JP2018162682A - Reducing agent addition device - Google Patents

Abstract

To provide a reducing agent addition device capable of securely fixing a reducing agent pipe with a simple configuration and reducing the influence of temperature and vibration on the reducing agent pipe. A reducing agent adding device provided in an exhaust purification device, wherein the reducing agent adding device includes an injector holder that accommodates a tip portion of an injector and includes a water jacket and is attached to the exhaust purification device. And a fixing member 26 that accommodates the rear end portion of the injector 16 and fixes the injector 16 to the injector holder 18. A pipe for installing the reducing agent pipe 13 connected to the injector 16 on the fixing member 26. A connecting seat 34 and a pipe fixing portion 36 that is formed in the vicinity of the pipe connecting seat 34 and fixes the reducing agent pipe 13 by a fixture 37 are provided. [Selection] Figure 3

Description

  The present invention relates to a reducing agent addition apparatus.

  2. Description of the Related Art In recent years, a selective reduction catalyst that includes a particulate filter that collects particulates in exhaust gas in the middle of an exhaust pipe, and that can selectively react NOx with ammonia even in the presence of oxygen on the downstream side of the particulate filter. It is proposed that urea water is sprayed as a reducing agent (additive) between the selective catalytic reduction catalyst and the particulate filter to simultaneously reduce particulates and NOx.

  In this case, the urea water is added to the selective catalytic reduction catalyst by an injector (reducing agent adding device) provided between the particulate filter and the selective catalytic reduction catalyst, but the urea water added to the exhaust gas is used. In order to secure a sufficient reaction time for the thermal decomposition into ammonia and carbon dioxide, it is necessary to increase the distance from the urea water addition position to the selective catalytic reduction catalyst. However, in this case, the interval between the particulate filter and the selective catalytic reduction catalyst becomes long, and the mounting property on the vehicle is significantly impaired.

  For this reason, a compact exhaust emission control device 50 as shown in FIGS. 5 and 6 has already been proposed. In the exhaust purification device 50 shown in FIGS. 5 and 6, a particulate filter 3 that traps particulates in the exhaust gas 1 is held in the middle of the exhaust pipe 2 through which the exhaust gas 1 from the engine flows. A first muffler 4 and a second muffler 6 embracing a selective catalytic reduction catalyst 5 which is arranged downstream of the particulate filter 3 and has the property of selectively reacting NOx with ammonia even in the presence of oxygen are arranged in parallel. And an outlet end portion of the particulate filter 3 and an inlet end portion of the selective catalytic reduction catalyst 5 are connected by a communication channel 7 having an S-shaped structure. The exhaust gas 1 discharged from the outlet side end of the particulate filter 3 is folded in the reverse direction and introduced into the inlet side end of the adjacent selective catalytic reduction catalyst 5.

  Here, the communication channel 7 surrounds the outlet side end of the particulate filter 3 and collects the exhaust gas 1 immediately after exiting from the outlet side end while changing the direction in a substantially perpendicular direction. A chamber 7A, a mixing pipe 7B for extracting the exhaust gas 1 collected in the gas collecting chamber 7A in a direction opposite to the exhaust flow of the particulate filter 3, and a direction in which the exhaust gas 1 guided by the mixing pipe 7B is substantially perpendicular The S-shaped structure is formed by the gas dispersion chamber 7C surrounding the inlet side end so that the dispersed exhaust gas 1 can be introduced into the inlet side end of the selective catalytic reduction catalyst 5 while being dispersed. It is configured as follows. In the example of FIG. 5, an oxidation catalyst 8 that oxidizes the exhaust gas 1 is provided in the first stage of the first muffler 4 in which the particulate filter 3 is held, An ammonia reduction catalyst 9 that oxidizes excess ammonia is provided at the rear stage in the second muffler 6 in which the selective catalytic reduction catalyst 5 is held. In the figure, reference numeral 10 denotes an exhaust port provided downstream of the ammonia reducing catalyst 9.

  The exhaust purification device 50 is mounted on the frame 11 as shown in FIGS. 5 and 6, the second muffler 6 having the exhaust port 10 downstream is located outside the frame 11, and the first muffler is the frame. 11 is fixed to the frame 11 so as to be located inside the frame 11.

