JP5368838B2 - engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine including an exhaust purification device excellent in exhaust emission control properties retaining a shape of the engine itself and facilitating replacement of a catalyst. <P>SOLUTION: This engine 100 includes an exhaust purification device 10 disposed at a middle part of an exhaust gas passage. In the exhaust purification device 10, a primary catalyst 41 for exhaust emission control which can be attached and be detached is disposed at an upstream side of an exhaust manifold 5 forming a part of the exhaust gas passage providing communication between a cylinder head 3 and a muffler 6, and a secondary catalyst 42 for exhaust emission control is disposed at a downstream side. The primary catalyst 41 for exhaust emission control includes a cover 43 for fixing at one end of the catalyst body, and another end thereof is inserted into the exhaust manifold 5 from an insertion opening 11b opening at a side surface of the exhaust manifold 5. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an engine exhaust gas purification device technique, and more particularly, to an arrangement of an exhaust gas purification catalyst and a replacement technique thereof.

  Exhaust gas discharged from an internal combustion engine such as a diesel engine contains nitrogen oxides and particulate matter that are highly likely to affect environmental pollution. Due to recent environmental considerations, exhaust gas regulations have become more stringent, and various exhaust purification devices have been proposed in order to respond to this. Moreover, in the case of an industrial diesel engine, there are various forms of mounting the exhaust purification device on a working machine, and the space of the mounting part is limited. Therefore, it is difficult to arrange an exhaust purification device separately from the engine. In addition, it is impossible for a construction machine or an agricultural machine used off-road to dispose the exhaust purification device at the bottom of the chassis of the work machine. Since the same engine is mounted on various working machines, when it is placed outside the engine room, specifications with different piping and the like are generated, and there is a concern about the effect of a decrease in purification performance due to a change in exhaust temperature.

  Therefore, in the technique disclosed in Patent Document 1, a technique for accommodating an oxidation catalyst in an exhaust path of an engine is known. In the technique disclosed in Patent Document 1, since the oxidation catalyst is accommodated in the exhaust path, the engine itself is not enlarged without installing an exhaust purification device separately, and the engine is installed in a conventional space. It can be installed and used. However, since the engine is assembled to the work machine, the exhaust path must be disassembled when the oxidation catalyst is replaced, and maintenance is difficult.

JP 2006-29121 A

  The present invention has been made in view of the circumstances as described above, and provides an engine equipped with an exhaust purification device that retains the shape of the engine itself and has an excellent exhaust purification capability that facilitates catalyst replacement. It is.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

According to a first aspect of the present invention, there is provided an engine including an exhaust purification device installed in a middle portion of the exhaust passage, wherein the exhaust purification device is an exhaust manifold that forms part of the exhaust passage communicating between a cylinder head and a muffler. A primary catalyst for exhaust purification that can be attached and detached is disposed on the upstream side, a secondary catalyst for exhaust purification is disposed on the downstream side, and the primary catalyst for exhaust purification is provided with a fixing lid at one end of the catalyst body, The other end is inserted into the exhaust manifold from the insertion port opened on the side surface of the exhaust manifold, and the primary catalyst body for exhaust purification is shaped to match the exhaust port opened to the cylinder head, It is configured to be inserted and supported in the exhaust port .

According to a second aspect of the present invention, in the engine according to the first aspect, the fixing lid is provided with a flange portion on an outer periphery thereof, and the flange portion, the exhaust manifold, and the cylinder head are fastened and fixed together .

According to a third aspect of the present invention, in the engine according to the first or second aspect, the exhaust manifold is formed with an opening on a side surface of the exhaust manifold so that the secondary catalyst for exhaust purification can be inserted. Is capable of being closed by a lid after inserting the exhaust purification secondary catalyst .

  As effects of the present invention, the following effects can be obtained.

According to a first aspect of the present invention, there is provided an engine including an exhaust purification device installed in a middle portion of the exhaust passage, wherein the exhaust purification device is an exhaust manifold that forms part of the exhaust passage communicating between a cylinder head and a muffler. Since the primary catalyst for exhaust purification that can be attached and detached is arranged on the upstream side, and the secondary catalyst for exhaust purification is arranged on the downstream side, the shape of the engine itself is maintained, and the primary catalyst for exhaust purification and the secondary catalyst for exhaust purification are used. Since purification is performed in two stages of the next catalyst, the purification performance can be improved.

  In addition, since the exhaust purification primary catalyst with a short replacement time can be attached and detached, it can be easily replaced and the life of the exhaust purification secondary catalyst can be extended.

The exhaust purification primary catalyst has a structure in which a fixing lid is provided at one end of the catalyst body, and the other end is inserted into the exhaust manifold through an insertion port opened on a side surface of the exhaust manifold. The primary catalyst can be easily exchanged like a cartridge type, the maintenance can be improved, and it can be easily attached and exchanged from the outside without removing the muffler.

