JPS635131B2 - - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention (Industrial Field of Application) The present invention relates to a plasma treatment apparatus for applying plasma treatment to the surfaces to be painted of bumpers and other synthetic resin products. This relates to an exhaust port for adjusting gas exhaust.

(Prior Art) Conventionally, this type of plasma processing equipment has been constructed by arranging bumpers made of synthetic resin of automobile parts made of polypropylene etc. in a layered manner in a sealed storage chamber, housing plasma injection tubes, and disposing the bumper surface. In order to make it easier for paint to adhere to the bumper surface, plasma gas such as oxygen was injected from the injection tube onto the bumper surface to activate it.

However, in this conventional device, the bumper is placed stationary within the storage chamber, and the pair of plasma injection tubes are arranged diagonally opposite each other, so it is difficult to control and control the plasma supply device etc. connected to each injection tube. There was a problem in that not only was maintenance and inspection troublesome, but also the equipment costs soared.

In recent years, in order to solve the above-mentioned problems, a device has been proposed as shown in Japanese Patent Application No. 58-236546, which was previously filed by the present applicant. That is, the apparatus shown in FIG. 9 includes a storage chamber 51 for accommodating objects to be painted such as a synthetic resin bumper B, and one plasma unit for injecting plasma to perform plasma treatment on the surface of the object to be painted. This is a plasma processing apparatus equipped with an injection pipe 52, and a pair of support disks 53a and 53b that rotate around one axis are provided in the storage chamber 51, and a workpiece to be coated is placed between the support disks 53a and 53b. It has a structure in which a plurality of support stands 54 for mounting are supported so as to be relatively rotatable.

Furthermore, an exhaust port 55 is formed at one location above the plasma injection tube 52 provided in the storage chamber 51 . The exhaust port 55 is used to reduce the pressure inside the accommodation chamber 1 to a predetermined pressure, and to prevent a pressure increase in the accommodation chamber 1 caused by the plasma gas irradiated after the pressure reduction and to maintain the plasma gas at a predetermined pressure. It is used for two purposes: for discharge.

However, since the exhaust port 55 is provided directly above the injection pipe 52, even if the plasma gas is irradiated, it will not spread to the entire storage chamber and a portion will flow back, as shown by the wavy line in Figure 10. , the exhaust port 5
There is a risk that the plasma gas may not be sufficiently distributed within the accommodation chamber 1. Therefore, when considering the flow of plasma gas within the storage chamber 1, the efficiency was extremely low.

(Problems to be Solved by the Invention) The present invention is intended to solve the problems that plasma processing efficiency is low and processing time is long.

Structure of the Invention (Means for Solving the Problems) In view of the above problems, the present invention provides a storage chamber for accommodating objects to be painted such as synthetic resin bumpers, and a method for applying plasma treatment to the surface of the objects to be painted. In a plasma processing apparatus equipped with a plasma injection tube that injects plasma into the storage chamber and an exhaust port that reduces the pressure inside the storage chamber, for adjusting the exhaust of the supply gas during plasma irradiation to a position facing the injection tube of the storage chamber. the second of
The structure is equipped with an exhaust port.

(Function) According to the present invention, the plasma gas spread from the injection pipe flows to the exhaust port on the opposite side, spreads sufficiently throughout the storage chamber, and then converges at the second exhaust port and is exhausted.

Embodiment Hereinafter, an embodiment embodying the present invention will be described in the first to
This will be explained according to FIG.

The airtight storage chamber 1 of the plasma processing apparatus is formed into a hollow cylindrical shape, and in FIG. 1, a door (not shown) that can open and close the storage chamber 1 is provided on its front wall. In addition, the storage chamber 1 is located in the center of the right side wall.
A first exhaust port 2 dedicated to reducing the pressure inside is formed, and has a valve 2a. A stainless steel injection pipe 3 for injecting plasma gas such as oxygen is provided below the first exhaust port 2.

