JPS5842574Y2 - Catalyst holding device for exhaust gas purification tube - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a catalyst body holding device for an exhaust gas purification tube that purifies exhaust gas of an internal combustion engine.

Injecting secondary air into the exhaust gas of an internal combustion engine to make it more flammable,
A device is known that purifies substances by bringing them into contact with a catalyst to cause an oxidation reaction.

However, the heat generated by the reaction causes thermal expansion of the purification cylinder to which the catalyst is attached, so the catalyst must be fixed so that it is not affected by this thermal expansion, resulting in a complicated structure. Manufacturing is troublesome and costs high.

This invention has been improved in view of these points, and an embodiment of the invention shown in the drawings will be described below.

The purification cylinder 1 has an open rear end 2 and an exhaust outlet 3 on one side near the rear end 2.

Then, the rear cover 4 is fitted to the rear end 2 and fixed with bolts and nuts.

A core shaft 5 is implanted inside the center of the rear lid 4 by welding.

The catalyst body 6 is a ceramic carrier provided with a core hole 7 and a large number of honeycomb-shaped small holes 8 and coated with a catalyst agent.

A buffer body 9 made of steel wool is wrapped around the outer periphery of the catalyst body 6.

The catalyst body 6 has a core hole 7 inserted into the tip of the core shaft 5, and a nut 10
Fix it with.

A catalyst body 6 provided with a buffer body 9 is inserted into the purification cylinder 1, and a rear cover 4 is fixed to the rear end 2 of the purification cylinder 1.

The effect will be explained.

When the exhaust gas passes through the small holes 8 of the catalyst body 6, it comes into contact with the catalyst agent, causes an oxidation reaction, is purified, and flows to the exhaust outlet 3.

Due to the high temperature heat generated by this reaction, the purifying cylinder 1 and the core shaft 5 expand mainly in the length direction, but the catalyst body 6
is fixed to the core shaft 5 and is completely free in the axial direction of the purification cylinder, so it can freely extend and move.

In addition, the catalyst body 6 has a ceramic carrier and is brittle, but the buffer body 9
This prevents vibration and prevents damage.

The buffer body 9 prevents exhaust gas from flowing through the gap between the catalyst body 6 and the purification cylinder 1.

As explained above, this invention provides a purification cylinder with the rear end open, a core shaft is planted in the center of the rear lid, a catalyst body is inserted and fixed at the tip of the core shaft, and a catalyst body is inserted and fixed around the catalyst body. Since the buffer body is wrapped, the catalyst body is inserted into the purification cylinder, and the rear cover is fixed to the rear end of the purification cylinder, the catalyst body is free in the axial direction with respect to the purification cylinder, and the catalyst body is inserted into the purification cylinder and the core shaft. There is no effect on the expansion of

Therefore, manufacturing does not require precision and can be made at low cost.

Furthermore, by fixing the catalyst body to the core shaft, the number of parts is reduced, and the cost is also reduced in this respect.

Further, the catalyst body is held by the buffer body, and there is little chance of cracking or damage.

Furthermore, the catalyst body can be attached and detached at the same time as the rear cover, making it easy to replace and assemble.

[Brief explanation of drawings]

The figure is a longitudinal sectional view showing an embodiment of the present invention. 1...Purification tube, 2... Rear end, 4... Rear lid, 5... core axis, 6...Catalyst body, 9...Buffer.

Claims (1)

[Scope of utility model registration request] A purification tube with an open rear end is provided, a core shaft is planted in the center of the rear cover, a catalyst body is inserted and fixed at the tip of the core shaft, a buffer is wrapped around the catalyst body, and the catalyst body is inserted into the purification tube. 1. A catalyst body holding device for an exhaust gas purification cylinder, characterized in that the rear cover is fixed to the rear end of the purification cylinder by being inserted into the catalyst body.