JP2007138837A - Antitheft device for diesel post treatment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antitheft device for a diesel post treatment device capable of preventing theft of a catalyst using expensive precious metal. <P>SOLUTION: A open circuit detection system 16 detecting breakage of an electrical wiring 15 of a temperature sensor connected to a casing 5 is provided as a theft detection means detecting detachment of the casing 5 having a front stage oxidation catalyst 6 and a particulate filter 7 carrying oxidation catalyst built therein, and a warning means 17 issuing warning such as buzzer when the open circuit detection system 16 as the theft detection means detects that the electrical wiring 15 of the temperature sensor 14 connected to the casing 5 is broken is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an antitheft device for a diesel aftertreatment device.

Conventionally, it has been practiced to equip an exhaust pipe with an aftertreatment device to purify exhaust gas. This type of aftertreatment device oxidizes NOx in exhaust gas when the exhaust air-fuel ratio is lean. NOx occlusion reduction catalyst has the property of temporarily storing in the form of nitrate and decomposing and releasing NOx through the intervention of unburned HC and CO when the O ₂ concentration in the exhaust gas decreases. It has been.

  As this type of NOx occlusion reduction catalyst, platinum / barium / alumina catalyst, platinum / potassium / alumina catalyst, and the like have already been known.

Then, in the NOx storage reduction catalyst, when the storage amount of NOx will reach a saturation amount increases, it becomes impossible occludes more NOx, O ₂ in the exhaust gas flowing into the regular NOx storage reduction catalyst It is necessary to decompose and release NOx by reducing the concentration.

For example, when used in a gasoline engine, the operating air-fuel ratio of the engine is reduced (the engine is operated at a rich air-fuel ratio), thereby reducing the O ₂ concentration in the exhaust gas and unburned in the exhaust gas. Although it is possible to promote the decomposition and release of NOx by increasing the reducing components such as HC and CO, it is difficult to operate the engine at a rich air-fuel ratio when the NOx storage reduction catalyst is used as an exhaust purification device of a diesel engine. It is.

For this reason, by adding fuel (HC) to the exhaust gas upstream of the NOx storage reduction catalyst, this added fuel is used as a reducing agent to react with O ₂ on the NOx storage reduction catalyst, and the O ₂ concentration in the exhaust gas. Must be reduced (see, for example, Patent Document 1).

  On the other hand, as a measure to reduce particulate matter (particulate matter) discharged from diesel engines, an aftertreatment device equipped with a pre-stage oxidation catalyst and a particulate filter carrying an oxidation catalyst is placed in the middle of the exhaust pipe. It has already been proposed to equip and collect particulates in the exhaust gas, and promote the oxidation reaction of the collected particulates with an oxidation catalyst to efficiently remove the particulates by burning.

In addition, the diesel engine is equipped with an aftertreatment device having a selective reduction catalyst having a property of selectively reacting NOx with a reducing agent in the middle of the exhaust pipe even in the presence of oxygen, A necessary amount of reducing agent is added upstream to cause the reducing agent to undergo a reduction reaction with NOx (nitrogen oxide) in the exhaust gas on the selective catalytic reduction catalyst, thereby reducing the NOx emission concentration. There are also things. Here, in the field of industrial flue gas denitration treatment in plants and the like, the effectiveness of a method for reducing and purifying NOx using ammonia (NH ₃ ) as a reducing agent is already widely known. In some cases, since it is difficult to ensure safety when traveling with a toxic substance such as ammonia, in recent years, the use of non-toxic urea water as a reducing agent has been studied (for example, , See Patent Document 2). That is, if urea water is added to the exhaust gas upstream of the selective catalytic reduction catalyst, the urea water is thermally decomposed into ammonia and carbon dioxide gas in the exhaust gas, and NOx in the exhaust gas is converted into the selective catalytic reduction catalyst. It will be reduced and purified well by ammonia.

  6 to 8 show an example of an aftertreatment device installed in a truck equipped with a diesel engine. FIG. 6 shows a vehicle longitudinal direction at a position below the loading platform 2 on the right side in the width direction of the truck 1. An example is shown in which an exhaust pipe 3 is disposed so as to extend to the rear, and an aftertreatment device 4 is provided in the middle of the exhaust pipe 3.

  In the example shown in FIG. 7, the post-processing device 4 has a configuration in which a casing 5 includes a pre-stage oxidation catalyst 6 and a particulate filter 7 carrying the oxidation catalyst. A front silencer 8 and a rear silencer 9 are connected to each other, and the exhaust pipe 3 on the upstream side of the front silencer 8 is supported by pipe hangers 10 and 11 so as to be suspended from the frame 1 a of the truck 1. This portion is supported by the large-diameter pipe hanger 12 so as to be suspended from the frame 1a, and the tail pipe 3a portion at the end of the exhaust pipe 3 is supported by the pipe hanger 13 so as to be suspended from the frame 1a.

