JP5880424B2 - Coating liquid recovery method and recovery device - Google Patents

Description

  The present invention relates to a method for efficiently recovering a coating liquid after being spray-coated on an outer surface of a workpiece, and a coating liquid recovery apparatus.

  For example, in order to form a glaze layer on the insulator surface of the spark plug, an apparatus that applies the glaze liquid by nozzle injection or dipping in the glaze liquid is employed. Application by nozzle injection is advantageous in that it can form a more uniform coating film on the workpiece surface than immersion, but the coating solution sprayed from the nozzle spreads behind the workpiece, allowing the coating solution to be collected while suppressing scattering. Equipment is required. On the other hand, conventionally, a shielding plate is arranged in a chamber provided behind the workpiece so as to be orthogonal to the spraying direction of the coating liquid, and the scattered coating liquid is received by the shielding plate and dropped along the shielding plate. It was collected by.

  Patent Document 1 discloses a surface treatment apparatus for surface-treating a workpiece, and discloses an apparatus for collecting a treatment liquid when a workpiece immersed in a treatment layer is pulled up. Patent Document 2 describes an apparatus for collecting a chemical solution from a chemical mist floating in the chamber.

JP 2011-127170 A JP 2003-279223 A

  However, in the conventional collection method, the coating liquid bounces off at the shielding plate, causing a problem that it reattaches to the product or the glaze floats as fine particles. In this case, if suspended particles adhere to the inner wall surface of the chamber or enter and accumulate in the duct provided in the upper part of the chamber, there is a risk of clogging of the piping, which not only lowers the recovery efficiency of the coating liquid. It becomes a cause of obstacles such as dirt and wear of equipment.

  The bounce at the shielding plate can be eliminated by adjusting the position of the shielding plate further away, but the equipment becomes large and unreasonable. Therefore, it was investigated that a liquid such as water flows down from above the shielding plate, and the coating liquid is dropped together with the flowing liquid and collected. However, it is difficult to evenly flow the liquid on the surface of the shielding plate from the upper side to the lower side of the shielding plate. If a part of the shielding plate is exposed, the effect of suppressing the rebound becomes insufficient. Furthermore, there is a possibility that the coating liquid is gradually deposited on the exposed surface or scattered as suspended fine particles, and the recovery effect by the liquid cannot be obtained.

  Accordingly, an object of the present invention is to provide a recovery method capable of efficiently recovering a coating liquid sprayed toward a workpiece by absorbing the coating liquid without splashing or floating, and without increasing the size of the apparatus. It is to provide a recovery device.

Invention of Claim 1 of this invention is the collection | recovery method of the coating liquid which collect | recovers the coating liquid sprayed from the horizontal direction with a spray nozzle on the workpiece | work surface,
A recovery chamber adjacent to the coating chamber for storing the workpiece is provided, and a bar-shaped member having a plurality of star-shaped cross sections is erected in the spreading direction of the coating liquid sprayed from the spray nozzle, and is formed on the outer peripheral surface of each bar-shaped member. The recovery liquid is caused to flow down along the surface, and the coating liquid flowing into the recovery chamber is recovered by contacting with the recovery liquid.

According to a second aspect of the present invention, there is provided an application liquid which is provided in a coating apparatus in which a work and an injection nozzle are arranged to face each other and collects the application liquid sprayed from the horizontal direction by the injection nozzle onto the work surface. A recovery device,
A recovery chamber adjacent to the coating chamber of the coating apparatus in which the workpiece is accommodated is provided, and a rod-shaped member having a plurality of star-shaped cross sections is provided in the recovery chamber in the spreading direction of the coating liquid sprayed from the spray nozzle. And a recovery unit having a recovery liquid tank for supplying recovery liquid to the outer peripheral surface of each bar-shaped member above the plurality of bar-shaped members, and the recovered liquid flowing down the outer peripheral surface of the plurality of bar-shaped members, The coating liquid flowing into the recovery chamber is contacted and recovered.

  According to a third aspect of the present invention, an air flow forming means for forming an air flow from the coating chamber side toward the recovery portion is provided in the recovery chamber.

  According to a fourth aspect of the present invention, in the recovery unit, the plurality of rod-shaped members are arranged in parallel across the spreading path of the coating liquid sprayed from the spray nozzle, and are arranged in a plurality of rows in the spreading direction. Is done.

