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公开(公告)号：JPH11300203A
公开(公告)日：1999-11-02
申请号：JP11107898
申请日：1998-04-21
Applicant: TOYOTA MOTOR CORP
Inventor： TAKESHIMA SHINICHI , YAMASHITA TETSUYA , TANAKA TOSHIAKI , IGUCHI SATORU
Abstract: PROBLEM TO BE SOLVED: To prevent a trouble wherein a NOx purification performance is deteriorated due to a high temperature endurance test by a method wherein in the case where a catalyst for purifying an exhaust gas is manufactured, noble metals contain at least Pt and Pd, and Pt and Pd are simultaneously supported by using a mixed solution of a Pt compound solution and a Pd compound solution. SOLUTION: An exhaust gas purifying catalyst for purifying an exhaust gas exhausted from an internal combustion engine of an automobile or the like is composed of a base material, a coat layer comprising a porous support formed on the surface of the base material, and noble metals and a NOx absorbing material which are supported by the coat layer. In the case such the exhaust gas purifying catalyst manufactured, the noble metals should contain at least Pt and Pd, and Pt and Pd are treated so as to be simultaneously supported by using a mixed solution of a Pt compound solution and a Pd compound solution. Thereby, Pt and Pd can be supported in a condition wherein they are uniformly highly dispersed, the degree of lowering of a front surface area of the noble metals is decreased even after the temperature endurance test, and decrease of a purification performance can be suppressed.
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公开(公告)号：JPH1181990A
公开(公告)日：1999-03-26
申请号：JP24134697
申请日：1997-09-05
Applicant: NIPPON SOKEN , TOYOTA MOTOR CORP
Inventor： OMICHI SHIGEKI , OYAMA NAOHISA , HIROTA SHINYA , IWASAKI EIJI , TANAKA TOSHIAKI
Abstract: PROBLEM TO BE SOLVED: To minimize energy consumed by a heating means in a case that a NOx catalyst is heated in order to prevent the catalyst from being poisoned by a reductant such as HC. SOLUTION: This reductant supply device for supplying and adding a reductant to a catalyst for purifying NOx contained in oxygen excessive exhaust gas exhausted from an internal combustion engine such as a Diesel engine, so as to assist the purifying action of the catalyst, comprises a heating means for heating the reductant, and a control means for determining whether the heating means is to be energized or not in accordance with a condition of the catalyst. For example, if the activating temperature of the catalyst is in the range of 200 to 350 deg.C, the reductant can be fed in this entire temperature range, but the heating means 2 for the reductant is energized in a narrow range from 200 to 220 deg.C (inflow gas temperature or catalyst temperature).
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公开(公告)号：JPH1162559A
公开(公告)日：1999-03-05
申请号：JP21481897
申请日：1997-08-08
Applicant: NIPPON SOKEN , TOYOTA MOTOR CORP , DENSO CORP
Inventor： OMICHI SHIGEKI , OYAMA NAOHISA , HIROTA SHINYA , IWASAKI EIJI , TANAKA TOSHIAKI
Abstract: PROBLEM TO BE SOLVED: To rationalize a supply of hydrocarbon to a catalyzer so as not to cause poisoning due to adsorption of this hydrocarbon being overabundant in the NOx catalyzer. SOLUTION: A fundamental hydrocarbon supply is calculated from a map or the like according to catalytic temperature and engine speed (step 102), and a hydrocarbon adsorptive quantity of a NOx catalyzer detected by a hydrocarbon adsorptive quantity detector is read out (step 103). This hydrocarbon adsorptive quantity is compared with the preset poisoning limit value (step 104), and if this HC adsorptive quantity exceeds the poisoning limit value, a target HC supply is set to zero (step 107), stopping supply of hydrocarbon to the NOx catalyzer. On the other hand, when the HC adsorptive quantity is less than the poisoning limit value, a compensation factor is calculated according to the HC adsorptive quantity at the point of time (step 105), and this compensation factor is multiplied to the fundamental HC supply, finding the target HC supply (step 106). Then, an amount of fuel (HC) equivalent to this target HC supply is fed to the NOx catalyzer.
