Method for manufacturing exhaust gas purification catalyst

Abstract

To provide a technology that enables the formation of a catalyst layer having approximately the same length at the position of the groove and at other positions on a honeycomb substrate having a groove with one end located on the edge of the end face provided on the end face. [Solution] A method for manufacturing an exhaust gas purification catalyst includes: installing a substrate having end face A and end face B, with a plurality of holes each extending from end face A to end face B, and with a groove formed in end face A, one end of which is located on the edge of end face A, so that end face A faces upward; installing a cylindrical portion so that the upper part of the substrate is located within the lower part of the cylindrical portion and the lower end of the cylindrical portion is located below the bottom of the groove, thereby creating a storage portion surrounded by the upper part of the cylindrical portion and end face A; installing a partition portion so that the lower region of the storage portion is divided into region A located above the groove and region B, which is another region; supplying slurry to regions A and B so that they are equal in depth; and guiding the slurry located in the storage portion into the holes.

Description

[Technical Field]

[0001] The present invention relates to a method for producing an exhaust gas purifying catalyst. [Background technology]

[0002] In the manufacture of exhaust gas purification catalysts, for example, a slurry containing catalytic metals or the like is sometimes applied to the partition walls of a honeycomb substrate to form a catalyst layer on the partition walls of the honeycomb substrate. Patent Document 1 describes an example of a manufacturing apparatus for performing such coating. In this manufacturing apparatus, a guide member is first installed at the upper end of an upright honeycomb substrate, forming a liquid reservoir together with the upper end face of the honeycomb substrate. Next, slurry is supplied to the liquid reservoir, and gas within the honeycomb substrate is sucked from the lower end side of the honeycomb substrate. In this way, the slurry is allowed to penetrate into the through-holes of the honeycomb substrate and applied to the partition walls of the honeycomb substrate.

[0003] Patent Document 2 describes a honeycomb substrate having grooves on the upper end surface for providing sensors. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 197177 [Patent Document 2] Special Publication No. 2023-504999 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a technology that enables the formation of a catalyst layer having approximately equal lengths at the position of the groove and at other positions on a honeycomb substrate having a groove on an end face, one end of which is located on the edge of the end face. [Means for solving the problem]

[0006] According to one aspect of the present invention, a honeycomb substrate having a first end face and a second end face, a plurality of holes each extending from the first end face to the second end face, and a groove having one end located at an edge of the first end face, is installed so that the first end face faces upward; and a cylindrical portion is installed so that an upper portion of the honeycomb substrate is located within a lower portion of the cylindrical portion and a lower end of the cylindrical portion is located below a bottom of the groove, thereby forming a honeycomb substrate by the upper portion of the cylindrical portion and the first end face. a partition member disposed in a lower region of the storage region so as to separate a first region located above the grooves from a second region that is another region; thereafter, supplying slurry to the first region and the second region so that the depths thereof are equal; and guiding the slurry located in the storage region into the plurality of holes by sucking gas in the honeycomb substrate from the second end face.

[0007] According to another aspect of the present invention, there is provided the manufacturing method according to the above aspect, wherein the lower end of the partition is made of elastomer.

[0008] According to yet another aspect of the present invention, there is provided the manufacturing method according to any one of the above aspects, wherein the slurry is supplied to the first region and the second region via a shower head.

[0009] According to yet another aspect of the present invention, there is provided a honeycomb substrate having a first end face and a second end face, the honeycomb substrate having a plurality of holes each extending from the first end face to the second end face and a groove in the first end face with one end located at an edge of the first end face, the holder holding the honeycomb substrate so that the first end face faces upward, and a cylindrical portion having an upper portion and a lower portion, the upper portion of the honeycomb substrate being located within the lower portion and the lower end of the cylindrical portion being located below the bottom of the groove, The present invention provides an exhaust gas purification catalyst manufacturing apparatus including: a cylindrical portion that creates a storage portion surrounded by an upper portion of the cylindrical portion and the first end face; a partition portion that divides a lower region of the storage portion into a first region located above the groove and a second region that is another region; a supply device that supplies slurry to the first region and the second region so that they are equal in depth; and a suction device that sucks gas in the honeycomb substrate from the second end face, thereby guiding the slurry located in the storage portion into the plurality of holes.

[0010] According to yet another aspect of the present invention, there is provided the manufacturing apparatus according to the above aspect, wherein the lower end of the partition is made of elastomer.

