JPH0120319Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement to the piping structure of a tank lorry, and has been improved so that no oil remains in the tank or piping after unloading, and the unloading can be done quickly. It is something that Since the cargo is a dangerous substance, any residual oil is dangerous, and if the next cargo (oil) is loaded with a different type of oil, the oils will be mixed, which is extremely dangerous.

Generally, the upper surface of the chassis frame of a tank truck that transports petroleum products is designed so that when loaded with cargo (hereinafter referred to as oil), the top surface of the chassis frame is almost horizontal, and when unloaded, the front side is slightly lower.
This is done in consideration of running performance and safety when the tank truck is loaded with oil. In this case, in the case of conventional piping that does not have a withdrawal pipe, residual oil will be generated in the front part.

On the other hand, the road surface at gas stations, etc. where cargo is unloaded is not necessarily level, but is often slightly sloped. Therefore, due to these changing road surfaces and vehicle postures, there is a problem in that a portion of the oil remains in the tank and piping when the oil is unloaded. Of course, this problem will not occur if the cargo is forcibly unloaded using a pump, etc., but when unloading hazardous materials such as oil into an underground storage tank at a gas station, a pump is used with safety in mind. Since the rule is not to do so, the above problem cannot be solved.

This invention was made with the intention of solving the above problem, and it is a tank lorry that is characterized by being able to quickly unload cargo without leaving any oil in the tank or pipes, regardless of the road surface or vehicle posture. The aim is to provide a piping structure for this purpose.

In conventional piping, there is no extraction pipe 8 in the device of this invention, which will be described in detail below, and point c is the lowest in Figures 2 and 3, so the distance between a and c is long and the slope of the piping is small. . In order to increase the slope so as not to hit the auxiliary piping 6, the height H of the subframe (see Figure 1) must be increased.
As a result, the entire vehicle body became taller and the center of gravity became higher, creating the risk of the vehicle tipping over.

The pipe is sloped so that there is no residual oil without increasing the height H of the subframe, and in order to increase the discharge amount and speed up unloading, point e is the lowest position, and the extraction pipe 8 is installed there. By installing this, two pipes flow from the main pipe 4 to the auxiliary pipe 6, resulting in a large discharge amount and rapid unloading. Finally, the oil flows through the extraction pipe 8, so that it can be drained without any residual oil. This structure is optimal for achieving a piping slope that overcomes the slope of the chassis without increasing the height H of the subframe regardless of whether it is tilted forward or backward.

Examples of this invention will be described below based on the drawings.

Figures 1 and 2 are a side view and a piping diagram of a tank truck having the piping structure of this invention, in which the interior of a tank 2 mounted on a chassis frame 1 has a plurality of chambers with partition walls (not shown). The main pipe 4 connects each bottom valve 3 arranged at the bottom of each chamber, and the main pipe 4 is connected via a switching valve 5 approximately in the middle of the main pipe 4 along the longitudinal direction of the vehicle. A piping system consisting of auxiliary piping 6 extending in the left-right direction is arranged inside the sub-frame 1' at the upper part of the chassis frame 1 at the lower part of the tank 2. In this case, the oil in each chamber of the tank 2 passes through the bottom valve 3 to the main pipe 4.
After being guided into the auxiliary pipe 6 through the switching valve 5, the left or right discharge port 6 is opened by discharge operation of the discharge valves 7 disposed at both ends of the auxiliary pipe 6.
The cargo is unloaded from a or 6b into a predetermined storage tank (not shown). At this time, in order to discharge all the oil in the piping, from the bottom valve 3 to the discharge port 6.
It is sufficient to absorb the slope of the road surface and the slope of the chassis frame 1 to a certain extent and provide a slope that slightly exceeds the slope of the road surface up to 6b. However, to create such a structure, the main pipe 4 must be inclined with the main pipe 4 intersecting with the auxiliary pipe 6, so the height H of the subframe 1' must be increased.
This results in the inconvenience that the overall height of the vehicle body increases.

Therefore, this invention was devised to solve the above problem, and as shown in FIGS. 2 and 3, from the front end portion a of the main pipe 4 to the auxiliary pipe 6
A convex curved portion 4a is formed downward at the point where the lowest point e of the main pipe 4 is formed, within a range that does not contact the auxiliary pipe 6. Point e and one side of the auxiliary pipe 6 are connected by a withdrawal pipe 8 having a downward slope toward the auxiliary pipe 6. Note that the slope of the extraction pipe 8 is considered to be greater than the sum of the forward tilt angle of the vehicle and the maximum road surface slope angle. Further, the extraction pipe 8 is provided with a extraction switching valve 9 connected to a pump (not shown) connected to the switching valve 5.

When unloading from the piping structure of this invention constructed as described above, depending on the condition of the road surface,
Although the vehicle is in a horizontal position, forward leaning position, or backward leaning position, by always stopping the vehicle in a horizontal position or forward leaning position, the height difference between points e and a of the main pipe 4 can be reduced to the maximum of the vehicle. If you set it appropriately considering the forward leaning posture, point e will always be the lowest point, and
Since the slope of the extraction pipe 8 is also steeper than the maximum forward tilt angle of the vehicle, the load is always completely unloaded by gravity from each bottom valve 3, and there is no possibility that oil etc. will remain in the main pipe 4. do not have. The extraction switching valve 9, which is opened when unloading due to gravity, is closed when the oil or the like in the tank 2 is discharged or when the oil or the like is sucked into the tank 2.

As explained above, according to the piping structure of this invention, by setting the vehicle in a horizontal or forward-leaning position, it is possible to quickly unload the cargo without leaving any oil in the tank or piping, thereby increasing delivery efficiency. In addition, since the extraction pipe 8 exclusively for gravity discharge is used when unloading, there is no resistance from the switching valve 5, etc., making it possible to unload more smoothly and in a shorter time. This has effects such as being able to carry out unloading work.

[Brief explanation of the drawing]

FIG. 1 is a side view of a tank truck having the piping structure of this invention, FIG. 2 is a schematic plan view of the piping structure of this invention, and FIG. 3 is a schematic sectional view taken along the line - in FIG. In the figure, 3... bottom valve, 4... main piping, 5...
...Switching valve, 6...Auxiliary piping, 6a, 6b...Discharge port, 7...Discharge valve, 8...Extraction pipe, 9...Switching valve for extraction, a...Front end portion of main piping 4, b
...The upper part of the auxiliary pipe of the main pipe 4, c...The switching valve connection part of the main pipe 4, d...The rear end part of the main pipe 4, e...The lowest point of the main pipe 4.

Claims (1)

[Scope of utility model registration request] A bottom valve 3 is installed in each chamber of the tank 2, which is mounted on the upper surface of the chassis and is partitioned into multiple chambers, and is designed to be almost horizontal when fully loaded (oil), and to tilt slightly forward as the load is unloaded. The tank lorry is equipped with discharge ports 6a, 6b, and is configured to flow the loaded liquid from the main pipe 4 along the longitudinal direction of the vehicle body connected to the bottom valves 3 to the discharge ports 6a, 6b via the switching valve 5. The auxiliary pipe 6 having 6b is connected to the main pipe 4.
The lowest point of the main pipe 4 within a range that is perpendicular to the lower center of the main pipe 4 and does not come into contact with the auxiliary pipe 6 from the front end part a of the main pipe 4 to the part b located above the auxiliary pipe 6. A piping structure for a tank lorry, in which a curved portion is formed downward to form a curved line e, and the lowest point e of the main piping 4 and the auxiliary piping 6 are connected through a withdrawal pipe 8.