.

[0073] In the above embodiment, the connection position between the first pipe 60 and the second pipe 62 is described as being located below the chassis frame 3, but such connection position may also be configured to be at the same height as the chassis frame 3 or to be located above the chassis frame 3. [Explanation of symbols]

[0074] 1 tanker truck 3 Chassis frame 4 Subframe 5 Tank 6 Delivery pipe 60 First Pipe 62 Second piping 62a 1st slope part 62b 2nd slope part 62c 3rd slope 7a Pressurized evaporator (first pressurized evaporator) 7b Pressurized evaporator (second pressurized evaporator) 71 Inlet header (inlet of pressurized evaporator) 8 Return pipe

Claims

1. a pair of pressurized evaporators disposed on both sides of the chassis frame in the vehicle width direction, for vaporizing liquefied gas in the tank and returning it to the tank, and for pressurizing the inside of the tank; and a delivery pipe connecting the inlets of the pair of pressurized evaporators, the inlets being arranged to face the center of the vehicle width, to the tank, and for delivering the liquefied gas in the tank to each of the pair of pressurized evaporators, a portion of the delivery pipe extending in the vehicle width direction has a gradient that slopes downward from the upstream side to the downstream side, the delivery pipe includes a first pipe extending downward from a rear portion of the tank, and a second pipe branching from a lower end of the first pipe in the vehicle width direction and connected to inlets of the pair of pressurized evaporators, a connection position between the first pipe and the second pipe and a connection position between the second pipe and the inlet of the pressurized evaporator are set at positions spaced apart in the front-rear direction, the second pipe is composed of a pair of first inclined portions extending from a lower end of the first pipe to both sides in the vehicle width direction, a pair of second inclined portions extending in the front-rear direction from outer ends of the pair of first inclined portions in the vehicle width direction, and a pair of third inclined portions extending outward in the vehicle width direction from the front-rear direction ends of the pair of second inclined portions and connected to an inlet of the pressurized evaporator, and has a gradient that slopes downward from the upstream side to the downstream side, A tank truck, wherein a connecting portion of the first inclined portion, the second inclined portion, and the third inclined portion is curved.

2. 2. The tank truck according to claim 1, wherein the downward slope of the delivery pipe is constant.

3. a pair of subframes fixed to the tank and spaced a predetermined distance apart in the vehicle width direction; a pair of the chassis frames supporting the pair of subframes; and a return pipe connecting outlets of the pair of pressurized evaporators to the tank and returning gas evaporated by the pressurized evaporators into the tank, the subframe is fixed to a tank unit in which the tank, the delivery pipe, the pressurized evaporator, and the return pipe are integrated, and the tank unit is mounted on the chassis frame via the subframe; the first pipe extends downward from a rear portion of the tank through a gap between the pair of chassis frames, 3. The tank truck according to claim 1, wherein the first pipe and the second pipe are connected to each other at a position lower than the chassis frame.

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