JP2009008073A - Exhaust gas purification device processing method - Google Patents

Abstract

An object of the present invention is to provide a chucking technique suitable for spinning a semi-finished product in which a columnar catalyst is inserted into a cylindrical body via a mat as a starting material.
As shown in FIG. (A), the semi-finished product is gently clamped by at least eight pressing pieces. Then, the spinning roller 53 is allowed to face one end of the semi-finished product 10. Then, as shown in (b), the exhaust gas purifying device 54 is obtained by reducing the diameter of one end while pressing the spinning roller 53.
[Effect] When chucking is performed with a pressing piece whose circumference is divided into 8 or more, chucking can be performed while suppressing flattening of the cylindrical body. Therefore, there is no concern that a compressive force acts locally on the catalyst, and the catalyst can be prevented from being damaged.
[Selection] Figure 8

Description

  The present invention relates to a processing technique of an exhaust gas purifying apparatus that performs spinning processing on a cylinder end.

  Various exhaust gas purification apparatuses are put into practical use as effective means for clearing exhaust gas regulations. Among them, an exhaust gas purifying apparatus for a vehicle is widely adopted to have a structure in which a catalyst is surrounded by a cylinder in order to intervene in an exhaust pipe of a vehicle. In order to exert the purification action, the diameter of the catalyst becomes larger than the diameter of the exhaust pipe. Therefore, it is necessary to reduce the diameter of the end of the cylinder surrounding the catalyst so as to match the diameter of the front and rear exhaust pipes.

The diameter reduction is performed, for example, by spinning (for example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 2002-239657 (FIG. 5)

Patent document 1 is demonstrated based on the following figure.
FIG. 10 is a view for explaining a conventional spinning method. As shown in FIG. 10B, the cylindrical body 101 is clamped by a lower clamp 102 and an upper clamp 103. FIG. Next, the one end 105 and the other end 106 are reduced in diameter by rotating the spinning rolls 104, 104, 104, 104 against the one end 105 and the other end 106 of the cylinder 101.
Such processing is called spinning processing or spatula drawing.

In the spinning process, the spinning roll 104 is strongly pressed against the one end 105 and the other end 106 of the cylinder 101, so that a large external force (bending force or twisting force) is applied to the cylinder 101.
Therefore, as shown in (a), the cylinder 101 is strongly sandwiched between the lower clamp 102 and the upper clamp 103 so that the cylinder 101 does not move.

  FIG. 11 is a diagram for explaining the problem of the conventional clamp. In FIG. 10B, the catalyst and the mat are omitted. However, in the case of an exhaust gas purifying apparatus, a columnar catalyst 109 is inserted into the cylinder body 101 via the mat 108. As is clear from FIG. 10B, the catalyst 109 cannot be inserted into the cylinder 101 after the both ends are reduced in diameter.

Therefore, as shown in FIG. 11, the semi-finished product 110 in which the columnar catalyst 109 is inserted into the cylindrical body 101 via the mat 108 is produced before the spinning process. Next, the semi-finished product 110 is subjected to a spinning process.
That is, the semi-finished product 110 is strongly sandwiched between the lower clamp 102 and the upper clamp 103. Then, a spinning process is performed.

In the spinning process, the semi-finished product 110 can be fixed more securely as the clamping force by the lower clamp 102 and the upper clamp 103 is larger.
Therefore, in actual work, the upper clamp 103 is strongly pressed against the lower clamp 102.

  When the clamping force increases, the cylinder body 101 becomes elliptical in a horizontally long manner. As a result, a compressive force is applied to the catalyst 109 up and down. This compressive force can be absorbed by the mat 108 to some extent, but if it exceeds that, it acts as a compressive force on the catalyst.

  The catalyst 109 is made of honeycomb ceramics, and the honeycomb includes a hole and a wall surrounding the hole. Any attempt to increase the contact area with the exhaust gas will inevitably become thinner. As a result, when an excessive compressive force is applied, defects such as cracks in thin walls occur.

