JPH0527471B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a masking jig used for coating the outer surface of a roots-shaped rotor with resin powder.

BACKGROUND ART A rotor for a Roots-type supercharger has a rotary shaft insertion hole in the center, and two rotors are used in mesh with each other in a housing. In order to reduce the gap between the two rotors and the gap between the rotor and the housing as much as possible and increase volumetric efficiency, the outer circumferential surface and end surface of the rotor are coated with synthetic resin.

Therefore, in order to efficiently form a resin layer of a desired thickness in a shorter time, the inventors of the present invention attempted to coat the inside of the resin powder by fusion bonding. That is, the rotor material is heated to a temperature equal to or higher than the melting point of the resin to be coated, and the rotor material is immersed in resin powder and fused before and after the heating.

Problems to be Solved by the Invention However, when coating the rotor material by immersing it in resin powder, parts used as reference surfaces during processing, such as the area around the rotation shaft insertion hole and the end face of the rotor, are used as reference surfaces during processing. It has become clear that since the resin is coated on the resin, it is necessary to carry out post-treatment to remove it, leading to a problem of increased manufacturing costs.

Means for Solving the Problems In order to solve these problems, the present invention has the following features:
When the rotor of a Roots-type supercharger with a rotating shaft insertion hole in the center is heated by induction and coated with resin powder by fusion, the rotor is heated around the opening of the rotating shaft insertion hole on the end face of the rotor and on the inner circumferential surface. The masking jig is made of a metal that is less susceptible to induction heating than the material of the rotor, and is tightly fitted around the rotary shaft insertion hole on the end face of the rotor. a sealing member that is fixed to the sealing member, which is made of a material with a lower thermal conductivity than the material of the sealing member, and a heat insulating material that holds the sealing member through the heat insulating material and fixes the sealing member to the rotor. and fixing means.

Effects of the Invention According to the masking jig configured as described above, in order to prevent the sealing member from coming into close contact with the periphery of the rotating shaft insertion hole on the end face of the rotor and the resin powder being fused, The periphery of the opening and the inner peripheral surface are not coated with resin powder, and can be used as a reference surface during processing without any post-processing.

In addition, since the sealing member of the masking jig according to the present invention is made of metal, there is no fear that it will get strained due to contact with the rotor when it is attached to or removed from the rotor, and it has excellent durability. There is. Moreover,
This metal is more difficult to be induction heated than the rotor material, so even if the rotor is induction heated, the temperature of the sealing member will not rise as much as the rotor, and the resin powder will be difficult to fuse, and even if it is fused, it will not be strong. Because it does not stick to the rotor, it easily peels off from the seal member when it is removed from the rotor, making it difficult to remove the seal member as it would be if a resin layer was formed on the surface of the seal member in the same way as the rotor. There is no fear that the resin layer formed on the rotor will peel off.

In addition, since the sealing member is held by a fixing means and fixed to the rotor through an insulating material made of a material with a lower thermal conductivity than itself, a large amount of heat transferred from the rotor to the sealing member due to thermal conduction is fixed. There is no possibility that the rotor will move to the device, the temperature drop of the rotor (especially the end surface where the sealing member is brought into close contact) will be small, and the resin powder will not be sufficiently fused to ensure a resin layer of a predetermined thickness. It won't be difficult.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

FIG. 9 is a diagram showing a rotor material (hereinafter referred to as rotor) 10 before being coated with synthetic resin powder of a cocoon-shaped rotor, which is a type of rotor for a roots-type supercharger. This rotor 1
0 is made of an aluminum alloy, especially an Al-Si alloy with a high silicon content of about 12% (for example, JIS A 4047, etc.) in this embodiment, and a rotating shaft insertion hole 12 is provided in the center of the aluminum alloy. On the other hand, one weight reduction hole 14 is formed in the blade portions on both sides of the rotary shaft insertion hole 12 by penetrating the blade portion in the axial direction, and is hollow. and,
The entire outer peripheral surface of the rotor 10, which is a hollow member, and the outer peripheral portions of both end surfaces 16 and 18, that is, the portions excluding the areas around the rotating shaft insertion hole 12 and the weight reduction hole 14, are scheduled to be coated with synthetic resin.
Examples of the synthetic resin powder to be coated include tetrafluoroethylene (tetrafluoroethylene).
Powder of Aphron (trade name...hereinafter referred to as Aphron), which is a copolymer of and ethylene, is used.