As shown in FIGS. 3 to 5, an introduction pipe 4 is connected to a plasma introduction port (not shown) formed approximately in the center of the injection pipe 3, and its end is connected to a plasma supply device (not shown) outside the storage chamber 1. ). A large number of injection tubes 5 are formed on the outer periphery of the injection tube 3 on both sides of the inlet, and the arrangement interval gradually decreases toward the end of the injection tube 3, and the inner diameter gradually increases. and,
Each injection port 5 is oriented forward at a predetermined angle θ1 with respect to the vertical plane S.
(30 degrees in this embodiment) opening 5a in the direction of inclination, and a predetermined angle θ2 (in this embodiment) towards the rear side.
5b which opens in the direction of inclination (30 degrees). Then, the injection port 5 tilts toward the front.
a and injection ports 5b that are inclined toward the rear side are arranged alternately. Further, the number of injection ports 5 on the side of the exhaust port 2 from the introduction pipe 3, that is, on the right side, is set to be 15% smaller than the number of injection ports 5 on the left side of the exhaust port 2.

Further, a second exhaust port 6 is provided at a position facing the injection pipe 3, and has a valve 6a. The exhaust port 6 is exclusively for plasma gas exhaust.
The diameter of the first exhaust port 2 is smaller than that of the first exhaust port 2, and the diameter is such that a balance can be maintained between the amount of plasma gas supplied and the exhaust speed. Next, the positional relationship between the plasma injection tube 3 and the second exhaust port 6 in this embodiment will be described. In FIG. 1, a plasma injection tube 3 is provided at a position rotated by 30 degrees counterclockwise from a vertical plane S1 to the bottom surface of the storage chamber 1, and a second
The exhaust port 6 is located at a position rotated counterclockwise by 210 degrees from the vertical plane S1.

A base 10 is provided at the bottom of the injection pipe 3, and a rotating device 1, which will be described later, is installed at the bottom of the base 10.
1 is provided. The rotating device 11 is supported by a rectangular frame 12 and pillars 13 facing each other on both left and right sides of the frame 12. A rotary shaft 14 is rotatably supported between the upper ends of both columns 13, and a pair of support disks 15a are provided at both ends of the rotary shaft 14.
15b is fixed so as to be rotatable together. Between the inner surfaces of both the support disks 15a and 15b, there are objects to be painted,
For example, six support stands 16 on which bumpers B made of synthetic resin such as polypropylene are placed are arranged at predetermined angular intervals.

As shown in FIG. 6, each support stand 16 includes a pair of support pieces 17 formed by bending a metal plate, an erection rod 18a installed between both support pieces 17, and each installation rod 1.
and a connecting rod 18b disposed on the lower surface of each support piece 17 so as to connect each end of the supporting piece 8a.
Each support piece 17 is supported by a metal fitting 19 or the like at its upper end so as to be relatively rotatable on each support disk 15a, 15b. Therefore, each support stand 16 is held in a horizontal position when the rotating shaft 14 and the support disks 15a, 15b are rotating and when they are stationary. Also,
A net 20 is adjusted in the central notch of each support piece 17 to allow passage of plasma gas.

Further, as shown in FIG. 1, a chain wheel 21 is fitted into the front end of the rotating shaft 14, and a chain wheel 22 and a transmission gear 23, which rotate around one axis, are mounted on the frame 12. is provided, and both chain wheels 2
A chain 24 is suspended between 1 and 22, and a drive gear 25 that is rotationally driven by a drive motor (not shown) is meshed with the transmission gear 23.

As the drive gear 25 rotates, the support disks 15a, 15b are connected to the rotating shaft 14 via the transmission gear 23, chain wheel 22, chain 24, and chain wheel 21.
is rotated.

Next, its effects will be explained.

First, the door that can open and close the storage chamber 1 is opened and bumpers B to be subjected to plasma treatment are placed on each support stand.

Next, the door of the storage chamber is closed and the valve 2a of the first exhaust port 2 is opened to reduce the pressure inside the storage chamber 1 to a predetermined pressure (the pressure reducing device is not shown). When the predetermined pressure is reached, the valve 2a is closed and the drive motor of the rotation device 11 is operated, and the rotation shaft 14 and the support disk 15 are moved through the drive gear 25, transmission gear 23, chain wheel 22, chain 24, and chain wheel 21. is rotated, and each support base 16 together with the bumper B rotates relative to each support disk 15 around its upper end, while each bumper B is held in a horizontal state even while each support disk 15 is rotating. .