If the clamping force by the lower clamp 102 and the upper clamp 103 is weakened in order to avoid the occurrence of cracks, the semi-finished product 110 moves during the spinning process.
That is, it can be said that the chuck structure described in Patent Document 1 (FIG. 5) is inappropriate for clamping the semi-finished product 110 in which the catalyst 109 is housed in the cylinder 101.

  The present invention provides a chuck technique suitable for spinning a semi-finished product with a column-shaped catalyst inserted through a mat and a semi-finished product having a variation in outer diameter as a starting material. It is an issue to provide.

The invention according to claim 1 comprises a step of obtaining a semi-finished product obtained by winding a mat around a columnar catalyst and inserting the mat into a cylinder, and reducing the diameter of the cylinder by a diameter reducing device and plastically deforming the cylinder. A chucking step of chucking the outer peripheral surface of the semi-finished cylinder transferred from the apparatus to the chuck apparatus with a plurality of pressing pieces, and reducing or expanding the diameter by pressing a spinning roller against the end of the cylinder in the chucked state In the processing method of the exhaust gas purification device comprising the spinning process,
Record the difference between the outer diameter of the semi-finished product before removing from the diameter reducing device and the outer diameter of the semi-finished product after removing from the diameter reducing device,
In the chucking process, the amount of advancement of the pressing piece is controlled so as not to exceed 1/2 of the recorded difference.

  The invention according to claim 2 is characterized in that a sprayed film formed by spraying is formed on a contact surface where the pressing piece hits the cylinder.

  The invention according to claim 3 is characterized in that the pressing piece is advanced by hydraulic pressure, and the hydraulic pressure of the same pressure is applied to the plurality of pressing pieces.

In the invention according to claim 1, the difference between the outer diameter of the semi-finished product before being removed from the diameter reducing device and the outer diameter of the semi-finished product after being removed from the diameter reducing device is recorded. The amount of advance is controlled so as not to exceed 1/2 of the recorded difference.
When the semi-finished product is removed from the diameter reducing device, the outer diameter increases due to the springback phenomenon. If the diameter is reduced in the chucking process by this amount of springback or less, there is no fear of adversely affecting the catalyst. That is, in the chucking process, if the advance amount of the pressing piece is controlled so as not to exceed 1/2 of the recorded difference, the chucking can be performed without adversely affecting the catalyst.

  In the invention which concerns on Claim 2, the sprayed film is formed in the contact surface where a press piece contacts a cylinder. The sprayed film has inevitable irregularities on the surface, and the coefficient of friction increases. When the cylinder is chucked with the pressing piece, the thermal spray film having a large friction coefficient comes into contact with the outer peripheral surface of the cylinder, so that the chucking force is increased. As a result, the pressing force can be reduced, and the damage to the catalyst can be avoided more reliably.

  In the invention which concerns on Claim 3, a press piece is moved hydraulically. The hydraulic pressure is the same by a plurality of pressing pieces. As a result, a plurality of pressing pieces can be pressed against the cylinder evenly.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is an explanatory view of a process of obtaining a semi-finished product. As shown in FIG. 1A, a mat 12 is wound around a columnar catalyst 11 and inserted into a metal cylinder 13. Next, as shown in (b), the cylindrical body 13 is reduced in diameter by the reduced diameter pieces 16 and 16 of the diameter reducing device 15 until the outer diameter becomes D1, and is plastically deformed. When the reduced diameter pieces 16, 16 are removed, a semi-finished product 10 as shown in (c) can be obtained.

When the diameter-reduced pieces 16, 16 are removed, the cylindrical body 13 is slightly returned (this phenomenon is referred to as springback), and the semi-finished product 10 has a slightly larger outer diameter D2.
That is, the outer diameter of the semi-finished product before being removed from the diameter reducing device 15 is D1, and the outer diameter of the semi-finished product after being removed from the diameter reducing device 15 is D2.