FIG. 8 shows an example of an apparatus for coating the rotor 10 with Aflon. In the figure, 20 is a fluidized tank, and in this fluidized tank 20 there is an Aphron powder P.
is inserted into the rotor 1 during coating.
0 is raised and lowered with its end surfaces 16 and 18 positioned above and below. After the rotor 10 is preheated, it is immersed in this Aphron powder P.
In order to facilitate the immersion of the rotor 10 into the afron powder P and its removal from the fluidized tank 2,
The afron powder P in the fluidizing tank 20 is brought into a fluidized state by vibrations applied by a vibrator 22 fixed to the bottom of the fluidizing tank 20 and compressed air supplied from an air supply port 24. Reference numeral 26 denotes an air filter, which is made of multiple layers of tracing paper (sulfuric acid paper), a porous plate made of polyethylene, ceramics, or metal. This serves to uniformly supply an appropriate amount of air supplied from the air supply port 24 to the Aflon powder P.

An upper coil 28 for inductively heating the rotor 10 is provided at a fixed position in the upper part of the fluidized tank 20. The upper coil 28 is of the same type as a coil used for induction hardening, has a similar shape that is larger than the rotor 10, and is arranged so as to surround the rotor 10 at a predetermined distance from the outside.
The rotor 10 is heated by electromagnetic induction when the coil power supply 30 supplies electricity.

Below the upper coil 28, a lower coil 34 is placed in a fixed position while being buried in the Aflon powder P. This lower coil 34 has the same structure as the upper coil 28, and is used to reheat the rotor 10 immersed in the Aflon powder P by induction heating by electricity supplied from the coil power supply 36.

A hydraulic cylinder 3 for raising and lowering the rotor 10 is located above the coating device configured as described above.
8 are arranged. The hydraulic cylinder 38 is attached to a fixed member 39, and a holder 42 is attached to the lower end of the piston rod 40. The retainer 42 is attached to the piston rod 40 via a plate 44.
A guide rod 46 erected at the other end of the piston rod 40 passes through the fixing member 39 and guides the movement of the piston rod 40 while preventing its rotation.

The retainer 42 has a proximal end 50 attached to the piston rod 40, as seen in FIG.
and a plate-shaped portion 5 extending downward from its base end portion 50.
2, and a plate-like part 54 extending horizontally from the lower end of the plate-like part 52 in a direction facing the base end part 50. A positioning protrusion 56 is provided in the vertically intermediate portion of the plate-shaped portion 52, while the plate-shaped portion 54
A U-shaped notch 60 that opens on the side opposite to the boundary with the plate-like portion 52 is formed in the hydraulic cylinder 3.
8 is attached to the fixing member 39 such that the notch 60 and the positioning protrusion 56 are located along the longitudinal direction of the cross-sectional shape of the coils 28, 34. Further, an engaging member 62 is embedded in a portion of the proximal end 50 facing the notch 60, and this engaging member 62 is biased by a spring (not shown) in a direction to protrude a certain amount from the proximal end 50. has been done.

A masking jig 64 is attached to the rotor 10 in order to prevent the Aflon powder P from being fused to the inner peripheral surfaces of the rotating shaft insertion hole 12 and the weight reduction hole 14 and around their openings. The masking jig 64 includes an upper mask member 66 and a lower mask member 68 attached to both sides of the rotor 10, respectively.
It is equipped with These mask members 66, 68
are seal members 70, 72 that are in close contact with the openings at both ends of the rotating shaft insertion hole 12 and the weight reduction hole 14, respectively, and close the openings of each hole 12, 14 to the upper and lower end surfaces 16, 18, respectively; 72 and fixed heat insulating materials 74 and 76. These sealing members 70 and 72 are made of a metal that is less susceptible to induction heating than the aluminum alloy forming the rotor 10, such as brass, copper, or stainless steel. The sealing members 70, 7 are made of a resin layer and are slightly thicker than the thickness.
The thickness is sufficient to make the surface in contact with 2 a straight end surface. Further, these seal members 70 and 72 are large enough to close the rotating shaft insertion hole 12 and the weight reduction hole 14, but are made smaller than the end surface of the rotor 10, and the shape of the outer periphery is As shown in FIGS. 2 and 3, the portions that close both holes 12 and 14, that is, the central portion and both ends in the longitudinal direction, are convex in a direction perpendicular to the longitudinal direction, while the portion between these convex portions is The part is said to be recessed towards the axis.

