JPH0592416U - Catalytic converter - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the durability of the silencer by preventing the surface burning of the outer cylinder of the silencer for a motorcycle with a catalytic converter and the direct action of impact on the catalyst carrier. [Structure] The mating surfaces of a pair of semi-cylindrical split mold cases are used as inner and outer fitting surfaces, and a catalyst carrier having a shape-retaining member on the outer peripheral surface is housed between the pair of split mold cases to form a split mold. Split mold case is welded and integrally joined at the mating surface while a constant load is applied to the mold case in the mating direction, and a larger diameter than the outer diameter of the case is attached to both ends of the cylindrical case. A short cylinder with a short cylinder is integrally provided, and a case with a short cylinder accommodating the catalyst carrier is fitted into the silencer outer cylinder, and the short cylinder is fixed to the outer cylinder so that it is between the silencer outer cylinder and the catalyst carrier case. Form a space.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a catalytic converter installed in an exhaust system of an internal combustion engine of a motorcycle.

[0002]

[Prior Art]

 As a catalyst carrier for a catalytic converter, a ceramic honeycomb structure is widely used because of its high function and cost. However, since this catalyst carrier is an integrally calcined product, the finished dimensional accuracy, particularly the radial dimension, varies, and since it lacks impact resistance, it is brittle and easily damaged. Therefore, the mating surfaces of the pair of split mold cases are used as the inner and outer mating surfaces so that a constant tightening load can be applied to the catalyst carrier housed in the pair of split mold cases. It is known to fix it under a condition that a constant load is applied from the outside. At that time, it is also known to add a shape-retaining material to the outer peripheral surface of the catalyst carrier (for example, Japanese Utility Model Laid-Open No. 58-48916). The catalytic converter installed in the exhaust system of the internal combustion engine of a motorcycle is usually incorporated in a silencer due to restrictions on the mechanical design and appearance of the entire vehicle.

[0003]

[Problems to be solved by the device]

 However, if the above-mentioned catalytic converter, which is advantageous in terms of function and cost, is directly incorporated into the silencer of a motorcycle, the reaction heat generated by the catalytic converter causes the surface of the plated surface of the silencer outer casing to burn. Spoil the appearance. Also, there is a risk of burns when touching the muffler. Furthermore, when the vehicle body falls down or another object hits the muffler, the impact directly affects the catalytic converter, which may damage the catalytic converter. The present invention has been proposed to solve the above problems in a catalytic converter incorporated in a silencer of an internal combustion engine of a motorcycle.

[0004]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention uses the mating surfaces 2c and 2d of a pair of semi-cylindrical split mold cases 20a and 20b as inner and outer mating surfaces, as shown in FIGS. The catalyst carrier 3 having the shape-retaining member 4 added to the outer peripheral surface is housed between the pair of split mold cases 20a and 20b, and the split mold cases 20a and 20b are fitted together with a constant load applied in the matching direction. The split case 20a, 20b is welded and integrally coupled at the surfaces 2c, 2d, and the cylindrical short case 20a, 20b is provided at both ends thereof with a mounting short cylinder having a diameter larger than the outer diameter of the case 20a, 20b. 8 is integrally provided, and the cases 20a and 20b with the short cylinder 8 containing the catalyst carrier 3 are fitted into the silencer outer cylinder 9 to fix the short cylinder 8 to the outer cylinder 9, whereby the silencer outer cylinder is provided. 9 and the catalyst carrier case 20a, 20b form a space 13 One in which the.

[0005]

[Action]

 Since the space 13 between the cases 20a and 20b accommodating the catalyst carrier 3 and the silencer outer cylinder 9 serves as a heat blocking layer for the catalyst carrier 3, the outer cylinder 9 is not burnt. Further, the impact applied from the outside to the place where the catalyst carrier 3 is incorporated is absorbed and relaxed in the space 13 around the catalyst carrier 3 and does not spread to the catalyst carrier 3.