  FIG. 2 is a cross-sectional view for explaining the structure of the semi-finished product and the chuck device according to the present invention. The chuck device for chucking the semi-finished product 10, that is, the chuck device 20 for processing the exhaust gas purification device, A slide cylinder 23 inserted in a large hole 22 opened laterally in the case 21 so as to be movable left and right in the drawing, a piston portion 24 integrally formed in a bowl shape on the outer periphery of the slide cylinder 23, and the piston portion 24, a first lid 28 and a second lid 29 that are attached to the case 21 with bolts 25, 25 to form a first oil chamber 26 and a second oil chamber 27, and a first oil chamber 26 that is formed to penetrate the case 21. A first oil passage 31 connected to the first oil passage 31, a second oil passage 32 penetratingly formed in the case 21 and connected to the second oil chamber 27, and tapered grooves 33, 3 provided on the inner periphery of the slide cylinder 23 If, consisting pressing piece 34 Metropolitan being inserted movably in the drawings the left and right of these tapered grooves 33, 33.

The pressing piece 34 is a divided piece divided into at least eight pieces on the circumference. The basis for the number of divisions will be described later.
Since the slide cylinder 23 is inserted into the hole 22 of the case 21 through the O-ring 36 fitted to the piston portion 24, there is a concern that it will rotate. Therefore, the slide cylinder 23 is connected to the first lid 28 via the arm 37 and the guide pin 38 to prevent rotation.

  Further, a plate 39 is provided on the left end surface of the pressing piece 34 and a stopper ring 41 is provided on the second lid 29. By restricting the movement of the plate 39 by the stopper ring 41, the pressing piece 34 comes out of the tapered groove 33. I tried not to. The relationship between the taper groove 33 and the pressing piece 34 will be described with reference to the next figure.

  FIG. 3 is a diagram for explaining the relationship between the taper groove and the pressing piece. The taper groove 33 is tapered in the front and back direction of the drawing, and left and right side grooves 42 and 42 are provided at the back of the groove (upward in the figure). It is a T-shaped groove. The pressing piece 34 has ridges 43, 43 that are loosely fitted into the side grooves 42, 42, and there is no fear that the pressing piece 34 will come out downward. That is, the pressing piece 34 is supported by the slide cylinder 23 so as to be movable in the front and back direction of the drawing.

  The tip (downward in the drawing) of the pressing piece 34 is an arch portion 44, and a sprayed film 47 is formed on the contact surface 46. The arch portion 44 is a divided piece obtained by dividing the ring into at least eight pieces together with the adjacent arch portions 44 and 44 indicated by imaginary lines. Therefore, the central angle θ formed by the radiation 51 and 51 passing through the center 49 of the slide cylinder 23 is represented by 360 ° / n (n is the number of divisions). In this example, since n is 8, θ is 45 °. The gap δ between the arch portions 44 and 44 is a clearance provided so that the arch portions 44 and 44 do not hit each other when the pressing piece 34 moves to the center 49 for diameter reduction.

FIG. 4 is a cross-sectional view of the pressing piece, and a sprayed film 47 is formed on the contact surface 46 of the pressing piece 34.
FIG. 5 is a view taken in the direction of arrow 5 in FIG. 4, and the sprayed film 47 is formed only on the contact surface 46, and is not formed on other portions of the pressing piece 34. Since the sprayed film 47 is provided only in a necessary portion, the spraying cost can be suppressed. Reference numeral 48 denotes an oil sump groove.

6 is an enlarged view of 6 parts of FIG. 4. The sprayed film 47 is formed by dissolving hard fine particles at a high temperature and spraying it on the surface of the pressing piece 34, and unavoidably on the outer surface. Unevenness 52 is generated. By further blasting the outer surface, it can be adjusted to an arbitrary roughness.
For example, the hard fine particles are a hard metal, tungsten carbide (WC), the film thickness is 70 μm, blasting is performed, and Ra (arithmetic average roughness) is adjusted to 5 to 7 μm.