Positioning protrusions 78 are formed at both ends in the longitudinal direction of the end surfaces of the seal members 70 and 72 that come into close contact with the rotor 10, respectively. These positioning protrusions 78 are shaped like annular protrusions whose outer diameter is equal to the diameter of the weight reduction hole 14, with the portions of the protrusions near each other cut out. Seal members 70, 72
positioning with respect to the rotor 10. In addition, in the center of the end surface of the sealing member 70 on the side that comes into close contact with the rotor 10,
As is clear from the figure, a shallow counterbore is provided to minimize the contact area with the rotor 10, and the sealing member 72 has an elongated hole 82 as shown in FIG. has been done.

On the other hand, the heat insulating materials 74 and 76 are made of a material having a lower thermal conductivity than the sealing members 70 and 72, such as asbestos with cement (trade name: Asbestos Hemit), ceramics, and heat-resistant resin. has been done. The heat insulating material 74 fixed to the seal member 70 has an oval plate shape as shown in FIGS. 1 and 3, and the seal member 70 and the heat insulating material 74
It is fixed to the seal member 70 by a bolt 84 made of the same material as either of the above. Further, the heat insulating material 76 fixed to the sealing member 72 has a stepped shape as shown in FIGS. 1 and 6, and is attached to bolts 86 similar to the bolts 84 at the flange portions extending on both sides in the longitudinal direction. Therefore, it is fixed to the seal member 72. An elongated hole 88 with a bottom that is continuous with the elongated hole 82 and a bottomed hole 90 with a circular cross section that opens at the bottom of the elongated hole 88 are formed on the end surface of the heat insulating material 76 on the side that comes into close contact with the sealing member 72. There is. Long hole 8
A plate 92 that closes the bottomed hole 90 is fixed to the bottom of the hole 8 , and the plate 92 has an elongated hole 94 opening with a length equal to the diameter of the bottomed hole 90 .
It is formed along the long hole direction.

The upper mask member 66 is a hollow rod 100.
is mounted for relative movement in the axial direction,
At the upper end of the rod 100 is a large diameter operated part 102.
and a held portion 104 are formed. The operated part 102 has a disk 108 at both ends of a cylinder 106,
110 are fixed by welding, and these disks 108 and 110 are attached to the rod 10.
It is fixed by being welded to 0. Further, the held portion 104 includes a large diameter portion 112 and a small diameter portion 11.
A rod 100 is inserted into a bottomed hole 116 that passes through the small diameter portion 114 in the axial direction and reaches the large diameter portion 112.
The upper ends of the two are fitted and fixed by welding. Positioning holes 118 with bottoms are formed in the axially intermediate portion of the large diameter portion 102 at positions directly apart from each other, and the positioning holes 118 are located above the positioning holes 118 and are different from the positioning holes 118. Engagement holes 12 at positions with a 90 degree phase difference
0 is formed. The large-diameter portion 112 further has an inverted conical recess 122 that opens at its upper surface, and both the upper and lower surfaces thereof are tapered surfaces.

A cylindrical member 124 is fixed to the lower part of the operated part 102 of the rod 100 by welding.
A spring retainer 1 is installed on the outside of the cylindrical member 124.
26 cylindrical portions 128 are fitted so as to be slidable in the axial direction. The rod 100 and the cylindrical member 124 are each formed with an elongated hole 130 extending axially through the rod 100 and the cylindrical member 124 at positions separated from each other in the diametrical direction.
6 refers to the pin 132 inserted into this elongated hole 130.
Since both ends of the cylinder are supported by the cylindrical part 128, relative rotation is not possible, but relative movement is possible by a certain distance in the axial direction. In addition, pin 132
is prevented from being pulled out by a ring-shaped cover 134 fitted onto the outer peripheral surface of the cylindrical portion 128.

