JPH0653267B2 - Resin coating method for metal parts - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement in a method for coating a surface of a metal part with a resin.

BACKGROUND ART One of the methods for coating the surface of a metal part with resin is to heat the metal part to a temperature above the melting temperature of the resin by induction heating or the like, and to store the powdered resin in a fluidized immersion tank in a fluidized state. By soaking the parts
There is one in which the powdery resin is welded to the surface of a metal part. For example, Japanese Patent Application No. 59-9 previously filed by the applicant
Those described in Japanese Patent Application No. 5418, Japanese Patent Application No. 60-21427 and the like are those.

Problems to be Solved by the Invention However, according to such a conventional resin coating method, the resin is welded to the metal part taken out from the dipping tank, and the surface of the welding resin or the holding jig for holding the metal part It was unavoidable that the unwelded resin powder adhered to the. For this reason, there has been a problem that the film thickness of the resin coated on the surface of the metal component after the subsequent reheating step becomes uneven. In particular, the above-mentioned inconvenience is remarkable when the outer peripheral surface of a metal part for which the accuracy of the coating film thickness is required, for example, the outer peripheral surface of an eyebrow type rotor for a roots type supercharger.

Means for Solving Problems The present invention has been made against the above circumstances.
The gist of the invention is a resin coating method for a metal component, in which a powdered resin is deposited on the surface of a heated metal component in a fluidized dipping tank that contains the powdered resin in a fluidized state. ) A flow stopping step of stopping the flow of the powdery resin in the fluidized dipping tank after the metal parts are dipped in the fluidized dipping tank, and (b) the powdery resin in the fluidized dipping tank. A pressing step of pushing down the metal part in a state where the flow is stopped, and (c) a pulling step of pulling the metal part out of the fluid immersion tank while reflowing the powdery resin in the fluid immersion tank. ,
(d) a gas injection step of injecting a compressed gas on the surface of the metal component pulled up from the powdery resin in a fluidized state to remove unwelded resin on the welded resin welded to the surface,
To include.

By doing so, in the flow stopping step, after the metal part is immersed in the fluidized immersion tank, the flow of the powdery resin in the fluidized immersion tank is stopped, and the fluid immersion in the pressing step is performed. The metal parts are pushed down while the flow of the powdery resin in the tank is stopped, and the metal parts are pulled up from the fluidized dipping tank while the powdery resin in the fluidized dipping tank is reflowed in the pulling process. The
In the gas injecting step, the compressed gas on the surface of the metal component pulled up from the powdery resin in a fluid state is injected to remove the unwelded resin on the welded resin welded to the surface.

As a result, when the powdered resin is welded to the surface by immersing the heated metal part in the fluidized dipping tank that contains the powdered resin in a fluidized state, the flow stop step causes The stopped dense powdery resin is evenly and closely contacted with the surface of the metal part, and when the metal part is further pushed down by the pressing process, it is formed on the lower side of the metal part in the flow stopped state. Since the air pockets are pressed down and the lower side of the surface of the metal part is brought into close contact with the powdery resin, the powdery resin is uniformly and densely welded to the surface of the metal part. Further, when the powdery resin in the fluidized dipping tank is made to flow again in the pulling step and the metal part is pulled up from the fluidized dipping tank, it is pulled up from the fluidized powdery resin in the gas injection step. By injecting the compressed gas on the surface of the metal part, the unfused resin powder remaining on the welded resin on the metal surface is forcibly removed. Therefore, the entire surface of the metal component is coated with the resin with a uniform and highly precise film thickness with high precision.

Embodiment Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a cocoon-shaped rotor 10 for a roots-type supercharger. An insertion hole 12 is formed in the center of the rotor 10, and holes 14 are formed in the blades on both sides of the insertion hole 12 in the axial direction to reduce the weight. The rotor 10 is resin-coated on the entire outer peripheral surface and the outer peripheral portions of both end surfaces, that is, the portions except the periphery of the insertion holes 12 and the holes 14.

