JP2000024840A - Manufacture of honeycomb structure body molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a honeycomb structure body molding die, allowing slit grooves to be machined with high accuracy and in a short lead time. SOLUTION: In a method of manufacturing a honeycomb structure body molding die having a plurality of material feed holes and slit grooves provided in grated shape being communicated with the feed holes so as to form material in honeycomb shape, the slit grooves are machined by electric-discharge- machining a groove formed face of die material a plurality of times using a small electric discharge machining electrode 1 with a machining face 10 smaller in area than the groove formed face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a die for forming a honeycomb structure having lattice-shaped slit grooves.

[0002]

2. Description of the Related Art For example, a ceramic honeycomb structure mainly composed of cordierite or the like is manufactured by extruding a material using a molding die. In this honeycomb structure, a large number of cells are configured by providing partition walls in a lattice shape, and the cell shape has various shapes such as a quadrangle and a hexagon.

[0003] For example, to manufacture a honeycomb structure having hexagonal cells, a mold having hexagonal lattice-like slit grooves is used. Specifically, supply holes 81 for material supply are provided.
And a die 8 having slit grooves 82 provided in a hexagonal lattice shape in communication with the supply holes 81 (see FIG. 1).

In manufacturing the mold 8, a hole forming surface 84 on which the supply hole 81 is provided and the slit groove 82 are provided.
A mold material 80 having a groove forming surface 85 provided with a groove is prepared (see FIG. 2). A supply hole 81 is provided on the hole forming surface by a drill or the like, and a hexagonal lattice-like slit groove 82 is provided on the groove forming surface by electric discharge machining so that the slit groove 82 and the supply hole 81 communicate with each other. The mold 8 is obtained.

As shown in FIG. 10, the electric discharge machining is performed by using an electric discharge machining electrode 9 provided with a grid-shaped machining surface 90 corresponding to the entire surface of a slit groove 82 to be obtained. It is performed by repeating the electric discharge through the machining fluid between the groove forming surface 85 of FIG. The supply of the machining fluid is performed from the machining fluid supply pipe 97 of the machining fluid supply jig 98 disposed on the back side of the electric discharge machining electrode 9.

[0006]

However, the above-mentioned conventional method for manufacturing a die for forming a honeycomb structure has the following problems. That is, conventionally, the processing of the slit groove 92 is as follows.
This is performed by electric discharge machining using an electric discharge machining electrode having a lattice shape corresponding to the shape of the entire slit groove to be obtained. At the time of this electric discharge machining, the electrode for electric discharge machining may be distorted or may be deformed due to uneven consumption. In this case, there is a quality problem that the depth of the obtained slit groove varies.

On the other hand, since the electrode for electric discharge machining is made of a material having a very high hardness such as a tungsten alloy, its production period requires a long period of, for example, several tens of days. Therefore, for example, when a new mold for forming a honeycomb structure is to be manufactured, it takes several tens of days to manufacture an electrode for electric discharge machining, and thereafter, the machining of the slit groove takes several tens of days. And lead to an extremely long lead time.

The present invention has been made in view of such conventional problems, and provides a method for manufacturing a die for forming a honeycomb structure, which can perform slit groove processing with high accuracy and with a short lead time. It is something to offer.

[0009]

According to the first aspect of the present invention, a plurality of supply holes for supplying a material, and a slit groove provided in a lattice shape in communication with the supply hole for forming the material into a honeycomb shape are provided. In the method for manufacturing a honeycomb structure forming die having the above-mentioned structure, the slit groove is formed by forming an electric discharge machining electrode having a processing surface having an area smaller than the area of the groove forming surface of the die material. And performing a plurality of times of electrical discharge machining using the method for manufacturing a mold for forming a honeycomb structure.

It is most remarkable in the present invention that the slit groove is subjected to electric discharge machining a plurality of times using an electric discharge machining electrode having a machining surface having an area smaller than the area of the groove forming surface of the mold material. It is to do by.

The electric discharge machining electrode has a machining surface having a smaller area than the groove forming surface as described above, and is smaller than a conventional electric discharge machining electrode. The plurality of EDMs may be repeated using one of the miniaturized EDM electrodes, or may be replaced with another small EDM electrode once or more than once. You may go.

