JPH0913959A - Exhaust gas purifying device - Google Patents

Abstract

PURPOSE: To prevent occurrence of a peeling phenomenon of exhaust gas flow against a wall face of a guide section connecting an exhaust pipe to a catalyst carrier or a filter in an exhaust gas purifying device, decrease a length of the guide section, and reduce a space. CONSTITUTION: This exhaust gas purifying device is constituted of a hold section 4 storing a catalyst carrier purifying exhaust gas and a filter 2, a guide section 3 connected to an inflow side exhaust pipe 10, and a discharge section 6 connected to an outflow side exhaust pipe 10. A passage cross sectional area of the hold section 4 is formed larger than the passage cross sectional area of the exhaust pipe 10, and the guide section 3 is formed into an expanding shape toward the hold section 4 side from the exhaust pipe 10 side. A guide member 7 is arranged at a passage center section over the whole length of the guide section 3 in the flow direction, the guide member 7 is formed into a rhombic cross section in the longitudinal direction, and both upstream and downstream ends of the guide member 7 are formed into sharp edges 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst carrier disposed in a case portion incorporated in an exhaust pipe, or a filter such as ceramic fiber, porous ceramics, wire mesh, etc. for purifying exhaust gas discharged from an engine. The present invention relates to an exhaust gas purifying device having a.

[0002]

2. Description of the Related Art Diesel engine combustion is based on so-called heterogeneous mixing in which fuel is injected into high-temperature, high-pressure air. Heterogeneous mixing is different from homogeneous mixture in that air and fuel are not uniformly mixed, so the carbon component in the fuel changes to soot, HC, etc. due to the high temperature heat of combustion, and they aggregate to form particulates, It is released to the outside. Conventionally, a catalyst carrier for oxidizing and purifying harmful substances in exhaust gas exhausted from a diesel engine, or carbon contained in the exhaust gas,
2. Description of the Related Art There is known an exhaust gas purification device such as DPF that collects particulates such as soot and HC with a filter and incinerates them. 2. Description of the Related Art As a conventional exhaust gas purifying device, for example, there is a device in which a casing is filled with a catalyst carrier or a filter as shown in FIG. 7 or 8.

The exhaust gas purifying apparatus shown in FIG. 7 has a casing 1 containing a catalyst carrier and a filter 2 for purifying the exhaust gas, which is incorporated in an exhaust pipe 10 for exhausting the exhaust gas from the engine. The casing 1 includes a tubular portion 5 having a uniform passage cross-sectional area, an introduction portion 3 that introduces exhaust gas that connects the tubular portion 5 and the inflow side exhaust pipe 10, and the tubular portion 5 and the exhaust side exhaust pipe 1.
It is composed of a discharge part 6 for connecting with 5. Further, a holding portion 4 for accommodating the catalyst carrier and the filter 2 is provided in a part of the tubular portion 5. The passage cross-sectional area of the tubular portion 5 is the exhaust pipe 1
The introduction portion 3 is formed to have a size larger than the passage cross-sectional area of 0.
Is formed in an expanded shape with a taper angle θ from the exhaust pipe 10 side toward the tubular portion 5 side. Furthermore, the length of the introduction part 3 is
It is formed to be about a quarter of the length of the tubular portion 5.

Further, the exhaust gas purifying apparatus shown in FIG.
Since the structure is substantially the same as that shown in FIG. 7, the same parts are designated by the same reference numerals. In this example, the tubular portion 5 is configured as the holding portion 4 that accommodates the catalyst carrier and the filter 2 over the entire length in the flow direction, and the tubular portion 5, the introduction portion 3, and the discharge portion 6 are configured to have substantially the same length. Has been done. In this example, from the introduction portion 3 exhaust pipe 10 side to the tubular portion 5
It is formed in an expanded shape with a gentle inclination of half the taper angle θ toward the side.

Further, Japanese Utility Model Laid-Open No. 52-128814 discloses a flow velocity distribution correction device in an exhaust gas purifying device of a vehicle. The flow velocity distribution correction device in the exhaust gas purification device has an object for flow velocity correction placed in the middle of an expanded diffuser on the inlet side of the exhaust gas purification device, and the flow velocity in the rear near the object decreases. Is used to cancel the portion of the catalyst layer where the flow velocity is large, so that the flow velocity distribution in the catalyst layer is corrected to be almost uniform.

