Honeycomb structure manufacturing method and manufacturing device

Abstract

To provide a manufacturing method of a honeycomb structure capable of more surely forming a slit and capable of reducing a risk of bruising a partition wall unnecessary, and a honeycomb apparatus.SOLUTION: A method for manufacturing a honeycomb structure according to the present invention includes steps of: adjusting a depth of penetration of a processing tool inward in a radial direction from an outer peripheral surface of a honeycomb structure body having a honeycomb structure portion; and forming at least one slit in the honeycomb structure element by an adjusted depth of penetration, where the penetration depth control is adjusted by adding a predetermined value to a wall thickness after measuring the wall thickness of the outer peripheral wall of the honeycomb structure element.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method and an apparatus for manufacturing a honeycomb structure. [Background technology]

[0002] Generally, electrically heated catalysts (EHCs) are known in which electrodes are placed on a honeycomb structure made of conductive ceramics, and the honeycomb structure itself is heated by passing electricity through it, thereby raising the temperature of the catalyst supported on the honeycomb structure to its activation temperature before the engine (internal combustion engine) is started, with the aim of purifying exhaust gases emitted when the engine is cold immediately after starting.

[0003] As described in Patent Document 1 below, a honeycomb structure has a columnar honeycomb structure portion having an outer peripheral wall and partition walls arranged inside the outer peripheral wall, and a pair of electrode portions for attaching electrodes. When a voltage is applied to the honeycomb structure portion through the electrodes and electrode portions, the honeycomb structure portion generates heat. For purposes such as suppressing bias in the temperature distribution of the honeycomb structure portion when a voltage is applied, a plurality of slits are formed in the honeycomb structure portion, extending radially inward from the outer peripheral wall of the honeycomb structure portion and extending in the extension direction of the cells of the honeycomb structure portion. The slits are formed using a processing tool such as a router. More specifically, the processing tool is inserted into the honeycomb structure portion from the outside of the outer peripheral wall by a predetermined set amount (fixed value). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-174011 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional manufacturing methods of honeycomb structures, slits are formed by inserting a processing tool into the honeycomb structure portion from the outside of the outer peripheral wall by a predetermined set amount. Therefore, if the outer peripheral wall is thicker than expected, the processing tool may not be able to penetrate the outer peripheral wall, and the slits may be formed incompletely. On the other hand, if the outer peripheral wall is thinner than expected, the processing tool may penetrate into the honeycomb structure portion more than necessary, and unnecessarily damage the partition walls.

[0006] The present invention has been made to solve the above-mentioned problems, and one of its purposes is to provide a manufacturing method and manufacturing apparatus for a honeycomb structure that can more reliably form slits and reduce the risk of unnecessarily damaging partition walls. [Means for solving the problem]

[0007] Item 1. In one embodiment, the present invention provides a method for manufacturing a honeycomb structure including a honeycomb structure part having an outer peripheral wall and partition walls disposed inside the outer peripheral wall to define a plurality of cells forming flow paths extending from one end face to the other end face, the honeycomb structure further including a plurality of slits extending radially inward from the outer peripheral surface of the honeycomb structure and extending in the extension direction of the cells, the method including: adjusting a penetration depth of a processing tool radially inward from the outer peripheral surface of a honeycomb structure element including the honeycomb structure part; and adjusting the penetration depth after the adjusted penetration depth. The processing tool is inserted into the honeycomb structure element until the honeycomb structure element and the processing tool are moved relatively in the extending direction of the cells. and forming at least one slit in the honeycomb structure body by the above method, and the adjustment of the penetration depth is performed by measuring the wall thickness of the outer wall of the honeycomb structure body and then adding a predetermined value to the wall thickness.

[0008] Item 2. The present invention may relate to the method for manufacturing a honeycomb structure according to Item 1, wherein the adjustment of the penetration depth includes measuring the wall thickness of the peripheral wall at both one end face and the other end face, defining the wall thickness of the peripheral wall at one end face as a first wall thickness and the wall thickness of the peripheral wall at the other end face as a second wall thickness, and when one of the first and second wall thicknesses is thicker than the other, adjusting the penetration depth by adding a predetermined value to one of the first and second wall thicknesses.

[0009] Item 3. The present invention may relate to a method for manufacturing a honeycomb structure according to Item 1 or 2, wherein, when the thickness of the processing tool is t (mm) and the pitch between cells is p (mm), the predetermined value is t×0.1 or more and p×0.35 or less.

[0010] Item 4. The present invention may relate to the method for manufacturing a honeycomb structure according to any one of Items 1 to 3, wherein the honeycomb structure element further includes a pair of electrode layers disposed on the outer surface of the outer wall on either side of the central axis of the honeycomb structure part so as to extend in a band-like manner in the extension direction of the cells, and the adjustment of the penetration depth when forming slits at the positions where the electrode layers are disposed is adjusted by measuring the wall thickness of the outer wall of the honeycomb structure element and the thickness of the electrode layer, and then adding a predetermined value to the total value of the wall thickness of the outer wall and the thickness of the electrode layer.

[0011] Item 5. The present invention may relate to the method for manufacturing a honeycomb structure according to Item 4, wherein the adjustment of the penetration depth when forming slits at positions where the electrode layers are provided includes measuring the wall thickness of the outer peripheral wall and the thickness of the electrode layer at both one end face and the other end face, setting the sum of the wall thickness of the outer peripheral wall and the thickness of the electrode layer at one end face as a first sum, and setting the sum of the wall thickness of the outer peripheral wall and the thickness of the electrode layer at the other end face as a second sum, and when either the first or second sum is thicker than the other, adjusting the penetration depth by adding a predetermined value to one of the first or second sum.

[0012] Item 6. The present invention may relate to a method for manufacturing a honeycomb structure according to any one of Items 1 to 5, further comprising a step of specifying outer peripheral surface positions of the honeycomb structure body at a plurality of positions aligned in the extension direction of the cells, and when forming slits, relative displacement between the honeycomb structure body and the processing tool is performed based on the outer peripheral surface positions specified at the plurality of positions.

[0013] Item 7. In one embodiment, the present invention relates to a honeycomb structure manufacturing apparatus for manufacturing a honeycomb structure including a honeycomb structure portion having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and defining a plurality of cells that form flow paths extending from one end face to the other end face, wherein the honeycomb structure further includes a plurality of slits extending radially inward from the outer peripheral surface of the honeycomb structure and extending in the extension direction of the cells, the honeycomb structure manufacturing apparatus including: a holding unit that holds a honeycomb structure body having the honeycomb structure portion; a processing tool that forms the plurality of slits in the honeycomb structure body held by the holding unit; a measuring unit that measures a wall thickness of the outer peripheral wall of the honeycomb structure body; and a control unit that adds a predetermined value to the wall thickness measured by the measuring unit to adjust the penetration depth of the processing tool radially inward from the outer peripheral surface of the honeycomb structure body, and controls the processing tool to penetrate radially inward from the outer peripheral surface of the honeycomb structure body at the adjusted penetration depth.

[0014] Item 8. The present invention may relate to the honeycomb structure manufacturing apparatus according to Item 7, wherein the measuring unit measures the wall thickness of the peripheral wall at both one end face and the other end face, and the control unit defines the wall thickness of the peripheral wall at one end face as a first wall thickness and the wall thickness of the peripheral wall at the other end face as a second wall thickness, and when one of the first and second wall thicknesses is thicker than the other, adjusts the penetration depth by adding a predetermined value to one of the first and second wall thicknesses.