[0006]

【Example】

 Fig. 1 is a vertical side view of only the portion of the silencer for a motorcycle in which the catalytic converter is incorporated, Fig. 2 is a cross-sectional front view seen in the direction of the arrow in Fig. 1, and 9 is the outer cylinder of the silencer. . The pair of split mold cases 20a and 20b each have a semi-cylindrical shape, and the mating surfaces 2c and 2d are formed so as to fit inside and outside. In addition, the mating flanges 15 for the inward flanges 8a of the mounting short cylinders 8 described later are integrally formed at both ends of each split mold case 20a, 20b. The mating flanges 15 each have a semi-ring shape, but when the split case 20a and 20b are fitted to each other and assembled into a cylindrical shape, a completely ring-shaped flange is formed.

The catalyst carrier 3 is a columnar body having a honeycomb structure integrally fired with a ceramic material containing silicon dioxide, aluminum oxide, and magnesium oxide as main components. The shape-retaining material 4 which surrounds the catalyst carrier 3 is a mat-like member having some cushioning property, such as stainless steel mesh or ceramic wool.

The catalyst carrier 3 wrapped with the shape retaining material 4 is housed between the pair of split mold cases 20a and 20b, and a constant tightening load is applied. While maintaining this state, the split mold cases 20a and 20b are welded at the inner and outer fitting mating surfaces 2c and 2d. By doing so, the catalyst carrier 3 is fixed in the split mold cases 20a and 20b with an appropriate tightening load and becomes stable.

The mounting short cylinders 8 having a diameter larger than the outer diameters of the cylindrical cases 20a and 20b are fixed to both ends of the cylindrical cases 20a and 20b as described above. In the illustrated example, the mating flange 15 on the cases 20a and 20b side and the inward flange 8a of the mounting short cylinder 8 are overlapped and welded, but it is limited to the fixing means between the cases 20a and 20b and the mounting short cylinder 8. There is no.

The outer diameter of the mounting short tube 8 is formed so as to fit closely inside the silencer outer tube 9. The mounting short cylinder 8 and the silencer outer cylinder 9 are fixed to each other by spot welding or the like from the outside of the outer cylinder 9. The mounting short cylinder 8 forms a space 13 between the cases 20a and 20b accommodating the catalyst carrier 3 and the silencer outer cylinder 9, and also serves as a partition plate. An exhaust expansion chamber is secured for this.

As shown in FIG. 3, a cushion material 12 may be sandwiched between the inward flange 8 a of the mounting short tube 8 and the end surface of the catalyst carrier 3 to protect the edge portion of the end surface of the catalyst carrier 3. .

[0012]

[Effect of the device]

 Since the catalytic converter of the present invention has the above-mentioned structure, the surface of the outer cylinder of the silencer of a motorcycle is not burnt on the plated surface for the purpose of anticorrosion and decoration. Further, since the external impact does not directly act on the catalyst carrier, the durability of the silencer is improved, and it is effective as a catalytic converter installed in the silencer for auto-bye.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a catalytic converter according to the present invention.

FIG. 2 is a cross-sectional front view of the catalytic converter according to the present invention.

FIG. 3 is a vertical sectional front view showing another embodiment of the catalyst carrier supporting portion.

[Explanation of symbols]

 20a, 20b Split case 2c, 2d Inner / outer mating mating surface 3 Catalyst carrier 4 Shape retention member 8 Short cylinder for mounting 8a Flange 9 Outer cylinder of silencer 12 Cushion material 13 Space 14 Welding 15 Flange

Claims (1)

[Scope of utility model registration request] 1. A mating surface of a pair of split mold cases having a semi-cylindrical shape is used as an inner and outer fitting surface, and between the pair of split mold cases,
A catalyst carrier with a shape-retaining member attached to the outer peripheral surface is housed, and the split mold case is welded and integrally joined at the mating surface while a constant load is applied to the split mold case in the cylindrical shape. Both ends of the case are integrally equipped with mounting short cylinders with a diameter larger than the outer diameter of the case, and the case with short cylinders containing the catalyst carrier is fitted inside the silencer outer cylinder to remove the short cylinder. A catalytic converter in which a space is formed between the silencer outer cylinder and the catalyst carrier case by being fixed to the cylinder.