Further, Japanese Utility Model Laid-Open No. 61-200409 discloses an exhaust gas purification device for an internal combustion engine. The exhaust gas purifying apparatus for an internal combustion engine includes a guide plate that is disposed in a passage that spreads from an exhaust gas inlet portion and intersects with a main exhaust gas flow direction, and that diffuses the main exhaust gas toward the entire area of the catalyst. A small hole was opened.

[0007]

However, in the exhaust gas purifying apparatus shown in FIG. 7, since the taper angle θ of the introduction portion 3 is large and the passage cross-sectional area is steeply changed, the introduction portion 3 is greatly changed. There is a problem that the exhaust gas becomes a vortex inside as indicated by an arrow A, and the exhaust gas cannot smoothly flow. Further, in order to make the flow in the exhaust gas purification device shown in FIG. 7 smooth, as shown in FIG. 8, the taper angle θ of the introduction part 3 is halved so as to avoid a rapid change in the passage cross-sectional area. In this case, the exhaust gas flows smoothly in the introduction portion 3 as shown by the arrow B, but since the length of the introduction portion 3 is formed to be approximately the same as that of the holding portion 4, space is reduced. There is a problem that the above efficiency deteriorates.

Further, the flow velocity distribution correction device in the exhaust gas purification device disclosed in Japanese Utility Model Laid-Open No. 52-128814 has reduced the flow velocity by placing an object for flow velocity correction in a high flow velocity region. Since the object for flow velocity correction is arranged in the middle of the diffuser that has been expanded, the flow of exhaust gas causes a separation phenomenon between the diffuser and the wall surface of the diffuser, and the ventilation resistance of exhaust gas increases. In general, when the ventilation resistance of the exhaust gas in the exhaust pipe increases, the exhaust pressure rises for the engine, and in particular, there is a problem that fuel consumption deteriorates.

Further, in the exhaust gas purifying apparatus for an internal combustion engine disclosed in Japanese Utility Model Laid-Open No. 61-200409, a guide plate is provided in the passage so as to spread from the exhaust gas inlet portion in order to expand the flow line of the exhaust gas to the outside. , To form streamlines inside,
A plurality of small holes are formed in the guide plate and exhaust gas is passed through the small holes. However, a vortex flow is generated on the back surface of the downstream end of the guide plate, and the flow velocity of the exhaust gas cannot be made uniform, and the flow resistance increases due to the vortex flow and the exhaust gas passes through the small holes. Therefore, there is a problem that the flow resistance due to the guide plate increases.

An object of the present invention is to solve the above-mentioned problems, and to enable the flow of exhaust gas discharged from an engine to flow uniformly and smoothly and to reduce the ventilation resistance of exhaust gas. By preventing the separation of exhaust gas from the wall surface by providing a guide member in the introduction part provided in the connecting area between the exhaust pipe and the casing part accommodating the catalyst carrier and the filter of the exhaust gas purification device, and exhausting the guide member It is an object of the present invention to provide an exhaust gas purification device formed in an optimum shape so that the gas flow is smooth and the flow resistance can be reduced.

[0011]

In order to achieve the above object, the present invention is constructed as follows. That is, the present invention has a casing containing a catalyst carrier for purifying the exhaust gas, which is incorporated in an exhaust pipe for exhausting exhaust gas from the engine, and a filter purifying means, and the casing holds the catalyst carrier and the filter. A holding section and an introducing section connected to the exhaust pipe, the holding section is formed to have a passage cross-sectional area larger than the passage cross-sectional area of the exhaust tube, and the introducing section is provided from the exhaust pipe side to the holding section. In the exhaust gas purification device that is formed in an expanded shape toward the side,
A guide member is disposed in the central portion of the passage over the entire length in the flow direction of the introduction portion, the guide member is formed in a rhombus in a cross section in the longitudinal direction, and both upper and lower ends of the guide member are formed to be pointed edges. The present invention relates to a characteristic exhaust gas purification device.

Further, the taper angle θ _{2 of the} rhombus cross section of the guide member on the exhaust pipe side and the taper angle θ _{3 of the} rhombus cross section on the case portion side are formed to be substantially the same, and these taper angles θ ₂ , θ ₃ is set to one half or less of the taper angle θ ₁ that spreads from the exhaust pipe side of the introduction portion toward the holding portion side.