As is clear from FIG. 3, the lower portion of the cylindrical portion 128 is formed in the same direction as the two positioning holes 118 of the held portion 104.
Two lug pieces 136 are formed that extend outward from positions separated from each other in the diametrical direction, and the upper mask member 66 is fixed to the lug pieces 136 with a plate-shaped operating member 138 in between. There is. The upper mask member 66 is fixed with its longitudinal direction extending in the direction in which the two ear pieces 136 are formed, and is disposed between the ear pieces 136 and the disk 110 of the operated section 102. It is urged downward by a compression coil spring 142. The upper mask member 66 is movable relative to the rod 100 within the range in which the pin 132 moves through the elongated hole 130, and the operating member 138 includes the upper mask member 66 as shown in FIG. Two flanges 140 are formed, each extending outward in a direction perpendicular to the longitudinal direction.

Furthermore, an engaging member 144 is fixed to the lower end of the rod 100. Engagement member 144
The rod 1 is connected to the bottomed cylindrical fitting part 146.
00 and is fixed by welding, and as shown in FIG. 7, a small-diameter leg portion 148 and a plate-shaped protrusion 150 are formed on the lower side of the fitting portion 146. The protrusion 150 is attached to the plate 92.
The engagement member 14 is shorter than the length in the longitudinal direction of the elongated hole 94 formed in the elongated hole 82 and the bottomed hole 90, and has a size that can be inserted into the elongated hole 82 and the bottomed hole 90.
4 is the rod 1 so that the protrusion 150 extends in a direction perpendicular to the longitudinal direction of the upper mask member 66.
It is fixed at 00.

The rod 100, spring retainer 126, operating member 138, spring 142, etc. are made of materials that are difficult to be heated by induction, such as brass, copper, and stainless steel, like the seal members 70 and 72. , insulation material 74,
76, the constituent members of the masking jig 64, including the bolts 84 and 86 that fix them together, and the rods 100, are coated with polytetrafluoroethylene (tetrafluoroethylene), known by the trade name of Teflon, and are coated with Aflon powder. P is prevented from being fused.

Then, the masking jig 64 is attached to the rotor 10, whose surface has been made suitable for resin coating through surface treatment, in the following manner.
That is, it has the operated portion 102 and the operating member 13
Move the upper mask member 66 toward the operated section 102 while compressing the compression coil spring 142 by placing your finger on the collar 140 of the rod 100.
is inserted into the rotating shaft insertion hole 12, and the positioning protrusion 78 of the seal member 70 is fitted into the weight reduction hole 14, so that the seal member 70 is brought into contact with the end surface 16. In this state, the engaging member 144 fixed to the lower end of the rod 100 protrudes from the lower surface of the rotor 10. Next, lower mask member 6
8, and insert the protrusion 150 into the bottomed hole 90 by aligning the elongated hole 94 formed in the plate 92 with the protrusion 150 of the engaging member 144. On this occasion,
Since the protrusion 150 is provided perpendicular to the longitudinal direction of the upper mask member 66, when the protrusion 150 is inserted into the bottomed hole 90, the elongated hole 94 is formed along the longitudinal direction of the lower Mask member 6
8 is in a posture with a phase difference of 90 degrees with respect to the upper mask member 66. If the lower mask member 68 is rotated 90 degrees from this state, the positioning protrusion 78 will be in a state where it can be inserted into the opening of the rotating shaft insertion hole 14, and the phase between the protrusion 150 and the elongated hole 94 will be shifted by 90 degrees. When the protrusion 150 is in a position capable of engaging with the plate 92, and the finger on the collar 140 is released, the compression coil spring 142 expands, and its biasing force brings the seal member 70 into close contact with the end surface 16 of the rotor 10. At the same time, as the rod 100 rises, the protrusion 150 engages with the plate 92. Due to this engagement, the biasing force of the spring 142 is also transmitted to the seal member 72, and the seal member 72 moves the positioning protrusion 78 into the weight reduction hole 14. They are fitted and brought into close contact with the end face 18.