The casing 5 of the post-processing device 4 is provided with a temperature sensor 14 for detecting the temperature of the exhaust gas on the inlet side of the particulate filter 7, and the temperature sensor 14 is connected via an electrical wiring 15. It is connected to a control device (not shown) that forms an engine control computer (ECU: Electronic Control Unit).
JP 2000-356127 A JP 2002-161732 A

  By the way, the post-processing device 4 has a structure in which the casing 5 can be disassembled so as to be separated from the front silencer 8 and the rear silencer 9, as shown in FIG. Therefore, there is a risk of theft targeting the pre-stage oxidation catalyst 6 using an expensive noble metal or the oxidation catalyst supported on the particulate filter 7, and countermeasures have been urgently required.

  In view of such circumstances, the present invention intends to provide an antitheft device for a diesel aftertreatment device that can prevent theft of a catalyst using an expensive noble metal.

The present invention is an antitheft device for exhaust gas purification diesel post-treatment device comprising a casing containing a catalyst using a noble metal in the middle of an exhaust pipe,
A theft detection means for detecting that the casing containing the catalyst is removed;
The present invention relates to a theft prevention device for a diesel aftertreatment device, characterized by comprising alarm means for issuing an alarm when it is detected that the casing is removed by the theft detection means.

  According to the above means, the following operation can be obtained.

  When it is detected by the theft detection means that the casing containing the catalyst is removed, an alarm is issued by the alarm means, so that it is possible to prevent the theft of the catalyst using an expensive noble metal.

  In the anti-theft device of the diesel aftertreatment device, the anti-theft means can be constituted by a disconnection detection system that detects that the electrical wiring connected to the casing in which the catalyst is built is cut.

  In the anti-theft device of the diesel post-processing device, the anti-theft means can also be constituted by a position sensor that irradiates light on the casing in which the catalyst is built and captures the reflected light.

  Furthermore, in the antitheft device of the diesel aftertreatment device, the antitheft means may be constituted by a piezoelectric sensor that detects a change in weight when the casing containing the catalyst is removed.

  According to the antitheft device of the diesel aftertreatment device of the present invention, it is possible to achieve an excellent effect that theft of a catalyst using an expensive noble metal can be prevented in advance.

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

  FIG. 1 is a first example of an embodiment of the present invention. In the figure, the same reference numerals as those in FIGS. 6 to 8 denote the same components, and the basic configuration is shown in FIGS. 8 is the same as the conventional one shown in FIG. 8, but the characteristic feature of this illustrated example is that a casing 5 in which a pre-stage oxidation catalyst 6 and a particulate filter 7 carrying an oxidation catalyst are incorporated is shown in FIG. As a theft detection means for detecting the removal, a disconnection detection system 16 for detecting that the electrical wiring 15 of the temperature sensor 14 connected to the casing 5 has been disconnected is provided, and a disconnection detection system as the theft detection means. 16 is provided with an alarm means 17 for issuing an alarm such as a buzzer when it is detected that the electrical wiring 15 of the temperature sensor 14 connected to the casing 5 is disconnected.

  Next, the operation of the illustrated example will be described.

  When an attempt is made to steal the pre-stage oxidation catalyst 6 using an expensive precious metal or the oxidation catalyst supported on the particulate filter 7, it is necessary to remove the casing 5, and in order to remove the casing 5, the temperature sensor 14 The electrical wiring 15 must also be cut.

  For this reason, it is only necessary to always monitor whether or not the electrical wiring 15 of the temperature sensor 14 connected to the casing 5 is disconnected.

  That is, when the disconnection detection system 16 detects that the electrical wiring 15 of the temperature sensor 14 is disconnected, an alarm such as a buzzer is issued by the alarm means 17, so that the pre-oxidation catalyst 6 using an expensive noble metal is used. And theft of the oxidation catalyst or the like carried on the particulate filter 7 can be prevented beforehand.

  In this way, it is possible to prevent theft of the pre-stage oxidation catalyst 6 using an expensive noble metal or the oxidation catalyst supported on the particulate filter 7 in advance.

  2 and 3 show a second example of the embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same components, and the basic configuration is shown in FIG. As shown in FIGS. 2 and 3, the casing 5 containing the pre-stage oxidation catalyst 6 and the particulate filter 7 carrying the oxidation catalyst is removed. As a theft detection means for detecting this, a position sensor 18 for irradiating the casing 5 with light and capturing the reflected light is provided, and when the position sensor 18 as the theft detection means detects that the casing 5 is removed. An alarm means 17 for issuing an alarm such as a buzzer is provided.

  As light with which the casing 5 is irradiated from the position sensor 18, for example, light emitted from a light emitting diode (LED), laser light, or the like can be used.

  In the second example shown in FIGS. 2 and 3, the casing 5 is irradiated with light from the position sensor 18 and the reflected light is captured, thereby recognizing that the casing 5 is correctly installed. However, if the casing 5 is to be removed in order to steal the pre-stage oxidation catalyst 6 using an expensive noble metal or the oxidation catalyst supported on the particulate filter 7, the position sensor 18 Since the object to which the irradiated light is reflected is lost, the position sensor 18 detects that the casing 5 is removed.

