JP5640939B2 - Piping support structure for urea water tank - Google Patents

Description

  The present invention relates to a piping support structure for a urea water tank used in an exhaust gas treatment device of a diesel engine.

2. Description of the Related Art Conventionally, as an exhaust gas treatment device for a diesel engine, the use of an SCR (Selective Catalytic Reduction) catalyst using urea for purifying nitrogen oxides (NO _x ) in exhaust gas has been put into practical use.

An exhaust gas treatment apparatus using an SCR catalyst has a property of selectively reacting nitrogen oxide (NO _x ) in exhaust gas with a reducing agent even in the presence of oxygen in the middle of exhaust soot through which exhaust gas flows. An SCR catalyst is provided, NO _X in the exhaust gas is selectively adsorbed on the SCR catalyst, injected into the exhaust slag upstream of the SCR catalyst in the purification device, and urea in the urea water is hydrolyzed to be a reducing agent. Ammonia (NH ₃ ) is supplied to the SCR catalyst, and NO _X adsorbed on the SCR catalyst is reduced, decomposed into nitrogen and water and discharged, thereby reducing the NO _X discharge concentration.

In a vehicle using such an exhaust gas treatment device using an SCR catalyst, it is necessary to mount a urea water tank that stores urea water for injection into the exhaust pipe.
In this case, the urea water tank is attached to the body of the diesel truck. In particular, the urea water tank is attached to the chassis outer side surface near the engine in order to inject urea water into the exhaust passage behind the engine.

  However, since the fuel tank is already mounted on the chassis outer side surface near the engine, the urea water tank is attached adjacent to the rear of the fuel tank. In addition, the urea water tank is required to be mounted close to the rear of the fuel tank in order to secure a space for mounting.

On the other hand, two urea water pipes and two anti-freezing hot water pipes (a total of four pipes) are connected to the urea water tank. One of the urea water tanks is a pipe that sends urea water to a urea water injection control unit that sprays urea water on the SCR catalyst. The other pipe is a pipe that returns excess urea water to the urea water tank in the urea water injection control unit.
Further, one of the antifreezing hot water pipes is an introduction pipe for keeping the temperature of the urea water in the urea water tank by cooling the engine from the engine cooling system and raising the temperature. The other is a pipe that returns the cooling water that has been kept warm in the urea water tank to the cooling system passage of the engine.
These four pipes need to be piped away from the fuel tank on the front side in order to circulate cooling water on the engine side or urea water in the urea water tank.
Thus, in order to avoid the fuel tank and perform piping, it is required to improve the assembling property in order to avoid interference between a plurality of pipes and connectors connected to the fuel tank.

  As such a piping structure with improved assemblability, functional parts mounted on the chassis external side near the engine by fixing individual pipes with brackets so as to maintain the positional relationship between multiple pipes There is known a piping structure that can prevent the interference with the piping and improve the piping workability of the harness (see Patent Document 1).

Japanese Patent Laid-Open No. 11-105643

  However, although the piping structure described in Patent Document 1 can be piped so as to avoid interference with functional parts by fixing individual pipes with brackets, as a conventional product for standardization of pipes, etc. Use of a connector having a rotation function may be forced. In such a case, there is a concern about interference between freely rotatable connectors and pipes, but even under such conditions, a plurality of pipes can be held in a stable state, and a gap with the fuel tank is secured. There has been a demand for a piping structure that improves the mountability of the space.

  In view of the problems of the prior art, the present invention improves the safety of various pipes connected to the urea water tank, improves the assembly of the pipes, and secures the space for mounting the urea water tank behind. Then, it aims at improving the mounting property of the apparatus mounted by the loading platform equivalent part by the use purpose of a truck.