[0015] Item 9. The present invention may relate to the honeycomb structure manufacturing apparatus according to Item 7 or 8, wherein when the thickness of the processing tool is t (mm) and the pitch between cells is p (mm), the predetermined value is t×0.1 or more and p×0.35 or less.

[0016] Item 10. The present invention may relate to the honeycomb structure manufacturing apparatus according to any one of Items 7 to 9, wherein the honeycomb structure element further includes a pair of electrode layers extending in a band shape in an extension direction of the cells on an outer surface of the outer wall on either side of a central axis of the honeycomb structure part, the measurement unit measures the wall thickness of the outer wall of the honeycomb structure element and the thickness of the electrode layer at the position where the electrode layer is provided, and the control unit adjusts the penetration depth by adding a predetermined value to the total value of the wall thickness of the outer wall and the thickness of the electrode layer when forming a slit at the position where the electrode layer is provided.

[0017] Item 11. The present invention provides a method for measuring the thickness of the outer peripheral wall and the thickness of the electrode layer at both one end face and the other end face, and a method for adjusting the penetration depth by adding a predetermined value to one of the first and second total values ​​when one of the first and second total values ​​is thicker than the other. 10 The present invention may relate to the honeycomb structure manufacturing apparatus described above.

[0018] Item 12. The present invention may relate to the honeycomb structure manufacturing apparatus according to any one of Items 7 to 11, further comprising an outer peripheral surface position specifying unit that specifies outer peripheral surface positions of the honeycomb structure body at a plurality of positions aligned in the extension direction of the cells, and the control unit controls the relative displacement between the honeycomb structure body and the processing tool based on the outer peripheral surface positions specified at the plurality of positions. [Effects of the Invention]

[0019] According to an embodiment of the manufacturing method and manufacturing apparatus for a honeycomb structure of the present invention, slits can be formed more reliably and the risk of unnecessarily damaging the partition walls can be reduced. [Brief explanation of the drawings]

[0020] [Figure 1]1 is a perspective view showing a honeycomb structure manufactured by a method for manufacturing a honeycomb structure according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of the slit and its surroundings at a position where the outer peripheral wall of FIG. 1 is exposed. FIG. [Figure 3] 2 is a cross-sectional view of a slit and its surroundings at a position where an electrode layer in FIG. 1 is provided. FIG. [Figure 4] 3 is a flowchart showing a method for manufacturing a honeycomb structure according to an embodiment of the present invention. [Figure 5] 1 is an explanatory view showing a honeycomb structure manufacturing apparatus according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to each embodiment, and the components can be modified and embodied without departing from the spirit of the present invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in each embodiment. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components of different embodiments may be appropriately combined.

[0022] Fig. 1 is a perspective view showing a honeycomb structure 1 manufactured by a manufacturing method of a honeycomb structure 1 according to an embodiment of the present invention. The honeycomb structure 1 shown in Fig. 1 includes a honeycomb structure portion 2, a plurality of slits 3, a filler 4, and a pair of electrode layers 5.

[0023] The honeycomb structure portion 2 is a columnar member made of ceramics, and has an outer peripheral wall 20 and partition walls 21 arranged inside the outer peripheral wall 20 and defining a plurality of cells 21a that form flow paths extending from one end face to the other end face.

[0024] The outer shape of the honeycomb structure part 2 is not particularly limited as long as it is columnar, and may be other shapes such as a columnar shape with circular end faces (cylindrical shape), a columnar shape with oval end faces, or a columnar shape with polygonal end faces (quadrangle, pentagon, hexagon, heptagon, octagon, etc.). A columnar shape can be understood as a three-dimensional shape having a thickness in the extension direction of the cells 21a (axial direction of the honeycomb structure part 2). The ratio (aspect ratio) of the axial length of the honeycomb structure part 2 to the diameter or width of the end face of the honeycomb structure part 2 is arbitrary. The columnar shape may also include a shape (flat shape) in which the axial length of the honeycomb structure part 2 is shorter than the diameter or width of the end face.

[0025] The size of the honeycomb structure portion 2 is set to an end surface area of ​​2000 to 20000 mm for the reason of increasing heat resistance (suppressing cracks in the circumferential direction of the outer peripheral wall 20). 2 It is preferable that the thickness is 5000 to 15000 mm 2 It is more preferable that:

[0026] Although there are no limitations on the shape of the cells 21a in a cross section perpendicular to the extension direction of the cells 21a, a square, a hexagon, an octagon, or a combination thereof is preferred. Among these, a square and a hexagon are preferred. By using such a cell shape, the pressure loss when exhaust gas flows through the honeycomb structure portion 2 is reduced, and the purification performance of the catalyst is improved.

[0027] The thickness of the partition walls 21 that define the cells 21a is preferably 0.1 to 0.3 mm, and more preferably 0.1 to 0.2 mm. When the thickness of the partition walls 21 is 0.1 mm or more, it is possible to prevent a decrease in the strength of the honeycomb structure section 2. When the thickness of the partition walls 21 is 0.3 mm or less, it is possible to prevent an increase in pressure loss when exhaust gas flows through the honeycomb structure section 2 when the honeycomb structure section 2 is used as a catalyst carrier and a catalyst is carried thereon. In the present invention, the thickness of the partition walls 21 is defined as the length of a portion of a line segment that connects the centers of gravity of adjacent cells 21a and that passes through the partition walls 21 in a cross section perpendicular to the extension direction of the cells 21a.

[0028] The honeycomb structure portion 2 has a cell density of 40 to 150 cells / cm in a cross section perpendicular to the extending direction of the cells 21a. 2 It is preferable that the number of cells is 70 to 100. 2 By setting the cell density in this range, it is possible to increase the purification performance of the catalyst while minimizing the pressure loss when exhaust gas flows through it. 2 If the cell density is 150 cells / cm or more, a sufficient catalyst carrying area is ensured. 2 If the cell density is less than this value, when the honeycomb structure part 2 is used as a catalyst carrier to support a catalyst, excessive pressure loss during the flow of exhaust gas is suppressed. The cell density is a value obtained by dividing the number of cells by the area of ​​one end face part of the honeycomb structure part 2 excluding the outer wall 20 part.

[0029] Providing the outer peripheral wall 20 of the honeycomb structure portion 2 is useful from the viewpoint of ensuring the structural strength of the honeycomb structure portion 2 and suppressing leakage of the fluid flowing through the cells 21a from the outer peripheral wall 20. Specifically, the thickness of the outer peripheral wall 20 is preferably 0.05 mm or more, more preferably 0.10 mm or more, and even more preferably 0.15 mm or more. However, if the outer peripheral wall 20 is made too thick, the strength becomes too high, which disrupts the strength balance with the partition walls 21 and reduces thermal shock resistance. Therefore, the thickness of the outer peripheral wall 20 is preferably 1.0 mm or less, more preferably 0.7 mm or less, and even more preferably 0.5 mm or less. Here, the thickness of the outer peripheral wall 20 is defined as the thickness in the direction normal to the tangent of the outer peripheral wall 20 at the measurement point when the portion of the outer peripheral wall 20 where the thickness is to be measured is observed in a cross section perpendicular to the extension direction of the cells 21a.