In this way, in this embodiment, the plate 92,
The rod 100, the compression coil spring 142, the protrusion 150, etc. constitute a fixing means for fixing the seal members 70, 72 to the rotor 10, and the seal members 70, 72 are made of metal. There is no fear that the positioning protrusion 78 will be damaged by impact when it is brought into close contact with the end faces 16 and 18 by the biasing force of the compression coil spring 142 or when the positioning protrusion 78 is inserted into the weight reduction hole 14.

The rotor 10 with the masking jig 64 attached as described above is transported to the coating device by a transport device (not shown). The conveying device holds the masking jig 64 and conveys the rotor 10, and the claws of the holding jig provided on the conveying device are engaged with the engagement holes 120 formed in the held portion 104.

Masking jig 6 held by a conveyance device
4 is a large diameter portion 92 of the held portion 84 after the held portion 104 is conveyed to a position facing the holder 42.
The small diameter portions 104 are respectively fitted into the notches 60 between the base end portion 50 and the plate-like portion 54 of the holder 42 . At this time, the large diameter portion 102 is fitted into the proximal end portion 50 by pushing the engagement member 62 into the base end portion 50 against the biasing force of the spring due to its tapered surface. In the properly fitted state, the positioning protrusion 56 is fitted into the positioning hole 118, and the held part 104 is attached to the holder 4.
2, it is held unrotatable. When held in this manner, the upper mask member 66
is fixed to the spring retainer 126 so that its longitudinal direction is in the same direction as the direction in which the two positioning holes 118 are formed, and the positioning protrusion 56 provided on the holder 42 also has a coil similar in shape to the rotor 10. Since the rotor 10 is formed in the same direction as the longitudinal direction of the cross-sectional shape of the coils 28 and 34, the rotor 10 is positioned on the fluidized tank 20 with its phase matching that of the coils 28 and 34.

Then, before the rotor 10 is immersed into the Aphron powder P housed in the fluidized bath 20, it is first positioned in the upper coil 28, and is induction heated by the upper coil 28 to a temperature higher than the melting point of the Aphron powder P. .
The rotor 10 heated by the upper coil 28 is
Next, the cylinder 38 is operated to lower the aphron powder P contained in the fluidized tank 20.
It makes you immerse yourself inside. In this immersion process, the aphron powder P is brought into a fluid state by operating the vibrator 22 and supplying compressed air from the air supply port 24. In addition, the coil power supply 36 of the lower coil 34 is
The rotor 10 is immersed in the Afron powder P which is kept in the OFF state and is in a fluid state as described above. At this time, since the surface of the rotor 10, which has already been heated to a temperature higher than the melting point of the Aphron powder P, and the Aphron powder P in the fluidization tank 20 come into contact with each other while moving relative to each other, the Aphron powder P instantly touches the surface of the rotor 10. At this stage, a thin resin layer is evenly formed on the surface of the rotor 10. and,
Furthermore, the rotor 10 is reheated by the lower coil 34,
Retention within the Aphron powder P is performed, and a resin layer with a desired thickness is formed.

When the rotor 10 is immersed in the Aflon powder P to form the resin layer in this manner, the seal members 70 and 72 are brought into close contact around the openings at both ends of the rotating shaft insertion hole 12 and the weight reduction hole 14, respectively. Because of this, Aphron powder P is applied to that area.
does not fuse. Further, since the seal members 70 and 72 are made of a material that is less susceptible to induction heating than the rotor 10, the temperature does not rise as much as the rotor 10, and the outer surfaces of the seal members 70 and 72 are coated with Teflon. The Aflon powder P will not be fused to the surface of the heat insulating materials 74, 76, the rod 100, etc.