Further, the primary catalyst main body for exhaust purification has a shape that matches the other end of the main body with the exhaust port opened in the cylinder head, and is configured to be inserted and supported in the exhaust port, so that the exhaust gas temperature is at the highest position. By disposing the primary catalyst for exhaust purification, the purification ability of the primary catalyst for exhaust purification can be maximized, leading to the effect of reducing exhaust gas emissions.

  In addition, both sides of the exhaust purification primary catalyst are supported, so that vibrations do not rattle or leakage of exhaust gas does not occur.

According to a second aspect of the present invention, in the engine according to the first aspect, the fixing lid is provided with a flange portion on an outer periphery thereof, and the flange portion, the exhaust manifold, and the cylinder head are fastened and fixed together. And the exhaust purification primary catalyst can be integrally attached and detached, and the maintainability is improved.

According to a third aspect of the present invention, in the engine according to the first or second aspect, the exhaust manifold is formed with an opening on a side surface of the exhaust manifold so that the secondary catalyst for exhaust purification can be inserted. Can be closed by the lid after inserting the secondary catalyst for exhaust purification, so that both the primary catalyst for exhaust purification and the secondary catalyst for exhaust purification can be easily replaced, and maintainability is improved. Improvements can be made.

The front view which showed the structure of the exhaust gas purification apparatus which concerns on Example 1 of this invention. FIG. 2 is a sectional view taken along line AA in FIG. 1. BB sectional drawing in FIG. The front view which showed the structure of the exhaust gas purification apparatus which concerns on Example 2 of this invention. The top view which showed the structure of the exhaust gas purification apparatus which concerns on Example 2 of this invention. The CC sectional view taken on the line in FIG. The front view which showed the structure of the exhaust gas purification apparatus which concerns on Example 3 of this invention. The top view which showed the structure of the exhaust gas purification apparatus which concerns on Example 3 of this invention. DD sectional view taken on the line in FIG. The perspective view which showed the whole structure of the engine which concerns on embodiment of this invention. The side sectional view showing the internal configuration of the engine concerning the embodiment of the present invention.

  Next, embodiments of the invention will be described.

  First, the overall configuration of an engine according to an embodiment of the present invention will be described with reference to FIGS. 10 and 11 using an air-cooled single-cylinder diesel engine as an example. In the following description, the direction of the arrow F in the figure is “front”, and the left, right, and rear are determined toward the front. The white arrow in the figure indicates the assembly direction of the exhaust manifold 5, and the thick arrow indicates the direction in which the exhaust gas flows.

  The main body of the engine 100 is mainly composed of a lower crankcase 1, a cylinder block 2 forming an upper cylinder 2a, and a cylinder head 3 thereon. In the center of the cylinder block 2, a cylinder 2a is formed in the vertical direction, and the piston 4 is accommodated in the cylinder 2a.

  A chamber surrounded by the cylinder 2a, the piston 4, and the cylinder head 3 is a combustion chamber, and an intake valve 31 and an exhaust valve 32 are slidably disposed in the cylinder head 3 above the cylinder 2a. An injection nozzle (not shown) is disposed in the vicinity of. The cylinder head 3 above the cylinder 2 a is provided with an intake port 33 and an exhaust port 34 so that the intake valve 31 can be opened and closed between the combustion chamber and the intake port 33, and between the combustion chamber and the exhaust port 34. The exhaust valve 32 can be opened and closed.

  The intake port 33 communicates with the air cleaner 8 via an intake manifold 8a. The exhaust port 34 communicates with the muffler 6 via the exhaust manifold 5.

  On the outer periphery of the cylinder head 3, an exhaust manifold 5 is disposed on the front side, a muffler 6 is disposed on the right side, a fuel tank 7 is disposed on the left side, and an air cleaner 8 is disposed on the rear side.

  With the above-described configuration, the exhaust gas having a high temperature is guided to the exhaust port 34, the exhaust manifold 5, and the muffler 6, and is discharged into the atmosphere through the piping while the temperature is lowered.

  Next, the configuration of the exhaust emission control device 10 according to the first embodiment will be described with reference to FIGS. 1 to 3. The exhaust purification device 10 is configured by installing a catalyst in the exhaust manifold 5. The exhaust purification device 10 is mainly composed of an exhaust manifold 5, an exhaust purification primary catalyst 41 (hereinafter referred to as a primary catalyst 41), and an exhaust purification secondary catalyst 42 (hereinafter referred to as a secondary catalyst 42). In the exhaust manifold 5 forming a part of the exhaust passage, the primary catalyst 41 is disposed on the exhaust upstream side, and the secondary catalyst 42 is disposed on the exhaust downstream side.

  The exhaust manifold 5 in Example 1 also serves as the case of the exhaust purification device 10 according to the present embodiment. The exhaust manifold 5 is mainly composed of a first case body 11 and a second case 12.

  The exhaust manifold 5 of the present embodiment is formed by combining the first case body 11 and the second case 12 into a cylindrical body having a substantially elliptical outer peripheral section as a whole, and the periphery is integrally fixed by welding or the like. Although configured, the shape is not limited. That is, the exhaust manifold 5 can be formed into a rectangular tube shape, a columnar shape, can be divided into two parts, can be formed integrally with bolts, etc., or can be formed into three or more parts in order to make the structure easy to mold. It is.

