JP2005096007A - Barrel polishing method for engine accessory parts - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a barrel polishing method for effectively performing surface polishing to sufficiently reduce surface roughness on the hollow part inner surface of an engine accessory part. <P>SOLUTION: In the method of barrel-polishing the hollow part inner surface of a hollow engine accessory part W, the engine accessory part W is put in a tank 7 of an exciting device 6 together with mixed abrasive grains 1 obtained by mixing spherical abrasive grains 2 and nonspherical abrasive grains 3, a compound solution and a polishing medium mixed with water, and the tank 7 is excited to rotate the engine accessory part W together with the polishing medium 9 and to lead the polishing medium 9 to the inside of the engine accessory part W at the same time to polish the hollow part inner surface Wd. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for barrel polishing an inner surface of an engine accessory.

  In general, engine accessory parts such as intake manifolds, air intake pipes, exhaust manifolds, exhaust pipes, cylinder heads, etc. are parts that constitute intake and exhaust passages for air, fuel gas, combustion gas, etc. If the surface roughness of the inner surface is large, the fluid resistance passing through the interior also increases, reducing the intake / exhaust efficiency of the engine, and as a result, it is difficult to increase the engine output. Therefore, it is desirable that such a hollow engine accessory is subjected to a surface treatment so that the surface roughness of the inner surface is minimized.

  On the other hand, in the prior art, barrel polishing may be performed in order to perform deburring and gloss polishing of various metal products. In this barrel polishing, a metal product to be polished is put in a tank and a polishing medium prepared by mixing spherical abrasive grains, a compound solution, water, etc. is placed in this tank, and the tank is vibrated and rotated in this state. In this method, the polishing medium is brought into contact with the product to perform surface polishing.

  However, when conventional barrel polishing is performed to polish the interior of the engine accessory, it is difficult to sufficiently reduce the surface roughness.

The reason is that the spherical abrasive grains used as the polishing medium have substantially the same size and shape, so that they are likely to be assembled and aligned to become a dense state. At that time, the random movement of the spherical abrasive grains is hindered to polish. This is because the effect becomes insufficient. In particular, inside the engine accessory, since the movement of spherical abrasive grains is spatially restricted, it is more likely to be denser and it is difficult to reduce the surface roughness.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a barrel polishing method capable of effectively performing surface polishing so that the surface roughness of the inner surface of an engine accessory is sufficiently small. To do.

  In order to achieve the above object, the barrel polishing method for an engine accessory according to the present invention is as follows.

  In other words, the barrel polishing method according to the first aspect of the invention is a method for barrel polishing the inner surface of a hollow part of an engine accessory having a hollow part that communicates from one opening to the other opening. A polishing medium is inserted into the inside of the tank with a vibration generating device that generates a rotational moment, and the direction of both openings of the hollow portion of the engine accessory matches the direction of the rotational moment generated in the tank. The engine accessory is embedded in the polishing medium by vibrating the tank, and the polishing medium is hollowed from one opening of the engine accessory while being rotated by a rotational moment generated in the tank. The inner surface of the hollow portion is polished so as to be introduced into the portion and led out from the other opening portion through the hollow portion.

  In this way, a rotational moment in a certain direction is positively generated in the tank of the barrel polishing apparatus by a vibration device, and an engine accessory having a hollow portion communicating from one opening to the other opening is provided in this tank. By throwing it into the polishing medium charged in the tank so that the direction of both openings of the hollow portion coincides with the direction of the rotational moment generated in the tank, and operating the vibration device of the tank The engine accessory is embedded in the polishing medium and rotated by a rotational moment generated in the tank.

  At this time, since the engine accessory part is put into the polishing medium so that both openings of the hollow part coincide with the direction of the rotational moment, the engine accessory part W rotates in the polishing medium as shown in FIG. However, as indicated by an arrow, the polishing medium 9 is introduced into the hollow portion Wb from the one opening Wa, and is led out from the other opening Wc through the hollow portion Wb. During rotation, the polishing medium 9 repeatedly circulates through the hollow portion Wb through the both openings Wa and Wc, and the polishing medium 9 does not move even if the hollow portion Wb has a complicated shape. Since the fluid flows smoothly, the inner surface Wd of the hollow part of the engine accessory W is uniformly polished, and the surface roughness can be sufficiently reduced to effectively polish.

  A barrel polishing method according to a second aspect of the present invention is the method according to the first aspect of the present invention, wherein the polishing medium is a mixed abrasive formed by mixing spherical abrasive grains and non-spherical abrasive grains, a compound It consists of what prepared the solution and water.

  As a result, the spherical abrasive grains are localized because the non-spherical abrasive grains are interposed between the spherical abrasive grains even in a complicated shape where the working space of the mixed abrasive grains is restricted, such as the inner hollow part of the engine accessory. Target, assembly, and alignment are prevented from becoming dense. That is, since the mixed abrasive grains can always move randomly, the polishing action is always kept good. Therefore, the inner surface of the hollow part of the engine accessory can be effectively polished, and the surface roughness can be reduced.