  According to a fifth aspect of the present invention, the workpiece is rotatably supported by a holding portion having a rotation mechanism provided in the coating chamber, and a coating liquid is applied to a surface exposed from the holding portion. .

  According to a sixth aspect of the present invention, the upper ends of the plurality of rod-shaped members are integrally fixed to a plate member disposed in the recovery liquid tank, and each bar-shaped member is attached to the bottom surface of the recovery liquid tank. A plurality of through holes through which the upper end portions of the members are inserted are provided, and recovery liquid supply holes are formed between the through holes and the rod-shaped members.

  According to the coating liquid recovery method and recovery apparatus of the present invention, the plurality of rod-like members to which the recovery liquid is supplied to the outer peripheral surface are arranged in the spreading direction of the coating liquid flowing from the coating chamber into the recovery chamber. Collides with the rod-shaped member, is absorbed by the recovered liquid, and is easily recovered together with the recovered liquid flowing down. Therefore, the coating liquid can be recovered with high efficiency while suppressing the splashing of the coating liquid and the enlargement of the apparatus (claims 1 and 2).

  Further, by forming an air flow in the apparatus, there is an effect that the coating liquid is guided in the direction of the plurality of rod-shaped members and the floating fine particles are prevented from adhering to the apparatus wall surface or the like. When a plurality of rod-shaped members are arranged in a plurality of rows so as to block the spreading path of the coating liquid, the collection efficiency of the coating liquid increases, and a uniform coating film is formed on the surface of the workpiece that is rotatably supported in the coating chamber. be able to. Preferably, when the upper ends of the plurality of rod-shaped members protrude into the collection liquid tank and are integrally fixed to the plate member, positioning is easy, and the collection liquid is drawn from the supply hole on the bottom surface of the collection liquid tank. Can be evenly supplied to the surface. (Claims 3 to 6)

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view illustrating an overall configuration of a coating apparatus that is a first embodiment of the present invention and is provided with a coating liquid recovery apparatus. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing an overall configuration of a coating apparatus that is a first embodiment of the present invention and is provided with a coating liquid recovery apparatus. It is the elements on larger scale of Drawing 1, and is a figure showing the detailed composition of the coating chamber which is the principal part of a coating device. It is the elements on larger scale of Drawing 2, and is a figure showing the detailed composition of the recovery chamber which is the principal part of a recovery device. It is typical sectional drawing for demonstrating the detailed structure of a collection | recovery part. It is the apparatus front view and top view for demonstrating the collection | recovery method of the coating liquid by the collection | recovery apparatus of this embodiment. It is a schematic diagram for demonstrating the action | operation of the principal part of a coating device. It is a schematic diagram for demonstrating the action | operation of the principal part of a collection | recovery apparatus. It is the 2nd Embodiment of this invention, and is a schematic block diagram which shows the other example of a shape of the rod-shaped member which comprises a collection | recovery part. It is the 3rd Embodiment of this invention, and is a schematic block diagram which shows the other example of a shape of the rod-shaped member which comprises collection | recovery.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. 1 and 2 show the overall configuration of the apparatus according to the present embodiment, and a coating apparatus 2 for spraying and applying a glaze liquid serving as a coating liquid F onto the outer surface of a spark plug P serving as a workpiece W, and A coating liquid recovery device 1 is provided. The inside of the housing H2 of the coating apparatus 2 is a coating chamber 21 that accommodates and holds the workpiece W, and the inside of the housing H1 of the collection apparatus 1 is a collection chamber 11 that collects the sprayed coating liquid. The housing H1 and the housing H2 are connected at the opening end, and the coating chamber 11 and the recovery chamber 21 are adjacently connected in the left-right direction in the drawing.