Next, the operation and effect of the present invention will be described.
In the method for manufacturing a honeycomb structure forming die according to the present invention, the processing surface of the electrode for electric discharge machining is made smaller than the groove forming surface of the die material, and the size is reduced as compared with the related art. For this reason, the above-mentioned electrode for electric discharge machining can reduce the deformation due to strain and reduce the variation in the discharge state depending on the place during electric discharge machining, as compared with the conventional large-sized case that covers the entire grooved surface. it can. Therefore, the deformation and the wear variation become smaller than before, and the formation depth of the slit groove can be controlled accurately.

Further, as described above, since the area of the machining surface is made smaller than before, the supply and discharge of the machining fluid used during electric discharge machining can be performed more smoothly and sufficiently than before. Therefore, sludge generated by electric discharge machining and hindering the subsequent electric discharge machining can be more efficiently removed than before. Therefore, the discharge phenomenon that occurs between the electrode and the mold material is more actively performed than before, thereby improving the processing speed.

Further, as described above, since the electrode for electric discharge machining is small, the manufacturing period can be shortened as compared with the related art. Therefore, the machining of the slit groove which can be started only after the production of the electrode for electric discharge machining can be started earlier than before. Therefore, the lead time in the production of the honeycomb structure forming mold can be significantly reduced as compared with the related art (see the embodiment).

As described above, according to the present invention, it is possible to provide a method for manufacturing a die for forming a honeycomb structure, which can perform slit groove processing with high accuracy and with a short lead time.

Next, as in the second aspect of the present invention, the machining surface of the electric discharge machining electrode is formed by machining one area when the groove forming surface is divided into n areas in the width direction. The electric discharge machining is performed by repeating a plurality of times a unit machining of machining the n regions to a predetermined depth using one or a plurality of the electrodes for electric discharge machining. Is preferred.

That is, instead of processing each of the above-mentioned regions to a desired depth by one electric discharge machining, first,
It is preferable that the entire groove forming surface is processed to a predetermined depth by the unit processing, and then the unit processing is repeated to increase the groove depth. In this way, by performing electric discharge machining stepwise in multiple steps not only in the width direction but also in the depth direction, individual local machining variations can be suppressed, and the machining accuracy of the slit groove is further improved. Can be done.

According to the third aspect of the present invention, in the unit machining, first, a central region located at a substantially central portion of the n regions is subjected to electric discharge machining, and then the unit region is close to the central region. It is preferable to process sequentially from the side. In this case, a change in the width of the slit groove due to a slight processing variation can be made substantially symmetrical. Therefore, the moldability when forming a honeycomb structure using the obtained honeycomb structure forming mold can be improved.

According to a fourth aspect of the present invention, in the machining surface of the electric discharge machining electrode, all portions contributing to machining have a lattice shape corresponding to the lattice shape of the slit groove. Therefore, it is preferable not to have an incomplete side portion that does not form a lattice. In this case, the machining accuracy at the boundary between adjacent electric discharge machining portions can be improved.

According to a fifth aspect of the present invention, in the second and subsequent electric discharge machining of the plurality of electric discharge machining, at least one of the lattices of the machining surface is replaced by the lattice formed by the previous electric discharge machining. It is preferable to perform the process by moving the electric discharge machining electrode so that the two overlap. In this case, it is possible to prevent misalignment of the resulting lattice of the slit grooves.

According to a sixth aspect of the present invention, the electric discharge machining electrode is provided with a machining fluid supply jig for supplying a machining fluid for electric discharge machining. It is preferable that the jig is provided with two or more processing liquid jet ports. In this case, the supply of the machining fluid to the machining surface can be made uniform to improve the sludge removal effect, thereby making the discharge uniform. Therefore, the processing accuracy of the slit groove can be further improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 A method for manufacturing a honeycomb structure forming die according to an embodiment of the present invention will be described with reference to FIGS. In this example, as shown in FIG. 1, a plurality of supply holes 81 for material supply are provided.
And a slit 8 provided in a lattice shape in communication with the supply holes 81 and formed into a honeycomb shape to form a material into a honeycomb shape. The processing of the slit groove 81 is as shown in FIGS.
The groove forming surface 85 of the mold material 80 is subjected to electric discharge machining a plurality of times by using the small electric discharge machining electrode 1 having the machining surface 10 having an area smaller than the area of the groove forming surface 85.

Hereinafter, this will be described in detail. The honeycomb structure forming die 8 manufactured in this example has a hexagonal lattice-like slit groove 81 as shown in FIG. In manufacturing the mold 8 for forming a honeycomb structure, first, as shown in FIG. 2A, a mold material 80 having a groove forming surface 85 and a hole forming surface 84 on both sides is prepared.