[0011] According to yet another aspect of the present invention, there is provided a manufacturing apparatus according to any one of the above aspects, wherein the supply device includes a showerhead. [Effects of the Invention]

[0012] According to the present invention, a technology is provided that enables the formation of a catalyst layer having approximately equal lengths at the position of the groove and at other positions on a honeycomb substrate having a groove with one end located at the edge of the end face formed on the end face. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a block diagram of a manufacturing apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of a coating device included in the manufacturing apparatus of FIG. [Figure 3]FIG. 3 is a perspective view schematically illustrating a honeycomb substrate. [Figure 4] FIG. 4 is a top view schematically showing the guide member. [Figure 5] FIG. 5 is a plan view schematically showing the nozzle head. [Figure 6] FIG. 6 is a cross-sectional view showing the transporting step. [Figure 7] FIG. 7 is a cross-sectional view showing the slurry supplying step. [Figure 8] FIG. 8 is a cross-sectional view showing the suction step. [Figure 9] FIG. 9 is a cross-sectional view showing a slurry supplying step in a manufacturing method according to a comparative example. [Figure 10] FIG. 10 is a cross-sectional view showing an exhaust gas purifying catalyst obtained by a production method according to a comparative example. [Figure 11] FIG. 11 is a perspective view schematically showing a partitioning section according to a modified example. [Figure 12] FIG. 12 is a cross-sectional view showing a slurry supplying step in a manufacturing method according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are more specific embodiments of any of the above aspects. The following items can be incorporated into each of the above aspects, either singly or in combination. Furthermore, the embodiments shown below are merely examples of configurations for embodying the technical concept of the present invention, and the technical concept of the present invention is not limited by the materials, shapes, structures, etc. described below. Various modifications can be made to the technical concept of the present invention within the technical scope defined by the claims.

[0015] In the drawings referred to below, elements having the same or similar functions are denoted by the same reference numerals, and redundant explanations will be omitted. The drawings are schematic, and the relationship between dimensions in one direction and dimensions in another direction, and the relationship between the dimensions of one member and the dimensions of another member, etc., may differ from the actual relationship. In the embodiments described below, the downward direction is the direction in which gravity is applied.

[0016] <1> First embodiment <1.1> Manufacturing equipment Fig. 1 is a block diagram of a manufacturing apparatus according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view of a coating device included in the manufacturing apparatus of Fig. 1. Fig. 3 is a perspective view schematically showing a honeycomb substrate.

[0017] 1 is an apparatus for producing a catalyst for purifying exhaust gases. The manufacturing apparatus 1 includes a coating device 10, a controller 16, an input device 17, and an output device 18.

[0018] The coating device 10 coats the honeycomb substrate 20 shown in FIG. 3 with a slurry.

[0019] The honeycomb substrate 20 has a first end face S1 and a second end face S2. The honeycomb substrate 20 has, for example, a cylindrical shape. The honeycomb substrate 20 may have an elliptical cylindrical shape or a rectangular prism shape. The maximum diameter of the honeycomb substrate 20 is, for example, in the range of 25 mm to 310 mm. The length of the honeycomb substrate 20 is, for example, in the range of 25 mm to 350 mm. The honeycomb substrate 20 is made of, for example, ceramic. The honeycomb substrate 20 may also be made of metal.

[0020] A plurality of holes P each extending from the first end face S1 to the second end face S2 are provided in the honeycomb substrate 20. The diameter of the hole P is, for example, in the range of 700 μm to 1600 μm.

[0021] The first end surface S1 is provided with a groove G, one end of which is located on the edge of the first end surface S1. The other end of the groove G is, for example, spaced apart from the peripheral edge of the first end surface S1. The groove G extends, for example, linearly. The groove G is, for example, a groove for accommodating a sensor for measuring the properties of exhaust gas that has passed through the hole P. The sensor is, for example, an oxygen sensor such as an O2 sensor or an air / fuel sensor.

[0022] The width of the groove G is, for example, in the range of 10 mm to 30 mm. The depth of the groove G is, for example, in the range of 5 mm to 20 mm. Although the hole P is not exposed on the side wall of the groove G shown in FIG. 3, the hole P may be exposed.

[0023] 2, the coating device 10 includes a support member 9, a guide member 11, a supply device 14, and a suction device 13. The coating device 10 further includes a conveying device 15A and a lifting device 15B shown in FIG.