The taper angles θ ₂ and θ ₃ are set to approximately one third of the taper angle θ ₁ .

The guide member is made of a material selected from heat-resistant and corrosion-resistant stainless steel, SUS, heat-resistant steel and ceramics.

[0015]

The exhaust gas purifying apparatus according to the present invention is constructed as described above and operates as follows. That is, in this exhaust gas purifying apparatus, since the guide member is disposed in the central portion of the passage over the entire length in the flow direction of the introduction portion and the guide member is formed in the rhombus in the longitudinal direction, the guide member allows the exhaust gas flow to flow. Exhaust gas can be uniformly diffused by the guide member and smoothly sent to the catalyst carrier or filter without causing phenomena such as separation phenomenon and eddy current that increase flow resistance, which deteriorates fuel efficiency. There is no.

In this exhaust gas purifying device, in particular, the upstream end of the guide member is formed at the edge, and the installation position of the edge is set at the expansion start point of the introduction portion, so that the exhaust gas is Guided by the guide member, it flows smoothly, no separation phenomenon occurs in contact with the wall surface of the introduction part, no swirl of exhaust gas occurs, and ventilation resistance can be reduced compared to conventional exhaust gas purification devices. Moreover, the exhaust gas is evenly spread over the entire surface of the inlet of the catalyst carrier or the filter by introducing the exhaust gas at a uniform flow velocity just before the inlet of the catalyst carrier or the filter, and is introduced into the catalyst carrier or the filter. Exhaust gas is satisfactorily purified by the carrier and the filter. Moreover, by installing the guide member in the introduction part, the length of the introduction part can be shortened, and the problem of space can be solved.

[0017]

Embodiments of the exhaust gas purifying apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view showing an embodiment of an exhaust gas purifying apparatus according to the present invention, FIG.
1 is a cross-sectional view taken along the line AA of FIG. 1, FIG. 3 is an enlarged cross-sectional view of a main part of the exhaust gas purification apparatus of FIG. 1, and FIG. 4 is an explanatory diagram showing an exhaust gas flow in the exhaust gas purification apparatus of FIG. is there. Since the exhaust gas purifying apparatus according to the present invention has a basic outer shape similar to that of the exhaust gas purifying apparatus shown in FIGS. 7 and 8, the same parts are designated by the same reference numerals. There is.

This exhaust gas purification apparatus has a casing 1 containing a catalyst carrier and a filter 2 which are purification means for purifying exhaust gas incorporated in an exhaust pipe 10 for exhausting exhaust gas from a diesel engine. 1 comprises a casing portion or holding portion 4 for holding the catalyst carrier and the filter 2, an introduction portion 3 connected to the inflow side exhaust pipe 10, and a discharge portion 6 connected to the outflow side exhaust pipe 15. The holding part 4 is formed of a tubular part 5 having a uniform cross-sectional shape. The holding part 4, the introduction part 3, and the discharge part 6 can be configured by three separate casing parts, but can also be configured by a three-part integral structure or the like.
Catalyst carrier or filter 2 is a carrier for supporting carbon, soot, or trapping particulates such as HC, or the catalytic metal can or to decompose harmful gas such as NO _X contained in the exhaust gas, for example, Various structures such as a case in which a granular catalyst carrier is filled in a case, a case in which ceramic fibers are laminated, a case in which porous ceramics is formed, or a case where a wire net is added to these materials. It is composed of.

In FIG. 3, the holding part 4, the introducing part 3 and the discharging part 6 which constitute the casing 1 are separately constructed,
A flange portion 11 provided at the end of the upstream exhaust pipe 10 and a flange portion 12 provided at the upstream end of the introduction portion 3 are fixed to each other, and a flange portion provided at the downstream end portion of the introduction portion 3 13 and a flange portion 14 provided at the upstream end of the holding portion 4.
And are fixed to each other. Further, the passage cross-sectional area of the holding portion 4 in the casing 1 is formed to be larger than the passage cross-sectional area of the exhaust pipe 10. Further, the introduction part 3 is formed in an expanded shape from the upstream side exhaust pipe 10 side toward the holding part 4 side, and the discharge part 6 is formed in a contracted shape from the holding part 4 side toward the downstream side exhaust pipe 15 side. Has been formed.