[0030] The honeycomb structure part 2 is preferably made of ceramics and has electrical conductivity. There are no particular restrictions on the volume resistivity of the honeycomb structure part 2 as long as it can generate heat by Joule heat when current is applied, but it is preferably 0.1 to 200 Ωcm, and more preferably 1 to 200 Ωcm. In the present invention, the volume resistivity of the honeycomb structure part 2 is a value measured at 25°C by a four-terminal method.

[0031] The material of the honeycomb structure member 2 is not limited, but can be selected from the group consisting of oxide ceramics such as alumina, mullite, zirconia, and cordierite, and non-oxide ceramics such as silicon carbide, silicon nitride, and aluminum nitride. Silicon-silicon carbide composites and silicon carbide / graphite composites can also be used. Among these, from the viewpoint of achieving both heat resistance and electrical conductivity, it is preferable that the material of the honeycomb structure member 2 contains a silicon-silicon carbide composite or a ceramic containing silicon carbide as the main component. When the material of the honeycomb structure member 2 is said to contain a silicon-silicon carbide composite as the main component, it means that the honeycomb structure member 2 contains 90 mass% or more of the silicon-silicon carbide composite (total mass) of the entire honeycomb structure member 2. Here, the silicon-silicon carbide composite material contains silicon carbide particles as aggregate and silicon as a binder that bonds the silicon carbide particles, and it is preferable that a plurality of silicon carbide particles are bonded by the silicon so as to form pores between the silicon carbide particles. When the material of the honeycomb structure part 2 is said to be mainly composed of silicon carbide, it means that the honeycomb structure part 2 contains silicon carbide (total mass) in an amount of 90 mass% or more of the entire material.

[0032] When the honeycomb structure part 2 contains a silicon-silicon carbide composite material, the ratio of the "mass of silicon as a binder" contained in the honeycomb structure part 2 to the sum of the "mass of silicon carbide particles as aggregate" contained in the honeycomb structure part 2 and the "mass of silicon as a binder" contained in the honeycomb structure part 2 is preferably 10 to 40 mass%, and more preferably 15 to 35 mass%.

[0033] The partition walls 21 may be porous. When the partition walls 21 are porous, the porosity of the partition walls 21 is preferably 35 to 60%, and more preferably 35 to 45%. The porosity is a value measured by a mercury porosimeter.

[0034] The average pore diameter of the partition walls 21 of the honeycomb structure portion 2 is preferably 2 to 15 μm, and more preferably 4 to 8 μm. The average pore diameter is a value measured by a mercury porosimeter.

[0035] The multiple slits 3 extend radially inward from the outer peripheral surface 1a of the honeycomb structure 1 and extend in the extension direction of the cells 21a. The slits 3 are arranged spaced apart from one another in the circumferential direction. The slits 3 extend in the extension direction of the cells 21a from one end face to the other end face of the honeycomb structure section 2. The number of slits 3 in the circumferential direction may be 2 or more and 12 or less. The depth of the slits 3 is preferably 60% or less, and more preferably 1% or more and 25% or less, of the radius of the honeycomb structure section 2 in a cross section perpendicular to the extension direction of the cells 21a. The width of the slits 3 may be 0.4 mm or more and 2.0 mm or less. The depth of the slits 3 may be understood as the distance from the outer peripheral surface of the outer wall 20 to the tip of the slit 3.

[0036] The outer peripheral surface of the outer wall 20 constitutes at least a part of the outer peripheral surface of the honeycomb structure 1. More specifically, at a position where the outer peripheral surface of the outer wall 20 is exposed, i.e., at a position where the outer peripheral surface of the outer wall 20 is not covered with the electrode layer 5, the outer peripheral surface of the outer wall 20 constitutes the outer peripheral surface of the honeycomb structure 1. On the other hand, at a position where a pair of electrode layers 5 is provided, the outer peripheral surfaces of the pair of electrode layers 5 constitute the outer peripheral surface of the honeycomb structure 1. From another perspective, when observing the appearance of the honeycomb structure 1, the surface where the multiple slits 3 appear may be considered as the outer peripheral surface of the honeycomb structure 1. It may be understood that the outer peripheral surface of the honeycomb structure 1 does not include the end faces of the honeycomb structure portion 2 where the cells 21a open.

[0037] The filler 4 is filled in the slits 3. The filler 4 is preferably filled in at least a part of the space of the slits 3. The filler 4 is preferably filled in 50% or more of the space of the slits 3, and more preferably filled in the entire space of the slits 3. In the embodiment shown in FIG. 1 , the filler 4 is filled in the entire space of the slits 3, forms flat surfaces integral with both end faces of the honeycomb structure section 2, and forms a curved surface integral with the outer peripheral surface 1 a of the honeycomb structure 1. However, the filler 4 may be filled up to a position axially inward from the end faces of the honeycomb structure section 2, or may be filled up to a position radially or widthwise inward from the outer peripheral surface 1 a of the honeycomb structure 1.

[0038] When the main component of the honeycomb structure portion 2 is silicon carbide or a silicon-silicon carbide composite, the filler 4 preferably contains 20 mass % or more, and more preferably 20 to 70 mass % of silicon carbide. This allows the thermal expansion coefficient of the filler 4 to be close to that of the honeycomb structure portion 2, thereby improving the thermal shock resistance of the honeycomb structure portion 2. The filler 4 may contain 30 mass % or more of silica, alumina, etc.

[0039] The pair of electrode layers 5 are provided on the outer surface of the outer wall 20, sandwiching the central axis of the honeycomb structure section 2, so as to extend in a strip shape in the extension direction of the cells 21a. Although not shown, electrode terminals can be provided on the electrode layers 5. A voltage can be applied to the honeycomb structure section 2 through these electrode terminals and electrode layers 5, causing the honeycomb structure section 2 to generate heat.

[0040] Each of the pair of electrode layers 5 has first and second partial electrode layers 51, 52 separated by a slit 3. That is, at the position where the electrode layer 5 is provided, the slit 3 extends radially inward from the electrode layer 5 and opens at the outer circumferential surface of the electrode layer 5. The filler material 4 may also be filled in the slit 3 between the first and second partial electrode layers 51, 52.

[0041] From the viewpoint of making it easier for electricity to flow through the electrode layers, the volume resistivity of the electrode layers is preferably 1 / 200 or more and 1 / 10 or less of the electrical resistivity of the honeycomb structure portion 2 .

[0042] The electrode layer may be made of conductive ceramics, metals, or composites (cermets) of metals and conductive ceramics. Metals include, for example, Cr, Fe, Co, Ni, Si, or Ti, or alloys containing at least one metal selected from the group consisting of these metals. Conductive ceramics include, but are not limited to, silicon carbide (SiC), and metal compounds such as metal silicides, including tantalum silicide (TaSi2) and chromium silicide (CrSi2).

[0043] In a manufacturing method of the honeycomb structure 1 having electrode layers, first, an electrode layer forming raw material containing ceramic raw materials is applied to the side surface of a dried honeycomb body, and then dried to form a pair of unfired electrode layers extending in a band shape in the extension direction of the cells 21a on the outer surface of the peripheral wall 20, sandwiching the central axis of the dried honeycomb body, thereby producing a dried honeycomb body with unfired electrode layers. Next, the dried honeycomb body with the unfired electrode layers is fired to produce a fired honeycomb body having a pair of electrode layers 5. In this way, the honeycomb structure 1 having electrode layers is obtained. Note that the pair of electrode layers 5 are not essential components, and the honeycomb structure 1 does not necessarily have to have the pair of electrode layers 5.