  The first case body 11 is a member that forms the front portion of the exhaust manifold 5 and is formed in a substantially semi-cylindrical shape in a side view. The first case body 11 is disposed in front of the cylinder head 3 so that the axial direction thereof is the left-right direction. The first case body 11 is formed so as to be inclined (squeezed) from the left and right midway portions toward the exhaust port 34, and the left end portion thereof is closed. The right end of the first case body 11 and the rear part of the first case body 11 are open. An insertion port 11 b is formed in the left front portion of the first case body 11. Around the upper and lower end portions and the left end portion of the first case body 11, flange portions 11a are provided so as to protrude outward. Bolt holes 63 and 63 are opened at a predetermined interval on the left side of the flange portion 11a.

  The second case 12 is a plate-like member that forms the rear part of the exhaust manifold 5, and is formed so that the outer periphery of the flange portion 11 a of the first case body 11 and the outer periphery of the second case 12 face each other. To do. Further, bolt holes 62 and 62 are formed on the left outer periphery of the second case 12 at a predetermined interval. The bolt holes 62 and 62 are formed at positions where they can coincide with the bolt holes 63 and 63 of the flange portion 11a in front view. An inlet portion 12 a is formed on the left side of the second case 12.

  Thus, the first case body 11 and the second case 12 are welded in a state where the flange portion 11a and the outer periphery of the second case 12 are overlapped and the respective bolt holes 63 and 62 are aligned. Integrate.

  The inlet portion 12 a is an opening disposed in the left rear portion of the second case 12 in order to allow the exhaust gas to flow into the exhaust manifold 5. The inlet portion 12a has substantially the same shape as the opening of the exhaust port 34 described above, and is formed at a position where it can be substantially matched when viewed from the front.

  The insertion port 11b is an opening disposed at the left front portion of the first case body 11 in order to put in and out a primary catalyst 41 described later. The insertion port 11b is an opening having substantially the same shape as the exhaust port 34 and the inlet portion 12a, and is formed at a position where it can substantially match with the front view.

  In the exhaust manifold 5, a catalyst holding portion 51 made of a projecting piece is disposed to hold a secondary catalyst 42 described later. The catalyst holding portion 51 protrudes rearward at predetermined intervals in the vertical direction on both the left and right sides of the inner surface of the first case body 11 of the exhaust manifold 5 so as to contact the left and right side surfaces on the front side of the secondary catalyst 42. It is installed. Similarly, the front and rear sides of the inner surface of the second case 12 are protruded forward at a predetermined interval in the vertical direction so as to come into contact with the left and right side surfaces on the rear side of the secondary catalyst 42. That is, the catalyst holding portion 51 is provided on the inner surface of the first case body 11 and the inner surface of the second case 12 so that the left and right sides of the secondary catalyst 42 can be held in accordance with the size of the secondary catalyst 42 vertically and horizontally. -51 ... are provided.

  The outlet portion 11 c is formed by an open portion at the right end of the first case body 11 and the second case 12 in order to allow the exhaust gas to flow out. The outlet portion 11 c is provided through an insertion port 6 a disposed on the front side of the left side surface of the muffler 6.

  Next, the primary catalyst 41 and the secondary catalyst 42 housed in the exhaust manifold 5 in the present embodiment will be described below.

  The primary catalyst 41 in the present embodiment is cylindrical and is formed so as to be fitted to the insertion port 11b, the inlet 12a and the exhaust port 34. Therefore, the size of the primary catalyst 41 is formed according to the exhaust port 34, the inlet 12a, and the insertion port 11b.

  The primary catalyst 41 is arranged by providing a fixing lid 43 on one end side and inserting it from the rear end into an insertion port 11b opened on the side surface of the exhaust manifold 5. Therefore, the other end portion of the primary catalyst 41 main body is inserted and supported by the inlet portion 12 a and the exhaust port 34.

  The fixing lid 43 is formed so as to cover the insertion port 11b of the first case body 11 and the periphery thereof. A flange 43 a is provided on the right outer periphery of the fixing lid 43. Bolt holes 64 and 64 are formed in the flange portion 43a. When the bolt holes 64 are installed in the exhaust manifold 5, the bolt holes 64 and 64 are spaced from each other at a position that coincides with the bolt holes 63 and 62 when viewed from the front. Open a hole. Further, at a position where the exhaust manifold 5 is attached to the cylinder head 3, the bolt hole 61 is opened so as to coincide with the bolt holes 63 and 62 in a front view.

  Thus, the exhaust manifold 5 is disposed on the front outer surface of the cylinder head 3 so that the bolt holes 61, 62, 63, and 64 are aligned with each other, and the fixing lid 43 is disposed on the left front outer surface of the exhaust manifold 5. Then, a gasket (not shown) is sandwiched between the members, and the members are fastened together with bolts 65 or the like in the bolt holes 61, 62, 63, 64 while maintaining airtightness.