In order to solve the above problems, a urea water tank piping support structure according to the present invention is a urea water tank attached adjacent to the rear of a vehicle body of a fuel tank mounted on a chassis outer surface of a truck equipped with a diesel engine. A urea water pipe for injecting urea water into the exhaust passage upstream of the SCR catalyst of the purification apparatus and returning the residual liquid from the purification apparatus; and a hot water pipe connected to the engine cooling system path for circulating hot water. In the urea water tank piping support structure,
To the chassis outer surface side of the urea water tank, hot water connector for connecting a rotatable urea water connector and the hot water pipe connected to the urea water pipe is arranged close respectively, the urea water pipe and the hot water pipe Is characterized in that a portion in the vicinity of the urea water connector and the hot water connector, and an extending portion extending toward the engine along the gap between the fuel tank and the chassis outer surface are held by a plurality of pipe holding means. To do.

  According to this invention, the urea water pipe and the hot water pipe connected to the rotatable connector disposed close to the chassis outer surface side (back side surface) of the urea water tank include the portion near the connector, the fuel tank, and the chassis. The extending portion extending toward the engine side along the gap with the outer side surface is bundled along the outer side surface of the chassis and is held by a plurality of pipe holding means. As a result, the free rotation of the connector is restricted, so that contact between the connectors and the pipes can be prevented, the space for various pipes can be saved, and a space for mounting the urea water tank can be secured. Therefore, the mountability of the apparatus mounted on the loading platform equivalent portion is improved depending on the purpose of use of the truck.

Preferably, in the present invention, the urea water tank is fixed to a vehicle body rear side surface of a bracket attached perpendicularly to a chassis outer surface behind the fuel tank, and the urea water connector and the hot water connector are disposed close to the rear surface side below the urea water tank that faces the chassis outer surface becomes, the said pipe holding means, the respectively spaced holding the urea water pipe before Symbol urea water connector and the hot water connector near 1 It is good to have holding means.
According to such a configuration, the first holding means is disposed close to the lower side of the rear surface of the urea water tank facing the outer surface of the chassis, so that the urea water pipe and the hot water pipe connected to the urea water tank are secured. Can be increased.

According to another embodiment of the present invention, the pipe holding means, the clamps holding the urea water pipe and the hot water piping launched toward the fuel tank upwardly from said first holding means in the vehicle body front side of the bracket and second holding means, the urea water pipe launched toward the fuel tank upwardly from said hot water pipe and the first holding means is curved in the fuel tank upper surface side from the second holding means, the said fuel tank and bundled along the gap between the chassis outer surface along the chassis outer surface so as to extend in the diesel engine side, characterized in that a third holding means for clamping retention.
According to such a configuration, the pipe holding means further includes the second and third holding means, so that the space of each pipe can be saved and the installation space on the rear side of the body of the urea water tank can be reduced. Since it can be ensured, the mountability of the device mounted on the part corresponding to the loading platform is improved depending on the purpose of use of the truck.

In the present invention, preferably, the hot water pipe has a configuration in which a heating wire is wound around an outer periphery of a resin pipe and a corrugated pipe is coated on the outer periphery thereof.
According to such a configuration, the hot water pipe is heated by the heating wire to heat the internal cooling water to generate hot water, so that the urea water can be prevented from freezing. Since it is bundled along the outer surface and clamped and held, the urea water pipe can be warmed by the residual heat of the hot water pipe.
Further, since the hot water pipe is bundled and held by the third holding means and disposed along the gap between the fuel tank and the chassis outer surface, damage caused by scattered gravel can be prevented.

As described above, according to the present invention, the urea water connector fixed to the chassis outer surface on the rear side of the vehicle body of the fuel tank and connected to the urea water pipe on the chassis outer surface side (back side surface) of the urea water tank and the hot water piping is hot water connector is placed close to connection, the urea water pipe and the hot water pipe, the urea water connector and the portion of the hot water connector near the engine side along the clearance between the fuel tank and the chassis outer surface The extending portion extending in the direction is held by a plurality of pipe holding means.
As a result, the free rotation of the connector is restricted, so that contact between the connectors and the pipes can be prevented even if vibration or the like occurs during vehicle travel, and the safety of each pipe connected to the urea water tank is improved. Can do. In addition, it is possible to save the space of various pipes, and by increasing the space behind the urea water tank, it is possible to improve the mountability of the device mounted on the cargo bed corresponding to the intended use of the truck.