[0044] Next, Fig. 2 is a cross-sectional view of the slit 3 and its surroundings at a position where the outer peripheral wall 20 in Fig. 1 is exposed. Fig. 2 shows the slit 3 in a state before it is filled with the filler 4. As shown in Fig. 2, the slit 3 has a first groove portion 3a formed in the outer peripheral wall 20 and a second groove portion 3b that communicates with the first groove portion 3a.

[0045] The first groove portions 3a penetrate the outer peripheral wall 20. That is, the first groove portions 3a are provided between the outer peripheral surface 20a and the inner peripheral surface 20b of the outer peripheral wall 20. As described above, in the positions where the outer peripheral wall 20 is exposed, the outer peripheral surface 20a of the outer peripheral wall 20 forms the outer peripheral surface 1a of the honeycomb structure 1.

[0046] The second groove portions 3b extend radially inward from the inner peripheral surface 20b of the outer peripheral wall 20 of the honeycomb structure portion 2. In the illustrated embodiment, the second groove portions 3b are formed by removing a portion of the partition wall 21 so as to connect adjacent cells 21a, as indicated by the two-dot chain line in the figure. However, the second groove portions 3b may be formed only by the outermost cells 21a that are in contact with the inner peripheral surface 20b of the outer peripheral wall 20. In other words, the second groove portions 3b do not need to have a missing portion of the partition wall 21.

[0047] 2 shows the first and second groove portions 3a, 3b in a plane perpendicular to the extension direction of the cells 21a. These first and second groove portions 3a, 3b, i.e., the slits 3, extend in the extension direction of the cells 21a (the direction perpendicular to the paper surface of FIG. 2) as shown in FIG.

[0048] The slits 3 can be formed by processing using a processing tool 62. The processing tool 62 can be a cutting tool such as a disc-shaped grinding wheel or a router. The processing tool 62 is advanced from the outer peripheral wall 20 (the outer peripheral surface 1a of the honeycomb structure 1) toward the inside of the honeycomb structure 1 in the radially inward direction. Furthermore, the processing tool 62 is moved in the extension direction of the cells 21a while advanced into the inside of the honeycomb structure 1. By processing using the processing tool 62, the first groove portions 3a penetrating at least the outer peripheral wall 20 can be formed. The second groove portions 3b may be formed by processing using the processing tool 62, or may be formed by manufacturing a precursor (honeycomb formed body) of the honeycomb structure portion 2 in a state where some of the partition walls 21 are missing. A method of manufacturing a honeycomb formed body in a state where some of the partition walls 21 are missing may be a method of removing some of the partition walls by blocking part of a die. When the second groove portion 3b is formed only by the outermost cells 21a as described above, the partition walls 21 do not need to be machined by the machining tool 62.

[0049] Next, Fig. 3 is a cross-sectional view of the slit 3 and its surroundings at the position where the electrode layer 5 in Fig. 1 is provided. Fig. 3 shows the slit 3 in a state before it is filled with the filler 4. As shown in Fig. 3, at the position where the electrode layer 5 is provided, the slit 3 further has a third groove 3c formed in the electrode layer 5 that communicates with the first groove 3a.

[0050] The third groove portions 3c penetrate the electrode layer 5. That is, the third groove portions 3c are provided between the outer peripheral surface 5a and the inner peripheral surface 5b of the electrode layer 5. As described above, at the positions where the electrode layers 5 are provided, the outer peripheral surface 5a of the electrode layer 5 forms the outer peripheral surface 1a of the honeycomb structure 1.

[0051] At the position where the electrode layer 5 is provided, the processing tool 62 is advanced into the honeycomb structure 1 from the outer peripheral surface 5a of the electrode layer 5 (the outer peripheral surface 1a of the honeycomb structure 1) toward the inside in the radial direction. Furthermore, the processing tool 62 is moved in the extension direction of the cells 21a while advanced into the honeycomb structure 1. By processing with the processing tool 62, it is possible to form at least first groove portions 3a penetrating the outer peripheral wall 20 and third groove portions 3c penetrating the electrode layer 5.

[0052] Next, Fig. 4 is a flowchart showing a manufacturing method of a honeycomb structure 1 according to an embodiment of the present invention. The manufacturing method of the honeycomb structure 1 shown in Fig. 4 is for manufacturing a honeycomb structure 1 including: a honeycomb structure portion 2 having an outer peripheral wall 20; partition walls 21 disposed inside the outer peripheral wall 20 and defining a plurality of cells 21a each forming a flow path extending from one end face to the other end face; a plurality of slits 3 extending radially inward from the outer peripheral surface 1a of the honeycomb structure 1 and extending in the extension direction of the cells 21a; and a pair of electrode layers 5 provided on the outer surface of the outer peripheral wall 20 on either side of the central axis of the honeycomb structure portion 2 so as to extend in a strip shape in the extension direction of the cells 21a.

[0053] 4, the method for manufacturing the honeycomb structure 1 according to the embodiment of the present invention includes a preparation step (step S1), an adjustment step (step S2), and a slit formation step (step S4). The method for manufacturing the honeycomb structure 1 may further include an outer peripheral surface position identification step (step S3).

[0054] The preparation step (step S1) is a step of preparing a honeycomb structure element 10 (see FIG. 5). The honeycomb structure element 10 has a honeycomb structure part 2. The honeycomb structure element 10 may further have a pair of electrode layers 5, and may have the same configuration as the honeycomb structure 1 of FIG. 1 except that it does not have the slits 3 and the fillers 4. In the preparation step, a honeycomb structure element 10 manufactured by a third party may be obtained. That is, the preparation step does not have to involve the manufacture of the honeycomb structure element 10.

[0055] The adjustment step (step S2) is a step of adjusting the penetration depth of the processing tool 62 radially inward from the outer peripheral surface 10a of the honeycomb structure body 10. The penetration depth of the processing tool 62 is determined by the amount of relative displacement between the honeycomb structure body 10 and the processing tool 62, and may be determined by the amount by which one of the honeycomb structure body 10 and the processing tool 62 is fixed and the other is moved closer to it, or may be determined by the amount by which both the honeycomb structure body 10 and the processing tool 62 are movably provided and the honeycomb structure body 10 and the processing tool 62 are moved closer to each other.

[0056] This adjustment of the penetration depth is performed by measuring the wall thickness WTh (see FIG. 2) of the outer peripheral wall 20 of the honeycomb structure element 10 and then adding a predetermined value to the wall thickness WTh. By adjusting the penetration depth of the processing tool 62 based on the measured value of the wall thickness WTh, even if the wall thickness WTh is thicker or thinner than initially expected, processing can be performed according to the wall thickness WTh. This makes it possible to more reliably form the slits 3 and reduce the risk of unnecessarily damaging the partition walls 21. The adjustment step of this embodiment can also be understood to include measuring the wall thickness WTh of the outer peripheral wall 20 and determining the penetration depth of the processing tool 62 based on the measured wall thickness WTh.