  The secondary catalyst 42 is arranged from the left and right midway part of the exhaust manifold 5 to the outlet part 11 c and is formed in accordance with the inner space formed by the first case body 11 and the second case 12. Therefore, the secondary catalyst 42 is held by the inner surface of the exhaust manifold 5. However, when the heat insulating material 25 is disposed between the secondary catalyst 42 and the exhaust manifold 5, the outer periphery of the secondary catalyst 42 is formed by a thickness of the heat insulating material and is held by the heat insulating material 25. The left and right ends of the secondary catalyst 42 are fixed by catalyst holding portions 15, 15... Fixed in the exhaust manifold 5.

  The catalyst bodies of the primary catalyst 41 and the secondary catalyst 42 in the present embodiment are monolithic carriers made of ceramics such as cordierite, and are partitioned by lattice-shaped or honeycomb-shaped porous partition walls in order to increase the specific surface area. Having a polygonal cross section. These partition walls are configured by sealing the exhaust gas inlet and outlet alternately in a large number of through holes formed in parallel to each other. The partition wall carries a catalytic metal such as platinum, and therefore has an oxidation catalyst function.

  In addition, although the material of the monolith carrier is cordierite in this embodiment, it is not particularly limited, and silicon carbide, stainless steel, or the like can be used. The catalyst body only needs to have a structure for increasing the specific surface area. For example, the catalyst body may be a mesh ring in which a large number of grid-like metal plate partitions are arranged. In this embodiment, platinum is used as the catalyst metal. However, this is not particularly limited, and palladium, rhodium, iridium, or the like can be used or a combination thereof can be used without any limitation.

With the above configuration, the primary catalyst 41 and the secondary catalyst 42 capture PM (floating particulate matter) in the exhaust gas by the porous partition walls. At the same time, the primary catalyst 41 and the secondary catalyst 42 are loaded with the catalyst metal, so that the nitrogen oxide (NOx), nitrogen monoxide (NO), carbon monoxide (CO), hydrocarbon (HC) in the exhaust gas is discharged. Is imparted with oxidizing power to produce carbon dioxide, water, nitrogen dioxide NO _{2 and the} like. Then, the oxidizing power of NO2 and the like produced in the exhaust gas by the catalyst metal and the high temperature of the exhaust gas near the exhaust port 34 are utilized, and the collected PM is continuously oxidized and removed by combustion. .

  With the exhaust purification apparatus 10 having the above-described configuration, the exhaust gas first passes through the primary catalyst 41 at the downstream portion of the exhaust port 34. Since the primary catalyst 41 is fitted from the exhaust port 34 to the inlet portion 12a, the exhaust gas passes through the primary catalyst 41 and is then guided into the exhaust manifold 5 near the inlet portion 12a. Then, the exhaust gas passes through the secondary catalyst 42 arranged from the left and right midway part to the downstream part of the exhaust manifold 5, and is guided into the muffler 6 from the outlet part 11c. Therefore, the exhaust gas is purified by passing through the primary catalyst 41 and the secondary catalyst 42, guided to the muffler 6, and discharged to the outside through a pipe separately provided in the muffler 6.

  When the exhaust gas purification capacity of the exhaust purification device 10 is reduced, the bolts 65 and 65 are removed, the fixing lid 43 is removed, and the primary catalyst 41 integrated with the fixing lid 43 is replaced. Again, the new primary catalyst 41 is arranged in the exhaust purification device 10 to maintain the exhaust gas purification capability.

  Next, the configuration of the exhaust emission control device 10 according to the second embodiment will be described with reference to FIGS. 4 to 6. The same reference numerals are used for the same members as in the first embodiment. The exhaust purification device 110 is configured by installing a catalyst in the exhaust manifold 5, and is mainly configured by the exhaust manifold 5 and the exhaust purification catalyst 23 disposed therein.

  The exhaust manifold 5 also serves as a case of the exhaust purification device 110 according to the present embodiment. The exhaust manifold 5 is mainly composed of a first case body 111 and a second case body 112.

  The exhaust manifold 5 of the present embodiment is formed in a rectangular tube shape having a substantially rectangular outer peripheral section as a whole by combining the first case body 111 and the second case body 112, and the periphery is integrally fixed by welding or the like. However, the shape is not limited. That is, the exhaust manifold 5 can be formed into a cylindrical body, can be divided into two parts, can be formed integrally with a bolt or the like, or can be formed into three or more parts in order to be easily formed.

  The first case body 111 is a member that forms the front portion of the exhaust manifold 5 and is formed in a substantially “U” shape in a side view. The first case body 111 is disposed in front of the cylinder head 3 so that the axial direction thereof is the left-right direction. The first case body 111 is formed so as to incline (squeeze) from the left and right midway portions toward the exhaust port 34, and closes the left end portion thereof. The right end of the first case body 111 and the rear part of the first case body 111 are open. Around the upper and lower end portions and the left end portion of the first case body 111, a flange portion 111a is provided so as to protrude outward. Bolt holes 63 and 63 are opened at a predetermined interval on the left side of the flange portion 111a.

