JPS596188B2 - Equipment that directly applies plasma spraying to the inner diameter of aluminum cylinders for internal combustion engines. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plasma spraying apparatus for spraying plasma onto the inner diameter of an aluminum cast cylinder of an internal combustion engine.

More specifically, the electrode nozzle part of the plasma spraying machine is moved up and down so that the electrode nozzle part faces into the inner diameter part of the cylinder, and the cylinder is rotated to spray the metal powder directly onto the inner diameter part of the hole, The present invention relates to a plasma spraying apparatus for forming a sprayed coating layer.

Internal combustion engine cylinders are made of aluminum alloy to reduce weight, but in this case, the inner diameter of the material itself cannot withstand heat, pressure, etc., so the inner diameter is hard and has excellent heat resistance. Metal cylinder sleeves and cylinder liners were press-fitted.

However, this press-fitting process increases the number of steps, requires separate parts, and has problems in terms of weight reduction.Recently, as a thermal spraying method for high-melting point metals has been developed and put into practical use, cylindrical workpieces with inner diameter Metal spraying has come to be used as a means of increasing the heat resistance and mechanical strength of parts. As metal spraying methods, detonation methods such as wire bombardment spraying and plasma spraying have been put into practical use, but when these methods are applied to cylindrical workpieces such as the cylinders of internal combustion engines, the following problems arise. In other words, in the wire bomb spraying method, the wire rods are fed one by one to the center of the inner diameter,
This is detonated to form a coating layer on the inner diameter of the workpiece, so in order to obtain the film thickness required for practical use, multiple blasts are required, and wire must be supplied each time. , the intermittent wire feeding mechanism, the wire holding electrode structure, etc. are inevitably complicated, and the above requires multiple bursts to obtain the desired film thickness, resulting in longer working hours, which causes problems in mass production. .

Furthermore, if the inner diameter of the workpiece is long in the axial direction, the wire may sag, making it difficult to obtain a uniform film thickness, and as a result, the axial length of the workpiece is also restricted.
This means that only workpieces with limited dimensions can be thermally sprayed.
On the other hand, in the plasma spraying method, the spraying material covers all metals, and the spraying is performed in a high-temperature gas environment, so the spray particles melt well and at high speed, so the spray layer is mechanically, metallically, and physically It is an ideal thermal spraying method as very good results can be obtained.

However, plasma spraying is generally performed manually using a gun-shaped spraying machine equipped with an electrode nozzle, which poses problems in terms of work efficiency. Although a device has also been proposed that sprays the outside of the cylinder while the inside diameter is relatively small, it is difficult to spray the inside diameter part of the cylinder of an internal combustion engine, which has a relatively small inside diameter, with these methods. That is, it is of course extremely difficult to form a sprayed coating layer uniformly over the entire circumference of the inner diameter of the cylinder using the above methods, and the work of forming the sprayed layer on such an inner diameter requires a thermal spraying machine to penetrate into the inner diameter. In addition, it is necessary to trace this along the inner wall, and if this is planned, the movement mechanism of the thermal spraying machine will become complicated, and as the structure of the thermal spraying machine becomes complicated, there is a risk that the external size will also increase. Although it can be used for cylinders with large inner diameters, it cannot be used for cylinders with small diameters.

In this way, the inner diameter of a cylindrical workpiece with a relatively small inner diameter, such as a cylinder for an internal combustion engine, can be automatically and accurately
Furthermore, an apparatus that directly performs plasma spraying to obtain a predetermined film thickness has not yet been proposed or put into practical use, and there is a high need for this type of plasma spraying apparatus. Therefore, instead of the cylinder, it may be possible to apply plasma spraying to the cylinder liner attached to the cylinder liner, etc. In this case, since the outer diameter part of the cylinder liner is a perfect circle, it is supported horizontally and rotated, and the inner diameter part of the cylinder liner is rotated. It is also possible to use a thermal spraying machine that can move forward and backward to perform plasma spraying on the inner diameter, but since both the outer and inner diameters of the workpiece are perfect circles and the outer diameter is flat, the clamping mechanism and rotation are difficult. Although the mechanism can be easily configured, the above method cannot directly apply plasma spraying to the inner diameter portion of a cast cylinder. In other words, the outer periphery of the cylinder is not necessarily a perfect circle, and there are many cooling fins, so it is actually extremely difficult to clamp the cylinder sideways, center it, and rotate it while ensuring roundness. , if this were not attempted, the device would become extremely complex.