[0057] The wall thickness WTh may be measured each time a slit 3 is processed, or may be measured for each honeycomb structure element 10. Furthermore, the wall thickness WTh at the position where the outer peripheral surface of the outer wall 20 is exposed may be measured for each lot of the honeycomb structure element 10. A lot of the honeycomb structure element 10 can be understood to mean a plurality of honeycomb structure elements 10 manufactured in a series under the same manufacturing conditions, such as the material ratio and the settings of the die through which the material is extruded. The honeycomb structure element 10 manufactured in a series is cut to a desired size, and a plurality of honeycomb structure elements 10 is obtained.

[0058] The predetermined value added to the wall thickness WTh can be determined so that the machining tool 62 penetrates to the inside of the inner peripheral surface 20b of the outer wall 20. When the tip of the machining tool 62 has a curved surface 62a as shown in FIG. 2, the predetermined value can be determined so that at least the curved surface 62a penetrates to the inside of the inner peripheral surface 20b of the outer wall 20. The predetermined value can also be determined according to the depth of the slit 3, so that the tip of the machining tool 62 does not unnecessarily contact the partition wall 21 located beyond the direction of the machining tool 62's penetration. As will be described later with reference to examples, when the thickness of the machining tool 62 is t (mm) and the pitch between the cells 21a is p (mm), the predetermined value (mm) added to the wall thickness WTh is preferably greater than or equal to t × 0.1 and less than or equal to p × 0.35. Setting the predetermined value to t × 0.1 or greater reduces the risk of the shape of the curved surface 62a of the machining tool 62 remaining in the slit 3. By setting the predetermined value to p×0.35 or less, it is possible to reduce the risk that the tip portion of the machining tool 62 will unnecessarily come into contact with the partition wall 21 located ahead of the machining tool 62 in the direction of entry.

[0059] The wall thickness WTh of the outer peripheral wall 20 may be measured by any method. For example, the wall thickness WTh of the outer peripheral wall 20 can be measured by image processing an image of an end face of the honeycomb structure body 10. Alternatively, the wall thickness WTh of the outer peripheral wall 20 may be measured using an instrument or device such as a thickness gauge. The measured wall thickness WTh may be input to a control device that controls the movement of the honeycomb structure body 10 and / or the processing tool 62. The control device can determine the penetration depth of the processing tool 62 based on the input wall thickness WTh.

[0060] Further, the adjustment of the penetration depth in the adjusting step (step S2) may include measuring the wall thickness WTh of the outer peripheral wall 20 at both one end face and the other end face of the honeycomb structure element 10, defining the wall thickness WTh of the outer peripheral wall 20 at one end face as a first wall thickness WTh1 and the wall thickness WTh of the outer peripheral wall 20 at the other end face as a second wall thickness WTh2, and when one of the first and second wall thicknesses WTh1, WTh2 is thicker than the other, adjusting the wall thickness WTh1, WTh2 by adding a predetermined value to one of the first and second wall thicknesses WTh1, WTh2 (the thicker of the first and second wall thicknesses WTh1, WTh2). This more reliably prevents the penetration depth of the machining tool 62 into the honeycomb structure element 10 from being insufficient due to unevenness in the wall thickness WTh of the outer peripheral wall 20 at one end face and the other end face, and more reliably forms the slits 3. The predetermined value (mm) added to one of the first and second wall thicknesses WTh1, WTh2 is also preferably equal to or greater than t×0.1 and equal to or less than p×0.35.

[0061] The penetration depth when forming the slits 3 at the positions where the electrode layers 5 are provided may be adjusted by measuring the wall thickness WTh of the outer peripheral wall 20 of the honeycomb structure body 10 and the thickness Th of the electrode layers 5 (see FIG. 3 ), and then adding a predetermined value to the total value TV of the wall thickness WTh of the outer peripheral wall 20 and the thickness Th of the electrode layers 5. This makes it possible to take into consideration not only the wall thickness WTh of the outer peripheral wall 20 but also the thickness Th of the electrode layers 5, thereby making it possible to more reliably form the slits 3 and reduce the risk of unnecessarily damaging the partition walls 21.

[0062] Like the measurement of the wall thickness WTh, the measurement of the thickness Th of the electrode layer 5 may be performed each time a slit 3 is processed, or may be performed for each honeycomb structure element 10. Moreover, the measurement of the thickness Th of the electrode layer 5 may be performed for each lot of the honeycomb structure element 10.

[0063] Furthermore, the adjustment of the penetration depth when forming the slits 3 at the positions where the electrode layers 5 are provided may include measuring the wall thickness WTh of the outer peripheral wall 20 and the thickness Th of the electrode layers 5 at both one end face and the other end face, setting the sum TV of the wall thickness WTh1 of the outer peripheral wall 20 and the thickness Th1 of the electrode layers 5 at one end face as a first sum TV1, setting the sum TV of the wall thickness WTh2 of the outer peripheral wall 20 and the thickness Th of the electrode layers 5 at the other end face as a second sum TV2, and adjusting the first and second sums TV1 and TV2 by adding a predetermined value to one of the first and second sums TV1 and TV2 when one of the first and second sums TV1 and TV2 is thicker than the other. This makes it possible to take into account not only the wall thickness WTh of the outer peripheral wall 20 but also the thickness Th of the electrode layers 5, thereby more reliably avoiding an insufficient penetration depth of the machining tool 62 into the honeycomb structure element 10 caused by non-uniformity in the wall thickness WTh of the outer peripheral wall 20 and / or the thickness Th of the electrode layers 5 between one end face and the other end face, and more reliably forming the slits 3.

[0064] The outer peripheral surface position specifying step (step S3) is a step of specifying the outer peripheral surface position of the honeycomb structure element 10 at a plurality of positions aligned in the extension direction of the cells 21a. The outer peripheral surface position can be understood as the position of the outer peripheral surface 10a of the honeycomb structure element 10 in a plane perpendicular to the extension direction of the cells 21a. The outer peripheral surface 10a of the honeycomb structure element 10 can be the outer peripheral surface 20a of the outer peripheral wall 20 at a position where the outer peripheral wall 20 is exposed, or the outer peripheral surface 5a of the electrode layer 5 at a position where the electrode layer 5 is provided. If a processing tool 62 is placed above the honeycomb structure element 10 and is lowered to enter the honeycomb structure element 10, the position of the outer peripheral surface 10a of the honeycomb structure element 10 can be understood as the height position of the outer peripheral surface 10a. The specified outer peripheral surface position of the honeycomb structure element 10 can be used in a subsequent slit forming step.

[0065] The slit forming step (step S4) is a step of forming at least one slit 3 in the honeycomb structure element 10 using the adjusted penetration depth. That is, one slit 3 is formed by inserting the processing tool 62 into the honeycomb structure element 10 to the adjusted penetration depth and relatively moving the honeycomb structure element 10 and the processing tool 62 in the extension direction of the cells 21a. After one slit 3 is formed, other slits 3 can be formed in the same manner at positions spaced apart from the slit 3 in the circumferential or radial direction of the honeycomb structure element 10.

[0066] When forming other slits 3, the wall thickness WTh of the outer peripheral wall 20 (and the thickness Th of the electrode layer 5) may be measured at that position, and the penetration depth of the machining tool 62 may be determined again based on the measured wall thickness WTh (and the thickness Th). That is, the adjustment step and the slit forming step (and the outer peripheral surface position specifying step) may be repeated until a predetermined number of slits 3 are formed.