1 is an overall perspective view showing a vehicle body structure of a diesel truck that employs a piping support structure for a urea water tank according to an embodiment of the present invention. It is a top view which similarly shows the piping support structure of a urea water tank. It is a side view which similarly shows the piping support structure of a urea water tank. It is the partial perspective view which similarly showed the piping support structure of the urea water tank, and abbreviate | omitted the fuel tank. It is the rear view which showed the piping support structure of the urea water tank which concerns on embodiment of this invention, and looked at the back surface side of the urea water tank from the inner side of the chassis.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, as long as there is no specific description, the dimensions, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.
In addition, the directionality of description of this invention displays the up-down direction, the left-right (vehicle width) direction, and the front-back direction in the state seated in the driver's seat.

  FIG. 1 is an overall perspective view showing a vehicle body structure of a diesel truck employing a urea water tank piping support structure according to the present invention.

In FIG. 1, reference numeral 2 denotes a vehicle body (chassis 2) of the diesel truck 1. A fuel tank 4 from the rear side is disposed on one side surface (left chassis) 2a in the vehicle width direction of the chassis 2, and urea water is used for purifying exhaust gas. The auxiliary device 5 in which the urea water injection control unit 5a for spraying the SCR catalyst on the SCR catalyst, the fuel strainer 5b, and the like are disposed are sequentially attached.
Reference numeral 10 denotes a urea water tank. The urea water tank 10 is a tank for storing urea water to be injected into an exhaust pipe upstream of the SCR catalyst in the purification device, and the urea water tank 10 is a left chassis. It is attached to the outer surface of 2a adjacent to the rear of the fuel tank 4. Although the left chassis 2a will be described, it is needless to say that the right chassis may be used.

Next, the urea water tank piping support structure according to the embodiment of the present invention will be described with reference to FIGS.
2 is a plan view showing a pipe support structure of a urea water tank according to an embodiment of the present invention, FIG. 3 is a side view showing the pipe support structure, and FIG. 4 is a partial perspective view in which the fuel tank showing the pipe support structure is omitted. FIG. 5 and FIG. 5 are rear views of the rear surface side of the urea water tank as viewed from the inside of the chassis.
In FIG. 2, arrow view X indicates the front (engine side) of the chassis 2, and arrow view Y indicates the outside of the center side of the chassis 2.

The auxiliary device 5 shown in FIGS. 2 and 3 is attached to the outer surface of the left chassis 2 a adjacent to the front of the fuel tank 4.
As shown in FIG. 4, the bracket 12 fixes the urea water tank 10, so that the outer surface of the left chassis 2 a is orthogonal to the outer surface so as to be adjacent to the rear of the fuel tank 4 indicated by a thick phantom line. Are fastened to each other via a base portion 14.
The bracket 12 is constituted by connecting two plate members 12a and 12b having a substantially right triangle shape with a predetermined distance apart in the front and rear direction, and the two plate members 12a and 12b are formed by two support tubes 15a, 15b.

The two support pipes 15a and 15b protrude rearward by a predetermined amount perpendicular to the rear plate 12b of the bracket 12. On the other hand, the urea water tank 10 is provided with two holding pipes 10c penetrating the inside corresponding to the two support pipes 15a and 15b. As a result, two through holes are formed in the side surface of the urea water tank 10 by the inner diameters of the two holding pipes 10c.
The two holding pipes 10c have an inner diameter through which the support pipes 15a and 15b can be inserted with a slight gap. Nuts (not shown) are fixed to the inner diameter portions of the end portions (rear side) of the support tubes 15a and 15b inserted through the two holding tubes 10c.
Accordingly, the two holding pipes 10c of the urea water tank 10 are fitted on the support pipes 15a and 15b, and a holding member (not shown) having an outer diameter larger than the outer diameter of the holding pipe 10c is sandwiched by bolts as described above. Screw onto the nut. As a result, the urea water tank 10 is fixed in close contact with the plate 12b on the rear side surface of the bracket 12.
The urea water tank 10 is provided with a supply port 10a on the upper slope protruding outward and a liquid level gauge 10b on the upper surface.