This exhaust gas purifying device is particularly suitable for the introduction part 3
The guide member 7 is disposed in the introduction portion 3 by the holding plate 8 in the central portion of the passage over the entire length in the flow direction of the guide member 7. Further, the guide member 7 is formed in a rhombus cross section in the longitudinal direction, and both upper and downstream ends of the guide member 7 are pointed. That is, it is formed on the edges 9, 9. In other words, the shape of the guide member 7 is determined according to the shape of the introduction portion 3, and when the introduction portion 3 is formed into a truncated cone tube shape, the front end portion has a conical shape. In addition, the rear end portion can be formed in a conical shape, and when the introduction portion 3 is formed in a truncated pyramid cylinder shape, the front end portion is formed in a pyramid shape and the rear end portion is formed in a pyramid shape. Is something that can be done.

The shape of the guide member 7 is specifically shown in FIG.
As shown in (A) of FIG. 4, the taper angle at which the introduction portion 3 expands is set to 2θ ₁ (hereinafter, half θ _{1 is referred} to as a taper angle), and the guide member 7 has a rhombus-shaped taper in section on the upstream exhaust pipe 10 side. The angle is set to 2θ ₂ (hereinafter, half θ _{2 is referred} to as a taper angle), and the taper angle of the rhombus section of the guide member 7 on the holding portion 4 side is 2θ ₃ (hereinafter, half θ _{3 is referred} to as a taper angle). To do. Here, it is assumed that θ ₂ and θ ₃ are formed at substantially the same angle. In addition, these taper angles θ ₂ and θ ₃ are set to ½ or less of the taper angle θ ₁ , respectively. In particular, each taper angle θ ₂ , θ ₃
Are set to approximately one-third of the taper angle θ ₁ , respectively, so that the spread state of the expansion of the exhaust gas can be improved without causing the separation phenomenon in the flow of the exhaust gas.

Further, in this exhaust gas purifying apparatus, the lengths of the holding portion 4 and the discharge portion 6 constituting the casing 1 are substantially the same, but the length of the introduction portion 3 is long. The holding portion 4 and the discharging portion 6 are formed to have a length that is almost half of the length in the longitudinal direction. Further, the guide member 7
Is made of a material selected from heat resistant and corrosion resistant stainless steel, SUS, heat resistant steel and ceramics.

With respect to this exhaust gas purifying apparatus, the spread state of the exhaust gas by the guide member 7 will be described with reference to FIGS. 5 and 6. In this exhaust gas purifying device, the separation phenomenon on the wall surface of the introduction portion of the exhaust gas by the guide member 7 is not determined by the size of the taper angles θ ₂ and θ ₃ at the point of the guide member 7, but by the guide member 7 This is due to the amount of change in the taper angles θ ₂ and θ _{3 on} the outer surface of. That is, the separation phenomenon of the exhaust gas from the wall surface of the inlet portion is due to the amount of change in the taper angles θ ₂ and θ ₃ at a certain point of the guide member 7.