Next, the operation of the chuck device 20 described above will be described.
FIG. 7 is an explanatory diagram of the operation of the chuck device according to the present invention, and supplies pressure oil to the first oil chamber 26 via the first oil passage 31 as indicated by an arrow (1). Then, as shown by arrows (2) and (2), the slide cylinder 23 moves to the left in the figure. Then, the pressing pieces 34 and 34 chuck the semi-finished product 10 as shown by arrows (3) and (3) by the taper action.

The higher the oil pressure in the first oil chamber 26 is, the more the slide cylinder 23 moves to the left, and the semi-finished product 10 can be strongly clamped. Therefore, the clamping force can be controlled by controlling the oil pressure in the first oil chamber 26.
Since the catalyst 11 incorporated in the semi-finished product 10 is fragile, the oil pressure is controlled so that the clamping force does not damage the catalyst 11.
That is, the outer periphery of the cylinder within the movable range of the pressing piece can always be chucked with a constant clamping force.

FIG. 8 is a diagram for explaining a chucking process and a spinning process according to the present invention.
As shown in (a), the semi-finished product 10 is gently clamped with at least eight pressing pieces 34. Then, the spinning rollers 53, 53, 53 are allowed to face one end of the semi-finished product 10.
And as shown to (b), the exhaust gas purification apparatus 54 can be obtained by reducing the diameter of one end, pressing the spinning rollers 53, 53, 53.

Next, the main part of the processing method according to the present invention will be described in detail.
First, an experiment was conducted to examine the relationship between D1 and D2 shown in FIG.
A plurality of catalysts having an outer diameter of 80 mm to 120 mm (applicable to engines having a displacement of 660 cc to 4500 cc) are prepared. Each of these catalysts was wound with a mat, inserted into a steel cylinder, and subjected to a diameter reducing device to reduce the diameter.

As described above, when the outer diameter of the cylindrical body before removal from the diameter reducing device is D1, and the outer diameter of the cylindrical body after removal from the diameter reducing device is D2, the springback amount is (D2-D1). Is determined.
According to said experiment, (D2-D1) was 0.22 mm-0.32 mm.

  In the next process (chucking process), when the cylinder is chucked, the outer diameter of the cylinder is D2, so no problem occurs even if the diameter is reduced to D1. Therefore, the amount of advancement of the pressing piece in the chucking process is limited to 0.11 mm which is 1/2 of the minimum value of 0.22 mm.

  That is, in the processing method of the present invention, as shown in FIG. 1, a mat 12 is wound around a columnar catalyst 11 and inserted into a cylinder 13, and the cylinder 13 is reduced in diameter by a diameter reducing device 15 to be plastically deformed. As shown in FIG. 8 (a), the outer peripheral surface of the cylindrical body 13 is pressed a plurality of times for the step of obtaining the semi-finished product 10 and the semi-finished product 10 transferred from the diameter reducing device 15 to the chuck device 20. Processing of the exhaust gas purification device 54 comprising a chucking process of chucking with the piece 34 and a spinning process of reducing the diameter by pressing the spinning roller 53 against the end of the cylindrical body 13 in the chucked state as shown in FIG. In the method, the difference (D2-D1) between the outer diameter D1 of the semi-finished product before being removed from the diameter reducing device 15 and the outer diameter D2 of the semi-finished product after being removed from the diameter reducing device 15 is recorded, and the chucking process Then, the advance amount of the pressing piece is the recorded difference (D2 And controlling so as not to exceed 1/2 of D1).

  In the chucking process, if the advance amount of the pressing piece is controlled so as not to exceed 1/2 of the recorded difference, the chucking can be performed without adversely affecting the catalyst.

Next, the number (number of divisions) of the pressing pieces 34 shown in FIG. 8 will be examined.
As is well known, since the catalyst is a fired product of ceramics, the outer diameter size varies. When the diameter of the cylinder is reduced in consideration of the actual dimensions of the catalyst, the outer diameter of the cylinder after the diameter reduction also varies.
FIG. 9 is a schematic diagram showing the relationship between the cylinder and the pressing piece. As shown in FIG. 9A, the pressing piece 34 has a radius of curvature of (D2mean / 2). When the cylindrical body 13 having an outer diameter of D2max comes into contact with such a pressing piece 34, it comes into contact at points A and B due to the difference in radius. As a result, a gap of δa is generated at the center.

