Method and apparatus for compressing a mat in exhaust gas cleaning device

A method for compressing a mat of an exhaust gas cleaning device having a catalyst, comprising the steps of:

• providing the exhaust gas cleaning device with the mat wrapped around the catalyst;
• orienting each of a first set of pressers and a second set of pressers so as to confront an external periphery of the mat in spaced-apart relation thereto, each presser of the first and second sets of pressers being integrally connected to respective ones of a plurality of rods movably mounted to a base;
• while each presser of the first and second sets of pressers is disposed in spaced-apart, confronting relation relative to the external periphery of the mat, performing a first compression step of compressing the mat by moving the rods corresponding to the first set of pressers, but not the rods corresponding to the second set of pressers, to bring the first set of pressers into contact with the external periphery of the mat to form convex portions of the mat between the pressers of the first set of pressers;
• and
• performing a second compression step of compressing the mat by moving rods corresponding to the second set of pressers to bring the second set of pressers into contact with the respective convex portions to press the convex portions while a compressed state is maintained by the first set of pressers.

An apparatus for compressing a mat against a cylindrical catalyst to provide an exhaust gas cleaning device having the catalyst and the mat wrapped around the catalyst, comprising:

• a plurality of pressers formed of a cylinder divided into an even number of four or more pieces providing a set of odd-numbered pressers and a set of even-numbered pressers disposed on a periphery of the mat, the plurality of pressers being integrally connected to respective ones of a plurality of rods movably mounted to a base;
• a plurality of presser support parts for movably supporting respective ones of the rods relative to the base;
• first drive means for moving only the rods corresponding to the set of odd-numbered pressers relative to the base to cause only the set of odd-numbered pressers to move forward into contact with the periphery of the mat to compress the mat;
• second drive means for moving only the rods corresponding to the set of even-numbered pressers relative to the base to cause only the set of even-numbered pressers to move forward into contact with the periphery of the mat to compress the mat;
• and
• a controller for causing the second drive means to operate after the first drive means is caused to operate.

An apparatus for compressing a mat against a cylindrical catalyst to provide an exhaust gas cleaning device having the catalyst and the mat wrapped around the catalyst, the apparatus comprising:

• a base;
• a plurality of rods movably mounted to the base;
• first and second set of pressers integrally connected to respective ones of the plurality of rods and configured to be disposed around an external periphery of the mat having first and second peripheral surface portions;
• first drive means for moving the rods corresponding to the first set of pressers, but not the rods corresponding to the second set of pressers, to bring the first set of pressers into pressure contact with the first peripheral surface portions of the mat so that the first peripheral surface portions are compressed and the second peripheral surface portions of the mat are formed into respective convex portions;
• and
• second drive means for moving the rods corresponding to the second set of pressers to bring the second set of pressers into pressure contact with the convex portions of the mat to compress the convex portions while the first set of pressers are maintained in pressure contact with the first peripheral surface portions of the mat.