  The coating apparatus 2 accommodates and holds the workpiece W in the lower portion of the coating chamber 21 and is opposed to the spray nozzle N disposed on the side of the coating chamber 21 (left side in the drawing). The collection device 1 is located on the opposite side of the spray nozzle N across the workpiece W, and guides the coating liquid sprayed from the spray nozzle N onto the workpiece W into the collection chamber 11 having a relatively large capacity with respect to the coating chamber 21. To do. In the collection chamber 11, there is provided a collection unit 3 in which rod-like members 31 extending in the vertical direction are arranged and arranged, and a collection liquid tank 32 is installed on the upper end side of a large number of standing rod-like members 31. The recovery liquid tank 32 is supplied with water as the recovery liquid from the supply port 33, and the coating liquid F splashing rearward from the workpiece W is brought into contact with the water flowing down along the outer peripheral surface of each rod-shaped member 31. And collect.

  As shown in FIG. 2, the coating apparatus 2 includes a plurality of spray nozzles N (two in this case) arranged in parallel in the width direction, and a holding portion 22 for the workpiece W is provided at a position facing each spray nozzle N. Yes. Each holding unit 22 can hold a plurality of workpieces W (two in this case), and simultaneously sprays the coating liquid from each spray nozzle N toward the plurality of workpieces W facing each other. Thereby, it is possible to efficiently apply the coating liquid simultaneously to a plurality of workpieces W in the spread range of the coating liquid ejected from each spray nozzle N. The plurality of workpieces W (four in this case) applied simultaneously from the plurality of injection nozzles N are arranged in an arc shape (shown by dotted lines in the figure) so that the distance from the opposing injection nozzle N is constant. .

  The coating apparatus 2 shown in an enlarged manner in FIG. 3 holds and fixes the lower half of the workpiece W in a cylindrical holding portion 22 and rotatably supports the lower end portion of the holding portion 22 on a housing H2. The holding portion 22 has a rotating shaft 23 extending below the housing H <b> 2 connected to the motor M via a plurality of gears 24. As a result, the plurality of workpieces W in the coating chamber 21 rotate around the axis at a predetermined rotation speed together with the plurality of holding portions 22 that are rotationally driven by the motor M. The coating chamber 21 is open at the top, and air flowing from the opening 25 can flow from the coating chamber 21 to the collection chamber 11.

  As the spray nozzle N, a known nozzle that mixes and sprays the coating liquid and air is used. The jet nozzle N1 of the jet nozzle N is at substantially the same height as the substantially central portion of the workpiece W exposed above the holding portion 22, and the coating liquid F jetted in the horizontal direction from the jet nozzle N1 Adjusted to reach the exposed surface sufficiently. In this embodiment, the insulator part of the spark plug P to be the workpiece W is protruded from the holding part 22, and the coating liquid F is formed on the surface of the insulator part using, for example, a glaze liquid made of an aqueous slurry containing ceramic particles. Form a glaze layer. Thus, by using the injection nozzle N, a uniform glaze layer having a predetermined thickness can be formed. The glaze layer is then baked to become a coating layer for preventing a decrease in insulation due to dirt or the like.

  Next, details of each part of the recovery device 1 that is a feature of the present invention will be described. In FIG. 1, the bottom surface of the recovery chamber 11 is an inclined surface that slopes downward from the coating chamber 21 side toward the other end side (the right end side in the figure), and is applied from the opening 12 provided on the other end side. Connected to the pipe 13 for liquid recovery. The collection unit 3 is located above the opening 12, and the rod-shaped member 31 is arranged so as to extend in the vertical direction from the vicinity of the top surface of the collection chamber 11 to a position directly above the opening 12 to block the coating liquid spreading path. The coating liquid F flows into the opening 12 together with the recovered liquid that flows down the rod-shaped member 31. The collection chamber 11 is closed at the end opposite to the coating chamber 21 and is an inclined wall that is inclined downward toward the opening 12, and forms a space between the collection chamber 3 and the collection chamber 3. Yes.

  At the upper end of this space, a duct 14 is provided on the top surface of the recovery chamber 11 and connected to an air flow path (not shown). A vacuum pump (not shown) is provided in the air flow path, and a negative pressure is formed therein, thereby forming an air flow from the opening 25 of the coating chamber 21 to the duct 14 through the recovery chamber 11 (air flow formation). means). This air flow is formed above the workpiece W and is guided to the collection unit 3 behind the workpiece W (right side in the figure) without disturbing the flow of the coating liquid F ejected from the ejection nozzle N. Further, the coating liquid F is prevented from diffusing around the workpiece W, and in particular, adhering to the upper wall surface, thereby improving the recovery efficiency.