  According to a third aspect of the present invention, the barrel polishing method according to the second aspect of the present invention is the method according to the second aspect, wherein the mixing ratio of the spherical abrasive grains and the non-spherical abrasive grains constituting the mixed abrasive grains is approximately 6-8. It is characterized by being set to one-to-one.

  As a result, a balance between the polishing action for reducing the surface roughness due to the spherical abrasive grains and the action for preventing the densification of the spherical abrasive grains due to the non-spherical abrasive grains can be balanced. be able to.

According to the present invention, the following effects can be obtained.
(1) According to the barrel polishing method for an engine accessory according to the first aspect of the present invention, the engine accessory is put into the polishing medium so that both openings of the hollow portion coincide with the direction of the rotational moment. Therefore, while the engine accessory rotates in the polishing medium, the polishing medium is introduced into the hollow portion from one opening thereof, and is led out from the other opening through the hollow portion. During rotation, the polishing medium repeatedly circulates in and out of the hollow portion through both openings, and the polishing medium flows smoothly even if the hollow portion has a complicated shape. Further, the inner surface of the hollow part of the engine accessory part is uniformly polished, and the surface roughness can be sufficiently reduced to effectively polish.

(2) According to the barrel polishing method for an engine accessory according to the second aspect of the present invention, since the non-spherical abrasive grains are interposed between the spherical abrasive grains, the spherical abrasive grains are locally assembled and aligned. And dense state is prevented. That is, since the mixed abrasive grains can always move at random, the fluidity is improved and the polishing action is always kept good. Therefore, the inner surface of the engine accessory can be effectively polished, and the surface roughness can be reduced.

(3) According to the barrel polishing method for an engine accessory according to the invention described in claim 3, in addition to the effect of the invention described in claim 2, a polishing action for reducing the surface roughness due to spherical abrasive grains, and a non-spherical shape Since it balances with the densification preventing action of the spherical abrasive grains by the abrasive grains, the fluidity of the mixed abrasive grains is further improved, and a good polishing action can always be maintained.

  Hereinafter, the barrel polishing method for engine accessory parts in the embodiment of the present invention will be described in detail.

  The engine accessory in this embodiment is an intake manifold W made of, for example, an aluminum alloy as shown in FIG. 5, and as shown in FIG. 4, the end on one side and the other on the other side across the hollow portion Wb. This is intended for parts having openings Wa and Wc at the ends.

  And the polishing medium used for this barrel polishing is a mixed abrasive grain 1 formed by mixing spherical abrasive grains 2 shown in FIG. 1 (a) and non-spherical abrasive grains 3 shown in FIG. 1 (b) at a predetermined ratio. use.

  Here, the spherical abrasive grains 2 and the non-spherical abrasive grains 3 constituting the mixed abrasive grain 1 are both made of steel, and the shape of the non-spherical abrasive grains 3 is not particularly limited as long as it is not spherical. However, in this example, a so-called sputonic type is used in which an annular flange portion projects from a spherical main body. And the mixing ratio of the spherical abrasive grains 2 and the non-spherical abrasive grains 3 is set to about 6 to 8: 1.

  When the ratio of the non-spherical abrasive grains 3 is larger than the above mixing ratio, the action of roughening the surface by the non-spherical abrasive grains 3 is larger than the action of reducing the surface roughness by the spherical abrasive grains 2. Therefore, there is a limit in reducing the surface roughness. On the other hand, when the ratio of the spherical abrasive grains 2 is larger than the mixing ratio, the spherical abrasive grains 2 are likely to be locally gathered and aligned to be in a dense state, and the random movement of the spherical abrasive grains 2 is restricted. The polishing action is insufficient. Therefore, the mixing ratio of the spherical abrasive grains 2 and the non-spherical abrasive grains 3 is set to about 6-8: 1, preferably about 7: 1 in order to improve the fluidity and maintain a good polishing action. Yes.

  Further, in the barrel polishing method in this embodiment, a vibration device 6 as shown in FIG. 2 is used. In this vibration exciter 6, a tank 7 is supported by a spring 8 so that it can vibrate, and a drive motor 8a for generating a rotational moment in a fixed direction is attached to the bottom of the tank 7 inside the tank 7.

  Then, in the tank 7 of the vibration device 6, polishing in which spherical abrasive grains 2 and non-spherical abrasive grains 3 are mixed at a predetermined ratio, a compound solution as an additive, and water are prepared. The engine accessory W is inserted together with the medium 9, and the drive motor 8a is rotated to vibrate the tank 7 while generating a rotational moment.