[0024] The transport device 15A includes a belt conveyor, a robot hand, and a robot arm (none of which are shown). The belt conveyor moves the honeycomb substrate 20 between a position away from the lifting device 15B and a position near the lifting device 15B. The robot hand holds the honeycomb substrate 20 on the belt conveyor and moves it onto the lifting table 151 of the lifting device 15B. The robot arm moves the guide member 11 between a position above the lifting device 15B and a position above a base 131 included in the suction device 13.

[0025] In this example, the robot arm has, at its tip, a support member 9 that supports the guide member 11. The support member 9 is a ring-shaped metal plate having an inner diameter that is sufficiently larger than the diameter of the honeycomb substrate 20. The thickness direction of the support member 9 is approximately parallel to the direction of gravity. The support member 9 has a plurality of through holes that each extend in the thickness direction. Second pins 115B are inserted into these through holes so that their tips protrude from the upper surface of the support member 9.

[0026] The lifting device 15B is an electric lifting device including a lifting table 151. The lifting device 15B may be a fluid pressure type lifting device including a pump. The lifting table 151 has an upper surface as a mounting surface on which the honeycomb substrate 20 is placed. The lifting table 151 can be raised and lowered below the guide member 11 during the mounting operation of mounting the guide member 11 to the honeycomb substrate 20 and during the detachment operation of removing the guide member 11 from the honeycomb substrate 20.

[0027] The guide member 11 includes a cylindrical portion 110 and a partition portion 12. As shown in Fig. 2, the cylindrical portion 110 includes a first member 111, a pressing member 112, a second member 113, an elastic member 114, a first pin 115A, a positioning member 116, a screw 117, and a receiving member 118. The guide member 11 further includes a fixing member (not shown).

[0028] The first member 111 includes an expanded diameter portion 1111 having a cylindrical shape with an expanded diameter at one end, and a first flange-shaped portion 1112 protruding outward from the other end of the expanded diameter portion 1111. A plurality of through holes are formed in the first flange-shaped portion 1112. The first member 111 is made of, for example, metal. The first member 111 is installed so that the one end of the expanded diameter portion 1111 is located above the other end.

[0029] The second member 113 has a cylindrical shape. The second member 113 is placed below the first member 111 so that one end surface faces the lower surface of the first flange portion 1112. The second member 113 is provided with a plurality of first through holes, each extending in the height direction of the guide member 11. The second member 113 also has second through holes that connect the outside and inside of the second member 113. The second member 113 is made of, for example, a cured resin. The second member 113 is made of, for example, polyethylene.

[0030] Elastic member 114 includes a cylindrical body portion 1141, a second flange portion 1142 protruding outward from one end of the body portion, and a third flange portion 1143 protruding outward from the other end of the body portion. Elastic member 114 is installed such that body portion 1141 is located inside second member 113 and second flange portion 1142 is interposed between first flange portion 1112 and second member 113. Second flange portion 1142 and third flange portion 1143 each have a plurality of through holes. Elastic member 114 is made of an elastomer such as rubber.

[0031] The pressing member 112 is a plate with an opening in the center. The pressing member 112 is installed so that its lower surface is in contact with the upper surface of the first flange portion 1112. A plurality of through holes are formed in the pressing member 112. Some of these through holes are provided with female threads that screw into the male threads of the screws 117.

[0032] The positioning member 116 is a plate with an opening in the center. The upper surface of the positioning member 116 faces the lower surface of the second member 113, with the third flange portion 1143 sandwiched therebetween. The positioning member 116 has an annular protrusion 1161 in a region along the inner periphery of its lower surface. The region along the outer periphery of the lower surface of the positioning member 116 is in contact with the upper surface of the support member 9, and the protrusion 1161 is inserted into an opening provided in the center of the support member 9.

[0033] The screws 117 are inserted from above into through holes in the presser member 112, which has an internally threaded portion. The tips of the screws 117 protrude downward from the underside of the presser member 112. Each of the first pins 115A has a hole in one end face thereof that extends in its longitudinal direction. The tips of the screws 117 are inserted into the holes in the first pins 115A. Each of the first pins 115A is inserted into the upper part of a first through hole provided in the second member 113 via the through holes in the first flange portion 1112 and the second flange portion 1142.

[0034] The through-hole of the second member 113, into whose upper part the first pin 115A is inserted, has a receiving member 118 inserted into its lower part. The lower ends of the receiving members 118 protrude downward from the lower surface of the second member 113. These protrusions are inserted into through-holes provided in the positioning member 116. Each of the receiving members 118 has a hole in its lower end surface, into which the second pin 115B is inserted.