  In FIG. 4, the collection unit 3 is disposed so as to span between both ends of the collection chamber 11 in the width direction (vertical direction in the figure). The rod-shaped members 31 of the collection unit 3 are arranged in parallel across the spreading path of the coating liquid. Specifically, a large number of rod-shaped members 31 are aligned at equal intervals in the width direction, and the longitudinal direction of the collection chamber 11 (see FIG. In the left and right direction). Here, they are arranged in a staggered pattern so that there are three rows in the longitudinal direction and adjacent rod-shaped members 31 are alternately positioned. A large number of rod-shaped members 31 have the same shape and are round rods having a circular section with a constant diameter and a fixed-length circular section, and the upper end portion and the lower end portion are respectively attached to a pair of plate members 34 and integrally held. It is fixed. Furthermore, each rod-like member 31 is arranged concentrically with a water supply hole 36 communicating with the recovery liquid tank 32, so that water as recovery liquid can be supplied to the outer periphery thereof. This mounting structure is shown in FIG.

  In FIG. 5, a large number of rod-shaped members 31 have screw holes at the upper end portion and the lower end portion, and are screwed to the predetermined positions of the plate member 34 using screws 35. The upper plate member 34 is located in the recovery liquid tank 32, and the four corners are fixed to the bottom surface of the recovery liquid tank 32. At this time, a circular through-hole 37 having a diameter larger than that of the rod-shaped member 31 is formed through the bottom surface of the recovered liquid tank 32 at a position corresponding to each rod-shaped member 31, and the upper end portions of many rod-shaped members 31 are passed through. It protrudes above the hole 37. Then, by arranging the rod-shaped members 31 concentrically in the through holes 37, an annular water supply hole 36 for supplying water as the collected liquid from the collected liquid tank 32 is provided around the upper end of each rod-shaped member 31. It is formed.

  When the recovery unit 3 is assembled, for example, the lower end portions of a large number of rod-shaped members 31 are screwed to the lower plate member 34, and in this state, the upper end portions of the large number of rod-shaped members 31 are connected to the recovery liquid tank 32. Are inserted into a large number of through holes 37. Next, the upper end portions of a large number of rod-shaped members 31 are fixed to the upper end plate member 34 with screws, and the plate member 34 is fixed to the recovery liquid tank 32 with bolts or the like. As described above, the rod-shaped member 31 is integrated using the plate member 34 to facilitate handling, and the rod-shaped member 31 is screwed to the plate member 34 so that the through hole 37 and the rod-shaped member 31 are positioned. Therefore, it is not necessary to adjust the position individually.

  In the present invention, the recovered liquid is supplied from the water supply hole 36 to the upper ends of a large number of rod-shaped members 31 of the recovery section 3, and a layer of water that flows down on the outer peripheral surface of the rod-shaped member 31 is formed. The size of the water supply hole 36 may be adjusted as appropriate according to the diameter, length, and the like of the rod-shaped member 31 as long as the recovery liquid necessary for constantly covering the surface of the rod-shaped member 31 can be continuously supplied. . The recovery liquid tank 32 is configured to store a sufficient amount of recovery liquid to be supplied to the water supply hole 36 and to replenish the recovery liquid flowing out from the water supply hole 36 through the supply port 33.

  With reference to FIG. 6, the operation of the coating apparatus 2 having the above-described configuration and the coating liquid F recovery apparatus 1 will be described. In FIG. 6, the spread of the coating liquid F sprayed from the spray nozzle N1 of the spray nozzle N into the coating chamber 21 is represented, and in a relatively high range of the coating liquid concentration (schematically indicated by arrows), The workpiece W is set to be positioned. At this time, as shown in FIG. 7, the coating liquid F is sprayed on the side surfaces of the facing workpiece W, and a coating film of the coating solution F is uniformly formed on the exposed surface of the rotating workpiece W. The sprayed coating liquid F passes through the workpiece W and spreads into the collection chamber 11 at the rear.

  Here, in the upper space in the apparatus, an air flow that flows from the opening 25 of the coating chamber 21 toward the duct 14 of the recovery chamber 11 is formed, and the spray of the coating liquid F follows this air flow. Then, it is transported to the downstream side and reaches the collection unit 3. Thereby, excessive adhesion to the workpiece W due to the floating fine particles returning to the upstream side and diffusion of the coating liquid F around the coating chamber 21 and the collection chamber 11 are suppressed, and the fine particles adhere to the wall surface and the like. Prevents equipment contamination, piping clogging, and wear.