  The opening 111b is an opening that is disposed in the middle of the left and right of the first case body 111 in order to take in and out a catalyst mechanism 20 equipped with an exhaust purification catalyst 23 described later. The opening 111 b opens to a size that allows the catalyst mechanism 20 to be inserted when the exhaust purification catalyst 23 is installed in the exhaust manifold 5. Mounting flanges 111d and 111d project from the upper and lower outer peripheral portions of the opening 111b in a substantially vertical outward direction, and mounting bolt holes 111e are spaced at predetermined intervals on the left and right outer peripheries of the mounting flanges 111d and 111d and the opening 111b. -111e ... is opened.

  The second case body 112 is a plate-like member that forms the rear portion of the exhaust manifold 5, and the flange portion 111a of the first case body 111 and the outer peripheral portion of the second case body 112 face each other and coincide with each other. Form to overlap. In addition, bolt holes 62 and 62 are formed on the left outer periphery of the second case body 112 at a predetermined interval. The bolt holes 62 and 62 are formed at positions where they can coincide with the bolt holes 63 and 63 of the flange portion 111a in front view.

  Thus, the first case body 111 and the second case body 112 are welded in a state where the flange portion 111a and the outer periphery of the second case body 112 are overlapped and the bolt holes 61 and 62 are aligned. To be integrated.

  The inlet portion 112 a is an opening disposed at the left rear portion of the second case body 112 in order to allow exhaust gas to flow into the exhaust manifold 5. The inlet 112a has substantially the same shape as the opening of the exhaust port 34 described above, and is formed at a position where it can be substantially matched when viewed from the front.

  In the exhaust manifold 5, a holding guide 13 made of a projecting piece is arranged to hold an exhaust purification catalyst 23 described later. When the catalyst structure 20 equipped with the exhaust purification catalyst 23 is installed, the holding guide 13 comes into contact with the left and right halfway parts, in other words, the holding guide 13 has a shape of the rear upper part and the rear lower part of the catalyst structure 20. As a configuration having the combined front side, the second case body 112 protrudes forward on the inner surface (front surface) of the second case body 112 at a predetermined interval in the vertical direction. The holding guides 13 and 13 are provided so as to fill a gap between the second case body 112 and the catalyst mechanism 20 to maintain airtightness and to hold the catalyst mechanism 20 at an appropriate position.

  The outlet portion 111c is formed by an open portion at the right end of the first case body 111 and the second case body 112 in order to allow the exhaust gas to flow out. The outlet portion 111 c is provided through the insertion port 6 a disposed on the front side of the left side surface of the muffler 6.

  Next, the catalyst mechanism 20 built in the exhaust manifold 5 in the present embodiment will be described below.

  The catalyst mechanism 20 mainly includes a lid 21, a catalyst fixing stay 22, an exhaust purification catalyst 23, and a sealing material 24. The catalyst mechanism 20 can be inserted into the opening 111 b of the exhaust manifold 5 and is formed in accordance with the inner space formed by the first case body 111 and the second case body 112 of the exhaust manifold 5.

  The lid 21 is a plate-like member for closing the opening 111b, and the upper and lower ends of the lid 21 in the front view when installed in the exhaust manifold 5 are attached to the mounting flanges 111d of the opening 111b. It is formed so as to substantially coincide with the outer periphery of 111d. Further, the left and right ends of the lid body 21 are formed to such an extent that the mounting bolt holes 111e, 111e,. Then, the lid 21 opens the mounting bolt holes 21a, 21a,... At positions that coincide with the mounting bolt holes 111e, 111e,.

  The catalyst fixing stay 22 is a member for holding the exhaust purification catalyst 23 in a space formed between the lid 21 and the catalyst fixing stay 22. The catalyst fixing stay 22 bends a plate-like member in accordance with the shapes of the rear surface and rear upper and lower parts of the exhaust purification catalyst 23 disposed behind the lid 21. Specifically, it is bent into a substantially U shape. Further, the catalyst fixing stay 22 has upper and lower portions protruding forward in the horizontal direction, and the front end portion of the upper horizontal portion is bent vertically upward and the front end portion of the lower horizontal portion is bent vertically downward to provide vertical portions 22a and 22a. . On both the left and right sides of the upper and lower vertical portions 22a and 22a, plate-like connecting portions 22b and 22b that are connected in the vertical direction so as not to form a gap are provided. The space formed by the lid 21 and the catalyst fixing stay 22 is open in the left-right direction.

  The vertical portions 22a and 22a and the connecting portions 22b and 22b are formed in a rectangular frame shape so as to coincide with the outer periphery of the lid body 21, and in positions corresponding to the mounting bolt holes 21a, 21a,. , Mounting bolt holes 22c, 22c... Are opened. The lid 21 and the vertical portions 22a and 22a and the connecting portions 22b and 22b of the catalyst fixing stay 22 are integrated by welding or the like.

