JPH04117137U - Monolith catalytic exhaust gas purification device - Google Patents

Abstract

(57) [Summary] [Purpose] When loading a monolithic catalyst body 1 with an oval or elliptical cross section into a cast iron catalyst case 2 formed with an oval or oval cross section with their axes aligned, The number of man-hours required for machining the inside of the catalyst case 2 is reduced, and damage to the monolithic catalyst body 1 is also reduced. [Structure] The upper surface of the receiving seat part 3 for the monolithic catalyst body 1 in the catalyst case 2 is machined with an end mill cutter tool 7 or the like so that it is perpendicular to the axis of the monolithic catalyst body 1 and is aligned with the monolithic catalyst body 1. Finished with a receiving plane 8 extending along the entire circumference.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is an exhaust gas purification system equipped with a monolithic catalyst body inside a cast iron catalyst case. This relates to improvements in equipment.

0002

[Conventional technology]

Monolith catalytic exhaust gas purification devices used in recent internal combustion engines are installed on the vehicle body. In order to improve loading performance, for example, the The monolithic catalyst body has an oblong or elliptical cross section, as shown in FIG. The cast iron catalyst case that houses the monolithic catalyst body is also formed into an oval or oval cross section. things are being done.

0003 By the way, when using a monolith catalyst to purify exhaust gas, this monolith catalyst When the axis of the medium is tilted with respect to the axis of the catalyst case that houses it, Exhaust gas cannot contact the entire area of the monolithic catalyst body. Therefore, the prior art described in the above-mentioned Utility Model Application No. 60-195921 is also A catalyst case made of cast iron is installed inside the catalyst case with an oval or oval cross section. When formed into an oval or elliptical cross section to match the lithium catalyst, this catalyst Partially machining the inner peripheral surface of the case on both major diameters. While finishing the surface into a circular arc, the upper surface of the receiving seat for the monolithic catalyst body is By machining both long diameter parts to make them partially flat, the front The axis of the catalyst body is configured to coincide with the axis of the catalyst case. There is.

0004

[Problem that the idea aims to solve]

However, as in this prior art, both major diameter portions of the inner peripheral surface of the catalyst case It takes a considerable amount of time to partially finish a part into a circular arc surface by machining. There is a problem in that the manufacturing cost increases significantly because it requires time and effort. Moreover, in the prior art, the upper surface of the receiving seat for the monolithic catalyst body is Both long diameter parts are partially finished flat by machining and placed inside the catalyst case. The installed monolithic catalyst body is partially cut on both planes finished by the above-mentioned machining process. The end face of the monolithic catalyst is partially supported relative to the catalyst case. Since the monolithic catalyst body is supported in a partially supported state, the There was also the problem that damage occurred in parts that were partially touched. In the present invention, the end face of the monolithic catalyst body is aligned with the axis of the monolithic catalyst body. Noting that it is formed at a fairly accurate right angle to the , the technical problem is to solve the above problem.

[0005]

[Means to solve the problem]

In order to achieve this technical problem, the present invention has developed a cast iron catalyst case with an open top. An oval or oval cross-section monolithic catalyst body is installed inside it. is formed into an elliptical cross section, and the monolithic catalyst body is formed around the bottom inside the catalyst case. In an exhaust gas purification device in which a receiving seat is integrally molded, the receiving seat is integrally formed. The upper surface of the seat is perpendicular to the axis of the monolithic catalyst body, and the entire surface of each monolithic catalyst body is The structure is such that it is formed into a receiving plane by machining that extends around the circumference.

[0006]

【Example】

Embodiments of the present invention will be described below with reference to the drawings (FIGS. 1 to 5). In the figure, reference numeral 1 denotes a monolithic catalyst formed in an oval or elliptical cross section, and reference numeral 2 denotes an open-top catalyst case formed in an oval or elliptical cross section to accommodate the monolithic catalyst 1. The catalyst case 2 is made of cast iron, and a receiving seat part 3 for the monolithic catalyst body 1 is formed at its lower part so as to extend over the entire circumference of the monolithic catalyst body 1, and at its lower end, The exhaust gas outlet 4 is integrally formed. Further, an exhaust manifold 5 from an internal combustion engine (not shown) is connected to the upper surface of the catalyst case 2. In this case, the inner circumferential surface of the catalyst case 2 is a casting surface, and the inner diameter D ₁ in the major axis direction and the inner diameter D ₂ in the minor axis direction are the outer diameter of the monolithic catalyst body 1 in the major axis direction. A cushion body 6 such as a wire net is provided between the inner peripheral surface of the catalyst case ₂ and the outer peripheral surface _of the monolithic catalyst body 1 with an appropriate dimension larger than the outer diameter d 1 and the outer diameter d 2 in the minor axis direction. The structure is configured to form a gap to be filled.