  δa can be obtained geometrically. The calculation method will be briefly described. As shown in (b), the difference h1 between the string connecting the point A and the point B and the arc is radius-radius × cos (θ / 2) = (D2max / 2) · (1−cos (θ / 2)). Similarly, the difference h2 is obtained by (D2mean / 2) · (1-cos (θ / 2)). The difference between h1 and h2 is δa.

  For example, if θ = 90 ° (corresponding to 4 divisions) and D2max = 134 mm, h1 = (D2max / 2) · (1-cos (θ / 2)) = (134/2) · (1-cos ( 90/2)) = 67 × 0.293 = 19.623 According to the calculation, h1 becomes 19.623 mm.

If D2mean = 132 mm, h2 = (D2mean / 2) · (1-cos (θ / 2)) = (132/2) · (1-cos (90/2)) = 66 × 0.293 = 19 According to the calculation of .331, h2 becomes 19.331 mm.
As a result, δa is 0.292 mm (= 19.623-19.331).

The D2max has been described above. Next, D2min will be described.
As shown in (c), when the cylinder outside 13 has a small diameter, gaps δb and δb are generated at both ends of the pressing piece 34. The gap δb can be calculated geometrically in the same manner as the gap δa, but the gap δa is directed to the center of the cylindrical body 13 whereas the gap b is directed to the center of the cylindrical body 13. Absent. Although detailed calculation was omitted, the gap b was about 10% larger than the gap a.

  The calculation described above was also performed for the changed θ. The results are shown in the following table.

  By the way, in Fig.9 (a), if the press piece 34 is advanced, the cylinder 13 will be displaced toward the center at the point a and the point b. Assuming that the pressing piece 34 is a rigid body, the gap δa approaches 0 as the displacement at the points a and b proceeds. If the gap δa becomes 0, it is considered that the pressing piece 34 hits the entire cylindrical body 13 and the diameter reducing effect on the cylindrical body 13 becomes small enough to be ignored.

  Since the gap δa is closely related to the deformation of the cylindrical body 13 in the chucking process, the gap δa is preferably as small as possible. If the gap δa is within the above-described range of the springback amount, it can be considered that the built-in catalyst is not adversely affected. The same applies to the gap δb.

  In the above description, when the outer diameter of the catalyst is in the range of 80 to 120 mm, the actual measured value of the springback amount (D2-D1) is in the range of 0.22 to 0.32 mm. Since this springback amount is determined by the diameter, it can be compared with δa and δb by halving. Therefore, the reference value of δa and δb is set to 0.110 mm which is half of the springback amount and the minimum value.

  In Table 1, when the number of divisions was 4, θ was 90 ° and δa was 0.292 mm as described above. δb increases by 10% to 0.321 mm. This 0.321 mm exceeds the control value of 0.110 mm. That is, at 0.321 mm, if the pressing piece is advanced, the catalyst may be adversely affected. Therefore, the determination is x.

In the case of the division number 6, δb is 0.147 mm, which exceeds the control value of 0.110 mm. Therefore, the determination is x.
In the case of the division number 8, δb is 0.084 mm, which is less than the control value 0.110 mm. Therefore, the determination is “good”.
In the case of the division number 12, δb is 0.037 mm, which is less than the control value 0.110 mm. Therefore, the determination is “good”.
In the case of the division number 16, δb is 0.021 mm, which is less than the control value 0.110 mm. Therefore, the determination is “good”.

