JP2008157053A - Manufacturing method of screw type supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a screw type supercharger capable of improving compression efficiency by decreasing minute clearance between a rotor and a casing. <P>SOLUTION: The manufacturing method of a screw type supercharger of the invention comprises processes for: coating end surfaces in the longitudinal direction and outer peripheral tip parts of blades of a male rotor 2 and a female rotor 3 with such a thickness that, when the male rotor 2 and the female rotor 3 are assembled into a rotor casing 4, the end surface in the longitudinal direction and the outer peripheral tip part of the blades of each rotor come into contact with an inner surface of the rotor casing 4; assembling the coated male rotor 2 and the female rotor 3 into the rotor casing 4; and cutting off a part of the coating by rotatively driving the male rotor 2 and the female rotor 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a screw-type supercharger that supplies air to an internal combustion engine or the like, and a method for manufacturing a screw-type supercharger that improves compression efficiency by reducing a minute gap between components such as a rotor and a casing. About.

  The screw-type supercharger rotates a helical male rotor and a female rotor meshing therewith in the casing in the reverse direction, sucks air from one end thereof, and is partitioned between the male rotor and female rotor and the casing. It is structured such that it is guided and compressed in the space, and is pumped in the axial direction and discharged from a discharge port formed at the other end.

In such a screw-type supercharger, since air is compressed, the temperature becomes high during operation, and the rotor and casing thermally expand. Moreover, since the rotor rotates at high speed, the surface of the rotor and the inner surface of the casing are coated in order to prevent welding due to contact between metals. Conventionally, a minute gap is provided between the rotor and the casing so that they do not come into contact with each other, and the gap is set to zero as much as possible (see, for example, Patent Documents 1 to 3).
JP-A-6-317277 JP 2003-176695 A JP-A-8-284673

  In the conventional screw-type supercharger described above, the casing is made of an aluminum alloy. Since this aluminum alloy has a larger coefficient of thermal expansion than the material of the rotor, the casing expands more than the rotor at a high temperature, which is the maximum rotation speed range, and the gap between the rotor and the casing increases to increase the air There has been a problem that the compression efficiency of the paper is reduced. For this reason, it is necessary to set the gap between the casing and the rotor to be zero as much as possible at a low temperature so that the gap does not become as large as possible at a high temperature. However, designing the part shape so that the gap between the casing and the rotor is zero as much as possible is limited in consideration of machining tolerances. It has been difficult to improve efficiency.

  On the other hand, in order to increase the compression efficiency in the maximum rotation speed range for the female rotor and the male rotor, it is necessary to set the gap between the rotors to be zero as much as possible in the maximum rotation speed range. However, since the female rotor and the male rotor are made of the same material, the thermal expansion coefficient is also the same. For this reason, when the compression ratio is low or when the rotational speed is low, both rotors contract at a low temperature, resulting in a problem that the clearance between the rotors becomes large and the compression efficiency decreases. For the female and male rotors, designing the part shape so that the gap is zero as much as possible is limited in consideration of machining tolerances. It was difficult to improve the compression efficiency.

  The objective of this invention is providing the manufacturing method of the screw type supercharger which reduced the micro clearance gap between the components which comprise a supercharger, and improved compression efficiency.

  In order to solve the above-described problem, a method for manufacturing a screw-type supercharger according to the present invention includes a male and female rotor having blades formed in a spiral shape and meshed with each other. In a manufacturing method of a screw-type supercharger that compresses and supercharges air by rotational driving, when the male and female rotors are incorporated in the casing, the longitudinal end surfaces of the male and female rotors and the A coating having a thickness such that the inner surface of the casing and / or the outer peripheral tip of the blade and the inner surface of the casing are in contact with each other and / or the surfaces of the blades of the male and female rotors. A coating process to be applied to the longitudinal end face of the rotor of the male and female and / or the outer peripheral tip of the blade and / or the surface of the blade, and the male and female coated Characterized in that it comprises a built step of incorporating an over data in the casing, and a cutting step of the rotor of the male and female rotary drive to scrape off a part of the coating.

  Further, in the coating step, of the longitudinal end surfaces of the male and female rotors, the end surface on the suction port side and / or the outer peripheral tip of the blade located near the suction port of the male and female rotors, and / or Alternatively, the surface of the blades of the male and female rotors located in the vicinity of the inlet of the male and female rotors is coated with a thickness that contacts the inner surface of the casing.