  5 and 6, an injector for adding urea water in a direction in which the exhaust gas 1 emitted from the outlet end portion of the particulate filter 3 is changed in a direction substantially perpendicular to the gas collecting chamber 7A. Equipped with 12. That is, the injector 12 supplies urea water into the gas collecting chamber 7A on the upper surface far from the frame 11 at the rear end portion (left end portion in FIG. 5) of the gas collecting chamber 7A toward the frame 11 side and obliquely downward. It is provided to inject.

  In FIG. 5, the case where the injector 12 is provided on the upper surface far from the frame 11 at the rear end of the gas collecting chamber 7A is shown by a solid line. Instead, as shown by the broken line in FIG. An injector 12 ′ that injects urea water toward the inside of the mixing pipe 7B may be provided on the side near the frame 11 at the rear end of the collecting chamber 7A. In the figure, reference numerals 13 and 13 'denote reducing agent pipes connected to the injectors 12 and 12' to supply a reducing agent to the injectors 12 and 12 '.

  If the above configuration is adopted, particulates in the exhaust gas 1 are collected by the particulate filter 3 and urea water is added to the exhaust gas 1 from the injector 12 or the injector 12 ′, thereby urea. Water is thermally decomposed into ammonia and carbon dioxide, and NOx in the exhaust gas 1 is reduced and purified well by ammonia on the selective catalytic reduction catalyst 5, so that simultaneous reduction of particulates and NOx in the exhaust gas 1 is achieved. Will be.

  At this time, the exhaust gas purification device 50 is configured such that the exhaust gas 1 discharged from the outlet side end portion of the particulate filter 3 is turned back in the reverse direction by the connecting flow path 7 and then the inlet side end of the adjacent selective catalytic reduction catalyst 5. Since the configuration is compactly arranged and the distance from the urea water addition position by the injector 12 to the selective catalytic reduction catalyst 5 is ensured long, the urea water to ammonia can be secured. Sufficient reaction time is ensured to produce.

  Incidentally, as prior art document information related to this type of compact exhaust purification apparatus, there is the following Patent Document 1 and the like.

JP 2015-48715

  As shown in FIGS. 5 and 6, reducing agent pipes 13 and 13 ′ are connected to the injectors 12 and 12 ′ provided in the exhaust purification device 50, and the reducing agent pipes 13 and 13 ′ are fixed somewhere. However, when the reducing agent pipes 13 and 13 'are fixedly supported on the exhaust purification device 50, the temperature of the exhaust purification device 50 heated by the exhaust heat, the exhaust vibration, and the like are taken into consideration. There is a need.

  For example, the reducing agent pipes 13 and 13 ′ may be fixed to the exhaust purification device 50 by a support bracket. In this case, the reducing agent pipes 13 and 13 ′ have the same vibration form as the exhaust purification device 50. Therefore, it is preferable.

  However, when the reducing agent pipes 13 and 13 'are fixed to the high-temperature exhaust gas purification apparatus 50 by the support bracket, the temperature of the pipe fixing portion (reducing agent temperature) by the support bracket is kept below a certain level. There is a need. That is, when the temperatures of the injectors 12 and 12 ′ and the reducing agent pipes 13 and 13 ′ are increased, the durability of the pipes may be reduced, or the resin material of the pipe fixing part may be melted. This problem needs to be prevented because it may not be performed well. For this reason, it is necessary to fix the support bracket to a portion where the temperature is as low as possible. Therefore, there is a problem that the distance between the injectors 12 and 12 ′ and the pipe fixing portion becomes long and the support bracket becomes large.

  The present invention has been made in view of the above circumstances, and provides a reducing agent addition apparatus that can reliably fix a reducing agent pipe with a simple configuration and can reduce the influence of temperature and vibration on the reducing agent pipe. The purpose is that.

The present invention is a reducing agent addition device provided in an exhaust purification device,
The reducing agent addition device accommodates a tip end portion of an injector and includes a water jacket and is attached to the exhaust purification device, and accommodates a rear end portion of the injector and fixes the injector to the injector holder. A fixing member,
A pipe connection seat having a connection port for installing a reducing agent pipe connected to the injector on the fixing member, and the reducing agent pipe is fixed via a fixture formed in the vicinity of the pipe connection seat. A pipe fixing part is provided.