[0007] Then, when casting the catalyst case 2, the thickness of the receiving seat 3 of the catalyst case ₂ is adjusted to a suitable finish as shown in FIGS. The thickness dimension _H2 is increased by the dimension H2, while the wall thickness of the portion of the catalyst case 2 adjacent to the receiving seat portion 3 is made thicker by an appropriate finish dimension than the predetermined wall thickness _T1 . 5 to 7, the upper surface of the receiving seat part ₃ is machined with an end mill cutter tool 7 or the like, so that the upper surface of the receiving seat part 3 is made perpendicular to the axis of the monolithic catalyst body 1. The structure is such that the receiving plane 8 extends along the entire circumference of the monolithic catalyst body 1.

[0008] In this way, the end face 1a of the monolithic catalyst body 1 is perpendicular to the axis. Since the angle is quite accurate, the monolithic catalyst body 1 is placed on the upper surface of the receiving surface 8. , by placing the monolith through a heat-resistant ring-shaped cushion body 9. The catalyst body 1 is placed in the catalyst case 2 so that its axis coincides with the axis of the catalyst case 2. It can be loaded while it is in the upright position.

[0009] In this case, the receiving plane 8 extends over the entire circumference of the monolithic catalyst body 1. By extending the monolithic catalyst body 1, the monolithic catalyst body 1 is supported by partial contact. Since the monolithic catalyst body 1 is supported evenly over its entire circumference without This can prevent partial damage caused by damage.

In addition, when finishing the upper surface of the receiving seat portion 3 into the receiving flat surface 8 by machining with an end mill cutter tool 7 or the like, the wall thickness T of the portion of the catalyst case 2 adjacent to the receiving seat portion 3 is ₂ is made thicker than a predetermined wall thickness _T1 by an appropriate finishing dimension, thereby leaving a thick wall portion 10 with an appropriate height h along the outer periphery of the receiving plane 8, the catalyst case Even if there is a dimensional error in the inner diameter D ₁ in the major axis direction and the inner diameter D ₂ in the minor axis direction when casting the catalyst case 2, the end mill cutter tool 7 will not cut into the catalyst case 2 within the wall thickness during the machining. It can definitely be avoided.

[0011]

[Actions and effects of the idea]

Therefore, according to the present invention, the catalyst case in the exhaust gas purification device is shaped like an oval or is formed into an oval or elliptical cross section to match the monolithic catalyst body with an oval cross section. In this case, the monolithic catalyst body is placed in the catalyst case with their axes aligned. and in a state where the monolithic catalyst body is less likely to be damaged. Moreover, the receiving seat in the catalyst case can be machined. All you have to do is finish the receiving surface, which reduces the amount of work required for machining. In addition, the time required for machining can be shortened, resulting in a significant reduction in manufacturing costs. have fruit.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of a catalyst case according to an embodiment of the present invention.

FIG. 2 is a partially cutaway right side view of FIG. 1;

FIG. 3 is a plan view of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 1;

FIG. 5 is a sectional view showing the main parts of the catalyst case after casting.

FIG. 6 is a sectional view taken along line VI-IV in FIG. 5;

FIG. 7 is a sectional view showing the main parts of the catalyst case after machining.

[Explanation of symbols]

1 Monolith catalyst body 1a End face of monolith catalyst body 2 Catalyst case 3 Receiving seat part 4 Exhaust gas outlet 5 Exhaust manifold 6,9 Cushion body 7 End mill cutter 8 Receiving plane

Claims (1)

[Scope of utility model registration request] Claim 1: A top-open cast iron catalyst case is formed into an oval or elliptical cross section to match a monolithic catalyst body with an oval or oval cross section to be installed inside the case, and the bottom of the catalyst case is In an exhaust gas purification device in which a receiving seat portion for the monolithic catalyst body is integrally formed around the periphery, the upper surface of the receiving seat portion is perpendicular to the axis of the monolithic catalyst body, and the entire surface of each monolithic catalyst body is A monolith catalytic exhaust gas purification device characterized by forming a receiving plane by machining that extends around the circumference.