A masking jig 66 for preventing the portions around the insertion hole 12 and the hole 14 of the rotor 10 from being resin-coated is configured as shown in FIG. The first mask member 68 and the second mask member 69 are used for the rotor 10
Of the first mask member 68 and the second mask member 69, which are in close contact with the openings of the insertion holes 12 and 14 and close the upper and lower end surfaces of the rotor 10, respectively. The end surface of is large enough to close the insertion hole 12 and the hole 14 and smaller than the end surface of the rotor 10.

The first and second mask members 68, 69 are provided with a pair of positioning protrusions 70 on their end faces facing each other. The positioning protrusions 70 are shaped such that the protrusions having a circular cross section whose diameter is equal to the diameter of the hole 14 of the rotor 10 are cut away from each other, and the diameter gradually decreases toward the tip end side. The first and second mask members 68, 69 are positioned with respect to the rotor 10 by being fitted into the holes 14 and contacting the opening edges of the holes 14.

The second mask member 69 has an elongated hole 72 that is open at the end surface on the side that is brought into close contact with the rotor 10 and has both ends that slightly bite into the positioning protrusion 70, and a bottomed hole 74 that opens at the bottom surface of the elongated hole 72. Are formed. A plate 76 for closing the bottomed hole 74 is fixed to the bottom surface of the long hole 72,
The plate 76 is formed with an elongated hole 78 having an elongated shape whose length in the longitudinal direction is equal to the diameter of the bottomed hole 74, with its longitudinal direction being the same as the longitudinal direction of the elongated hole 72.

On the other hand, the first mask member 68 is attached to the hollow engagement shaft 80 so as to be relatively movable in the axial direction, and the upper end portion of the engagement shaft 80 is an operated member including a cylindrical member 86 and discs 88, 90. A portion 82 and a held portion 84 are provided.
The operated portion 82 is fixed by welding the disks 88 and 90 to the engagement shaft 80. Further, the held portion 84 is fixed to the engaging shaft 80 by fitting and welding the upper end of the engaging shaft 80 into a bottomed hole 96 formed in the axial direction thereof. The held portion 84 is formed with two positioning holes 98 in the radial direction, and an inverted conical recess 102 is formed on the upper surface thereof.

The cylindrical member 1 is provided on the lower portion of the operated portion 82 of the engagement shaft 80.
04 is fixed by welding, and the cylindrical portion 108 of the spring retainer 106 is fitted in the cylindrical member 104 so as to be slidable in the axial direction. Engaging shaft 80 and cylindrical member 1
A through hole 110 is formed in the shaft 04 in the radial direction so as to penetrate the both, and the engaging shaft 80 and the spring retainer 10 are formed.
The reference numeral 6 indicates that both ends of the pin 112 inserted into the through hole 110 are supported by the cylindrical portion 108 so that they cannot be relatively rotated and can be relatively moved in the axial direction by a certain distance. The pin 112 is prevented from coming off by a ring-shaped cover 114 fitted on the outer peripheral surface of the cylindrical portion 108.

The cylindrical portion 108 is formed with a pair of ear pieces 116 protruding radially from the outer periphery of the cylindrical portion 108, and the lower end portion of the cylindrical portion 108 is the first mask member 68.
The ear piece 116 is fixed to the first mask member 68 with the plate-shaped operation member 118 interposed therebetween, and thus is connected to the first mask member 68.

The first mask member 68 is a compression coil spring 122 disposed between the ear piece 116 and the disc 90 of the operated portion 82.
Always urged downward by. That is, the first mask member 68 is movable in the axial direction relative to the engaging shaft 80 within the range in which the pin 112 moves in the through hole 110.