Therefore, a device that directly performs plasma spraying on the inner diameter of a cylinder has not been put to practical use.

The present inventor focused on the characteristics of the plasma spraying method, and created the present invention in order to directly form a plasma spray coating layer on the inner diameter portion of an aluminum cast cylinder for an internal combustion engine.

The object of the present invention is to move an electrode nozzle part of a plasma spraying machine up and down, so that the electrode nozzle part faces the inner diameter part of a vertically supported cylinder, and to rotate the cylinder. To provide an apparatus for directly applying plasma spraying to the inner diameter part of a cylinder for an internal combustion engine, which sprays metal powder directly to the inner diameter part of the cylinder.

Therefore, the object of the present invention is to easily and reliably form a plasma sprayed layer directly on the inner wall of the cylinder inner diameter by combining the vertical movement of the electrode nozzle toward the inner diameter of the cylinder and the rotation of the cylinder. To provide an apparatus for directly applying plasma spraying to the inner diameter part of an internal combustion engine cylinder, which is highly practical as a means for plasma spraying the inner diameter part of an internal combustion engine cylinder made of cast aluminum alloy.

Another object of the present invention is to simply move the thermal spraying machine up and down as described above, simplify the movement mechanism of the thermal spraying machine, and reduce the external size of the machine. To provide a plasma spraying device that enables direct plasma spraying onto the inner diameter of a small cylinder, improves the practicality of plasma spraying, and has a large processing capacity that contributes to its practical application.

Furthermore, the object of the present invention is to move the thermal spraying machine up and down to face the inner diameter of the cylinder and rotate the cylinder to perform the work, so that the thermal spraying process can be carried out in a short time and the working time can be shortened. We aim to provide equipment that is convenient for mass production. Furthermore, the object of the present invention is that the structure of the device is simple because it is a combination of a mechanism that moves the thermal spray machine up and down and a mechanism that rotates a vertically clamped cylinder, and the plasma To provide a thermal spraying device that can provide thermal spraying means simply, easily and at low cost,
Furthermore, because of the above mechanism, a thermal spraying apparatus is provided that can automate work, save labor, and improve work efficiency.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a front view of the device according to the present invention, FIG. 2 shows a cutaway front view of the same, and FIG. 3 shows a side view.

Reference numeral 1 designates a table equipped with legs 3 hanging downwardly around the periphery, and a support member 4 is fixed and vertically installed in the center of the table. Fit the upper part of the main body into the mounting hole 2 provided on 1,
A mounting flange portion 5 provided on the outer circumference of the supporting member 4 is secured to the periphery of the mounting hole 2, and a table 1
It hangs down from the bottom of the.

This support member 4 is formed of a cylindrical body with a vertical hole 6 extending in the axial direction in the center, and a vibrator-shaped rotating member 7 having a vertical passage 8 inside is inserted vertically into the vertical hole 6. There is. The upper part of the rotary member 7 protrudes onto the support member 4 facing the table 1 , and a rotary support table 9 is fixedly mounted on the top of this protrusion, and this table 9 has a concentric passage that matches the longitudinal passage 8 of the rotary member 7 . A hole 10 is provided.