FIG. 5B shows a comparison of the spread state of the exhaust gas between the passage structure TG in which the guide member is provided in the introduction portion and the passage structure NG in which the guide member is not provided. In channel structure TG, is obtained by arranging the guide member 7 to the inlet portion 3, the guide member _{7 θ 2 = θ 3 = θ} 1/2
It is formed to the dimensions of the relationship. Inside the exhaust pipe 10, it is a uniform cylinder, and the amount of change in the cross-sectional area of the passage is zero. Therefore, the spread of the exhaust gas does not occur. Further, when the change amount of the taper angle in the introduction portion 3 is θ ₁ or more, it is assumed that the exhaust gas separation phenomenon occurs at a limit angle. At point A in FIG. 5, the change amount of the taper angle of the passage structure TG is θ ₁ −
While θ ₂ = θ _1/2 , the change amount of the passage structure NG is θ ₁ . At point B in FIG. 5, the change amount of the taper angle of the passage structure TG is (θ ₁ + θ ₃ ) − (θ ₁ −θ ₂ ) = θ
₂ + θ ₃ , whereas the amount of change in the passage structure NG is 0
It is. That is, the change amount of the taper angle at the introduction portion is in the state shown by the solid line in the passage structure NG and in the state shown by the dotted line in the passage structure TG. When the exhaust gas is made to flow through the introduction portion and observed, the passage structure TG is smaller than θ _{1 at the} point A.
Although the separation of exhaust gas from the wall surface of _{No. 2} did not occur, the passage structure NG was θ _{1 at} point A, and the separation of exhaust gas from the wall surface of the introduction portion 3 occurred. Further, in the passage structure TG, the change amount of the taper angle at the point B is θ.
₂ + θ ₃ = θ ₁ , and at point B it becomes θ ₁
Exhaust gas was separated from the wall surface of the. From the above phenomenon, if the amount of change in the taper angle at point B in the passage structure TG becomes θ ₁ or less, the exhaust gas separation phenomenon will not occur. Therefore, in the exhaust gas purifying apparatus, if the taper angles θ ₂ and θ ₃ of the guide member 7 provided in the introduction part 3 are set to ½ or less of the taper angle θ ₁ for expanding the introduction part 3, respectively, the exhaust gas The peeling phenomenon will not occur.

Further, FIG. 5C shows a comparison of the spread state of the exhaust gas between the passage structure TG in which the guide member is provided in the introduction portion and the passage structure NG in which the guide member is not provided. In the passage structure TG, the guide member 7 is arranged in the introduction portion 3, and the guide member 7 is arranged with θ ₂ = θ ₃ = θ ₁
It is formed to have a dimension of / 3. Inside the exhaust pipe 10, it is a uniform cylinder, and the amount of change in the cross-sectional area of the passage is zero. Therefore, the spread of the exhaust gas does not occur. Further, when the change amount of the taper angle in the introduction portion 3 is θ ₁ or more, it is assumed that the exhaust gas separation phenomenon occurs at a limit angle. At point A in FIG. 5, the change amount of the taper angle of the passage structure TG is θ ₁ −
θ ₂ = (2/3) θ ₁ while the passage structure is NG
The change amount of is θ ₁ . At point B in FIG. 5, the passage structure TG
The amount of change in the taper angle of (θ ₁ + θ ₃ ) − (θ ₁ −
θ ₂ ) = θ ₂ + θ ₃ = (2/3) θ ₁ whereas the change amount of the passage structure NG is 0. That is, the change amount of the taper angle at the introduction portion is in the state shown by the solid line in the passage structure NG and in the state shown by the dotted line in the passage structure TG. When the exhaust gas was made to flow through the introduction portion and observed, the passage structure TG was smaller than θ _{1 at} point A, and the separation phenomenon of the exhaust gas on the wall surface of the introduction portion 3 did not occur, whereas in the passage structure NG at point A. It became θ _{1 and the} phenomenon of exfoliation of exhaust gas from the wall surface of the introduction part 3 occurred. In the passage structure TG, the taper angle change amount at the point B is θ ₂ + θ ₃ = (2/3) θ ₁
Therefore, at the point B, it became smaller than θ ₁ , and the phenomenon of exfoliation of the exhaust gas from the wall surface of the introduction part 3 did not occur. That is,
By setting the taper angle theta ₂ of the guide member 7, the theta ₃ to theta _1/3, so that the peeling phenomenon of the exhaust gas does not occur.
Therefore, in the exhaust gas purifying apparatus, if the taper angles θ ₂ and θ ₃ of the guide member 7 provided in the introduction part 3 are set to one third of the taper angle θ ₁ for expanding the introduction part 3, respectively, the exhaust gas The peeling phenomenon will not occur.

Next, referring to FIG. 6, what is the most suitable numerical value of the taper angles θ ₂ and θ ₃ of the guide member 7 installed in the introduction portion 3 will be considered. In FIG. 6, the vertical axis represents the spread angle (= θ ₁ ) of the exhaust gas, and the horizontal axis represents the guide member 7
If the taper angles θ ₂ and θ ₃ are set to, when the guide member 7 is provided in the introduction portion 3, the divergence angle at the point A changes like a straight line AG, and the divergence angle at the point B is It changes like a straight line BG. As can be seen from the graph, at the point where the divergence angle at point A and the divergence angle at point B match, the exhaust gas spreads evenly over the entire length of the introduction part 3, and the separation phenomenon of the flow of exhaust gas does not occur. It will be. Therefore, the taper angles θ ₂ and θ ₃ of the guide member 7 installed in the introduction part 3 are set to θ
Most preferably it is seen that the set _1/3.