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公开(公告)号：JPH1157493A
公开(公告)日：1999-03-02
申请号：JP22274597
申请日：1997-08-19
Applicant: TOYOTA MOTOR CORP
Inventor： FUJIMOTO YOSHIO , OHASHI NOBUMOTO , TANAKA TOSHIAKI
Abstract: PROBLEM TO BE SOLVED: To improve particulate cleaning efficiency in a catalyst for purifying exhaust gas of a diesel engine. SOLUTION: In a diesel engine exhaust gas cleaning catalyst comprising a carrier base, a coating layer and a catalyst component 6 for cleaning particles borne on the coating layer, a matrix constituent of the coating layer constitutes primary particles 4 and an aggregate of the primary particles constitutes a secondary particle 5 and the catalyst component is dispersed not only among the secondary particles of the matrix material of the coating layer but also among the primary particles. In this case, the secondary particles are provided with such diameters as to form clearances in the range of 0.01-0.5 μm between the secondary particles.
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公开(公告)号：JPH1047041A
公开(公告)日：1998-02-17
申请号：JP20486796
申请日：1996-08-02
Applicant: TOYOTA MOTOR CORP
Inventor： HIROTA SHINYA , MIZUNO TATSUJI , KIBE KAZUYA , TANAKA TOSHIAKI
Abstract: PROBLEM TO BE SOLVED: To perform excellent purification of NOX by a method wherein NOX is temporarily stored in a storage material and by discharging the stored NOX, NH3 is produced from NOX, SOLUTION: The cylinders of an internal combustion engine are divided into first and second cylinder groups 1a and 1b and the first cylinder group 1a is further divided into first and second auxiliary cylinder groups 1aa and 1ab. NOX storage reduction catalysts 12a and 12b are arranged in the exhaust branch pipes 8 of the auxiliary cylinder groups 1aa and 1ab, respectively. The NOX storage reduction catalysts 12a and 12b and the second cylinder group 1b are brought into a state to be confluent with each other and to connect it to an emission control catalyst 10. By enriching an exhaust air-fuel ratio of exhaust gas, flowing in the NOX storage reduction catalyst 12a, NOX is discharged to produce NH3 . The NH3 purifies NOX discharged from the second cylinder group 1b in the emission control catalyst 10. By bringing an exhaust air-fuel ratio of exhaust gas, flowing in the storage reduction catalyst 12b, into a lean state, NOX is stored. When a storage NOX amount of the NOX storage reduction catalyst 12a is reduced to a value lower than a lower limit threshold, an exhaust air-fuel ratio of exhaust gas flowing in the storage reduction catalysts 12a and 12b are brought into a lean and a rich state, respectively.
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Patent Agency Ranking
公开(公告)号：JPH1037742A
公开(公告)日：1998-02-10
申请号：JP28081296
申请日：1996-10-23
Applicant: TOYOTA MOTOR CORP
Inventor： HIROTA SHINYA , TANAKA TOSHIAKI , IGUCHI SATORU , MIZUNO TATSUJI , KIBE KAZUYA
Abstract: PROBLEM TO BE SOLVED: To keep a catalyst temperature in a temperature area for allowing exhaust emission controlling with high possibility. SOLUTION: In an exhaust emission control device, an exhaust emission controlling catalyst 17 is arranged inside an engine exhaust passage 16, for performing exhaust emission controlling in a predetermined temperature area by means of the catalyst 17. In such a case, a cooling device 22 is arranged on an upstream end 20 of the catalyst, while a heating device 26 is arranged on a downstream end 24 of the catalyst. When the engine is started, the cooling device 22 and the heating device 26 are operated. At least a part of the catalyst 17 is in the temperature area for allowing exhaust emission controlling.
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公开(公告)号：JPH09122443A
公开(公告)日：1997-05-13
申请号：JP29007995
申请日：1995-11-08
Applicant: TOYOTA MOTOR CORP
Inventor： TANAKA TOSHIAKI , SHIRATANI KAZUHIKO , ARAKI YASUSHI
Abstract: PROBLEM TO BE SOLVED: To provide an exhaust emission control process for reducing the exhaust amount of particulate matters without lowering the HC oxidizing power of a precious metal. SOLUTION: Exhaust gas is applied on an exhaust gas passage of a catalyst making a precious metal 3 and a transition metal oxide 4 for purifying a hydrocarbon content in exhaust gas, and SO3 formed by a sulfur oxide in exhaust gas is occluded as sulfate into the transition metal oxide 4 by the action of the precious metal 3, and then occluded sulfate is discharged as SO2 by thermal decomposition.