  According to the present invention, the longitudinal end surface of the male and female rotors and the inner surface of the casing and / or the outer peripheral tip of the blades and the inner surface of the casing and / or the surfaces of the blades of the male and female rotors A coating with such a thickness as to contact the male and female rotors is applied to the longitudinal end faces of the male and female rotors and / or the outer peripheral tips of the blades and / or the surfaces of the blades of the male and female rotors. Since part of the coating is scraped off by rotating at a high temperature, the gap between the above parts can be made almost zero by the coating layer that remains uncut at high temperatures, improving compression efficiency at high temperatures. Can be made. Further, since the gap can be narrowed by the amount of the coating layer that remains without being cut at low temperatures, the compression efficiency can be improved as compared with the conventional case even at low temperatures.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the structure of a screw-type supercharger manufactured by the method for manufacturing a screw-type supercharger according to this embodiment.

  As shown in FIG. 1, the screw-type supercharger 1 of the present embodiment includes a male rotor 2 and a female rotor 3 that compress the air that is meshed with each other and a rotor casing 4 that houses the male rotor 2 and the female rotor 3. The M-axis 5 serving as the rotation axis of the male rotor 2, the suction-side bearing 6 that rotatably supports the suction port side of the M-axis 5, and the discharge-side bearing that rotatably supports the discharge port side of the M-axis 5 7, an F shaft 8 serving as a rotation shaft of the female rotor 3, a suction side bearing 9 that rotatably supports the suction port side of the F shaft 8, and a discharge side that rotatably supports the discharge port side of the F shaft 8 The bearing 10, the suction port 11 that supplies air to the male rotor 2 and the female rotor 3, the discharge port 12 that discharges the air compressed by the male rotor 2 and the female rotor 3, and the M shaft 5 and the F shaft 8 are rotated. Timing gears 14 and 15 for driving are provided.

  As shown in FIG. 2, the male rotor 2 is composed of a blade 21 and an M shaft 5, and the blade 21 is formed of an aluminum alloy, and the M shaft 5 is mainly formed of iron. The blade 21 and the M shaft 5 can be integrated and manufactured by casting an iron shaft when the male rotor 2 is cast. When the male rotor 2 is assembled in the rotor casing 4, at least one of the longitudinal end faces 22 and 23 of the male rotor 2 and the outer peripheral tip 21 a of the blade 21, The coatings are so thick that the outer peripheral tip 21a of the blade 21 and the inner surface of the rotor casing 4 are in contact with each other.

  Similarly, the female rotor 3 is also composed of blades 31 made of an aluminum alloy and an F shaft 8 made mainly of iron. When the female rotor 3 is assembled in the rotor casing 4 on at least one of the end surfaces 32 and 33 in the longitudinal direction of the female rotor 3 and the outer peripheral tip 31a of the blade 31, the end surface of the female rotor 3 and Coatings having a thickness such that the outer peripheral tip 31a of the blade 31 and the inner surface of the rotor casing 4 are in contact with each other are applied.

  Furthermore, when the male rotor 2 and the female rotor 3 are assembled into the rotor casing 4, the blades 21 and 31 come into contact with the surface of the blade 21 of the male rotor 2 and the surface of the blade 31 of the female rotor 3. Each is coated with a different thickness.

  The gap between the longitudinal end faces 22 and 23 of the male rotor 2 and the inner surface of the rotor casing 4, the gap between the longitudinal end faces 32 and 33 of the female rotor 3 and the inner face of the rotor casing 4, and the blades 21 of the male rotor 2. The gap between the outer circumferential tip 21a and the inner surface of the rotor casing 4, the gap between the outer circumferential tip 31a of the blade 31 of the female rotor 3 and the inner surface of the rotor casing 4, the surface of the blade 21 of the male rotor 2 and the blade of the female rotor 3 31. By incorporating the male rotor 2 and the female rotor 3 into the rotor casing 4 so that the gap between the surface of the rotor 31 and the surface of the rotor 31 is in consideration of the thickness of the coating layer, the end face in the longitudinal direction of the male rotor 2 is obtained. 22, 23 and the inner surface of the rotor casing 4, the longitudinal end surfaces 32 and 33 of the female rotor 3, the inner surface of the rotor casing 4, and the outer peripheral tip of the blade 21 of the male rotor 2. 21 a and the inner surface of the rotor casing 4, the outer peripheral tip 31 a of the blade 31 of the female rotor 3 and the inner surface of the rotor casing 4, and the surface of the blade 21 of the male rotor 2 and the surface of the blade 31 of the female rotor 3, respectively Can be made.

  The male rotor 2 and the female rotor 3 configured as described above are installed in the rotor casing 4 as shown in FIG. 3 and are assembled so as to mesh with each other.