Next, as shown in FIG. 2B, a large number of supply holes 81 are formed in the hole forming surface 84 of the die material 80 by drilling. Thereafter, as shown in FIGS. 2C and 6, hexagonal lattice-shaped slit grooves 82 are formed by electric discharge machining.

In the electric discharge machining, as shown in FIGS. 3 and 4, a small electric discharge machining electrode 1 is used. In the electrode 1 for electric discharge machining of this embodiment, the length L of the machining surface 10 is 80
The width (diameter) R of the groove forming surface 85 is larger than the width (diameter) R of the groove forming surface 85, but the width W of the processing surface 10 is smaller than the width R of the groove forming surface 85.

More specifically, the processing surface 1
At 0, 15 rows of hexagonal lattices 15 are provided in the width direction to make the width dimension W. The width W is determined by the groove forming surface 8.
5 is about 1/9 of the width R. In addition, the machining surface 10 of the electric discharge machining electrode 1 has a hexagonal lattice shape in all portions contributing to machining, and does not have an incomplete side portion where a lattice is not formed. Specifically, as shown in FIG. 4 (a), all the end portions of the processing surface 10 are also hexagonal grid-like electrodes, and do not form a hexagonal shape as shown in FIG. 4 (b). It does not have the complete edge 109. Further, the hexagonal lattice of the machining surface 10 in the electrode 1 for electric discharge machining is provided so as to penetrate to the back surface 19.

As shown in FIG. 5, a machining fluid supply jig 5 is provided on the back surface 19 of the electric discharge machining electrode 1. The processing liquid supply jig 5 has a 7
Supply pipes 55 are connected, and 7
A machining fluid jet (not shown) at a location is provided on the electrode contact surface. On the upstream side of the seven supply pipes 55, each supply pipe 55
A branch jig 56 for adjusting the distribution of the processing fluid to the nozzle and the flow rate thereof is connected. The branch jig 56 is connected to a feed pipe 58 for feeding a working fluid from further upstream, and is provided with seven knobs 57 for adjusting the flow rate of each supply pipe 55.

The electric discharge machining electrode 1 provided with the machining fluid supply jig 5 is used by being set in an electric discharge machining apparatus 6 as shown in FIG. The electric discharge machining device 6 has a table 61 on which a mold material 80 is set, and a head 62 for holding the electrode 1 for electric discharge machining. Head 62
As shown in FIG. 5, the electric discharge machining electrode 1 and the machining fluid supply jig 5 are fixed to the ends thereof, and are provided so as to be movable up, down, left and right.

Next, a procedure for forming a slit groove in the groove forming surface 85 of the mold material 80 will be described with reference to FIG. First, as shown in the figure, the groove forming surface 85 is divided into nine regions S1 to S9 in the width direction. These areas S1 to
The width of S9 is set to a width slightly smaller than the width W of the machining surface 10 of the electric discharge machining electrode 1.

Electric discharge machining is performed on these nine regions S1 to S9 using the electric discharge machining electrode 1 described above. In this example, after the electric discharge machining is performed to a desired slit groove depth in one region, the electric discharge machining electrode 1 is moved to an adjacent region, and the electric discharge machining is performed again to a desired slit groove depth D (FIG. 1A). I do. By repeating this electric discharge machining nine times, the machining of the slit groove 82 is completed.

The electric discharge machining electrode 1 was moved so that at least one row of the grid on the machining surface 10 overlapped the grid formed by the previous electric discharge machining.
Specifically, as shown in FIG. 8, a case where a new slit groove grid B (FIG. 8B) is formed next to a slit groove grid A (FIG. 8A) which has been previously subjected to electric discharge machining. Has
The electric discharge machining electrode 1 was moved so that the grids C for both rows overlapped each other.

The electric discharge machining electrode 1 is replaced with a new one according to the state of wear. For example, if the EDM electrodes 1 are replaced every two EDMs, a total of four EDM electrodes 1 will be used.

Next, the operation and effect of this embodiment will be described. In the method for manufacturing the honeycomb structure forming die of this example,
The machining surface 10 of the electrode 1 for electric discharge machining is made much narrower than in the prior art to reduce the size. Therefore, the electrode for electric discharge machining 1
Deformation due to distortion can be made smaller than before,
In addition, it is possible to reduce the variation in the discharge state depending on the place during the electric discharge machining. Therefore, the deformation and wear variation of the electrode for electric discharge machining 1 are smaller than those in the related art.