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公开(公告)号：JPH08260948A
公开(公告)日：1996-10-08
申请号：JP6594795
申请日：1995-03-24
Applicant: TOYOTA MOTOR CORP
Inventor： ASANUMA TAKAMITSU , KIHARA TETSUO , TAKESHIMA SHINICHI , TANAKA TOSHIAKI , KATO KENJI , IGUCHI SATORU
IPC: B01D53/94 , F01N3/08 , F01N3/18 , F01N3/20 , F01N3/24 , F01N11/00 , F02D41/02 , F02D41/04 , F02D41/14
Abstract: PURPOSE: To control the discharge of NOx from the NOx absorbing agent based on the detected amount of the actual NOx in the NOx absorbing agent. CONSTITUTION: The NOx absorbing agent 18 is arranged in the engine emission passage. An O2 sensor 22 where the current proportional to the air fuel ratio is generated is arranged in the engine emission passage downstream of the NOx absorbing agent 18, and the amount of NOx which is actually absorbed in the NOx absorbing agent 18 when NOx is discharged is calculated based on the output signal of the O2 sensor 22. The estimated NOx is corrected based on the calculated NOx amount so as to express the actual amount of absorbed NOx , and the discharging effect of NOx from the NOx absorbing agent is made when the corrected value of the estimated NOx amount reaches the preset value.
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公开(公告)号：JPH08243393A
公开(公告)日：1996-09-24
申请号：JP5140595
申请日：1995-03-10
Applicant: TOYOTA MOTOR CORP
Inventor： YAMASHITA TETSUYA , TAKESHIMA SHINICHI , ITAKURA SATOMI , TANAKA TOSHIAKI
Abstract: PURPOSE: To improve NOx absorption performance and to keep high NOx absorption performance and high ternary activity after endurance by carrying a NOx absorbing material in fine pores of an alumina carrier, which have a specific diameter. CONSTITUTION: In an exhaust gas purifying catalyst, the NOx adsorbing material is carried in the fine pores of the alumina carrier, which have pore diameter of >=10Å. Then the NOx absorbing material, carried in high dispersibility without being carried partially in high concentration, is prevented from reacting with alumina. Then, the NOx absorbing material can be impregnated by ultrasonic method or the like. The absorbing material, in the case of an alkali metal, is carried on mol per 1m surface area of the alumina carrier and in the case of alkaline earth metal, on mol per 1m surface area of the alumina carrier. As a result, since the alumina carrier hardly reacts with the NOx absorbing material, the sintering of the alumina carrier is prevented after endurance.
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公开(公告)号：JPH0847640A
公开(公告)日：1996-02-20
申请号：JP18360694
申请日：1994-08-04
Applicant: TOYOTA CENTRAL RES & DEV , TOYOTA MOTOR CORP , CATALER IND CO
Inventor： YOKOTA KOJI , SHINJO HIROBUMI , TAKAHASHI NAOKI , YAMAZAKI KIYOSHI , IIJIMA TOMOKO , HIROSE MIHARU , DOI HARUO , MIYOSHI NAOTO , SUZUKI HIROMASA , TANIZAWA TSUNEYUKI , ISHIBASHI KAZUNOBU , IGUCHI SATORU , TANAKA TOSHIAKI , TAKESHIMA SHINICHI , KASAHARA KOICHI , TATEISHI SHIYUUJI
Abstract: PURPOSE:To prevent poisoning with sulfur and to improve high temp. durability of the purification performance for NOx. CONSTITUTION:This catalyst for purification of exhaust gas is used to purify at one time CO, HC and NOx in exhaust gas in an oxygen-rich atmosphere and it consists of a porous carrier, noble metals as the catalyst carried on the porous carrier, iron oxide added as an iron powder on the carrier, and at least one kind of NOx absorbent selected from among alkali metals, alkaline earth metals, and rare earth elements. The iron oxide has a much larger particle size compared to the case that iron oxide is deposited in a soln. state by impregnation. Therefore, the reaction with the porous carrier is hardly caused and the decrease in the specific surface area of the porous carrier is hardly caused.
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