[0067] When the manufacturing method of the honeycomb structure 1 includes the outer peripheral surface position specifying step (step S3), when forming the slits 3, the honeycomb structure element 10 and the processing tool 62 are relatively displaced with respect to each other, using the outer peripheral surface positions specified at a plurality of positions as a reference (zero point position). The outer peripheral surface positions can be specified at a plurality of positions spaced at predetermined intervals in the extension direction of the cells 21a. The intervals at which the plurality of positions are specified are arbitrary, but are preferably 12 mm or less. That is, when the manufacturing method of the honeycomb structure 1 includes the outer peripheral surface position specifying step (step S3), in the slit forming step (step S4), after the processing tool 62 has once entered the honeycomb structure element 10, the position of the processing tool 62 may be adjusted with respect to the direction in which the processing tool 62 enters the honeycomb structure element 10 when the honeycomb structure element 10 and the processing tool 62 are moved relatively in the extension direction of the cells 21a. This makes it possible to more reliably prevent the machining tool 62 from penetrating deep enough into the honeycomb structure body 10, even if the external shape of the honeycomb structure body 10 is deformed and the position of the outer surface 10a of the honeycomb structure body 10 is misaligned in the axial direction, and to more reliably form the slits 3.

[0068] In the manufacturing method of this embodiment, at the stage where a plurality of slits 3 are formed in the honeycomb structure element 10, the honeycomb structure element 10 is treated as the honeycomb structure 1. The honeycomb structure 1 may be subjected to a post-process such as filling the slits 3 with a filler 4.

[0069] Next, FIG. 5 is an explanatory diagram showing an apparatus 6 for manufacturing a honeycomb structure 1 according to an embodiment of the present invention. The apparatus 6 for manufacturing a honeycomb structure 1 shown in FIG. 5 is for manufacturing a honeycomb structure 1 including a honeycomb structure portion 2 having an outer peripheral wall 20 and partition walls 21 disposed inside the outer peripheral wall 20 to define a plurality of cells 21a that form flow paths extending from one end face to the other end face, and further including a plurality of slits 3 extending radially inward from the outer peripheral surface 1a of the honeycomb structure 1 and in the extension direction of the cells 21a. The honeycomb structure 1 may further include a pair of electrode layers 5 extending in a strip-like shape in the extension direction of the cells 21a on the outer surface of the outer peripheral wall 20, with the central axis of the honeycomb structure portion 2 sandwiched therebetween. Although not limited thereto, the above-mentioned method for manufacturing a honeycomb structure 1 can be carried out using the apparatus 6 for manufacturing a honeycomb structure 1 shown in FIG. 5.

[0070] As shown in FIG. 5, the manufacturing apparatus 6 for the honeycomb structure 1 includes a holding unit 61 , a processing tool 62 , a measuring unit 63 , a control unit 64 , and an outer peripheral surface position specifying unit 65 .

[0071] The holding part 61 is for holding the honeycomb structure element 10 having the honeycomb structure part 2 (see FIG. 1) (and the electrode layer 5). As described above, the honeycomb structure element 10 may have the same configuration as the honeycomb structure part 2 in FIG. 1 except that it does not have the slits 3 and the filler material 4.

[0072] The processing tool 62 is used to form a plurality of slits 3 in the honeycomb structure element 10. The honeycomb structure element 10 held by the holding part 61 and the processing tool 62 may be provided so as to be relatively displaceable. That is, one of the honeycomb structure element 10 held by the holding part 61 and the processing tool 62 may be provided so as to be displaceable relative to the other, or both of them may be provided so as to be displaceable.

[0073] In the illustrated embodiment, a holding portion 61 is fixed to a base (not shown), and a honeycomb structure element 10 is placed on the holding portion 61. The holding portion 61 holds the honeycomb structure element 10 so that it cannot be displaced in any of the circumferential and radial directions of the honeycomb structure element 10 and the extension direction of the cells 21a. By performing a predetermined operation, the holding of the honeycomb structure element 10 by the holding portion 61 can be released, and the position and orientation of the honeycomb structure element 10 can be adjusted.

[0074] The processing tool 62 is composed of a rotatable disc-shaped grindstone, and is arranged above the honeycomb structure element 10 held by the holding part 61. The processing tool 62 is provided so as to be movable in the radial direction of the honeycomb structure element 10 held by the holding part 61 and in the extension direction of the cells 21a of the honeycomb structure element 10 held by the holding part 61. The radial direction of the honeycomb structure element 10 may include the height direction and the left-right direction perpendicular to the plane of the paper in FIG. 5 .

[0075] While the processing tool 62 is being rotated, the processing tool 62 is lowered and moved in the extension direction of the cells 21a, thereby forming one slit 3 in the honeycomb structure element 10. After forming one slit 3, other slits 3 can be formed in the same manner by adjusting the orientation of the honeycomb structure element 10 and / or the position of the processing tool 62.

[0076] The measuring unit 63 is for measuring the wall thickness WTh of the outer peripheral wall 20 of the honeycomb structure element 10. The measuring unit 63 may further measure the wall thickness WTh of the outer peripheral wall 20 of the honeycomb structure element 10 and the thickness Th of the electrode layer 5 at a position where the electrode layer 5 is provided. In the illustrated embodiment, the measuring unit 63 is configured to be able to measure the wall thickness WTh (WTh1, WTh2) of the outer peripheral wall 20 and the thickness Th (Th1, Th2) of the electrode layer 5 at both one end face and the other end face of the honeycomb structure element 10. The measuring unit 63 may be configured to be able to measure the wall thickness WTh of the outer peripheral wall 20 and the thickness Th of the electrode layer 5 at only one end face of the honeycomb structure element 10. The measuring unit 63 may be arranged so that the wall thickness WTh of the outer peripheral wall 20 and the thickness Th of the electrode layer 5 can be measured at a position where the machining tool 62 enters. The measuring unit 63 may be disposed so as to be able to measure the wall thickness WTh of the outer peripheral wall 20 and the thickness Th of the electrode layer 5 at the top of the outer peripheral wall 20 (the highest position in the vertical direction).

[0077] In the illustrated embodiment, the measuring unit 63 is configured by a camera. The measuring unit 63 includes a first camera 631 arranged to capture an image of the outer peripheral wall 20 and the electrode layers 5 at one end face of the honeycomb structure element 10, and a second camera 632 arranged to capture an image of the outer peripheral wall 20 and the electrode layers 5 at the other end face of the honeycomb structure element 10. The images captured by the first and second cameras 631, 632 are input to a processing device (not shown). The processing device processes the images captured by the first and second cameras 631, 632 to obtain the wall thickness WTh of the outer peripheral wall 20 and the thickness Th of the electrode layers 5. Hardware constituting the control unit 64 (described later) may also function as the processing device.

[0078] The control unit 64 adjusts the penetration depth of the machining tool 62 from the outer peripheral surface 10a of the honeycomb structure body 10 inward in the radial direction by adding a predetermined value to the wall thickness WTh measured by the measuring unit 63, and controls the machining tool 62 so that it penetrates radially inward from the outer peripheral surface 10a of the honeycomb structure body 10 at the adjusted penetration depth. In other words, the control unit 64 can determine the penetration depth of the machining tool 62 from the outer peripheral surface 10a of the honeycomb structure body 10 inward in the radial direction by adding a predetermined value to the wall thickness WTh measured by the measuring unit 63. The control unit 64 can control the displacement of the honeycomb structure body 10 and / or the machining tool 62 held by the holding unit 61 so that the machining tool 62 penetrates into the outer peripheral wall 20 of the honeycomb structure body 10 to the determined penetration depth of the machining tool 62. In the illustrated embodiment, the control unit 64 controls the displacement of the machining tool 62. The control of the displacement of the processing tool 62 may include control of the displacement of the processing tool 62 in the radial direction of the honeycomb structure element 10 and control of the displacement of the processing tool 62 in the extension direction of the cells 21a.