Further, a bottomed cylindrical fitting member 126 is fitted to the lower end of the engaging shaft 80 and fixed by welding.
A plate-shaped protrusion 130 is formed below the fitting member 126. The projection 130 is shorter than the longitudinal length of the long hole 78 formed in the plate 76 and has a size that can be inserted into the bottomed hole 74.
After the insertion, the projection 130 is set in a state in which the longitudinal direction of the projection 130 extends in a direction perpendicular to the longitudinal direction of the elongated hole 78 to prevent the protrusion 130 from coming off the elongated hole 78. As a result, the engagement shaft 80 and the second mask member 69 are engaged with each other, and the second mask member 69 and the rotor 10 are prevented from being separated from each other.

The first and second mask members 68 and 69 are made of asbestos with cement (trade name: asbestos hemit) or a dielectric material such as ceramics, and further, tetrafluoroethylene (tetrafluoroethylene). ), And the other part of the masking jig 66 is also made of a material such as brass and stainless steel which is difficult to be heated by induction heating. Are not fused together.

1 and 3 show a resin coating apparatus 16 for applying a resin coating method including a resin welding step and a gas injection step to the rotor 10, and FIG. 3 is a front view of FIG. Is. Booth 18 constructed by assembling plate-like member 17 to frame 20
A fluid tank 24 that can be freely put in and taken out from the booth 18 and contains a resin powder 22 which is a powder of a copolymer of ethylene tetrafluoride and ethylene (trade name: AFLON), for example, is provided inside. It is fixed. The resin powder 22 in the fluid tank 24 is passed through a filter 26 provided at the bottom of the opening of the fluid tank 24 from an air feeder (not shown) to an air passage 28.
It is in a fluidized state by sending air into the fluidized tank 24 via the. The filter 26 is preferably a stack of a plurality of tracing papers (sulfuric acid paper) or a porous plate made of polyethylene or ceramics, which prevents the resin powder 22 from passing and allows air to pass. Is tolerated.

Above the flow tank 24, a pair of left and right upper coils 30r,
30 l is fixed on the frame 20 of the booth 18. The upper coils 30r and 30l are of the same type as the coils used for induction hardening and have a similar shape to that of the rotor 10, and are arranged so as to surround the rotor 10 at a predetermined distance from the outside, and further have electric wires inside. Are respectively connected to the electric wirings 32 through which electric power is supplied and electric power is supplied from a coil power source (not shown) through the electric wirings 32 to preheat the rotor 10 by electromagnetic induction.

Inside the flow tank 24, a pair of left and right lower coils 36r, 36
1 is fixed to the frame 20 of the booth 18 and disposed on the bottom surface of the hanging coil frame 38 in a state of being buried in the resin powder 22. This lower coil 36r, 36
Reference numeral 1 denotes a structure similar to that of the upper coils 30r and 30l, which are respectively connected to the electric pipes 40 and are energized by a coil power source through the electric pipes 40 to reheat the rotor 10 by electromagnetic induction. Although not shown, the upper coils 30r and 30l and the lower coil 3
6r and 36l are hollow, and cooling water is flown therein to maintain their heating efficiency.

Upper coils 30r and 30l and lower coils 36r and 36l
In between, air injection devices 42r and 42l are fixed to the lower surface of the frame 20 to which the upper coils 30r and 30l are fixed. Since the air injection device 42r and the air injection device 42l have the same configuration, only one air injection device 42r will be described, and the subsequent description will be omitted. One air injecting device 42r shown in FIG. 4 is a plan view of the air injecting device 42r of FIG. 1, and as shown in FIG. 5 (V-V view in FIG. 4), A second member 48 having an annular groove 46 that is substantially the same shape as the cross-sectional shape of the member 44 and the rotor 10 and is larger than that is formed by being assembled to the frame 20 of the booth 18 by a bolt 49, and as a result, the inside An air passage 50 is formed in the. The first member 44 and the second member 48 are provided with an insertion hole 52 that is substantially the same shape as the cross-sectional shape of the rotor 10, is slightly larger than that, and is slightly smaller than the annular groove 46. 50 on the inner surface of the
A plurality of injection ports 54 communicating with the above are opened at two locations, respectively. That is, the air injection devices 42r and 42l inject air sent from an air feeder (not shown) from the injection port 54 through the air passage 50.