[0035] The fixing member is one or more members that integrate the first member 111, the second member 113, the elastic member 114, and the positioning member 116. According to one example, the fixing member includes the first member 111, the second member 113, the elastic member 114, bolts inserted in this order into the through-hole of the positioning member 116, the through-hole of the third flange-shaped portion 1143, the through-hole of the second member 113, the through-hole of the second flange-shaped portion 1142, the through-hole of the first flange-shaped portion 1112, and the through-hole of the pressing member 112, and nuts attached to the ends of these bolts.

[0036] In this cylindrical portion 110, the second member 113 and the elastic member 114 constitute a holder that holds the honeycomb substrate 20 so that the first end face S1 faces upward, as will be described below.

[0037] That is, the inner peripheral surface of second member 113 and the outer peripheral surface of body portion 1141 face each other with a gap therebetween. Second flange portion 1142 is sandwiched between second member 113 and first flange portion 1112. Third flange portion 1143 is sandwiched between second member 113 and positioning member 116. In this way, second member 113 and elastic member 114 form an annular sealed space therebetween.

[0038] A second through-hole provided in the second member 113 connects the sealed space to a pressure adjusting device (not shown). When the pressure adjusting device is operated and the pressure in the space increases, the sealed space expands. As a result, the elastic member 114 comes into close contact with the honeycomb substrate 20, and the honeycomb substrate 20 is held by a holder consisting of the second member 113 and the elastic member 114. The holder that holds the honeycomb substrate 20 may be composed of one or more other parts.

[0039] The partition portion 12 has a shape corresponding to the shape of the opening of the groove G on the first end face S1 side. Specifically, the partition portion 12 is a plate-like portion having a shape corresponding to the outline of the opening of the groove G on the first end face S1 side when viewed from the vertical direction. The partition portion 12 is provided on the cylindrical portion 110 so as to surround the upper region of the groove G together with the cylindrical portion 110 when the guide member 11 is attached to the honeycomb substrate 20. Here, the partition portion 12 is provided so as to come into contact with the honeycomb substrate 20 after the attachment operation of the guide member 11 to the honeycomb substrate 20 is completed. The partition portion 12 is made of, for example, metal.

[0040] The height of the partition 12 is, for example, in the range of 1.5 cm to 10 cm.

[0041] 2, the guide member 11 is installed so that the upper part of the honeycomb substrate 20 is located within the lower part of the cylindrical portion 110, and the lower end of the cylindrical portion 110 is located below the bottom of the groove G. When the guide member 11 is installed in this manner, a storage section is created that is surrounded by the upper part of the cylindrical portion 110 and the first end face S1.

[0042] 4 is a top view schematically showing guide member 11. Partition 12 divides the area below the storage section into a first area R1 and a second area R2. First area R1 is the area below the storage section that is located above groove G. Second area R2 is another area of ​​first area R1.

[0043] The thickness T of the partition 12 is preferably in the range of 0.5 mm or more and 1.5 mm or less, and more preferably in the range of 0.5 mm or more and 1.0 mm or less.

[0044] The supply device 14 supplies the slurry to the storage unit and includes a tank (not shown), a metering pump (not shown), a liquid transfer pipe (not shown), and a nozzle head 141.

[0045] The tank contains a slurry. The slurry is a raw material for the catalyst layer or a part thereof to be formed on the partition walls of the honeycomb substrate 20. In one example, the slurry contains a solution containing a catalyst metal, a heat-resistant support, and / or a co-catalyst. In another example, the slurry contains a catalyst metal, a heat-resistant support, and / or a co-catalyst. In the slurry containing a catalyst metal, a heat-resistant support, and / or a co-catalyst, the catalyst metal may be dissolved in a dispersion medium, may be dispersed in the dispersion medium, or may be supported on at least one of the heat-resistant support and the co-catalyst.

[0046] The catalytic metal may be, for example, a platinum group metal such as platinum, palladium, and rhodium compounds; other transition metals such as iron and copper; alkali metals such as lithium and potassium; alkaline earth metals such as barium; or two or more thereof.

[0047] The heat-resistant support is, for example, a refractory inorganic oxide such as alumina. The co-catalyst is, for example, an oxygen storage material such as ceria or ceria-zirconia composite oxide; an alkali metal-containing nitrogen oxide (NO X ) storage materials; hydrocarbon adsorbents such as zeolites; or two or more thereof.

[0048] The dispersion medium is, for example, water, but may also be an organic solvent or a mixture of an organic solvent and water.