If plasma gas such as oxygen is introduced into the injection tube 3 through the introduction pipe 4 at the same time as the rotating device 11 is driven, the plasma gas is uniformly injected from each injection port. Further, the valve 6a of the second exhaust port 6 is opened at the same time as the plasma gas is injected, and the pressure inside the storage chamber 1 is kept constant while balancing the amount of gas to be supplied and the exhaust speed.

At this time, since the second exhaust port 6 is provided at a position facing the plasma gas injection tube 3, the flow of plasma gas spreading out from the injection port 5 in a shower shape is as shown by the dotted line in FIG. It becomes a flow. This indicates that after the plasma gas has sufficiently spread throughout the storage chamber 1, it converges at the exhaust port 6 and is exhausted, and the bumper B is efficiently irradiated with the plasma gas, covering the surface of the bumper B. This makes it possible to activate the product uniformly. Therefore, plasma processing efficiency is significantly increased, and processing time can be shortened.

Note that the present invention is not limited to the above-mentioned embodiments, and can be embodied as follows, for example.

The exhaust port 6 is not limited to a position facing the injection pipe 3, but may be located at a location where the shower-like plasma gas is efficiently spread into the storage chamber 1 and then converged, for example, facing the injection pipe 3. It may be provided within a range of 45 degrees both above and below the position.

As shown in FIG. 8, by providing the exhaust port 6 with an exhaust pipe 26 having the same structure as the injection pipe 3, the plasma gas injected from the injection pipe 3 is absorbed and exhausted from one hole. than,
It can be absorbed and exhausted more uniformly.

Effects of the Invention As detailed above, the present invention provides a second exhaust port for adjusting the exhaust of plasma gas in the plasma gas, by providing the second exhaust port at a position facing the injection pipe.
When plasma gas is supplied into the containment chamber, it spreads sufficiently throughout the containment chamber and then converges at the exhaust port and is exhausted, which improves plasma processing efficiency and shortens processing time. It has a great effect.

[Brief explanation of the drawing]

1 and 2 are a sectional view and a perspective view of a plasma processing apparatus embodying the present invention, FIG. 3 is a front view of an injection tube, FIG. 4 is a sectional view taken along the line A--A in FIG. 3, and FIG. 5 is a sectional view taken along line BB in FIG. 3, FIG. 6 is an enlarged perspective view showing a part of the support base, and FIG. 7 is a schematic diagram showing the flow of plasma gas when using the plasma processing apparatus of the present invention. , FIG. 8 is a sectional view showing another example of the present invention, FIG. 9 is a perspective view showing a conventional plasma processing apparatus, and FIG. 10 is a schematic diagram showing the flow of plasma gas when using the conventional plasma processing apparatus. It is a diagram. Containment chamber...1, first exhaust port...2, injection pipe...3,
Second exhaust port...6.

Claims (1)

[Scope of Claims] 1. A storage chamber 1 for accommodating objects to be painted such as a synthetic resin bumper B, a plasma injection tube 3 for injecting plasma to perform plasma treatment on the surface of the object to be painted, and In a plasma processing apparatus equipped with an exhaust port 2 for depressurizing the inside of the chamber 1, the storage chamber 1
A plasma processing apparatus characterized in that a second exhaust port 6 is provided at a position facing the injection tube for adjusting the exhaust of the supplied gas during plasma irradiation. 2. Claim 1, characterized in that a large number of injection ports 5 are formed on the outer periphery of the plasma injection tube 3, the arrangement interval gradually decreasing toward the end of the injection tube, and the inner diameter gradually increasing. The plasma processing apparatus described. 3. The plasma processing apparatus according to claim 1, wherein the second exhaust port 6 has a diameter that balances the amount of supplied gas and the exhaust speed. 4. An auxiliary valve 6a that operates independently on the second exhaust port 6 to control the exhaust speed.
2. The plasma processing apparatus according to claim 1, further comprising a plasma processing apparatus.