Above the upper coils 30r and 30l, a pair of left and right brackets 56r fixed to the plate-shaped member 17 of the booth 18,
Four guide rollers 58 provided in each 56l
There is provided a pair of left and right rods 60r and 60l which are sandwiched between r and 581 and are guided in the vertical direction by preventing lateral sway. Rod 60
The holding members 62r and 62r are provided at the lower ends of the r and 60l, respectively.
1 is attached to the holding members 62r and 62l.
When the masking jig 66 is engaged with the masking jig 66, the rotor 10 having the masking jig 66 loaded from the openable / closable door 64 of the booth 18 is connected to the rods 60r and 60l, respectively. Has become. Since the door 64 is opened only when the rotor 10 is carried in, the inside of the resin coating device 16 is shielded from the outside during the resin coating so that the resin powder 22 is not sealed. It is possible to prevent the environment from being scattered and polluting the environment.

Since the holding members 62r and 62l that engage the masking jig 66 and hold the rotor 10 have the same configuration, only the holding member 62r will be described below. Holding member 6
As shown in detail in FIG. 7, 2r is attached to the rod 60r by attaching the plate member 132 to the lower end portion of the rod 60r with a screw.
2, the block member 134, the thin plate 136, and the hook 13
8 is integrated by being screwed with a screw.

A stepped hole 140 and a hole 142 are formed in the block member 134 and the hook 138, respectively, and the notch 144 and the spring 146 are accommodated therein. Since both ends of the spring 146 are fixed to the inner bottom surface of the notch 144 and the lower surface of the thin plate 136, respectively, the spring 146 always urges the notch 144 downward.
4 is inserted into the hook 138, the recess 102
When the head of the notch 144 presses the
4 is positioned from above. An ear-shaped stopper 148 is formed on the opening-side edge of the notch 144, and the stopper 148 serves as the block member 134.
By contacting the step between the hook and the hook 138,
Notch 144 is prevented from moving further downwards.

As shown in FIG. 8 (FIG. 7 VIII-VIII view), the hook 138 has a U-shaped notch 150 formed in parallel with the loading direction of the rotor 10, and the rod 80 is provided in the notch 150. The rod 80 is housed in the housing to prevent the rod 80 from wobbling laterally. Furthermore, on the side wall of the hook 138,
A positioning member 152 is attached in parallel with the notch 150 and engages with a positioning hole 98 formed in the held portion 84 to prevent relative rotation of the rotor 10 connected to the held portion 84. There is.

The brackets 56r of the rods 60r and 60l provided with the holding members 62r and 62l configured as described above, respectively.
On the side opposite to the 56l side, the rack 156 is arranged along the axial direction.
r and 156l are respectively provided, and the rack 156 is provided.
As shown in detail in FIG. 9, the r and 156l are respectively engaged with the pinions 160r and 160l which are fitted to the first support shaft 158 so as to be relatively unrotatable and axially immovable. The support frame 162 fixedly mounted on the booth 18 that rotatably supports both ends of the first support shaft 158 also rotatably supports both ends of the second support shaft 164 parallel to the first support shaft 158. The first support shaft 158 and the second support shaft 164 are attached to the support frame 16 at one of the tip ends thereof protruding from the support frame 162.
2 via the intermediate member 165 provided on the chain 166
Are provided with sprockets 168 and 169, respectively. A pinion 170 is fitted to the second support shaft 164 so as not to be relatively rotatable and axially movable, and a rack 172 that meshes with the pinion 170 is provided on the drive rod 174 along the axial direction as shown in FIG. A hydraulic cylinder 176 is connected to the lower end of the hydraulic cylinder 176 so that it can be driven in the vertical direction. At that time, drive rod 1
The 74 is sandwiched by a pair of guide rollers 178 so that it can be guided in the up-and-down direction in which lateral vibration is prevented. Since the hydraulic cylinder 176 is configured as described above, the vertical driving force of the hydraulic cylinder 176 is equal to the driving rod 174.
Moves up and down to rotate the second support shaft 164 and transmit the rotation to the first support shaft 158 through the chain 166, so that the rotation is transmitted to the two rods 60r and 60l.