In particular, in the present embodiment, the working fluid jet is
Since the portions are also provided, a sufficient amount of the working fluid can be supplied to the working portion in a uniform state. Therefore, by improving the sludge removal effect, the discharge state during electric discharge machining can be made more uniform. Therefore, uneven wear of the electrode can be further suppressed, and the formation depth of the slit groove can be accurately controlled.

In this embodiment, the electrode 1 for electric discharge machining is used.
No incomplete side portion is provided on the processed surface 10 of FIG. In the second and subsequent electric discharge machining operations of the plurality of electric discharge machining operations, the electric discharge machining electrode 1 is moved so that one row of the grid on the machining surface overlaps the grid formed by the previous electric discharge machining. Do it. For this reason, it is possible to prevent the resulting misalignment of the lattice of the slit groove, and it is possible to improve the machining accuracy at the boundary portion of the repeated electric discharge machining.

Further, as described above, it is possible to reduce the variation in electric discharge depending on the place where the electric discharge machining is performed.
Further, as described above, by making the area of the machining surface 10 smaller than before, the supply and discharge of the machining fluid used during electric discharge machining can be performed more smoothly and sufficiently than before. Therefore, sludge generated by electric discharge machining and hindering the subsequent electric discharge machining can be more efficiently removed than before. Therefore, the discharge phenomenon that occurs between the electrode and the mold material is more actively performed than before, thereby improving the processing speed.

Further, since the electrode for electric discharge machining is smaller than before, the manufacturing period can be greatly shortened as compared with the conventional case. Therefore, the processing of the slit groove can be started earlier than before, and as a result, the lead time in the production of the die for forming the honeycomb structure can be greatly reduced as compared with the conventional case.

The effect of shortening the lead time will be described more specifically with reference to FIG. In the figure, the elapsed time is shown on the horizontal axis, and each process is shown in time series with arrows. The upper part shows a case of manufacturing a conventional large-sized (integrated type) electric discharge machining electrode, and the lower part shows a case of manufacturing a small-sized electric discharge electrode 1 of this example.

As can be seen from the figure, in the conventional case, the production A of the electrode for electric discharge machining is 50 days, the production of the die material 80 and the processing of the supply hole (material processing) B are 15 days, and the slit groove processing is performed. C1 is 55 days. Here, since the material processing B can be performed in parallel with the production A of the electrode for electric discharge machining, the production lead time of the die for forming the honeycomb structure is 10% of A + C1.
It was five days.

On the other hand, in the case of the present embodiment, considering the case where four electric discharge machining electrodes 1 are used, the manufacture of each of the electric discharge machining electrodes 1 to A4 is carried out for 7 days on each of the mold blanks 80. And the supply hole processing (material processing) B is 15 days, and the slit groove processing C2 is 28 days. Here, the processing of the slit groove can be started at the time when the manufacture A1 and the material processing B of one electric discharge machining electrode 1 are completed. Therefore, the manufacturing lead time of the honeycomb structure forming die of this example is B +
It is 43 days of C2.

Therefore, in this embodiment, a lead time reduction of about 60 days can be realized. The reason why the above-mentioned slit groove processing C2 period is shorter than before is that the sludge elimination effect is improved with the improvement of the supply and discharge capacity of the processing liquid due to the downsizing of the processing surface, as described above. This is a major factor.

As described above, according to the present embodiment, it is possible to provide a method for manufacturing a die for forming a honeycomb structure, in which slit grooves can be processed with high precision and with a short lead time.

Embodiment 2 This embodiment is a specific example in which the order of a plurality of electric discharge machining in Embodiment 1 is changed. That is, in this example, the above 9
For each of the regions S1 to S9, unit machining is performed by performing electric discharge machining to a depth of 1/4 of the desired slit groove depth D (FIG. 1). Was machined to the desired depth D. The electric discharge machining electrodes 1 were replaced with new ones for each unit machining, and a total of four electrodes were used.

In this example, the unit machining is
Of the nine regions, the central region S5 located at the central portion was first subjected to electrical discharge machining, and then sequentially processed from the side closer to the central region. Specifically, in FIG.
4, S6, S3, S7, S2, S8, and S9 were processed in this order.