  Thus, according to the above configuration, the fixing member for holding the injector and fixing it to the injector holder is provided with the pipe connection seat for fixing the reducing agent pipe connected to the injector, and the pipe connection seat. Since the pipe fixing portion that is formed in the vicinity of the pipe and fixes the reducing agent pipe with a fixture is provided, the reducing agent pipe can be securely fixed to the reducing agent adding device with a compact configuration.

  Moreover, since the fixing member fixed to the injector holder having the water jacket is kept at a low temperature, the temperature of the reducing agent pipe fixed to the fixing member by the fixing tool can be kept low. Furthermore, since the reducing agent pipe is fixed to a fixing member integral with the injector holder, the problem of the reducing agent pipe vibrating is reduced.

  According to the reducing agent addition apparatus of the present invention described above, various excellent effects as described below can be obtained.

  A fixing member for holding the injector and fixing it to the injector holder, a pipe connection seat for fixing the reducing agent pipe connected to the injector, and the reducing agent pipe formed by a fixture formed in the vicinity of the pipe connection seat Therefore, the reducing agent pipe can be reliably fixed to the reducing agent adding device with a compact configuration.

  Furthermore, since the fixing member fixed to the injector holder having the water jacket is kept at a low temperature, the temperature of the reducing agent pipe fixed to the fixing member by the fixing tool can be kept low. Further, since the reducing agent pipe is fixed to a fixing member integral with the injector holder, the problem of the reducing agent pipe vibrating can be reduced.

It is a longitudinal cross-sectional view of the fixing member which comprises the reducing agent addition apparatus which implements this invention. It is a top view of the fixing member of FIG. It is a side view of a reducing agent addition apparatus. It is an assembly drawing which shows the structure of a reducing agent addition apparatus. It is a top view which shows an example of the exhaust gas purification apparatus which has an injector. FIG. 6 is a side view of the exhaust purification device of FIG. 5.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 4 show an example of an embodiment for carrying out the present invention. In this embodiment, an injector is provided for an exhaust purification apparatus 50 having a configuration substantially similar to that shown in FIGS. 16 is provided with a reducing agent addition device 14 adapted to accommodate 16.

  The reductant addition device 14 shown in FIGS. 1 to 4 is located inside the frame 11 at the rear end (left end in FIG. 5) of the gas collecting chamber 7A of the exhaust purification device 50 shown in FIGS. A case in which urea water is provided on the upper surface so as to inject into the gas collecting chamber 7A toward the outside of the frame 11 and obliquely downward is shown.

  The reducing agent adding device 14 has an injector holder 18 having a pocket 17 for receiving and fitting the tip 16a of the injector 16 shown in FIG. A water jacket 20 is formed on the outer periphery of the pocket 17 in the injector holder 18 to circulate the cooling water supplied from the cooling water pipe 19 and cool it. The injector holder 18 is fixed to the gas collecting chamber 7A of the exhaust purification device 50 by a bolt 22 (FIG. 3) passed through the bolt hole 21.

  A fixing member 26 that surrounds the rear end portion 16 b (upper end portion) of the injector 16 and is fixed to a bolt hole 24 provided in the injector holder 18 via a fixing bolt 25 is provided on the upper portion of the injector holder 18. . Reference numeral 27 denotes a leaf spring that urges the injector 16 so as not to move when the fixing member 26 is fastened and fixed to the injector 16 by the fixing bolt 25. 3, 28 is a protective cover provided so as to cover the front surface facing the frame 11 of the reducing agent adding device 14 shown in FIG. 5, and the protective cover 28 is a bolt hole 29 as shown in FIG. 3 and is fixed to a mounting seat 30 provided on the injector holder 18 with bolts 31 as shown in FIG.

  1 is a longitudinal sectional view of the fixing member 26, and FIG. 2 is a plan view of FIG. 1. A lower end of the fixing member 26 is airtightly fitted to a rear end portion 16b (upper end portion) of the injector 16. A surrounding fitting hole 32 is formed, and a pipe connection seat 34 having a connection port 33 communicating with the fitting hole 32 is provided at the upper part of the fixing member 26.