[0079] Furthermore, when forming the slits 3 at the positions where the electrode layers 5 are provided, the control unit 64 may adjust the penetration depth of the machining tool 62 by adding a predetermined value to the total value TV of the wall thickness WTh of the outer peripheral wall 20 and the thickness Th of the electrode layers 5, and control the machining tool 62 to penetrate radially inward from the outer peripheral surface 10a of the honeycomb structure body 10 at the adjusted penetration depth. In other words, the control unit 64 can determine the penetration depth of the machining tool 62 radially inward from the outer peripheral surface 5a of the electrode layers 5 by adding a predetermined value to the total value TV of the wall thickness WTh and the thickness Th of the electrode layers 5 measured by the measuring unit 63.

[0080] The control unit 64 can be configured with hardware such as a computer or a dedicated circuit. The predetermined values ​​to be added to the wall thickness WTh and the total value TV when determining the penetration depth of the machining tool 62 may be input to the control unit 64 via a predetermined interface or may be registered in the control unit 64 in advance.

[0081] The outer peripheral surface position specifying unit 65 is for specifying the outer peripheral surface position of the honeycomb structure element 10 at a plurality of positions aligned in the extension direction of the cells 21a. The outer peripheral surface position specifying unit 65 can be configured by, for example, a laser displacement meter or the like.

[0082] The control unit 64 controls the relative displacement of the honeycomb structure body 10 and the processing tool 62 based on the outer peripheral surface position of each position identified by the outer peripheral surface position identifying unit 65. Furthermore, after the processing tool 62 has once entered the honeycomb structure body 10, the control unit 64 can adjust the position of the processing tool 62 in the direction in which the processing tool 62 enters the honeycomb structure body 10 when relatively moving the honeycomb structure body 10 and the processing tool 62 in the extension direction of the cells 21 a.

[0083] As shown in the figure, when the measuring unit 63 measures both the first wall thickness WTh1 of the outer peripheral wall 20 at one end face of the honeycomb structure body 10 and the second wall thickness WTh2 of the outer peripheral wall 20 at the other end face, the control unit 64 can determine whether or not one of the first and second wall thicknesses WTh1, WTh2 is thicker than the other. When one of the first and second wall thicknesses WTh1, WTh2 is thicker than the other, the control unit 64 adjusts the penetration depth by adding a predetermined value to one of the first and second wall thicknesses WTh1, WTh2. This makes it possible to avoid an insufficient penetration depth of the machining tool 62 into the honeycomb structure body 10, and to more reliably form the slits 3.

[0084] In addition, as shown in the figure, when the measuring unit 63 measures both the first wall thickness WTh1 of the outer peripheral wall 20 and the first thickness Th1 of the electrode layer 5 at one end face of the honeycomb structure element 10 and the second wall thickness WTh2 of the outer peripheral wall 20 and the second thickness Th2 of the electrode layer 5 at the other end face, the control unit 64 can determine whether or not one of the first total value TV1 (the sum of the first wall thickness WTh1 and the first thickness Th1) and the second total value TV2 (the sum of the second wall thickness WTh2 and the second thickness Th2) is greater than the other. When one of the first and second total values ​​TV1 and TV2 is greater than the other, the control unit 64 adjusts the penetration depth by adding a predetermined value to one of the first and second total values ​​TV1 and TV2. This makes it possible to avoid insufficient penetration depth of the machining tool 62 into the honeycomb structure element 10, and to more reliably form the slits 3.

[0085] Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present invention. [Example]

[0086] Examples will be given below to better understand the present invention and its advantages, but the present invention is not limited to these examples. The inventors investigated the shape of the slits 3 by adjusting the penetration depth of the machining tool 62 radially inward from the outer peripheral surface 10a of the honeycomb structure element 10 based on the thickness t (mm) of the machining tool and the pitch p (mm) between the cells 21a. Specifically, the first and second wall thicknesses WTh1 and WTh2 of the honeycomb structure element 10 as a test specimen were measured, and a predetermined value to be added to the thicker of the first and second wall thicknesses WTh1 and WTh2 (one of the first and second wall thicknesses WTh1 and WTh2) was variously changed as a function of the thickness t (mm) of the machining tool or the pitch p (mm) between the cells 21a. The results are shown in the following table.

[0087] [Table 1]

[0088] As shown in Example 1, when the predetermined value added to the thicker of the first and second wall thicknesses WTh1 and WTh2 was t × 0.1, the shape of the curved surface portion 62a of the machining tool 62 remained slightly in the slit 3. In the table, the state in which the shape of the curved surface portion 62a of the machining tool 62 remained in the slit 3 is referred to as "grindstone R remaining." The remaining shape of the curved surface portion 62a in Example 1 was not particularly problematic in practice. On the other hand, as shown in Comparative Example 1, when the predetermined value was t × 0.05, the shape of the curved surface portion 62a of the machining tool 62 remained largely in the slit 3. These results confirmed that it is preferable for the predetermined value (mm) added to the thicker of the first and second wall thicknesses WTh1 and WTh2 to be t × 0.1 or more. This also applies when measuring only one of the first and second wall thicknesses WTh1 and WTh2.

[0089] In the table, "x" in the judgment column indicates that an abnormality was found in the test processing (a situation in which the shape of the curved surface portion 62a of the processing tool 62 remains significantly in the slit 3 or damage to the partition wall 21 occurs). Also, "x" indicates a situation in which, even in desk calculations, it is assumed that the shape of the curved surface portion 62a of the processing tool 62 remains significantly in the slit 3 or damage to the partition wall 21 occurs, and thus the quality is significantly affected.

[0090] "△" indicates a situation in which, in test machining, the shape of the curved surface portion 62a of the machining tool 62 remains slightly in the slit 3. Also, "△" indicates a situation in which, even in desk calculations, it is assumed that the shape of the curved surface portion 62a of the machining tool 62 remains in the slit 3, the partition wall 21 is not damaged, and the practical quality impact is small.

[0091] Furthermore, "◯" indicates a situation in which no abnormalities were found in the test processing. Furthermore, "◯" indicates a situation in which, although it is assumed in desk calculations that the shape of the curved surface portion 62a of the processing tool 62 will remain in the slit 3, whether or not this will occur will vary depending on variations, the partition wall 21 will not be damaged, and there will be substantially no impact on quality.

[0092] Furthermore, "◎" indicates a situation in which no abnormalities were found in the test processing. Furthermore, "◎" indicates a situation in which, even in theoretical calculations, it is assumed that the shape of the curved surface portion 62a of the processing tool 62 will not remain in the slit 3, the partition wall 21 will not be damaged, and there will be no impact on quality. As in Examples 4 to 6, in order to more reliably ensure that the shape of the curved surface portion 62a of the processing tool 62 will not remain in the slit 3, it is more preferable that the predetermined value (mm) is t×0.25 or more.