A cylinder positioning jig 11 is provided on the center of the support table 9, and a concentric through hole 12 communicating with the through hole 10 and the vertical passage 8 is also provided in this jig 11. And this jig 1
1. The upper surface is horizontal to ensure the verticality of the cylinder hole. Also, a plurality of cylinder clampers 13 are provided around the support table 9. The cylinder W, which is a workpiece, is a cast cylinder for an internal combustion engine made of aluminum alloy or the like, and is mounted on the workpiece positioning jig 11 described above.
Place the workpiece W on the jig 11 vertically, that is, so that the vertical hole W of the workpiece W is vertical, and match the hole 12 of the jig 11 with the hole W. Press the parts to fix the cylinder W.

In this case, the cylinder W has its top and bottom surfaces cut and flat, so it can be easily positioned and clamped by simply placing it on a jig and pressing the top surface with the clamper 13. Even if there is a protrusion, centering and clamping can be performed extremely easily, and positioning and clamping can be performed using a simple device as shown. On the other hand, the lower end of the rotating member 7 is protruded downwardly below the support member 4, and a driven disc 14 such as a sprocket or pulley is provided on the outer periphery of this protruding part. 4 drive discs 16 such as fixed sprockets or pulleys
and the driven disk 14 are connected by a transmission member 17 such as a chain or a belt.

Of course, a gear transmission mechanism may be used instead of this. A connecting member 18 that also serves as a bearing is provided at the lower end of the rotating member 7.
A through hole 19 communicating with the vertical passage 8 provided therein is connected to a dust collector (not shown) via a dust collecting tube 20, and the vertical through hole W1 of the cylinder W is connected through the through holes 12, 10, 8, 19. This will communicate with the tube 20, and together they will constitute a dust discharge passage. The cylinder W set on the table 1 and its support mechanism are covered with a soundproof and dustproof cover 21 provided on the table 1.
1 is equipped with a light shielding plate 22 on the front so that the internal working status can be monitored during thermal spraying.

As shown in FIG. 4, the cover 21 is connected to the main body 23,
It consists of a lid body 24 which is pivotally connected at one end and can be opened and closed, and a sealing member 25 is interposed between the lid body 24 and a sealing member 25 to provide a soundproof and dustproof seal. A dust discharge port is formed at the lower side of the cover 21, and this communicates with a discharge duct 26.The duct 26 is connected to a dust collector (not shown) via a tube 27, and the duct 26 is connected to an electrode of a plasma spraying machine, which will be described later. It is provided at the lower side of the nozzle in the spray powder injection direction.

Further, a hot air discharge passage 28 is opened and communicated with the upper side of the duct 26 of the cover 21 to relieve the high temperature atmosphere inside the cover 21 during thermal spraying. And also part of the cover 21,
For example, a cooling means 29 such as a blower is provided on the lid 24 so as to face the cylinder W at a distance, and cools the cylinder W after the thermal spraying operation is completed. Above cover 21
A cooling vibrator 30 is installed surrounding the outer wall of the duct 26 and the exhaust passage 28 to alleviate the atmosphere inside the cover 21,
Cools dust and discharged hot air. A hole 31 is provided directly above the center of the hole W1 of the cylinder W located below on the upper surface of the cover 21, and a rod portion 33 of a thermal spraying machine 32 is slidably fitted into this hole 31. electrode nozzle 3
4 faces into the cover 21 and is located directly above the center of the hole 31 of the cylinder W.

A rod 33 extends vertically through the upper surface of the cover 21.
A main body 35 is provided at the upper end of the main body 35, and a cooling water tube 36, an electric control tube 37, a powder material supply tube 38 containing an antioxidant shielding gas, and the like are connected to the main body 35. Further, this main body 35 is connected and supported by a driven bracket 40 of the vertical feed mechanism 39, the rod 33 is extended downwardly, and guide parts 41, 41 provided on the left and right sides of the lower part of the bracket 40 are connected to the machine frame 43 of the mechanism 39. A driven piece body 42 is provided at the lower center of the bracket 40 and has, for example, a female thread formed on its inner wall, and is integrated with the bracket 40. has been done. A driving member 45 such as a feed screw is installed vertically on the machine frame 43, and is screwed into the driven piece 42.
It is driven by a motor 46 and a drive mechanism 47 such as a sprocket, a chain, a belt, or a pulley, which are fixed to the motor 46 . Next, the plasma spraying operation of the inner diameter portion of the cylinder W using this apparatus will be explained step by step.