  The exhaust purification catalyst 23 is disposed in a space formed by the lid 21 and the catalyst fixing stay 22. In the gap between the space and the exhaust purification catalyst 23, a heat insulating material 25 is interposed so that the airtightness and the temperature of the exhaust gas are maintained.

  The sealing member 24 is bonded to the upper and lower surfaces and the rear surface of the catalyst fixing stay 22 where the inner space of the exhaust manifold 5 and the outer peripheral surface of the catalyst fixing stay 22 abut when the catalyst mechanism 20 is installed. The exhaust manifold 5 is configured to maintain the airtightness.

  In this way, the lid 21, the catalyst fixing stay 22, the sealing material 24, the heat insulating material 25, and the exhaust purification catalyst 23 are integrated to form the catalyst mechanism 20.

  The gasket 26 is a plate-like member that is disposed to maintain airtightness when the catalyst structure 20 is installed in the exhaust manifold 5. The gasket 26 is formed so as to coincide with the outer shape of the lid body 21, and an opening that coincides with the opening 111 b is provided at a substantially center, and the mounting bolt holes 26 a and 26 a are formed so as to coincide with the mounting bolt hole 21 a of the lid body 21. ... are formed. That is, the shape is substantially the same as the shape formed by the vertical portions 22a and 22a and the connecting portions 22b and 22b.

  Therefore, the catalyst structure 20 is installed by inserting the catalyst structure 20 from the opening 111b through the gasket 26 between the catalyst structure 20 and the exhaust manifold 5, and along the holding guides 13 and 13, while the second case body 112. Install so that it touches the back. The sealing member 24 and the holding guides 13 and 13 maintain the airtightness between the catalyst structure 20 and the exhaust manifold 5. Further, the outer periphery of the opening 111b including the vertical portions 22a and 22a and the connecting portions 22b and 22b of the catalyst fixing stay 22 and the mounting flange portions 111d and 111d is interposed between the exhaust manifold 5 and the catalyst mechanism 20 via the gasket 26. The exhaust purifying catalyst 23 is installed in the exhaust manifold 5 by being fastened and fixed to the mounting bolt holes 21a, 22c, 26a, 111e with connecting bolts 27, 27,.

  The catalyst main body of the exhaust purification catalyst 23 in Example 2 and Example 3 to be described later has the same configuration as the primary catalyst 41 and the secondary catalyst 42 in Example 1. In other words, it is a monolithic carrier made of ceramics such as cordierite and has an oxidation catalyst function. Further, in this embodiment, one exhaust purification catalyst 23 is installed in the exhaust manifold 5, but this is not a limitation, and the upstream side is a DOC (diesel oxidation catalyst) equipped with an oxidation catalyst function, and the downstream side. It is also possible to configure the side as a DPF (diesel particulate filter).

  By configuring the exhaust purification device 110 as described above, exhaust gas is guided from the exhaust port 34 into the exhaust manifold 5 through the inlet 112a. Then, the exhaust gas passes through the exhaust purification catalyst 23 arranged from the left and right midway part to the downstream part of the exhaust manifold 5, and is guided into the muffler 6 from the outlet part 111c. Therefore, the exhaust gas is purified by passing through the exhaust gas purification catalyst 23, guided to the muffler 6, and discharged to the outside through a pipe separately provided in the muffler 6.

  When the exhaust gas purification capacity of the exhaust purification device 110 is reduced, the connecting bolts 27, 27,... Are removed, and the catalyst mechanism 20 is removed from the exhaust manifold 5. The exhaust purification catalyst 23 integrated with the removed catalyst mechanism 20 is replaced, and the catalyst mechanism 20 that becomes the new exhaust purification catalyst 23 is disposed again in the exhaust purification device 110, thereby improving the exhaust gas purification capability. keep.

  Next, the configuration of the exhaust emission control device 210 according to the third embodiment will be described with reference to FIGS. The same reference numerals are used for the same members as those in the first and second embodiments.

  The exhaust purification device 210 is mainly composed of the exhaust manifold 5 and the exhaust purification catalyst 23 disposed therein.

  The exhaust manifold 5 also serves as the case of the exhaust purification device 210 according to the third embodiment. Although the exhaust manifold 5 of the third embodiment has the same shape as that of the second embodiment, the shape thereof is not limited. In other words, the exhaust manifold 5 can be formed into a cylindrical shape or the like, or can be divided into two parts in a plane parallel to the direction in which the exhaust gas flows, and can be integrally formed with bolts or the like so as to be easily formed. is there. The exhaust manifold 5 is a case of the same form in the state in which the opening 111b and the mounting bolt holes 111e, 111e,... Are closed (see FIG. 4), and the case is perpendicular to the direction in which the exhaust gas flows. The surface is divided in the vicinity of the insertion opening 6a, and the upstream side of the case is the upstream case 81, and the downstream side of the case is the downstream case 82. However, the dividing surface may be arranged in the middle of the left and right of the exhaust manifold 5 or may be arranged in the vicinity of the inlet 112a. That is, the first case body 111 and the second case body 112 on the exhaust upstream side are the upstream case 81, and the first case body 111 and the second case body 112 on the exhaust downstream side are the downstream case 82 (see FIG. 6).