Further, the sealing members 70 and 72 are made as thin as possible and only slightly thicker than the resin layer formed on the rotor 10, and the positioning protrusion 78 also forms a part of the annular protrusion.
The heat capacity of the seal members 70 and 72 is made small because the size is the minimum necessary for positioning the rotor 10, and the end face of the seal member 70 that comes into close contact with the rotor 10 is provided with a counterbore. The contact area of the rotor 10 is reduced by forming a long hole 82 in the sealing member 72 as well.
Since the contact area with the seal members 70 and 72 is smaller, it is difficult for heat to transfer, and less heat is transferred from the rotor 10 to the seal members 70 and 72. Moreover, the seal member 7
0 and 72 are held by the fixing means through the heat insulating materials 74 and 76, and the heat transferred from the rotor 10 does not directly escape to the fixing means, so that the temperature of the rotor 10 due to heat conduction is reduced. The drop is small, and there is no possibility that a resin layer of a predetermined thickness cannot be obtained due to insufficient fusion of the Aflon powder P.

After the resin coating has been applied to the desired thickness as described above, the rotor 10 is transferred to the hydraulic cylinder 38.
is raised by the operation of the Aphron powder P and taken out from within the Aphron powder P. After this removal, the rotor 10 is transferred to the masking jig 64 by the conveyance device.
The entire body is removed from the holder 42.

Thereafter, the masking jig 64 is removed from the rotor 10, but since this can be done by performing the reverse operation for mounting, the explanation will be omitted. During this removal,
Since the Afron powder P is not fused to the surface of the masking jig 64, the resin powder continues to be fused to the masking jig 64 from the rotor 10, making it difficult to remove the masking jig 64 from the rotor 10. This prevents the resin layer formed on the rotor 10 from becoming loose or peeling off when the masking jig 64 is removed.

Note that if the insulation materials 74 and 76 are made of asbestos and cement, a particularly inexpensive insulation material with excellent heat insulation properties can be obtained.
6 to the seal members 70, 72
4 and 86 can be made from brass, copper, stainless copper, etc., and not only can they be manufactured at low cost, but also provide bolts with excellent durability.
6. The manufacturing cost of the masking jig 64 itself can be reduced by manufacturing the bolts 84 and 86 at low cost.

In addition, sealing members 70, 72 and heat insulating materials 74, 7
6 is not limited to the bolts 84 and 86, but may be fixed by other means such as adhesion or insert molding.

Furthermore, in the above embodiment, the seal member 7
0 and 72 were plate-shaped or square-shaped, but at least the sealing member 70 constituting the upper mask member 66 is shaped like a dome together with the heat insulating material 74, so that when the rotor 10 is taken out from the fluidized bed 20, The aphron powder P on the upper side of the upper mask member 66 may be made to slide down.

Although not illustrated in detail, the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing a state in which a masking jig according to an embodiment of the present invention is attached to a rotor. FIG. 2 is a plan view showing the lower mask member of the masking jig in relation to the rotor, and FIG. 3 is a plan view showing the upper mask member fixed to the spring retainer together with the operating member of the jig. FIG. 4 is a bottom view of the seal member constituting the upper mask member, and FIG. 5 is a side sectional view thereof. FIG. 6 is a bottom view of the lower mask member. FIG. 7 is a front sectional view showing a state in which the protrusion formed on the rod of the jig and the plate fixed to the lower mask member are engaged. FIG. 8 is a front sectional view showing an apparatus for coating the rotor with Aphron powder. FIG. 9 is a perspective view of the rotor. 10: Rotor, 12: Rotating shaft insertion hole, 14: Weight reduction hole, 16, 18: End face, 64: Masking jig, 66: Upper mask member, 68: Lower mask member, 70, 72: Seal member, 74, 76: Insulating material, {92: Plate, 100: Rod, 14
2: Compression coil spring, 150: Protrusion (fixing member), P: Afron powder (resin powder).

Claims (1)

[Claims] 1. A roots-type supercharger rotor having a rotary shaft insertion hole in the center is heated by induction,
A masking jig that prevents the resin powder from being fused around the opening of the rotary shaft insertion hole and on the inner peripheral surface of the end face of the rotor when coating the resin powder by fusion bonding, the material of the rotor a sealing member made of a metal that is more difficult to be heated by induction and tightly adheres to the periphery of the rotating shaft insertion hole in the end face of the rotor; and a heat insulating material made of a material having a lower thermal conductivity than the material of the sealing member and fixed to the sealing member. 1. A masking jig for coating a roots-type rotor, comprising: a fixing means for holding the sealing member via the heat insulating material and fixing the sealing member to the rotor.