Further, two hot water connectors 23a and 23b and urea water connectors 27a and 27b are attached in close proximity to the lower side of the urea water tank 10 facing the outer surface of the left chassis 2a.
Two urea water pipes 26a and 26b and hot water pipes 22a and 22b are connected to the hot water connectors 23a and 23b and the urea water connectors 27a and 27b. The urea water pipes 26a and 26b and the hot water pipes 22a and 22b are connected to each other. The hot water connectors 23a and 23b and the urea water connectors 27a and 27b are held in the vicinity.
Various pipe groups 20 extending toward the engine along the gap between the fuel tank 4 and the left chassis 2a are held by a plurality of pipe holding means that are bundled and held along the outer surface of the left chassis 2a. Yes. The pipe holding means includes a first holding means, a second holding means, and a third holding means.

The urea water connectors 27a and 27b are constituted by rotatable connectors. The two urea water pipes 26a, 26b connected to the urea water connectors 27a, 27b are first held attached to the base portion 14 of the bracket 12 which is a portion in the vicinity of the urea water connectors 27a, 27b. It is clamped and raised by the fixtures 30a and 30b of the plate-like bracket 30 serving as means.
The two urea water pipes 26 a and 26 b that have been clamped and raised by the first holding means are clamped and held by a clamp 25 that is a second holding means attached to the front side surface of the bracket 12. The urea water pipes 26a and 26b have a configuration in which a heating wire is wound around the outer circumference of the resin pipe and a corrugated pipe (corrugated pipe) is covered around the outer circumference, so that the urea water passing through the inside is heated by energization. It has become.

  Also, hot water pipes 22a and 22b are connected to the two hot water connectors 23a and 23b, and one of the hot water pipes 22a serves as a second holding means attached to the front side surface of the bracket 12 up and down. The clamps 24a and 24b are clamped and raised.

The various pipe groups 20 including the one hot water pipe 22a and the two urea water pipes 26a and 26b, which are raised upward in this way, are bent in the gap between the fuel tank 4 and the outer surface of the left chassis 2a. Along the outer surface of the left chassis 2a, the extension portions are bundled by the plurality of clamps 32 that are arranged along the third holding means.
The supply-side urea water pipe 26b is connected to a urea water injection control unit 5a that extends to the engine side along the left chassis 2a and sprays urea water (not shown) onto the SCR catalyst. On the other hand, the urea water pipe 26a on the return side is connected to the urea water injection control unit 5a, and the residual liquid is returned from the urea water injection control unit 5a to the urea water tank 10.

Next, the operation of each pipe of the urea water tank will be described with reference to FIGS.
First, a urea aqueous solution is stored in the urea water tank 10, and this urea water passes through a urea water pipe 26 b on the supply side connected to a rotatable urea water connector 27 b on the lower side of the back surface of the urea water tank 10. It is sent to the water injection control unit 5a.

The urea water sent to the urea water injection control unit 5a is adjusted to an optimum amount according to the engine parameters and the engine speed by the urea water injection control unit 5a, and the exhaust pipe on the upstream side of the SCR catalyst in the purification device (not shown). It is designed to spray inside.
Urea in the urea water is hydrolyzed to supply ammonia (NH ₃ ) as a reducing agent to the SCR catalyst, and NO _X is reduced to decompose into nitrogen gas (N ₂ ) and water vapor (H ₂ O). By exhausting, the exhaust concentration of nitrogen oxide (NO _X ) in the exhaust gas can be reduced.

Further, the residual liquid of the purification device is returned to the urea water tank 10 through the urea water connector 27a that can rotate from the urea water pipe 26a on the return side.
On the other hand, the two anti-freezing hot water pipes 22a and 22b are connected to the urea water tank 10 and the cooling water system on the engine side, and circulate the coolant circulating through the cooling water system between the urea water tank 10 and the urea water tank 10. It is like that.
The two antifreezing hot water pipes 22a and 22b have a configuration in which a heating wire is wound around the outer periphery of a resin tube and a corrugated tube (corrugated tube) is covered around the outer periphery of the resin tube. The cooling water is warmed to prevent the urea water in the urea water tank 10 from freezing.