FIG. 2 shows a state in which the cylinder W is vertically fixed and set in a predetermined position on the jig 11 by the clamper 13 as described above, and the electrode nozzle portion 34 of the thermal spraying machine 32 located directly above the hole W1 of the cylinder W is It is held in a predetermined position on the cylinder W within the cover 21.

The rotating member 7 is rotationally driven by the motor 15, and the cylinder W including the support table 9, jig 11, and clamper 13 connected thereto is rotated while being held vertically.

At the same time, the motor 46 is driven, and the drive feed screw 4
5 is rotationally driven, the piece body 42 is moved downward by screw feeding action, and the bracket 40 is lowered. This descent is done by rod 44
The verticality is maintained by the action of the guide 41, and the electrode nozzle 34 is vertically lowered via the rod portion 33 including the main body 35 supported by the bracket 40. Then, the spray powder starts to be ejected at a position close to the cylinder W, and as it continues to descend, the nozzle 34 enters the center of the hole W1 of the cylinder W.
invades. The nozzle 34 performs only a descending motion, and by a combination of the rotational motion of the cylinder W and the descending motion of the nozzle 34, the entire inner diameter portion is scanned by the nozzle 34, and plasma spraying is performed on the inner diameter portion to form a sprayed coating layer. When the nozzle 34 enters the inner diameter of the cylinder W by vertical downward movement, the excess sprayed powder passes through the above-mentioned dust discharge passages 12, 10, 8, and 19, which are provided directly below the inner diameter and communicate with the inner diameter. The dust then reaches the tube 20 and is collected by a dust collector. In this case, considering that the dust is at a high temperature, it is preferable to provide a cooling means in the above-mentioned passage and the collection passage.

In addition, the powder that is preliminarily injected at the time when the nozzle 34 starts injecting and before it enters the inner diameter of the cylinder W is transferred to the cover 2.
In this injection direction, hot air is sucked into a duct 26 provided at the lower side and collected by a dust collector, and the hot air generated by the above injection is discharged from an exhaust passage 28. Although significant noise is generated during thermal spraying, since this work is performed within the cover 21, the noise is not so loud as to impair the working environment. After the thermal spraying work on the inner diameter of the hole W1 of the cylinder W is completed, the energization and powder supply to the electrode nozzle section 34 are stopped, the motor 46 is reversed, the nozzle section 34 is vertically raised and removed from the hole W1, and The rotation of the cylinder W is stopped by stopping the motor 15.

Then, the thermal spraying machine 32 including the electrode nozzle part 34 is raised to a predetermined position, and the cooling means 29 is driven to cool the cylinder W. After cooling, open the lid 24, open the clamper 13, take out the cylinder W, set a new cylinder, repeat the above process, and perform post-processing such as honing on the cylinder W after thermal spraying to improve the inner diameter. processed,
A cylinder for an internal combustion engine made of cast aluminum having a plasma sprayed layer directly on the inner diameter is obtained. In the above, the cylinder W is arranged vertically and rotated, and the thermal spraying machine is moved vertically up and down to insert and remove the cylinder W into the inner diameter of the hole, and plasma spraying is applied to the inner periphery of the inner diameter. The formation of the layer is ensured by the combination of vertical motion and rotational motion.