[0027]

The exhaust gas purifying apparatus according to the present invention is constructed as described above and has the following effects.
That is, in this exhaust gas purification device, a guide member is disposed in the central portion of the passage over the entire length in the flow direction of the introduction portion that connects the exhaust pipe and the holding portion that holds the purification means for the catalyst carrier and the filter. Since the longitudinal cross section is formed in a rhombus shape, and the upper and lower ends of the guide member are formed to have sharp edges, it is possible to prevent the phenomenon of separation from the wall surface of the exhaust gas introducing portion. Moreover, if the taper angle of the guide member is set to ½ or less of the taper angle of the introduction portion, the occurrence of the peeling phenomenon can be reliably prevented, and particularly if the taper angle is set to ⅓. Thus, the peeling phenomenon can be reliably prevented over the entire length of the introduction portion. Moreover, by providing the guide member in the introduction part, the length of the introduction part can be shortened, and the space occupied by the exhaust gas purification device itself for incorporating the exhaust gas purification device in the exhaust pipe can be reduced. it can.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing an embodiment of an exhaust gas purifying device according to the present invention.

FIG. 2 is a cross-sectional view taken along line AA of FIG.

FIG. 3 is an enlarged cross-sectional view of a main part of the exhaust gas purification device of FIG.

FIG. 4 is an explanatory diagram showing an exhaust gas flow in the exhaust gas purification device of FIG. 1.

FIG. 5 is an explanatory diagram showing a spread state of exhaust gas in the exhaust gas purification device.

FIG. 6 is a graph showing a spread state of exhaust gas in the exhaust gas purification device.

FIG. 7 is a schematic explanatory view showing an example of a conventional exhaust gas purification device.

FIG. 8 is a schematic explanatory view showing another example of a conventional exhaust gas purification device.

[Explanation of symbols]

1 casing 2 catalyst carrier or filter 3 introduction part 4 holding part 5 cylinder part 6 discharge part 7 guide member 8 holding plate 9 pointed edge 10 exhaust pipe θ ₁ taper angle for expanding the introduction part θ ₂ exhaust member side of guide member θ ₂ Taper angle of tip θ ₃ Taper angle of tip of holding part of guide member

Claims (5)

[Claims] 1. A holding unit for holding a catalyst carrier and a filter for purifying the exhaust gas, which is incorporated in an exhaust pipe for exhausting exhaust gas from an engine, the casing holding the catalyst carrier and the filter. It is composed of an introduction part connected to the inflow side exhaust pipe and a discharge part connected to the outflow side exhaust pipe, and the passage cross-sectional area of the holding part is formed in a size larger than the passage cross-sectional area of the exhaust pipe, and the introduction part is In an exhaust gas purifying device that is formed in an expanded shape from the exhaust pipe side toward the holding portion side, a guide member is arranged in the central portion of the passage over the entire length in the flow direction of the introduction portion, and the guide member has a longitudinal section. An exhaust gas purifying device, which is formed in a rhombus shape, and both upper and lower ends of the guide member are formed to have sharp edges. 2. A taper angle θ _{2 of a} rhombus cross section of the guide member on the exhaust pipe side and a taper angle θ _{3 of a} rhombus cross section on the holding portion side are formed at substantially the same angle, and these taper angles θ ₂ , The exhaust gas according to claim 1, wherein θ ₃ is set to one half or less of a taper angle θ ₁ that spreads from the exhaust pipe side of the introduction section toward the holding section side. Purification device. 3. The exhaust gas purifying apparatus according to claim ₂ , wherein the taper angles θ ₂ and θ ₃ are set to approximately one third of the taper angle θ ₁ . 4. The length of the introducing portion in the longitudinal direction is formed to be approximately half the length of the discharging portion in the longitudinal direction. Exhaust gas purifier according to. 5. The guide member is made of a material selected from heat-resistant and corrosion-resistant stainless steel, SUS, heat-resistant steel, and ceramics.
The exhaust gas purification device according to any one of 4 above.