  Then, an alarm such as a buzzer is issued by the alarm means 17, so that it is possible to prevent theft of the pre-stage oxidation catalyst 6 using an expensive noble metal or the oxidation catalyst supported on the particulate filter 7 in advance.

  Thus, in the case of the second example shown in FIGS. 2 and 3, as in the case of the first example shown in FIG. 1, the oxidation catalyst carried on the pre-stage oxidation catalyst 6 or the particulate filter 7 using an expensive noble metal. Etc. can be prevented in advance.

  4 and 5 show a third example of an embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same components, and the basic configuration is shown in FIG. As shown in FIGS. 4 and 5, the casing 5 containing the pre-stage oxidation catalyst 6 and the particulate filter 7 carrying the oxidation catalyst is removed. As a theft detection means for detecting this, a piezoelectric sensor 19 for detecting a change in weight when the casing 5 is removed is provided in the pipe hanger 11 and the casing 5 is removed by the piezoelectric sensor 19 as the theft detection means. It is in the point which provided the alarm means 17 which issues alarms, such as a buzzer, when detecting this.

  Needless to say, the position of the piezoelectric sensor 19 may be the pipe hanger 12 supporting the rear silencer 9 instead of the pipe hanger 11 supporting the exhaust pipe 3.

  In the third example shown in FIGS. 4 and 5, the weight of the casing 5 in which the pre-stage oxidation catalyst 6 and the particulate filter 7 supporting the oxidation catalyst are incorporated is added to the piezoelectric sensor 19 via the pipe hanger 11. As a result, it is recognized that the casing 5 is correctly installed. However, in order to steal the oxidation catalyst 6 supported on the upstream oxidation catalyst 6 or the particulate filter 7 using an expensive noble metal, the casing 5 When it is going to be removed, the weight applied to the piezoelectric sensor 19 becomes light, so that the removal of the casing 5 is detected by the piezoelectric sensor 19.

  Then, an alarm such as a buzzer is issued by the alarm means 17, so that it is possible to prevent theft of the pre-stage oxidation catalyst 6 using an expensive noble metal or the oxidation catalyst supported on the particulate filter 7 in advance.

  Thus, in the case of the third example shown in FIGS. 4 and 5, the pre-oxidation catalyst 6 using an expensive noble metal is used, as in the case of the first example shown in FIG. 1 and the second example shown in FIGS. And theft of the oxidation catalyst or the like carried on the particulate filter 7 can be prevented beforehand.

  The antitheft device of the diesel post-processing device of the present invention is not limited to the above-described illustrated example, and the casing 5 includes a pre-stage oxidation catalyst 6 and a particulate filter 7 carrying the oxidation catalyst. The present invention is not limited to the post-processing device 4 and can be applied to a post-processing device in which a casing 5 includes a catalyst such as a NOx storage reduction catalyst or a selective reduction catalyst to which urea water is added. Of course, various changes can be made without departing from the scope of the invention.

It is a schematic block diagram which shows the 1st example of the form which implements this invention. It is a schematic block diagram which shows the 2nd example of embodiment which implements this invention. FIG. 3 is an equivalent view taken along the line III-III in FIG. 2. It is a schematic block diagram which shows the 3rd example of embodiment which implements this invention. It is a VV arrow equivalent view of FIG. It is a figure which shows the truck carrying a diesel engine, Comprising: (a) is a side view, (b) is a top view. It is a schematic block diagram which shows an example of the conventional post-processing apparatus, Comprising: It is a VII-VII arrow equivalent view of FIG.6 (b). It is a figure which shows the state which decomposed | disassembled the conventional post-processing apparatus shown by FIG.

Explanation of symbols

3 Exhaust pipe 4 Post-treatment device 5 Casing 6 Pre-stage oxidation catalyst (catalyst)
7 Particulate Filter 14 Temperature Sensor 15 Electrical Wiring 16 Disconnection Detection System 17 Alarm Means 18 Position Sensor 19 Piezoelectric Sensor

Claims (4)

An anti-theft device for a diesel aftertreatment device for exhaust purification comprising a casing containing a catalyst using a noble metal in the middle of an exhaust pipe,
A theft detection means for detecting that the casing containing the catalyst is removed;
An anti-theft device for a diesel aftertreatment device, comprising: alarm means for issuing an alarm when it is detected that the casing is removed by the theft detection means.   The antitheft device for a diesel aftertreatment device according to claim 1, wherein the theft detection means is constituted by a disconnection detection system for detecting that the electrical wiring connected to the casing in which the catalyst is incorporated is cut.   The antitheft device for a diesel aftertreatment device according to claim 1, wherein the theft detection means is constituted by a position sensor that irradiates light on a casing in which a catalyst is built and captures the reflected light.   The antitheft device for a diesel aftertreatment device according to claim 1, wherein the theft detection means is constituted by a piezoelectric sensor that detects a change in weight when the casing containing the catalyst is removed.

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