  The end of the reducing agent pipe 13 is connected to the connection port 33 of the pipe connection seat 34.

  Further, a pipe fixing portion 36 having a mounting hole 35 is formed at a position near the pipe connection seat 34 in the fixing member 26, and the reducing agent pipe 13 is fixed to the mounting hole 35 of the pipe fixing portion 36. It is fixed by a bolt 38 via a tool 37. In the example of FIGS. 1 and 2, the folded portions 37 b at both ends of the fixing band 37 a wound around the reducing agent pipe 13 are fixed to the mounting holes 35 by bolts 38. 2 is a mounting hole for mounting a pressure gauge 40 (FIG. 3) for detecting the pressure of the reducing agent at the connection port 33.

  Note that the selective catalytic reduction catalyst 5 shown in FIG. 5 has a property capable of selectively reacting NOx with HC gas even in the presence of oxygen, and therefore, the reducing agent sprayed by the reducing agent adding device 14 is reduced. In the case of a fuel, the conversion of the fuel into HC gas is promoted. Therefore, fuel can be used as the reducing agent in addition to urea water.

  The reducing agent addition device 14 can also be applied to an exhaust purification device having a structure other than the exhaust purification device 50 shown in FIGS.

  According to the embodiment shown in FIGS. 1 to 4, the reducing agent pipe 13 connected to the injector 16 is fixed to the fixing member 26 that holds the injector 16 and fixes the injector 16 to the injector holder 18. Since the pipe connection seat 34 is provided, and the reducing agent pipe 13 is fixed to the pipe fixing portion 36 formed in the vicinity of the pipe connection seat 34 by the fixture 37, the reducing agent pipe 13 has a compact configuration. Can be reliably fixed to the fixing member 26 of the reducing agent adding device 14.

  Further, since the injector holder 18 having the water jacket 20 is held at a low temperature, the fixing member 26 fixed to the injector holder 18 is also held at a low temperature, and thus the reduction member fixed to the fixing member 26 by the fixing tool 37. The temperature of the agent pipe 13 can be kept low.

  Further, the reducing agent pipe 13 is fixed to a fixing member 26 that is integrally fixed to the injector holder 18 to have the same vibration form, thereby reducing the problem of the reducing agent pipe 13 vibrating.

  In addition, since the injector 16 is fixed to the injector holder 18 by the fixing member 26, the injector 16 can be securely fixed with a small configuration. Furthermore, since the reducing agent pipe 13 is fixed to the fixed member 26 of the reducing agent adding device 14 which is configured in a compact manner, the entire reducing agent adding device 14 becomes small, and the reducing agent adding device 14 with respect to the exhaust purification device 50 is reduced. Mountability can be improved.

  In the above embodiment, the case where the reducing agent addition device 14 is provided at the position of the injector 12 provided on the upper surface far from the frame 11 in the rear end portion (left end portion) of the gas collecting chamber 7A in FIG. 5 will be described. However, as shown by a broken line in FIG. 5, the same applies to the case where the reducing agent addition device 14 is arranged at the position of the injector 12 ′ provided on the side near the frame 11 at the rear end of the gas collecting chamber 7A. can do.

  In addition, the reducing agent addition apparatus of the present invention is not limited to the above-described embodiment. The shape of the fixing member 26 can be arbitrarily changed, and various modifications can be made without departing from the scope of the present invention. Of course, it can be added.

13 Reducing agent piping 13 'Reducing agent piping 14 Reducing agent adding device 16 Injector 16a Front end portion 16b Rear end portion 18 Injector holder 20 Water jacket 33 Connection port 34 Piping connection seat 36 Piping fixing portion 37 Fixing device 37a Fixing band (fixing device)
50 Exhaust gas purification device

Claims (1)

A reducing agent addition device provided in an exhaust purification device,
The reducing agent addition device accommodates a tip end portion of an injector and includes a water jacket and is attached to the exhaust purification device, and accommodates a rear end portion of the injector and fixes the injector to the injector holder. A fixing member,
A pipe connection seat having a connection port for installing a reducing agent pipe connected to the injector on the fixing member, and the reducing agent pipe is fixed via a fixture formed in the vicinity of the pipe connection seat. A reducing agent addition apparatus comprising a pipe fixing portion.

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