  Further, as shown in FIG. 4 which is a cross-sectional view taken along the line A-A of FIG. 1, the suction side bearing portion has a central portion where the suction side bearing 6 of the male rotor 2 and the suction side bearing 9 of the female rotor 3 are fixed. And a suction port 11 is formed around it.

  The screw-type supercharger 1 of the present embodiment configured as described above is an air introduced through the suction port 11 by rotating the male rotor 2 and the female rotor 3 meshed with each other in opposite directions by engine output or the like. Is compressed between two rotors and discharged from the discharge port 12 as pressurized air. The pressurized air discharged from the screw type supercharger 1 is supercharged to the air supply side of the internal combustion engine.

  Next, the manufacturing method of the screw type supercharger 1 concerning this embodiment is demonstrated based on the flowchart of FIG.

  As shown in FIG. 5, the coating process which coats the manufactured male rotor 2 and female rotor 3 first is implemented (step S101). In this coating process, coating is performed on the longitudinal end faces 22 and 23 of the male rotor 2 and the longitudinal end faces 32 and 33 of the female rotor 3. At this time, the coating may be performed so that at least one of the end faces is thicker than a normal coating. For example, in the case of the male rotor 2, both end faces 22 and 23 may be coated thickly, or only one of the end faces may be thickly coated and the other end face may be coated with a normal thickness. Also good. The same applies to the female rotor 3.

  Here, when the male rotor 2 and the female rotor 3 are assembled in the rotor casing 4, the longitudinal thickness of each rotor and the inner surface of the rotor casing 4 are set as the thickness of the coating in the case of making it thicker than a normal coating. It is desirable that the thickness be such that the contact is made at a high temperature when rotated at the maximum number of rotations in a cutting process described later, even if they are not in contact with each other or are not contacted during assembly.

  In step S101, the outer peripheral tip 21a of the blade 21 of the male rotor 2 and the outer peripheral tip 31a of the blade 31 of the female rotor 3 are coated so as to be thicker than normal coating.

  Here, as the thickness of the coating in the case of making it thicker than the normal coating, when the male rotor 2 and the female rotor 3 are incorporated in the rotor casing 4, the outer peripheral tip of each rotor blade and the rotor casing 4 Even if it is in contact with the inner surface or is not in contact with the built-in, the thickness is set such that it comes into contact with a high temperature when it is rotated at the maximum number of rotations in a cutting process described later.

  Further, in step S101, the surface of the blade 21 of the male rotor 2 and the surface of the blade 31 of the female rotor 3 are coated so as to be thicker than normal coating.

  Here, as the thickness of the coating in the case of making it thicker than a normal coating, when the male rotor 2 and the female rotor 3 are assembled in the rotor casing 4, the surfaces of the blades 21 and 31 of each rotor are in contact with each other. Or even if it does not contact at the time of assembling, it is set to such a thickness that it contacts when heated at the maximum rotational speed in the cutting process described later.

  In addition, as a coating material in the said coating process, a common coating material should just be utilized, for example, a Teflon (trademark) type resin, a fluorine resin, etc. can be used.

  After coating the male rotor 2 and the female rotor 3 in this manner, an assembling step for incorporating the male rotor 2 and the female rotor 3 into the rotor casing 4 is subsequently performed (step S102). In this assembling process, the male rotor 2 and the female rotor 3 are engaged with each other and incorporated in the rotor casing 4, and the suction side bearing is set and completed.

  Next, a cutting process is performed in which the male rotor 2 and the female rotor 3 are rotationally driven to scrape off the coating formed thicker than usual (step S103). In this cutting process, the rotors 2 and 3 are driven at the maximum number of rotations, and the coating of the male rotor 2 and the end face in the longitudinal direction of the female rotor 3 formed in advance, the coating of the outer peripheral tip of the blade, and the blade Remove the surface coating.

  Thereby, the clearance between the longitudinal end surface of the male rotor 2, the female rotor 3 and the inner surface of the rotor casing 4, the clearance between the outer peripheral tip of the blade and the inner surface of the rotor casing 4, and the male rotor 2 The gap between the surface of the blade 21 and the surface of the blade 31 of the female rotor 3 can be made substantially zero by the coating layer remaining without being shaved. Therefore, the compression efficiency at high temperatures can be improved. And even when the temperature drops, these gaps can be made narrower than in the past by the amount of the coating layer that remains without being scraped, so that the compression efficiency can be improved more than in the past even at low temperatures. .

  In the above-described coating process, the coating on at least one of the end surfaces of the male rotor 2 and the female rotor 3 is thickened. Of the end surfaces in the longitudinal direction of the rotor, the end surface on the suction port 11 side and / or the suction surface. You may make it thicken only the coating | coated of the outer peripheral front-end | tip part of the blade | wing located in about 1/3 of the rotor longitudinal direction in the vicinity of the opening | mouth 11, and / or the surface of the blade | wing located in the suction opening 11 vicinity.