In the case of the present embodiment, the above-mentioned regions S1 to S9 are not subjected to one-time electric discharge machining to form a groove to a desired depth, but the unit machining is repeated to increase the groove depth. By this stepwise electric discharge machining, individual local machining variations can be suppressed, and the machining accuracy of the slit groove can be further improved.

Further, by performing the above-mentioned unit processing in the above-described order, it is possible to make the change of the slit groove width or the like due to minute processing variation substantially symmetrical. Therefore, the moldability when forming the honeycomb structure using the obtained honeycomb structure forming mold can be improved. Otherwise, the same operation and effect as those of the first embodiment can be obtained.

In each of the above embodiments, the case where the lattice shape of the slit groove is a hexagonal shape has been described.
Similar effects can be obtained in other shapes such as a square shape, an octagonal shape, and the like.

[Brief description of the drawings]

FIG. 1A is a partially cutaway perspective view of a mold for forming a honeycomb structure according to a first embodiment, and FIG.

FIG. 2 is an explanatory view showing a procedure for manufacturing a honeycomb structure forming mold according to the first embodiment.

FIG. 3 is a perspective view of an electric discharge machining electrode according to the first embodiment.

FIGS. 4A and 4B show (a) no incomplete edge in the first embodiment;
(B) Explanatory drawing which shows the specific example of the existence of an incomplete side.

FIG. 5 is an explanatory view showing a connection state between an electric discharge machining electrode and a machining fluid supply jig in the first embodiment.

FIG. 6 is an explanatory view showing an electric discharge machine according to the first embodiment.

FIG. 7 is an explanatory diagram showing divided regions of electric discharge machining in the first embodiment.

FIG. 8 is an explanatory view showing a movement position of an electric discharge machining electrode in the first embodiment.

FIG. 9 is an explanatory diagram showing a lead time shortening effect in the first embodiment.

FIG. 10 is an explanatory view showing an electric discharge machining electrode in a conventional example.

[Explanation of symbols]

 1. . . 9. electrode for electric discharge machining, . . Processing surface, 5. . . 5. Jig for supplying working fluid, . . 7. EDM machine, . . 80. A die for forming a honeycomb structure, . . Mold material, 81. . . Supply hole, 82. . . Slit groove, 84. . . Hole forming surface, 85. . . Groove forming surface,

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshiyasu Ando 1-1-1, Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 3C059 AA01 AB01 EC01 HA09 HA20 4G054 AB09 BD19

Claims (6)

[Claims] 1. A die for forming a honeycomb structure having a plurality of supply holes for supplying a material and slit grooves provided in a lattice shape in communication with the supply holes for forming the material into a honeycomb shape. In the method of forming a slit groove, the groove forming surface of the mold material is subjected to electric discharge machining a plurality of times by using a small electric discharge machining electrode having a processing surface having an area smaller than the area of the groove forming surface. A method for manufacturing a honeycomb structure forming mold. 2. The electric discharge machining electrode according to claim 1, wherein the machining surface of the electric discharge machining electrode has a size enough to process one area when the groove forming surface is divided into n areas in the width direction. And the electric discharge machining is performed by repeating a plurality of times of unit machining of machining each of the n regions to a predetermined depth using the electric discharge machining electrode. Mold manufacturing method. 3. The unit machining according to claim 2, wherein, in the unit machining, a central region located at a substantially central portion of the n regions is first subjected to electric discharge machining, and then sequentially machined from a side closer to the central region. A method for manufacturing a honeycomb structure forming die. 4. The method according to claim 1, wherein:
The machining surface of the electric discharge machining electrode has a lattice shape corresponding to the lattice shape of the slit groove in all portions contributing to machining, and does not have an incomplete side portion that does not form a lattice. A method for manufacturing a honeycomb structure forming mold, comprising: 5. The method according to claim 1, wherein:
Of the above multiple EDMs, the second and subsequent EDMs are:
A method for manufacturing a die for forming a honeycomb structure, comprising: moving the electrode for electric discharge machining so that at least one of the lattices on the machining surface overlaps a lattice formed by previous electric discharge machining. 6. The method according to claim 1, wherein:
The electric discharge machining electrode is provided with a machining fluid supply jig for supplying a machining fluid for electric discharge machining, and the machining fluid supply jig is provided with two or more machining fluid jets. A method for manufacturing a die for forming a honeycomb structure, comprising: