JPH08267266A - Cladding by welding equipment of piston for internal combustion engine - Google Patents

Abstract

PURPOSE: To prevent the powder stuck near starting end of cladding by welding layer from carrying over to working completion position by quickly removing the powder. CONSTITUTION: A vibration type powder removing brush 9, which has sliding contact with a cladding by welding layer 8, is arranged at just beside a piston 1 at working, the residual powder stuck near the starting end 8a of cladding by welding layer 8 is focedly brushed off. At the same time, by measuring a shape of the cladding by welding layer 8 by a measuring head 10, the propriety discrimination of cladding by welding quality is executed based on presence/ absence of shortage of stock.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston build-up device for an internal combustion engine, and particularly for the purpose of imparting wear resistance to a portion of a piston where a ring groove for mounting a piston ring is formed in a later step. The present invention relates to a device for forming a built-up layer.

[0002]

2. Description of the Related Art As shown in FIG. 4, a wear-resistant material layer 3 made of a copper alloy or the like is formed around a ring groove 2 in which a top ring (piston ring) of an internal combustion engine piston 1 is mounted. Forming by a build-up processing method has been tried.

In order to manufacture such a piston 1, for example, a processing apparatus as shown in FIGS. 5 and 6 is used, and as shown in FIG. 7, a ring groove is formed in the post process of the piston 1 after casting. A peripheral groove 4 having a substantially V-shaped cross section is formed in advance in the portion where 2 is formed along the circumferential direction, and a powder 6 such as a copper alloy is continuously supplied from the powder supply nozzle 5 to the peripheral groove 4. Of the powder 6 and the laser beam 7 is irradiated from above the powder 6, and the piston 1 is rotated at a predetermined speed with respect to the laser beam 7. As a result, the powder 6 supplied so as to fill the circumferential groove 4 is once melted by the laser beam energy and then solidified, whereby a buildup layer 8 of a copper-based alloy or the like is formed along the circumferential groove 4. become.

Thereafter, as shown in FIG. 7, the built-up layer 8 is cut so as to be flush with the outer peripheral surface 1a of the piston 1, and then the ring groove 2 is formed by groove processing. As a result, the wear-resistant material layer 3 as the buildup layer 8 such as a copper alloy is finally formed so as to surround the ring groove 2.

[0005]

In the above-mentioned build-up processing apparatus, even if the powder 6 is continuously supplied from the powder supply nozzle 5 in synchronization with the rotation of the piston 1, the build-up processing start position is increased. Then, since the supply of the powder 6 is suddenly started, the powder supply amount is unstable, and the powder 6 tends to scatter and spread more than necessary, so that the powder supply width tends to vary. Therefore, in the vicinity of the start end portion 8a of the build-up layer 8 where the build-up process is first started, the powder 6a that cannot be completely melted by the irradiation of the laser beam 7 is generated in the outer peripheral surface 1a of the piston 1 and the build-up layer 8. May remain attached to the surface.

The above-mentioned build-up processing start position, that is, the start end portion 8a of the build-up processing layer 8 is the end portion which is the last portion of the build-up processing layer 8 at the build-up processing end position. Since they are overlapped, the powder 6a remaining in the vicinity of the starting end portion 8a of the buildup layer 8 remains attached and is again irradiated with the laser beam 7.

As a result, the overlay processing becomes unstable in the overlapping portion between the start and end portions of the overlay layer 8 described above, and cracks are generated in the overlay layer 8 due to, for example, variations in heat input, There is a limit to the improvement of the build-up processing quality.

The present invention has been made by paying attention to the above problems, and the purpose of the present invention is to prevent excess surplus remaining in the buildup layer from becoming the buildup layer, especially near the starting end. It is an object of the present invention to provide a structure that enables the powder to be effectively removed before the start end overlaps the end at the build-up processing end position.

[0009]

According to a first aspect of the present invention, a peripheral groove is formed in advance in a circumferential direction on a portion of the outer peripheral surface where a ring groove for mounting a piston ring is formed in a later step. The piston is positioned and supported, and the laser beam is applied while the powder of the build-up material is supplied to the peripheral groove and the piston is rotated with respect to the laser beam, thereby melting the powder and along the peripheral groove. A device for forming a build-up layer, which is a powder removal device that removes excess powder adhering to the surface of the build-up layer in front of the build-up processing position by laser beam irradiation in the rotation direction of the piston. It is characterized by the provision of means.

According to a second aspect of the present invention, in addition to the structure of the first aspect, the powder removing means is a powder removing brush that makes sliding contact with the buildup layer as the piston rotates. There is.

According to a third aspect of the present invention, in addition to the configuration of the second aspect, a measurement for measuring the shape of the build-up layer in front of the installation position of the powder removing brush in the rotation direction of the piston. It features a head.

According to a fourth aspect of the present invention, in addition to the structure according to the third aspect, the piston is rotated in a horizontal posture with the shaft center thereof as a rotation center, and the piston is provided on the upper surface side of the horizontal piston. A build-up processing position by laser beam irradiation is set in the vicinity of a crossing position of a vertical axis passing through the axis of the piston and the outer peripheral surface of the piston, and the phase is shifted by 90 degrees in the rotation direction of the piston from the build-up processing position. The powder removing brush is installed, and the measuring head is installed at a position further deviated in phase by 90 degrees from the powder removing brush installation position in the rotation direction of the piston.

[0013]

According to the first aspect of the present invention, powder removing means such as a brush, an air blow nozzle, or a suction device is provided in front of the buildup processing position by laser beam irradiation in the rotation direction of the piston to be processed. Since the extra powder adhered to the surface in the vicinity of the start end of the build-up layer, which is the starting position for the build-up process, is removed by the powder removing means while the piston is rotating, those powders are removed. It will not be brought to the end portion of the built-up layer, which is the finishing position. This stabilizes the build-up processing state at the portion where the start and end portions of the build-up layer overlap at the build-up processing end position, and prevents the occurrence of cracks as in the conventional case and improves the build-up processing quality. Will be able to contribute to the improvement of.

According to the second aspect of the invention, since the powder removing means is a brush, the remaining powder is removed by the buildup layer slidingly contacting the brush according to the rotation of the piston. Therefore, the reliability of powder removal is high, the structure is simple, and the cost is advantageous, and especially when the brush is vibrated in the longitudinal direction of the buildup layer, the powder removal efficiency is further improved.

According to the third aspect of the present invention, since the measuring head is provided further forward than the powder removing brush in the rotational direction of the piston, the shape of the buildup layer is measured in parallel with the buildup processing. Then, for example, it is possible to determine whether or not the quality of the buildup layer is appropriate in substantially real time, for example, regarding the presence or absence of lack of meat. Moreover, since the measurement with the measuring head is performed after the removing work with the powder removing brush,
The reliability of the measurement result is improved because it is not affected by the residual powder.

According to the fourth aspect of the present invention, the laser beam is irradiated from directly above the piston which rotates in the horizontal posture to perform the overlaying process, and the 90 ° phase is shifted from the overlaying position by the laser beam irradiation. Excess powder removal work is performed with the powder removal brush at the shifted position, and the phase is further shifted by 90 degrees from the brush installation position, that is, at the position opposite to the build-up processing position across the brush installation position. A head measurement is performed.

Therefore, if the powder removed by the brush falls directly below, the possibility of the powder reattaching to the piston or the buildup layer is minimized, and the measurement position of the measuring head is built up by laser beam irradiation. Since it is the farthest position from the position, even when an optical type is used as the measuring head, for example, it is unlikely to be affected by other light including the light at the buildup processing position, and the measurement accuracy and thus the measurement The reliability of the results will be improved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1A and 1B are views showing an embodiment of the present invention, in which the same parts as those of the conventional example shown in FIGS.

As shown in FIG. 1, a piston 1 to be machined is positioned and supported so as to be in a horizontal posture, and while the piston 1 is being rotated, a copper-based material is provided from directly above the piston 1 to the circumferential groove 4. It is the same as the conventional method that the powder 6 such as an alloy is continuously supplied and the laser beam 7 is irradiated to the powder supply position. That is, on the upper half side of the horizontal piston 1, the position where the vertical axis passing through the axial center of the piston 1 and the outer peripheral surface 1a of the piston 1 intersect is defined as the build-up working position P _{1 and the} build-up working position P _{1 1} , the powder 6 is continuously supplied from the powder supply nozzle 5, and the laser beam 7 is irradiated.

Meanwhile, the 90 ° phase shifted positions the rotational direction of a just beside the piston 1 padding processing position the piston 1 from P ₁ powder removing brush 9 is provided. The powder removing brush 9 is arranged so as to be in contact with the build-up layer 8 after the build-up process, and is reciprocally driven in the longitudinal direction of the build-up layer 8 in synchronization with the rotation of the piston 1 to vibrate. There is.

Further, directly below the piston 1, that is, at a position opposite to the buildup processing position P ₁ with the powder removing brush 9 interposed therebetween, a measuring head 10 for measuring the surface shape of the buildup layer 8 after the buildup processing. Is provided. This measuring head 1
Reference numeral 0 denotes a light source unit 12 that irradiates the overlay light 8 with slit light 11 such as infrared rays, and the slit light 11 that is applied to the overlay layer 8 is imaged by an image sensor and the overlay layer is formed by a light cutting method. Sensor unit 13 for detecting the surface shape of 8
It consists of and. Then, the output signal of the measuring head 10 is captured by a signal processing device (not shown) and compared with a preset reference shape signal, so that it is possible to determine in real time whether or not there is a deficiency in the buildup layer 8. There is.

Therefore, in such a structure,
As shown in FIG. 1, while the piston 1 is rotated at a predetermined speed, the powder 6 of copper alloy is continuously supplied from the powder supply nozzle 5 to the circumferential groove 4 at the build-up processing position P ₁ and the laser beam is emitted. 7 is applied to form a built-up layer 8 along the circumferential groove 4 as in the conventional case. At the same time, the powder removal brush 9
To reciprocate vertically.

As a result, the buildup layer 8 which is continuously formed in a bead shape from the starting end 8a is sequentially brushed by the powder removing brush 9 and remains on the surface of the buildup layer 8. The powder is brushed off.

At this time, since the powder removing brush 9 is installed right next to the piston 1, the powder removed by the powder removing brush 9 falls directly below, whereas the piston 1 moves in the falling direction. Since it does not exist, there is no possibility that the powder that has been scraped off will reattach to the buildup layer 8.

Further, the build-up layer 8 from which the powder has been removed by the powder removing brush 9 sequentially moves to the measuring head portion 10 side, and as described above, the surface shape of the build-up layer 8 can be measured by the light cutting method. The measurement is performed by the measurement head 10 to determine whether or not there is a deficiency in the buildup layer 8.

At this time, since the measuring head 10 measures the buildup layer 8 after the powder removal by the powder removing brush 9, the measurement accuracy is not affected by the adhesion of the residual powder.

In this embodiment, AC8C material (JIS standard)
Outer surface 1a of piston 1 made of aluminum alloy
A peripheral groove 4 having a substantially V-shaped cross section is formed on the inner surface of the peripheral groove 4, and the aluminum bronze powder 6 is supplied to the peripheral groove 4 from the powder supply nozzle 5.
Laser output 4.0k while continuously supplying at 0g / min
A laser beam 7 of W was applied to perform overlay processing to form an overlay layer 8. The laser beam 7 was subjected to an optical treatment so that the shape at the irradiation position was a rectangle of 6 mm × 2 mm, and the long side thereof was irradiated so as to match the groove width direction of the circumferential groove 4.

Further, an oscillating powder removing brush 9 is installed at a position which is out of phase with the laser beam irradiation position P ₁ by 90 ° in the rotational direction of the piston 1, and brushing is performed. An infrared type measurement head 10 was provided at a position further shifted in phase by 90 degrees in the rotational direction of the piston 1 from the position where the brush was installed, and the surface shape of the built-up layer 8 was measured by the optical cutting method. By applying the brush with the powder removing brush 9 as described above, the removed powder falls directly below the powder removing brush 9, and thus reattachment to the buildup layer 8 was not observed.

FIG. 2 is a diagram showing the shape of the overlapping portion between the start and end portions of the build-up layer 8 with and without brushing. When brushing is applied, residual powder adheres. Since the bead-shaped build-up layer 8 has a small variation in the width direction and is finished uniformly, when the brushing is not applied, the residual powder 6a is observed to be attached, which is why the build-up layer 8 is formed. Both the width and height of No. 8 varied greatly, and cracks were often found.

Further, FIG. 3 is a view showing an image of a cross-sectional shape captured by the measuring head 10 with respect to the built-up layer 8 shown in FIG. 2. Particularly, when no brushing is applied, an image in the height direction is shown. Disturbances are noticeable.

The build-up layer 8 formed as described above is machined in the same procedure as in the prior art shown in FIG. 7, and the wear-resistant material layer 3 is formed around the ring groove 2. Will be formed.

[0032]

According to the first aspect of the present invention, the removing means for removing the residual powder adhering to the surface of the build-up layer in front of the build-up processing position by laser beam irradiation in the rotation direction of the piston. With the provision of the above, especially, the surplus powder adhering to the starting end surface of the surfacing layer at the surfacing start position is removed by the powder removing means while the piston is rotating, and the surplus powder is deposited. It will not be brought to the processing end position. Therefore, the build-up processing state is stabilized at the portion where the start and end portions of the build-up layer overlap at the build-up processing end position, and for example, cracks are prevented from occurring as in the conventional case and the build-up processing quality is improved. It can greatly contribute to improvement.

According to a second aspect of the present invention, as the powder removing means according to the first aspect, a powder removing brush which is in sliding contact with the buildup layer as the piston rotates is used. In addition to the same effects as the invention, the reliability of powder removal is high, the structure is simple and the cost is advantageous, and especially if the brush is vibrated in the longitudinal direction of the buildup layer, the powder removal efficiency is further improved. improves.

According to the third aspect of the present invention, by providing the measuring head for measuring the surface shape of the buildup layer in front of the installation position of the powder removing brush in the rotation direction of the piston, the buildup is achieved. In parallel with the processing, the surface shape of the build-up layer can be measured, and the quality of the build-up layer can be judged in real time, for example, regarding the presence or absence of a deficiency, and the quality of the build-up layer can be further improved. improves.

According to the fourth aspect of the present invention, the piston is placed in a horizontal posture, the piston is rotated about the axis of the piston, and the vertical axis passing through the axis of the piston on the upper surface side of the horizontal piston. A build-up processing position by laser beam irradiation is set near the intersection of the axis and the outer peripheral surface of the piston, and the powder removal brush is installed at a position 90 degrees out of phase from the build-up processing position in the rotation direction of the piston. Further, since the measuring head is installed at a position which is further out of phase by 90 degrees in the rotation direction of the piston from the installation position of the powder removing brush, the powder removed by the powder removing brush falls directly under the measuring head, and the padding is completed. There is no re-adhesion to the layer, the quality is improved especially at the overlap part between the start and end parts of the buildup layer, and Since the measurement position is the farthest position from the laser beam irradiation position, even when using an optical type measuring head, for example, it is less likely to be affected by other light including the light at the laser beam irradiation position. ,
The measurement accuracy and thus the reliability of the measurement result are improved.

[Brief description of drawings]

1A and 1B are views showing an embodiment of the present invention, in which FIG. 1A is an explanatory view of the configuration, and FIG. 1B is a right side view of FIG. 1A.

FIG. 2 is an explanatory diagram showing changes in the shape of the buildup layer depending on the presence or absence of residual powder.

FIG. 3 is an explanatory view showing a change in cross section of the overlay layer shown in FIG.

FIG. 4 is a sectional view of a piston having a wear resistant material layer.

FIG. 5 is a structural explanatory view showing an example of a conventional overlay processing apparatus.

6 is a right side view of FIG.

FIG. 7 is an explanatory view of a process until a ring groove is formed in a piston.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Piston 1a ... Outer peripheral surface 2 ... Ring groove 3 ... Abrasion resistant material layer 4 ... Circumferential groove 5 ... Powder supply nozzle 6 ... Powder 7 ... Laser beam 8 ... Build-up layer 9 ... Powder removal brush 10 ... Measuring head P ₁ … Pouring position

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F02F 3/10 F02F 3/10 B

Claims (4)

[Claims] 1. A piston having a peripheral groove formed in advance in a circumferential direction of a portion of the outer peripheral surface where a ring groove for mounting a piston ring is formed in a later step is positioned and supported, and the peripheral groove is built up. An apparatus configured to irradiate a laser beam while supplying a powder of material and rotate a piston with respect to the laser beam to melt the powder to form a buildup layer along a circumferential groove. In the piston for an internal combustion engine, a powder removing means for removing residual powder adhering to the surface of the buildup layer is provided in front of the buildup processing position by laser beam irradiation in the rotation direction of the piston. Overlay processing device. 2. The build-up processing device for a piston for an internal combustion engine according to claim 1, wherein the powder removing means is a powder removing brush that comes into sliding contact with the build-up layer as the piston rotates. 3. A measuring head for measuring the shape of the build-up layer is provided in front of the installation position of the powder removing brush in the rotation direction of the piston.
A built-up processing device for a piston for an internal combustion engine as described. 4. The piston is rotated horizontally with the axis of the piston in a horizontal position, and the piston is rotated near the intersection of the vertical axis passing through the axis of the piston and the outer peripheral surface of the piston on the upper surface of the horizontal piston. The build-up processing position by laser beam irradiation is set, and the powder removing brush is installed at a position 90 degrees out of phase from the build-up processing position in the rotation direction of the piston, and the powder removing brush is installed from the position where the powder removing brush is installed. The build-up processing device for a piston for an internal combustion engine according to claim 3, wherein the measuring head is installed at a position which is further out of phase by 90 degrees in the rotational direction.