  A case flange 71 having a predetermined width is formed on the outer periphery of the divided portion of the upstream case 81, and a case flange 72 having a predetermined width is formed on the outer periphery of the divided portion of the downstream case 82. The case flanges 71 and 72 are formed so that the connection bolt holes 71a, 71a,... And the connection bolt holes 72a, 72a,.

  In the inner space of the upstream case 81, a catalyst holding portion 14 made of a projecting piece is arranged to hold an exhaust purification catalyst 23 described later. The catalyst holding portion 14 protrudes in the inner air direction at predetermined intervals in the vertical direction on both the front and rear sides of the inner surface of the upstream case 81 so as to contact the upstream end surface of the exhaust purification catalyst 23. That is, on the inner surface of the upstream case 81, catalyst holding portions 14, 14,... Are provided vertically and horizontally to match the size of the exhaust purification catalyst 23 so that the upstream side of the exhaust purification catalyst 23 can be held.

  The catalyst mechanism 120 is mainly constituted by the catalyst flange 126, the heat insulating material 25, and the exhaust purification catalyst 23.

  The catalyst flange 126 is a gasket member that is provided at one end of the exhaust purification catalyst 23 and is arranged to maintain airtightness when the catalyst mechanism 120 is installed in the exhaust manifold 5. The catalyst flange 126 is disposed between the case flanges 71 and 72 and is formed so as to coincide with the outer shape of the case flanges 71 and 72 in a side view. The catalyst flange 126 is provided with connecting bolt holes 126a and 126a, and the connecting bolt holes 126a and 126a are located at positions where they can coincide with the connecting bolt holes 71a and 72a of the case flanges 71 and 72 in a side view. Form. Further, an opening 126 b is formed in the catalyst flange 126 at a position that can coincide with the insertion port 81 a that is an opening at the downstream end of the upstream case 81.

  The heat insulating material 25 covers the outer periphery of the exhaust purification catalyst 23, is molded in accordance with the inner space of the upstream case 81, and the exhaust purification catalyst 23 is installed when the exhaust purification catalyst 23 is installed in the exhaust manifold 5. It is also possible to fill the gap between the outer surface 23 and the inner surface of the exhaust manifold 5 and keep the temperature of the exhaust gas at a high temperature. The exhaust purification catalyst 23 captures and oxidizes PM in the exhaust gas as described above, and the outer periphery of the downstream end thereof is inserted into the opening 126b of the catalyst flange 126. However, the opening 126b of the catalyst flange 126 may be formed to be smaller than the insertion port 81a, and the upstream surface of the catalyst flange 126 and the outer periphery of the downstream surface of the exhaust purification catalyst 23 may be bonded.

  Thus, the catalyst mechanism 120 is inserted into the upstream case 81 so that the upstream surface of the exhaust purification catalyst 23 comes into contact with the catalyst holding portions 14, 14, 14, 14 to hold the exhaust purification catalyst 23, and the exhaust The exhaust purification catalyst 23 is held by the contact between the outer peripheral surface of the purification catalyst 23 and the inner peripheral surface of the upstream case 81. However, when the heat insulating material 25 is wound, the exhaust purification catalyst 23 is held by the contact between the outer peripheral surface of the heat insulating material 25 and the peripheral surface without the upstream case 81.

  Further, airtightness is maintained by sandwiching the catalyst flange 126 between the case flanges 71 and 72, and the connection bolts 27 are screwed into the connection bolt holes 71a, 126a, and 72a, so that the case flanges 71 and 72 and the catalyst flanges are inserted. The exhaust manifold 5 in which the exhaust purifying catalyst 23 is housed is formed by fastening 126 together. Further, the exhaust manifold 5 is arranged on the front outer surface of the cylinder head 3 so that the bolt holes 61, 62, 63, 64 coincide with each other as in the second embodiment.

  When the exhaust gas purification capacity of the exhaust purification device 210 is lowered, the bolts 65 and 65 are removed from the bolt holes 61, 62 and 63, and the exhaust manifold is separated from the cylinder head 3. Further, the connecting bolt 27 is removed from the connecting bolt holes 72a, 126a, 71a so that the upstream case 81, the catalyst structure 120, and the downstream case 82 can be separated, and the catalyst structure 120 is taken out from the upstream case 81 and replaced. Then, the exhaust purification catalyst 23 of the catalyst mechanism 120 is replaced with a new exhaust purification catalyst 23. The exhaust gas purification ability is maintained by arranging a new exhaust gas purification catalyst 23 in the exhaust gas purification device 210 again.