In addition, 180 is a balance device, and the hydraulic cylinder 17
In order to reduce the load applied to No. 6, a weight (not shown) for keeping the balance between the rods 60r and 60l side and the hydraulic cylinder 176 side is lowered at the tip of the wire on the hydraulic cylinder 176 side.

Upper coils 30r, 30l and lower coils 36r, 3
Energization to 6l, and upper coil 30r, lower coil from within 30l 36r, the movement time of the rotor 10 into 36l is intended to be controlled by a timer (not shown) sets the pattern shown in FIG. 10, t ₁ Is the upper coil 30 when the rotor 10 is in the upper coils 30r and 30l.
Power supply time to r, 30l, t ₂ is upper coil 30r, 3
After the heating with 0 l is completed, the lower coils 36r, 36
The time until heating by 1 is started, t ₃ is the rotor 1
0 lower coil 36r, 36r lower coil when it is in the 36l, power supply time to 36l, _{t 4} the upper coil 30r of the rotor 10, the lower coil from within 30l 36r, 36
The moving time to the inside of 1 is shown, respectively. Further, the heating temperature control of the upper coils 30r, 30l and the lower coils 36r, 36l is performed by a high-frequency heating coil control board (not shown).

Hereinafter, the resin coating method applied to the above-described resin coating device 16 will be described, but only the operation of the right device of the pair of left and right devices performing the same operation will be described, and the description thereof will be omitted.

First, the door 64 of the booth 18 is opened, and the rotor 10 previously engaged with the masking jig 66 is loaded by an automatic loading device (not shown) to engage the holding member 62r at the tip of the rod 60r with the masking jig 66. , The door 64 is closed. Next, when the hydraulic cylinder 176 supplied with hydraulic oil from an oil source (not shown) drives the drive rod 174 upward, the driving force is transmitted and the rod 60r is driven downward, so that the rotor 10 moves. Upper coil 30
inserted in r.

At the same time that the rotor 10 is inserted into the upper coil 30r, the upper coil 30r is supplied with power from the coil power source for t ₁ seconds according to the pattern shown in FIG. 10, and the surface temperature of the rotor 10 is heated to the melting point of the resin powder 22 or higher. It At the same time, the rod 60r is driven further downward to move the rotor 10 into the lower coil 36r in the fluidized tank 24 in which the resin powder 22 is in a fluidized state. When the rotor 10 stops inside the lower coil 36r, the flow of the resin powder 22 is stopped. This corresponds to the stopping step. In this stopping step, the resin powder 22 begins to accumulate around the rotor 10, but at that time, air traps often occur below the lower end surface of the rotor 10, and the resin powder 22 is welded to the lower end surface of the rotor 10. Therefore, according to the pattern of FIG. 10, the rod 60r is driven further downward and the rotor 10 is pushed downward to prevent defective welding of the resin powder 22 due to air accumulation. This corresponds to the pressing step. The time required to move the rotor 10 up to this point is t ₄ seconds. After t ₂ seconds from the end of the power supply to the upper coil 30r, the power supply to the lower coil 36r is started and maintained for t ₃ seconds. As a result, the rotor 1
The surface temperature lowered for 0 t ₂ seconds is again raised to assist the welding of the resin powder 22 to the surface of the rotor 10. In this way, the rotor 10 heated in the fluid tank 24
The resin welding step of welding the resin powder 22 to the surface of the is completed.