  Due to the vibration of the tank 7, the engine accessory W is rotated in the tank 7 together with the polishing medium 9 in a certain direction (for example, clockwise in this case). At this time, since both end openings Wa and Wc of the engine accessory are placed in advance so as to face the direction of the rotational moment generated in the tank 7, the polishing medium 9 is thereby opened in one opening of the engine accessory W. Wa is introduced into the hollow portion Wb, the inner surface Wd is barrel-polished, and the polishing medium 9 is led out from the other opening Wc. During rotation of the engine accessory in the polishing medium, the polishing medium 9 is the hollow portion Wb. Then, the lead-in / out is repeatedly circulated through both the openings Wa and Wc, and the polishing medium 9 flows smoothly even if the hollow portion Wb has a complicated shape. The hollow portion inner surface Wd is uniformly polished, and the surface roughness can be sufficiently reduced to effectively polish.

  Further, since the non-spherical abrasive grains 3 are interposed between the spherical abrasive grains 2, the spherical abrasive grains 2 are prevented from being locally gathered and aligned to become a dense state. That is, since the mixed abrasive grains 1 can always move at random, the polishing action is always kept good. Accordingly, the inner surface Wd of the hollow portion Wb in the engine accessory W can be effectively polished, and the surface roughness can be reduced.

  In this embodiment, a case where an aluminum alloy intake manifold is barrel-polished as an engine accessory W will be described as an example. FIG. 3 shows an internal structure in which the intake manifold W is vertically cut.

  As the polishing medium 9, when the type of abrasive grains and the type of compound are changed, and the amplitude and polishing time of the tank 7 of the vibrating device 6 are changed and the intake manifold is barrel-polished, the surface roughness of the inner surface thereof is changed. The average value (Ra) was measured. The results are shown in Table 1.

  Here, in the mixed abrasive grain 1, the mixing ratio of the spherical abrasive grain 2 and the non-spherical abrasive grain 3 is set to approximately 7 to 1. Compound A agent is acidic powder (trade name: FS-75 manufactured by Uji Electric Chemical Co., Ltd.), and B agent is an ingredient shown in Table 2 (trade name: NF manufactured by Uji Electric Chemical Co., Ltd.) -44N). The intake manifold W was rotated in such a manner that the opening Wa on the intake port side circulated in the clockwise direction.

  As can be seen from Table 1, the surface roughness (Ra) of the inner surface of the hollow part of the intake manifold can be made extremely small when the mixed abrasive and compound B agent are used in combination as the polishing medium.

  Therefore, the intake manifold W was barrel polished under the barrel polishing conditions shown in Table 3, and the average value (Ra) of the surface roughness at each position p1 to p4 on the inner surface was measured as shown in FIG. The results are shown in Table 4.

  As can be seen from Table 4, the surface roughness (Ra) at each of the positions p1 to p4 on the inner surface of the intake manifold W is generally small, and it is understood that the barrel polishing is good.

  In the above-described embodiment, the case where the inner surface of the intake manifold is barrel-polished as the engine accessory W has been described as an example, but the present invention is not limited to this, for example, an intake surge tank, The present invention can be applied when barrel-polishing the inner surface of a hollow engine accessory that allows mixed abrasive grains 1 to enter and exit, such as an air intake pipe, air intake fitting, exhaust manifold, exhaust pipe, and cylinder head. Is possible.

It is a perspective view which expands and shows the spherical abrasive grain and non-spherical abrasive grain which comprise the mixed abrasive grain used as a grinding | polishing medium in the barrel grinding | polishing method of the engine accessory of embodiment of this invention. It is explanatory drawing of the barrel grinding | polishing state of the engine accessory of this invention. It is explanatory drawing which shows the measurement location of the surface roughness of the hollow part inner surface of this manifold after barrel-polishing an intake manifold. It is a vertical side view of an intake manifold, and is a figure explaining the flow of a polishing medium. It is a figure which shows the external appearance of an intake manifold.

Explanation of symbols

W Engine accessories (intake manifold)
DESCRIPTION OF SYMBOLS 1 Mixed abrasive grain 2 Spherical abrasive grain 3 Non-spherical abrasive grain 6 Vibration apparatus 7 Tank 8 Spring 8a Drive motor 9 Polishing medium

Claims (3)

  A method of barrel-polishing the inner surface of a hollow part of an engine accessory having a hollow part communicating from one opening part to the other opening part, wherein a polishing medium is provided inside a tank with a vibration generator that generates a rotational moment in a certain direction. In addition, the engine accessory is inserted so that the direction of both opening portions of the hollow portion coincides with the direction of the rotational moment generated in the tank, and the tank is vibrated to vibrate the engine accessory. Is embedded in the polishing medium and rotated by a rotational moment generated in the tank, and the polishing medium is introduced into the hollow part from one opening of the engine accessory, and from the other opening through the hollow part. A method for polishing a barrel of an engine accessory, wherein the inner surface of the hollow portion is polished as described above.   The barrel polishing method according to claim 1, wherein the polishing medium is prepared by mixing a mixed abrasive formed by mixing spherical abrasive grains and non-spherical abrasive grains, a compound solution, and water. The barrel polishing method for an engine accessory according to claim 2, wherein a mixing ratio of the spherical abrasive grains and the non-spherical abrasive grains constituting the mixed abrasive grains is set to about 6 to 8 to 1.

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