  Further, when the exhaust purification catalyst 23 is replaced, the upstream end and the downstream end of the exhaust purification catalyst 23 are reversely arranged and returned to the installed state, so that the use period of the exhaust purification catalyst 23 can be extended. is there.

  The exhaust purification device 23 may be configured by detachably arranging the exhaust purification catalyst 23 of the second or third embodiment in the exhaust manifold 5 of the first embodiment, in addition to the three embodiments. For example, referring to FIG. 1, FIG. 4 and FIG. 5, in the first embodiment, the secondary catalyst 42 arranged on the downstream side is replaced with the exhaust purification catalyst 23 (catalyst mechanism 20) of the second embodiment. An opening 111b, a mounting flange 111d, a mounting bolt hole 111e, and a holding guide 13 similar to those of the second embodiment are arranged on the front side surface of the first case body 11 of Example 1, and the catalyst mechanism 20 and the first are connected by a connecting bolt 27 and the like. The case body 11 is configured by being fastened and fixed together. With the above configuration, the secondary catalyst 42 of the first embodiment can be attached to and detached from the exhaust manifold 5 in the same manner as the primary catalyst 41 of the first embodiment.

  As described above, the engine 100 according to the present embodiment enables the exhaust purification device 10 to be detachable on the upstream side of the exhaust manifold 5 that forms part of the exhaust passage that communicates between the cylinder head 3 and the muffler 6. An exhaust purification primary catalyst 41 is disposed, and an exhaust purification secondary catalyst 42 is disposed downstream. With this configuration, the shape of the engine 100 itself is maintained, and purification is performed in two stages of the exhaust purification primary catalyst 41 and the exhaust purification secondary catalyst 42, so that purification performance can be improved. Since the exhaust purification primary catalyst 41 having a short replacement time can be attached and detached, it can be easily replaced, and the life of the exhaust purification secondary catalyst 42 can be extended.

  The exhaust purification primary catalyst 41 is provided with a fixing lid 43 at one end of a catalyst main body, and the other end is inserted into the exhaust manifold 5 through an insertion port 11 b opened in the side surface of the exhaust manifold 5. With this configuration, the exhaust purification primary catalyst 41 can be easily replaced like a cartridge type, and maintenance can be improved, and it can be easily mounted and replaced from the outside without removing the muffler 6. it can.

  The main body of the primary catalyst 41 for exhaust purification has a configuration in which the other end of the main body is matched with the exhaust port 34 opened in the cylinder head 3 and is inserted into and supported by the exhaust port 34. With this configuration, the exhaust purification primary catalyst 41 can be maximized by arranging the exhaust purification primary catalyst 41 at a position where the temperature of the exhaust gas is the highest. This leads to a reduction effect. Both sides of the exhaust purification primary catalyst 41 are supported, so that there is no vibration and no exhaust gas leakage.

  The fixing lid 43 is provided with a flange portion 43a on the outer periphery thereof, and is configured to fasten and fix the flange portion 43a, the exhaust manifold 5 and the cylinder head 3 together. With this configuration, the cylinder head 3, the exhaust manifold 5, and the exhaust purification primary catalyst 41 can be integrally attached and detached, and maintenance is improved.

  The exhaust manifold 5 is formed with an opening 111b having a size capable of inserting the exhaust purification secondary catalyst 42 on a side surface, and the opening 111b can be closed by a lid 21. By comprising in this way, both the primary catalyst 41 and the secondary catalyst 42 can be replaced | exchanged easily, and the improvement of maintenance property can be aimed at.

3 Cylinder Head 5 Exhaust Manifold 6 Muffler 10 Exhaust Purification Device 11b Insertion Port 21 Lid 34 Exhaust Port 41 Primary Catalyst for Exhaust Purification (Primary Catalyst)
42 Secondary catalyst for exhaust purification (secondary catalyst)
43 Fixing lid 43a Flange 100 Engine 111b Opening

Claims (3)

An engine having an exhaust purification device installed in the middle of the exhaust passage,
In the exhaust purification device, an detachable primary catalyst for exhaust purification is disposed on the upstream side of an exhaust manifold forming a part of the exhaust passage communicating between the cylinder head and the muffler, and the exhaust purification secondary catalyst is disposed on the downstream side. Place the next catalyst,
The exhaust purification primary catalyst has a structure in which a fixing lid is provided at one end of the catalyst body, and the other end is inserted into the exhaust manifold from an insertion port opened in a side surface of the exhaust manifold.
The engine characterized in that the primary catalyst main body for exhaust purification has a configuration in which the other end of the main body is matched with an exhaust port opened in a cylinder head, and is inserted into and supported by the exhaust port . The engine according to claim 1, wherein the fixing lid is provided with a flange portion on an outer periphery thereof, and the flange portion, the exhaust manifold, and the cylinder head are fastened and fixed together . The engine according to claim 1 or 2, wherein the exhaust manifold is formed with an opening on a side surface of the exhaust manifold so that the secondary catalyst for exhaust purification can be inserted. An engine characterized in that it can be closed by a lid after inserting a secondary catalyst .

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