According to the embodiment described above, the urea water pipes 26 a and 26 b connected to the rotatable urea water connectors 27 a and 27 b disposed close to the lower side of the back surface of the urea water tank 10 are provided at the rear side end of the bracket 12. It is held apart by the fixtures 30a and 30b of the plate-like bracket 30 which is the first holding means that is suspended and attached.
As a result, since the urea water connectors 27a and 27b are restricted in free rotation, even if vibrations or the like occur during vehicle travel, the urea water connectors 27a and 27b and the urea water pipes 26a and 26b can be prevented from contacting each other. In addition, the security of the pipes 26a and 26b connected to the urea water tank 10 can be improved.

Further, the hot water pipe 22 a and the urea water pipes 26 a and 26 b raised from the first holding means to the upper side of the fuel tank 4 are clamped and held on the front outer surface of the bracket 12 by the second holding means, and the upper surface side of the fuel tank 4 The hot water pipe 22a and the urea water pipes 26a and 26b that are curved from the front and extend forward on the engine side are bundled and clamped on the outer surface of the left chassis 2a along the gap between the fuel tank 4 and the outer surface of the left chassis 2a by the third holding means. Retained.
As a result, it is possible to save the space of each pipe and to improve the mounting performance of the device mounted on the portion corresponding to the loading platform depending on the purpose of use of the truck by securing the space on the chassis outer surface behind the urea water tank 10. be able to.

  Although the pipe support structure of the urea water tank has been described as the pipe support structure attached to the body of the diesel truck, it can be applied to the pipe support structure of fluid equipment such as railway vehicles, ships, heavy machinery, and aircraft. Moreover, it is suitable not only for piping of fluid equipment but also for a support structure for electric wires and a support structure for optical cables.

DESCRIPTION OF SYMBOLS 1 Diesel engine truck 2a Left side chassis 4 Fuel tank 5a Urea water injection control unit 10 Urea water tank 12 Brackets 22a and 22b Hot water piping 23a and 23b Hot water connector 25 Clamp (2nd holding means)
26a, 26b Urea water pipes 27a, 27b Urea water connector 30 Plate bracket (first holding means)
32 Clamp (Third holding means)

Claims (4)

A urea water tank that is mounted in contact with the rear side of a fuel tank mounted on a chassis outer surface of a truck equipped with a diesel engine, and injects urea water into an exhaust passage upstream of the SCR catalyst of the purification device and performs the purification. In the urea water tank pipe support structure comprising a urea water pipe for returning the residual liquid from the apparatus and a hot water pipe connected to the engine cooling system to circulate hot water,
To the chassis outer surface side of the urea water tank becomes hot connector for connecting a rotatable urea water connector and hot pipe connected to the urea water pipe is disposed near each of the urea water pipe and the hot water pipe The urea water tank is characterized in that a portion in the vicinity of each connector and an extending portion extending toward the engine along the gap between the fuel tank and the chassis outer surface are held by a plurality of pipe holding means. Piping support structure. The urea water tank is fixed to a vehicle body rear side surface of a bracket attached perpendicularly to a chassis outer surface behind the fuel tank, and the urea water connector and the hot water connector face the outer surface of the chassis. be disposed close to the rear surface side below the water tank, the pipe holding means, that before Symbol urea water connector and the hot water connector vicinity and a first holding means for each space holding the urea water pipe The urea water tank pipe support structure according to claim 1, wherein the urea water tank is a pipe support structure. The pipe holding means comprises a second holding means for clamping holding the urea water pipe and the hot water piping launched toward the fuel tank upwardly from said first holding means in the vehicle body front side of the bracket, the second the urea water pipe from the hot water pipe and the first holding means is curved in the fuel tank upper surface launched toward the fuel tank upward from the holding means, along a gap between the chassis outer side and the fuel tank tube support structure of the urea water tank according to claim 2, characterized in that it comprises a third holding means for clamping holding bundles along the chassis outer surface so as to extend in the diesel engine side Te.   The urea water tank piping support structure according to claim 1, wherein the hot water piping has a configuration in which a heating wire is wound around an outer periphery of a resin tube and a corrugated tube is coated on the outer periphery thereof.

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