Plasma spraying to the inner diameter part is as described above, so it requires appropriate insertion speed and positional relationship of the spraying machine into the inner diameter part, rotational speed of the cylinder W, etc. Since the rotation of the cylinder W, which is clamped vertically so that the hole is vertical, is performed independently by a separate mechanism, it is easy to adjust and control this, and a speed suitable for the thermal spraying conditions can be easily obtained. Furthermore, since it is a combination of the vertical movement of the thermal spraying machine and the rotational movement of the cylinder, the thermal spraying operation can be performed by controlling the above-mentioned movements in time, and the plasma thermal spraying operation can be automated and labor-saving. As is clear from the above, according to the present invention, an aluminum cast cylinder for an internal combustion engine is clamped vertically so that its hole is vertical, and rotated, and a thermal spraying machine is vertically moved up and down on the inside diameter of the hole. This makes it possible to apply plasma spraying directly to the inner diameter of internal combustion engine cylinders with relatively small inner diameters, making it possible to apply plasma spraying to the inner diameter of internal combustion engine cylinders made of cast aluminum. It is practically possible to perform formation by plasma spraying. Further, according to the present invention,
The above was achieved by clamping the cylinder vertically so that its hole was vertical, rotating it, and moving the thermal spraying machine up and down, which contributed to simplifying the configuration of the thermal spraying equipment, and also made it possible to perform each of the above movements. Therefore, it contributes to automation and labor saving of plasma spraying work, is convenient for mass production, and the equipment can be obtained at a relatively low cost.

Particularly, according to the present invention, by paying attention to the fact that the upper and lower surfaces of the cast cylinder are flat, the cylinder is placed on a positioning jig on a rotary table so that the cylinder hole is vertical, and the periphery of the upper surface is clamped. Because the cylinder is supported vertically, the casting itself can be set, cooling fins etc. protrude around the cylinder, and even if the cylinder is not a perfect circle, it can be set with a simple positioning jig and clamp mechanism, and the plasma spray can be applied by vertical movement of the thermal spraying machine. Thermal spraying can be carried out, and a plasma sprayed coating can be easily and reliably formed directly on the inner diameter of the cylinder.

Furthermore, since the sprayed coating is formed on the inner diameter of the workpiece by combining the vertical movement of the thermal spraying machine and the rotational movement of the workpiece as described above, it is possible to easily obtain a sprayed layer of a desired thickness by controlling the speeds of each of the above-mentioned movements. By controlling this and controlling the start and stop of the movement, it is possible to easily obtain an automatic plasma spraying apparatus that can directly form a plasma sprayed layer on the inner diameter of a cylinder for an internal combustion engine with good performance.

Furthermore, since the thermal spraying machine only moves up and down, and the workpiece only rotates, it is easy to install soundproof and dustproof covers, and installation of covers and soundproof and dustproof seals are easy and reliable.
It is possible to obtain a plasma spraying device that improves the working environment with a simple structure and easy means, and since the powder spraying direction of the thermal spraying machine is specified, dust removal can be performed easily and reliably.
In addition, since the work only moves in rotation, dust can be easily discharged by providing a passage communicating with the cylindrical hole, and the structure of incidental equipment such as dust countermeasure equipment accompanying plasma spraying can be simplified. It is extremely practical.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; Fig. 1 is a front view, Fig. 2 is a vertical front view, Fig. 3 is a side view, and Fig. 4 is a cross-sectional view of the upper part of the soundproof and dustproof cover. FIG. In the drawing, W is a cylinder, W1 is a hole, 7, 9, and 11 are rotating members, 13 is a clamp, 14, 15, and 16 are rotating mechanisms for the workpiece, 32 is a plasma spraying machine, and 40, 41, and 42 are supports for this. 45, 46, and 47 are vertical movement drive mechanisms for this.

Claims (1)

[Claims] 1. A clamping mechanism that positions an internal combustion engine cylinder made of aluminum and cast vertically on a rotary mounting table and clamping the top surface of the cylinder for positioning; and a mechanism that rotates the cylinder by rotating the table. and a plasma spraying machine that is positioned above the hole in the cylinder and moves vertically up and down by a vertical movement feed mechanism.The cylinder is rotated while being clamped vertically, and the spraying machine is moved up and down to vertically The spraying machine is inserted into and removed from the inner diameter of a hole supported in the same direction, and plasma spraying is performed directly onto the inner diameter of the bore of the cylinder. A device that performs thermal spraying.