[0093] Furthermore, as shown in Example 7, when the predetermined value added to the thicker of the first and second wall thicknesses WTh1, WTh2 was p × 0.35, the tip of the machining tool 62 did not come into contact with the partition wall 21 located further in the direction of entry of the machining tool 62. On the other hand, as shown in Comparative Example 2, when the predetermined value was p × 0.40, the partition wall 21 located further in the direction of entry of the machining tool 62 was damaged by contact with the machining tool 62. From these results, it was confirmed that the predetermined value (mm) added to the thicker of the first and second wall thicknesses WTh1, WTh2 is preferably p × 0.35 or less. This also applies when measuring only one of the first and second wall thicknesses WTh1, WTh2. [Explanation of symbols]

[0094] 1: Honeycomb structure 1a: Outer surface 2: Honeycomb structure 20:Outer wall 20a: Outer surface 21: Bulkhead 21a: Cell 3: Slit 5: Electrode layer 5a: Outer surface 6: Manufacturing equipment 61: Holding part 62: Processing tools 63: Measuring part 64: Control section 65: Outer surface position identification part 10: Honeycomb structure element 10a: Outer surface

Claims

1. A method for manufacturing a honeycomb structure including a honeycomb structure part having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and defining a plurality of cells that form flow paths extending from one end face to the other end face, wherein the honeycomb structure further includes a plurality of slits extending radially inward from the outer peripheral surface of the honeycomb structure and extending in an extension direction of the cells, a step of adjusting an insertion depth of a processing tool from an outer peripheral surface of a honeycomb structure element having the honeycomb structure portion to an inward radial direction; a step of inserting the processing tool into the honeycomb structure body to the adjusted penetration depth and relatively moving the honeycomb structure body and the processing tool in the extension direction of the cells, thereby forming at least one slit in the honeycomb structure body; Including, The adjustment of the penetration depth is performed by measuring the wall thickness of the outer peripheral wall of the honeycomb structure body and then adding a predetermined value to the wall thickness. A method for manufacturing a honeycomb structure.

2. adjusting the penetration depth includes measuring the wall thickness of the outer peripheral wall at both the one end face and the other end face, defining the wall thickness of the outer peripheral wall at the one end face as a first wall thickness and the wall thickness of the outer peripheral wall at the other end face as a second wall thickness, and adjusting the penetration depth by adding a predetermined value to one of the first and second wall thicknesses when either one of the first and second wall thicknesses is thicker than the other. The method for manufacturing a honeycomb structure according to claim 1 .

3. When the thickness of the processing tool is t (mm) and the pitch between the cells is p (mm), the predetermined value is equal to or greater than t×0.1 and equal to or less than p×0.

35. The method for manufacturing a honeycomb structure according to claim 1 or 2.

4. the honeycomb structure element further includes a pair of electrode layers provided on the outer surface of the outer peripheral wall, with a central axis of the honeycomb structure part interposed therebetween, so as to extend in a band shape in an extension direction of the cells, The adjustment of the penetration depth when forming the slits at the positions where the electrode layers are provided is adjusted by measuring the wall thickness of the outer wall of the honeycomb structure body and the thickness of the electrode layer, and then adding a predetermined value to the total value of the wall thickness of the outer wall and the thickness of the electrode layer. The method for manufacturing a honeycomb structure according to claim 1 or 2.

5. The adjustment of the penetration depth when forming the slit at the position where the electrode layer is provided includes measuring the wall thickness of the outer peripheral wall and the thickness of the electrode layer at both the one end face and the other end face, setting the sum of the wall thickness of the outer peripheral wall and the thickness of the electrode layer at the one end face as a first sum, and setting the sum of the wall thickness of the outer peripheral wall and the thickness of the electrode layer at the other end face as a second sum, and when either of the first and second sums is thicker than the other, adjusting the penetration depth by adding a predetermined value to one of the first and second sums. The method for manufacturing a honeycomb structure according to claim 4.

6. The method further includes a step of specifying the outer peripheral surface position of the honeycomb structure element at a plurality of positions aligned in the extension direction of the cells, When forming the slits, the honeycomb structure body and the processing tool are displaced relative to each other with reference to the outer peripheral surface positions specified at the plurality of positions. The method for manufacturing a honeycomb structure according to claim 1 or 2.

7. A honeycomb structure manufacturing apparatus for manufacturing a honeycomb structure including a honeycomb structure part having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and defining a plurality of cells that form flow paths extending from one end face to the other end face, wherein the honeycomb structure further includes a plurality of slits extending radially inward from the outer peripheral surface of the honeycomb structure and extending in the extension direction of the cells, a holding portion for holding a honeycomb structure element having the honeycomb structure portion; a processing tool for forming the plurality of slits in the honeycomb structure body held by the holding part; a measuring unit for measuring a wall thickness of the outer peripheral wall of the honeycomb structure element; a control unit that adds a predetermined value to the wall thickness measured by the measuring unit to adjust the penetration depth of the processing tool from the outer peripheral surface of the honeycomb structure body inward in the radial direction, and controls the processing tool to penetrate from the outer peripheral surface of the honeycomb structure body inward in the radial direction at the adjusted penetration depth; Equipped with Honeycomb structure manufacturing equipment.

8. the measuring unit measures the wall thickness of the outer peripheral wall at both the one end face and the other end face, the control unit defines a wall thickness of the outer peripheral wall at the one end face as a first wall thickness and a wall thickness of the outer peripheral wall at the other end face as a second wall thickness, and when one of the first and second wall thicknesses is thicker than the other, adjusts the penetration depth by adding a predetermined value to one of the first and second wall thicknesses. The honeycomb structure manufacturing apparatus according to claim 7 .

9. When the thickness of the processing tool is t (mm) and the pitch between the cells is p (mm), the predetermined value is equal to or greater than t×0.1 and equal to or less than p×0.

35. The honeycomb structure manufacturing apparatus according to claim 7 or 8.

10. the honeycomb structure element further includes a pair of electrode layers provided on the outer surface of the outer peripheral wall, with a central axis of the honeycomb structure part interposed therebetween, so as to extend in a band shape in an extension direction of the cells, the measuring unit measures the wall thickness of the outer peripheral wall of the honeycomb structure element and the thickness of the electrode layer at a position where the electrode layer is provided, When forming the slit at the position where the electrode layer is provided, the control unit adjusts the penetration depth by adding a predetermined value to the sum of the wall thickness of the outer peripheral wall and the thickness of the electrode layer. The honeycomb structure manufacturing apparatus according to claim 7 or 8.

11. the measuring unit measures the wall thickness of the outer peripheral wall and the thickness of the electrode layer at both the one end face and the other end face; the control unit sets a first total value as a sum of the wall thickness of the outer peripheral wall and the thickness of the electrode layer at the one end face, and a second total value as a sum of the wall thickness of the outer peripheral wall and the thickness of the electrode layer at the other end face, and when one of the first and second total values ​​is thicker than the other, adjusts the penetration depth by adding a predetermined value to one of the first and second total values. The honeycomb structure manufacturing apparatus according to claim 10.

12. an outer peripheral surface position specifying unit for specifying an outer peripheral surface position of the honeycomb structure element at a plurality of positions aligned in the extension direction of the cells, the control unit controls the relative displacement between the honeycomb structure body and the processing tool based on the outer peripheral surface positions specified at the plurality of positions. The honeycomb structure manufacturing apparatus according to claim 7 or 8.

Images