[0049] The slurry may further contain additives such as a thickener such as hydroxyethyl cellulose, a dispersion stabilizer, and a binder. When the coating liquid contains a thickener such as hydroxyethyl cellulose, the concentration thereof is preferably in the range of 0.3% by mass to 1% by mass.

[0050] The slurry was subjected to a shear rate of 3.83 s -1 The viscosity at this point is preferably in the range of 500 mPa·s or more and 15,000 mPa·s or less, and more preferably in the range of 3,000 mPa·s or more and 15,000 mPa·s or less.

[0051] Here, the viscosity of the slurry is a viscosity that can be measured at room temperature using a commercially available shear viscometer. For example, the viscosity at the above shear rate can be easily measured using a dynamic viscoelasticity measuring device (rheometer) that is standard in the field. Here, "room temperature" refers to a temperature within a range of 15°C to 35°C, typically a temperature within a range of 20°C to 30°C, for example, 25°C.

[0052] The metering pump is connected to the tank and one end of the liquid feed pipe. The metering pump measures a fixed amount of the coating liquid from the tank and discharges it to one end of the liquid feed pipe. The metering pump is, for example, a reciprocating pump such as a piston pump or a plunger pump.

[0053] A nozzle head 141 is connected to the other end of the liquid supply pipe. FIG. 5 is a bottom view schematically showing the nozzle head 141. As shown in FIG. 5, the nozzle head 141 is a shower head. The nozzle head 141 drives a metering pump to discharge a fixed amount of slurry into the guide member 11. The nozzle head 141 shown in FIG. 5 can simultaneously supply the slurry to the first region R1 and the second region R2 described above. Specifically, the nozzle head 141 can simultaneously supply the slurry to the first region R1 and the second region R2 at equal supply amounts per area.

[0054] The suction device 13 includes a base 131, an air box 132, a connecting member (not shown), and a vacuum pump (not shown).

[0055] The air box 132 has a hollow structure and has a first opening connected to the connecting member and a second opening opposite the first opening. The air box 132 has a rim surrounding the second opening.

[0056] The base 131 is provided on the edge of the air box 132. The base 131 supports the lower part of the honeycomb substrate 20. The base 131 is made of, for example, an elastomer such as rubber.

[0057] The connecting member has a hollow structure and has an opening connected to a vacuum pump and an opening connected to an air box 132. The connecting member is made of, for example, metal. The suction device drives the vacuum pump while the honeycomb substrate 20 is fixed to the base 131, thereby sucking gas, for example, air, from inside the honeycomb substrate 20.

[0058] The controller 16 includes a processing unit 16A and a storage unit 16B. The processing unit 16A includes a central processing unit (CPU). The storage unit 16B is connected to the processing unit 16A. The storage unit 16B includes a non-volatile memory that stores programs read by the processing unit 16A and data supplied from the processing unit 16A.

[0059] The controller 16 is connected to the suction device 13, the supply device 14, the transport device 15A, the lifting device 15B, the input device 17, and the output device 18. The controller 16 controls the operations of the suction device 13, the supply device 14, the transport device 15A, the lifting device 15B, and the output device 18 based on commands, information, etc. input by an operator via the input device 17.

[0060] The input device 17 is a human interface device that allows an operator to input commands and information to the controller 16. The input device is, for example, one or more of a button, a keyboard, a mouse, a touch panel, and a voice input device.

[0061] The output device 18 outputs warning information that can be recognized by an operator. The output device 18 is, for example, one or more of a display, a warning light, a voice guidance device, and a buzzer. The display is, for example, a liquid crystal display or an organic electroluminescence display. The warning light includes, for example, a light-emitting diode.

[0062] <1.2> Manufacturing method By using the above-described production apparatus 1, a catalyst for purifying exhaust gas can be produced, for example, by the following method.

[0063] In the method described here, first, an operator inputs a command to start production to the controller 16 via the input device 17. At this time, the operator can also input further information such as the number of exhaust gas purification catalysts to be produced to the controller 16 via the input device 17.

[0064] Next, the operator places the honeycomb substrate 20 on a belt conveyor (not shown). The controller 16 controls the operation of the belt conveyor so as to transport the honeycomb substrate 20 to the vicinity of the robot hand.

[0065] Next, the controller 16 controls the operation of the robot hand so that the honeycomb substrate 20 moves from the belt conveyor onto the mounting table. The honeycomb substrate 20 placed on the mounting table is positioned directly below the guide member 11, as shown in Fig. 6. At this time, the groove G and the partition portion 12 are aligned when viewed from the vertical direction.