Subsequently, as the drive rod 174 is driven downward by the hydraulic cylinder 176, the rod 60r is driven upward and the rotor 10 is taken out of the fluid tank 24. This corresponds to pulling up and processes. At this time, the resin powder 22
Is brought into a fluidized state again, and the rotor 10 from the fluidized tank 24 is
It is designed to be easy to remove. Here, when the rotor 10 passes through the insertion hole 52 of the air injection device 42r, the air sent from the air feeder is injected from the injection port 54 of the air injection device 42r toward the rotor 10, and the rotor 10 The unfused resin powder 22 adhering to the welding resin on the surface and the surface of the masking jig 66 and the like is blown off and removed. After the gas injection process is completed in this way, the rotor 10 is carried out from the door 64, a new rotor is carried in, and the resin welding process and the gas injection process are executed again. The resin welding process and the gas injection process described above are similarly performed in the device on the left side.

As described above, according to the present embodiment, when the surface of the rotor 10 is coated with the resin powder 22, the flow-stopped high-density resin powder 22 is brought into intimate contact with the surface of the rotor 10 evenly. At the same time, when the rotor 10 is further pushed down, the air pockets formed on the lower side of the rotor 10 in the flow stopped state are pushed down and the rotor 1 is
Since the lower side of the surface of 0 is brought into close contact with the resin powder 22,
The powdery resin is uniformly and densely adhered to the surface of the rotor 10. When the rotor 10 is pulled up from the fluid tank 24 while the resin powder 22 in the fluid tank 24 is being reflowed, the air injection devices 42r, 42 are attached to the surfaces of the rotor 10 pulled up from the resin powder 22 in the fluidized state.
By injecting the compressed gas from l, the unfused resin powder remaining on the fused resin of the rotor 10 is forcibly removed. Therefore, it is possible to obtain the effect that the resin is coated on the entire surface of the rotor 10 with a uniform and highly accurate film thickness with high precision.

The above description is merely one embodiment of the present invention, and the present invention can be variously modified without departing from the spirit thereof.

[Brief description of drawings]

FIG. 1 is a side view showing the inside of a resin coating apparatus to which the present invention is applied. FIG. 2 is a perspective view showing a cocoon-shaped rotor for a roots-type supercharger which is resin-coated in the apparatus shown in FIG. FIG. 3 is a front view of FIG. FIG. 4 is a plan view of the air blow shown in FIG. FIG. 5 is a sectional view of FIG. 4 seen from the line VV. FIG. 6 is a sectional view of the masking jig attached to the rotor of FIG. 2 as seen from the side surface. FIG. 7 is a sectional view of an essential part of the holding member engaging with the masking jig shown in FIG. 6 as viewed from the side. FIG. 8 is a view of FIG. 7 viewed from the line VIII-VIII. FIG. 9 is a plan view showing a part of the resin coating apparatus of FIGS. 1 and 3. FIG. 10 is a diagram showing heating and movement patterns of the rotor in the resin welding step. 10: Rotor (metal part) 22: Resin powder (powdered resin) 24: Flow tank (fluid immersion tank)

 ─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-60-139367 (JP, A) JP-A-57-78975 (JP, A) JP-B-57-52113 (JP, B2)

Claims (1)

[Claims] 1. A resin coating method for a metal component, wherein a powdered resin is deposited on the surface of a heated metal component in a fluidized dipping tank containing the powdered resin in a fluidized state, wherein the metal component is After being immersed in the fluidized-bed tank, a flow stopping step of stopping the flow of the powdery resin in the fluidized-bed tank, and a state in which the flow of the powdery resin in the fluidized-bed tank is stopped. A pushing down step of pushing down the metal part, a pulling up step of pulling up the metal part from the fluidized dipping tank while reflowing the powdery resin in the fluidized dipping tank, and a pulling up step from the powdered resin in a fluidized state. A gas injection step of injecting a compressed gas onto the surface of the metal part to remove the unfused resin on the welded resin adhered to the surface, and a resin coating method for the metal part. .