  Thereby, when removing the resin (shavings) after shaving the coating, the suction port 11 can be used, so that the resin can be easily removed. On the other hand, when both the end surfaces of the male rotor 2 and the female rotor 3 are coated, when the end surface on the discharge port 12 side is coated, and on the outer peripheral tip of the blade located in the vicinity of the discharge port 12 side When the coating is applied to the part, and when the coating is applied to the surface of the blade located in the vicinity of the discharge port 12 side, it is difficult to remove the resin because the resin must be removed from the triangular discharge port. .

  As described above, in the method of manufacturing the screw-type supercharger according to the present embodiment, the longitudinal ends of the male rotor 2 and the female rotor 3 and the inner surface of the rotor casing 4, and the blades of the male rotor 2 and the female rotor 3 are used. The outer peripheral tip and the inner surface of the rotor casing 4, the blades of the male rotor 2, and the blades of the female rotor 3 are coated so as to contact each other. Since the screw-type supercharger 1 is manufactured by scraping the coating by being incorporated in the casing 4 and rotating, the male rotor 2, the female rotor 3, and the like are separated by the coating layer that remains uncut at high temperatures. The gap between the rotor casing 4 and the gap between the male rotor 2 and the female rotor 3 can be made almost zero, and it is not scraped even at low temperatures. Min only Tsu coating layer, it is possible to narrow these gaps conventionally, it is possible to improve the compression efficiency.

  Further, in the coating process, only the end face on the suction port 11 side of the longitudinal end faces of the male rotor 2 and the female rotor 3 and / or the outer peripheral tip of the blade located near the suction port 11 and / or the vicinity of the suction port 11 By thickening the coating only on the surface of the blade located at, it becomes possible to easily remove the resin after the coating has been shaved.

  In the present embodiment, as the best mode for carrying out the invention, that is, as a combination considered to be most effective in improving the compression efficiency, (1) the longitudinal end faces of the male rotor 2 and the female rotor 3 (2) coating with a thickness such that the outer peripheral tips of the blades of the male rotor 2 and the female rotor 3 and the inner surface of the rotor casing 4 are in contact with each other; 3) An example in which a coating having a thickness such that the blade surfaces of the male rotor 2 and the blade surfaces of the female rotor 3 are in contact with each other is shown. However, two of these coatings (1) to (3) may be combined, or any one of them may be performed. Thus, even if it is a case where it implements combining one or two of the coating of (1)-(3), compression efficiency can be improved conventionally.

It is sectional drawing which shows the structure of the screw-type supercharger which concerns on embodiment of this invention. It is a figure which shows the structure of the male rotor and female rotor of the screw type supercharger which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the screw-type supercharger which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the bearing part of the screw type supercharger which concerns on embodiment of this invention. It is a flowchart for demonstrating the manufacturing method of the screw type supercharger which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screw type supercharger 2 Male rotor 3 Female rotor 4 Rotor casing 5 M axis 6 Suction side bearing 7 Discharge side bearing 8 F axis 9 Suction side bearing 10 Discharge side bearing 11 Suction port 12 Discharge port 14, 15 Timing gear 21, 31 Blade 21a, 31a Outer peripheral tip 22, 23, 32, 33 End face of rotor

Claims (2)

In a method for manufacturing a screw-type supercharger, in which a male and female rotor having blades formed in a spiral shape is assembled and meshed in a casing, and the male and female rotors are rotationally driven to compress and supercharge air. ,
When the male and female rotors are incorporated into the casing, the longitudinal end surface of the male and female rotors and the inner surface of the casing and / or the outer peripheral tip of the blades and the inner surface of the casing And / or a coating having a thickness such that the blade surfaces of the male and female rotors are in contact with each other, a longitudinal end surface of the male and female rotors, and / or an outer peripheral tip of the blade, and / or Or a coating process applied to the surface of the blade;
An assembling step of incorporating the male and female rotors coated in the casing;
A cutting step of rotating and driving the male and female rotors to scrape off a part of the coating;
The manufacturing method of the screw-type supercharger characterized by including.   In the coating step, of the longitudinal end faces of the male and female rotors, the end face on the inlet side, and / or the outer peripheral tip of the blade located near the inlet of the male and female rotors, and / or 2. The screw type according to claim 1, wherein a coating having a thickness in contact with an inner surface of the casing is applied to a surface of the blade of the male and female rotors located in the vicinity of an inlet of the male and female rotors. A method of manufacturing a turbocharger.

Images