From the above description, the configuration of the chuck device according to the present invention can be summarized as follows.
A semi-finished product 10 (FIG. 1) obtained by winding a mat 12 around a columnar catalyst 11 and inserting it into a cylinder 13 and reducing the diameter of the cylinder 13 by a diameter reducing device 15 and plastically deforming the cylinder 13 is reduced. When the spinning roller 53 is pressed against the end of the cylindrical body 13 while the outer peripheral surface of the cylindrical body 13 of the semi-finished product 10 taken out is chucked by the plurality of pressing pieces 34 (FIG. 8). A chuck device 20 for processing an exhaust gas purifying device that chucks the outer peripheral surface of the cylinder 13, wherein the pressing piece is divided into at least eight pieces on the circumference under the following conditions. And

  Under the above-mentioned conditions, an equal pressure can be obtained by dividing the eight pieces. As a result, there is no concern that a compressive force acts locally on the catalyst, and the catalyst can be prevented from being damaged.

Next, an experiment was performed on the sprayed coating performed in the present invention.
Experiments 1-2:
The number of divisions of the pressing pieces was 8, and these pressing pieces were advanced by a hydraulic pressure of 1.5 to 3.0 MPa to chuck the semi-finished product, and this semi-finished product was subjected to spinning processing.

In Experiment 1, a pressing piece without a sprayed film was used. A good chuck could be achieved with a hydraulic pressure of 3.0 MPa.
In Experiment 2, a pressing piece with a sprayed film was used. A good chuck could be achieved with a hydraulic pressure of 1.5 MPa.

  That is, the oil pressure could be lowered by applying the sprayed film. Since the sprayed film has fine irregularities, it is considered that the friction coefficient of the pressing piece could be increased by applying the sprayed film. If the hydraulic pressure can be reduced, the diameter reduction of the cylinder during chucking can be reduced, and damage to the internal catalyst can be prevented more reliably.

  In addition, although the diameter reduction process was demonstrated in the Example, the spinning process may be a diameter expansion process.

  The present invention is suitable for manufacturing a cylindrical exhaust gas purification device mounted on an exhaust pipe of a vehicle.

It is explanatory drawing of the process of obtaining a semi-finished product. It is sectional drawing explaining the structure of the semi-finished product and chuck | zipper apparatus which concern on this invention. It is a figure explaining the relationship between a taper groove and a pressing piece. It is sectional drawing of a pressing piece. FIG. 5 is a view taken in the direction of arrow 5 in FIG. 4. FIG. 6 is an enlarged view of 6 parts in FIG. 4. It is operation | movement explanatory drawing of the chuck apparatus which concerns on this invention. It is a figure explaining the chuck | zipper process and spinning process which concern on this invention. It is a schematic diagram which shows the relationship between a cylinder and a press piece. It is a figure explaining the conventional spinning processing method. It is a figure explaining the problem of the conventional clamp.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Semi-finished product, 11 ... Catalyst, 12 ... Mat, 13 ... Cylindrical body, 15 ... Diameter reduction device, 20 ... Chuck apparatus for processing exhaust gas purification device, 34 ... Pressing piece, 46 ... Contact surface, 47 ... Sprayed film 53 ... Spinning roller, 54 ... Exhaust gas purification device.

Claims (3)

A step of obtaining a semi-finished product obtained by winding a mat around a columnar catalyst and inserting it into a cylinder, reducing the diameter of the cylinder with a diameter reducing device and plastically deforming the cylinder, and moving the cylinder from the diameter reducing device to the chuck device Exhaust gas purification comprising a chucking process for chucking the outer peripheral surface of a semi-finished cylinder with a plurality of pressing pieces, and a spinning process for reducing or expanding the diameter by pressing a spinning roller against the end of the cylinder in the chucked state. In the processing method of the device,
Record the difference between the outer diameter of the semi-finished product before removing from the diameter reducing device and the outer diameter of the semi-finished product after removing from the diameter reducing device,
In the chucking process, the amount of advance of the pressing piece is controlled so as not to exceed 1/2 of the recorded difference.   The processing method of the exhaust gas purification apparatus according to claim 1, wherein a sprayed film formed by thermal spraying is formed on a contact surface where the pressing piece hits the cylindrical body.   3. The processing method for an exhaust gas purifying apparatus according to claim 1, wherein the pressing piece is advanced by hydraulic pressure, and the same pressure is applied to the plurality of pressing pieces.

Images