[0066] Next, the controller 16 controls the operation of the lifting device 15B so that the upper part of the honeycomb substrate 20 is inserted into the guide member 11. Specifically, the controller 16 controls the operation of the lifting device 15B so that the table on which the honeycomb substrate 20 is placed rises until the first end face S1 of the honeycomb substrate 20 comes into contact with the partition portion 12.

[0067] Next, the controller 16 controls the operation of the pressure adjusting device so that the annular sealed space expands. As described above, when the sealed space expands, the elastic member 114 comes into close contact with the honeycomb substrate 20, and the honeycomb substrate 20 is held by a holder consisting of the second member 113 and the elastic member 114. Furthermore, as the elastic member 114 comes into close contact with the honeycomb substrate 20, a storage section is created that is surrounded by the upper part of the tubular section 110 and the first end face S1. The lower region of the storage section is then partitioned by the partition 12 into the first region R1 and the second region R2 described above.

[0068] Next, the controller 16 controls the operation of the robot arm so that the guide member 11 moves together with the honeycomb substrate 20 from above the lifting device 15B to above the pedestal 131. Subsequently, the controller 16 controls the operation of the robot arm so that the honeycomb substrate 20 is placed on the pedestal 131.

[0069] Next, the controller 16 controls the operation of the supply device 14 so that the nozzle head 141 discharges a predetermined amount of slurry 3. Specifically, the controller 16 controls the operation of the supply device 14 so that the nozzle head 141 supplies the first region R1 and the second region R2 with the same amount of slurry per area, and the amount of slurry supplied is a predetermined amount. Through this operation, as shown in FIG. 7 , the slurry is supplied to the first region R1 and the second region R2 so that the depths of the slurry are equal in the first region R1 and the second region R2, i.e., so that the thickness of the slurry layer in the first region R1 and the thickness of the slurry layer in the second region R2 are equal.

[0070] Next, the controller 16 controls the operation of the suction device 13 so as to suck the gas inside the honeycomb substrate 20 from the second end face S2 side. As a result, the slurry 3 is introduced into the holes P, and as shown in Fig. 8, a coating layer 3C made of the slurry 3 is formed on the partition walls of the honeycomb substrate 20. This operation makes it possible to form a coating layer having approximately the same length at the groove positions and other positions on the honeycomb substrate 20.

[0071] Next, the controller 16 controls the operation of the suction device 13 to stop suction. Subsequently, the controller 16 controls the operation of the robot arm so that the honeycomb substrate 20 and the guide member 11 are transported from above the pedestal 131 to above the mounting table, controls the operation of the pressure adjustment device so as to contract the annular sealed space, controls the operation of the lifting device 15B so as to lower the mounting table, controls the operation of the robot hand so that the honeycomb substrate 20 with the coating layer formed thereon moves from above the mounting table onto the belt conveyor, and controls the operation of the belt conveyor so that the honeycomb substrate 20 with the coating layer formed thereon moves downstream. In this manner, the processing by the manufacturing apparatus 1 is completed.

[0072] Thereafter, the honeycomb substrate 20 thus coated is fired to obtain an exhaust gas purifying catalyst.

[0073] <1.3> Effects As described above, the honeycomb substrate 20 has grooves G on the first end face S1, one end of which is located on the edge of the first end face S1. When slurry is supplied to such a honeycomb substrate 20 without providing the above-described partitions 12, the length of the catalyst layer below the grooves becomes longer than the length of the catalyst layer at other positions. This will be explained below.

[0074] Fig. 9 is a cross-sectional view showing a slurry supplying step in a manufacturing method according to a comparative example. The slurry supplying step shown in Fig. 9 is the same as the slurry supplying step described with reference to Fig. 7, except that the slurry is supplied without the partition 12. As shown in Fig. 9, this step results in the slurry layer in the groove G being deeper than the slurry layer at other positions.

[0075] FIG. 10 is a cross-sectional view showing the state obtained by performing the above-described suction process following the state shown in FIG. 9. As shown in FIG. 10, if the suction process is performed in a state in which the slurry layer at the position of the groove G is deeper than the slurry layer at other positions, the length of the coating layer at the position of the groove G will be longer than the length of the coating layer at other positions. If an oxygen sensor is installed in the groove of an exhaust gas purification catalyst obtained using such a honeycomb substrate 20, the oxygen concentration obtained by measurement at the position of the groove will be significantly different from the oxygen concentration at other positions. In this case, it is difficult to measure properties such as the oxygen concentration in exhaust gas with high accuracy.

[0076] On the other hand, in the method described with reference to Figures 6 to 8, by providing the above-mentioned partition 12, the depth of the slurry layer at the position of the groove G can be made approximately equal to the depth of the slurry layer at other positions immediately before the start of the suction process. If the above-mentioned suction process is performed in this state, it is possible to form a catalyst layer having approximately the same length at the position of the groove and other positions. In this case, the oxygen concentration obtained by measurement at the position of the groove can be made equal to the oxygen concentration at other positions. In this case, properties such as the oxygen concentration in the exhaust gas can be measured with high accuracy.

[0077] The shape of the dividers 12 is preferably the same as the shape of the openings of the grooves G on the first end face S1 side. If the shape of the dividers 12 is significantly larger than the shape of the grooves G on the first end face S1 side, the slurry supplied to the first region R1 is likely to flow into the grooves G. In this case, the length of the catalyst layer at the positions of the grooves G is likely to be longer than the lengths of the catalyst layer at other positions. Also, if the shape of the dividers 12 is significantly smaller than the shape of the openings of the grooves G on the first end face S1 side, the slurry supplied to the second region R1 is likely to flow into the grooves G. In this case, too, the length of the catalyst layer at the positions of the grooves G is likely to be longer than the lengths of the catalyst layer at other positions.

[0078] <2> Variations The above-described manufacturing apparatus and manufacturing method can be modified in various ways. For example, the partition 12 may be the one shown in Fig. 11. Fig. 11 is a perspective view schematically showing a partition 12 according to a modified example. The partition 12 shown in Fig. 11 includes a first portion 121 that includes the upper end of the partition 12 and a second portion 122 that includes the lower end of the partition 12.

[0079] The first portion 121 is made of, for example, metal. The second portion 122 is made of, for example, an elastomer such as rubber. With such a partition portion 12, the honeycomb substrate 20 is less likely to be damaged when the upper part of the honeycomb substrate 20 is inserted into the guide member 11.

[0080] In addition, in the above-described manufacturing apparatus, the partitioning portion 12 is fixed to the cylindrical portion 110, but they do not need to be fixed to each other. For example, the partitioning portion 12 may be installed after the cylindrical portion 110 is attached to the top of the honeycomb substrate 20.

[0081] In the manufacturing apparatus described above, the nozzle head 141 is a shower head, but instead of the nozzle head 141, the manufacturing apparatus may include one or more nozzle heads, each having one nozzle.

[0082] 12, a single nozzle head having only one nozzle may be provided instead of the nozzle head 141. In this case, the supply of the slurry to the first region R1 and the second region R2 may be performed sequentially. Alternatively, the supply of the slurry to the first region R1 and the second region R2 may be performed by supplying the slurry from the nozzle head to the first region R1 and then allowing the slurry to overflow from the first region R1 and supply the slurry to the second region R2.

[0083] According to another example, two nozzle heads each having one nozzle may be provided instead of the nozzle head 141. In this case, the nozzle heads may supply the slurry to the first region R1 and the second region R2 simultaneously or sequentially.

[0084] In the above-described method, the slurry is supplied while the lower end of the partition 12 is in contact with the first end face S1 of the honeycomb substrate 20. However, there may be a gap between the lower end of the partition 12 and the first end face S1. For example, by increasing the viscosity of the slurry to such an extent that the slurry does not pass through the gap, the movement of the slurry through the gap can be suppressed, and the depth of the slurry layer in the first region R1 and the second region R2 can be made equal. In this case, the gap is preferably in the range of more than 0 mm and not more than 3 mm. In addition, in this case, the shear rate is 3.83 s -1 In this case, the viscosity of the slurry is preferably in the range of 3000 mPa·s to 15000 mPa·s.

[0085] The manufacturing apparatus 1 may be modified so that one or more of the operations that it performs automatically can be performed manually. For example, the operations performed by one or more of the supply device 14, the conveying device 15A, and the lifting device 15B may be modified so that they can be performed manually. For example, the conveying device 15A may be omitted, and the holder 8 may be installed at the coating position so that it can move up and down, and the honeycomb substrate 20 may be attached to and detached from the holder 8 manually. Furthermore, the honeycomb substrate 20 may be placed on the belt conveyor automatically instead of manually.

[0086] The manufacturing apparatus 1 may be modified so that some or all of the controls performed by the controller 16 are performed manually. When all of these controls are performed manually, the controller 16 can be omitted. [Example]

[0087] The following describes examples of the present invention. (Example 1) An exhaust gas purification catalyst was manufactured by the method described with reference to Figures 6 to 8 using the manufacturing apparatus 1 described with reference to Figures 1, 2, 4 and 5 and the honeycomb substrate 20 described with reference to Figure 3.

[0088] Here, the slurry used had a solid content of 34% by mass and a viscosity of 3000 mPa·s or more at a temperature of 25°C and a shear rate of 3.83 / s. Suction by the suction device 13 was performed for 3 seconds. When coating was completed, the air velocity above the honeycomb substrate 20 was 40 m / s.

[0089] The exhaust gas purifying catalyst thus produced was cut, and the length of the coating layer at the position of the groove G and at other positions was examined.

[0090] As a result, the length of the coating layer at the position of the groove G was 62 mm, and the length of the coating layer at other positions was 59 mm.

[0091] (Example 2) An exhaust gas purifying catalyst was produced in the same manner as in Example 1, except that a slurry having a viscosity of less than 3000 mPa·s was used.

[0092] The length of the coating layer of this exhaust gas purifying catalyst was also examined in the same manner as above. As a result, the length of the coating layer at the position of the groove G was 70 mm, and the length of the coating layer at other positions was 65 mm. [Explanation of symbols]

[0093] 1... manufacturing apparatus, 3... slurry, 3C... coating layer, 9... support member, 10... coating device, 11... guide member, 12... partition section, 13... suction device, 14... supply device, 15A... conveying device, 15B... lifting device, 16... controller, 16A... processing section, 16B... memory section, 17... input device, 18... output device, 20... honeycomb substrate, 110... cylindrical section, 111... first member, 112... pressing member, 11 3...second member, 114...elastic member, 115A...first pin, 115B...second pin, 116...positioning member, 118...receiving member, 121...first part, 122...second part, 131...base, 132...wind box, 141...nozzle head, 151...lifting platform, 1111...expanded diameter portion, 1112...first flange-shaped portion, 1141...body portion, 1142...second flange-shaped portion, 1143...third flange-shaped portion, 1161...protrusion portion.

Claims

1. a honeycomb substrate having a first end surface and a second end surface, a plurality of holes each extending from the first end surface to the second end surface, and a groove having one end located on an edge of the first end surface, the honeycomb substrate being disposed in the first end surface, with the first end surface facing upward; a cylindrical portion is installed so that an upper portion of the honeycomb substrate is positioned within a lower portion of the cylindrical portion and a lower end of the cylindrical portion is positioned below a bottom portion of the groove, thereby forming a storage portion surrounded by an upper portion of the cylindrical portion and the first end surface; A partition is provided to separate a lower region of the storage section into a first region located above the groove and a second region that is another region; Thereafter, supplying slurry to the first region and the second region so that the depths thereof are equal; guiding the slurry located in the storage portion into the plurality of holes by sucking gas from within the honeycomb substrate through the second end surface; A method for producing an exhaust gas purification catalyst comprising the steps of:

2. 2. The method for producing an exhaust gas purifying catalyst according to claim 1, wherein the lower end of the partition is made of an elastomer.

3. 2. The method for producing an exhaust gas purifying catalyst according to claim 1, wherein the slurry is supplied to the first region and the second region through a shower head.

4. a holder configured to hold a honeycomb substrate having a first end face and a second end face, the holder having a plurality of holes each extending from the first end face to the second end face, and a groove in the first end face, the groove having one end located on an edge of the first end face, with the first end face facing upward; a cylindrical portion having an upper portion and a lower portion, wherein the honeycomb substrate is disposed so that an upper portion of the honeycomb substrate is positioned within the lower portion and a lower end of the cylindrical portion is positioned below a bottom portion of the groove, thereby forming a storage portion surrounded by the upper portion of the cylindrical portion and the first end surface; a partition portion that divides a lower region of the storage portion into a first region located above the groove and a second region that is another region; a supply device that supplies slurry to the first region and the second region so that the depths thereof are equal; a suction device that guides the slurry located in the storage portion into the plurality of holes by sucking gas in the honeycomb substrate from the second end surface; An exhaust gas purification catalyst manufacturing device equipped with the above components.

5. 5. The manufacturing apparatus for an exhaust gas purifying catalyst according to claim 4, wherein the lower end of the partition is made of an elastomer.

6. 5. The apparatus for producing an exhaust gas purifying catalyst according to claim 4, wherein the supply device includes a shower head.

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