  In the recovery chamber 11, the recovered liquid drips continuously from the water supply holes 36 of the upper recovered liquid tank 32 along the outer peripheral surfaces of the many rod-shaped members 31 constituting the recovery unit 3. As shown in FIG. 8, the large number of rod-shaped members 31 are positioned concentrically with the water supply holes 36 of the plate member 34, and the recovered liquid is evenly supplied to the entire outer surface of the rod-shaped member 31. A layer of the recovered liquid is formed to cover the surface. Further, here, a large number of rod-shaped members 31 are arranged in three rows in the flow direction of the coating liquid F, the rows are arranged at equal pitch intervals, and the central row is arranged with a half-pitch shifted from the front row and the rear row. The rod members 31 in the central row are located between the rod members 31 in the front and rear rows, and the interval between the adjacent rod members 31 is set to such an extent that the air flow can easily pass (for example, about 2 mm).

  Here, when the coating liquid F flows in along with the air flow (in the direction of the arrow in the figure), it collides with a large number of rod-shaped members 31 of the collecting section 3, and the coating liquid F is absorbed by the collected liquid flowing down the surface of the rod-shaped member 31. Is done. Then, the coating liquid F that is an aqueous slurry liquid mixes with the water that is the recovery liquid, moves downward, falls from the lower end of the rod-shaped member 31, and is a pipe for recovering the coating liquid from the opening 12 in FIG. 1. 13 is recovered. At this time, since air is sent into the gap between the rod-shaped members 31 in the same direction as the injection direction, the stagnant suspended matter that has passed through the collection unit 3 is prevented by the air flow, and the air flows along with the air flow from the upper duct 14 to the outside of the apparatus. Discharged.

  If the recovered liquid is an aqueous liquid having affinity with the aqueous coating liquid F, the same effect can be obtained. However, the water easily absorbs and mixes with the aqueous coating liquid F, and is easily obtained and processed. It is preferable without affecting the apparatus. In addition, when the coating liquid F used with respect to the workpiece | work W is not an aqueous liquid, according to the kind of coating liquid F, an optimal collection | recovery liquid can be selected suitably.

  Since the collection unit 3 has a large number of rod-shaped members 31 arranged alternately at narrow intervals in the spreading path of the coating liquid, even if the coating liquid F passes through the rod-shaped members 31 in the front row, the central row, the rear row It collides with a high probability to the rod-shaped member 31 and is recovered. Furthermore, the rod-shaped member 31 having a circular cross section used in this embodiment easily forms a turbulent flow, stirs the air flow, makes it easy for particles of the coating liquid F to come out on the surface, and increases the chance of contact with the rod-shaped member 31. Let Further, the rod-shaped member 31 having a circular cross section has a recovery liquid layer stably formed on the surface and is difficult to peel off, and can efficiently collect the coating liquid F. Preferably, the rod-shaped member 31 is made of a synthetic resin, and the recovered liquid is less likely to peel than a metal member. The metal may be subjected to a hydrophilic surface treatment.

  9 and 10 show the second and third embodiments of the present invention, in which the shape of the bar-shaped member 31 of the collection unit 3 is changed. As shown in FIG. 7, it is desirable for the recovery liquid to flow down along the outer peripheral surface of the rod-shaped member 31 in order to increase the recovery efficiency, but when peeling from the surface of the rod-shaped member 31 by the air flow or the like in the apparatus, There is a possibility that the coating liquid F adheres to the surface of the rod-shaped member 31 and is difficult to be collected. Therefore, as a shape in which the recovery liquid is less likely to be peeled off, the rod-shaped member 31 can be formed into a cross-sectional shape having a number of corners, for example, a regular polygonal cross-section, or a shape having a star-shaped cross section as shown in FIG. In this way, since a large number of linear portions 311 extending in the vertical direction are formed on the side surfaces of the rod-shaped member 31, the recovered liquid can easily flow along the linear portions, and there is an effect of suppressing peeling.

  Further, while the rod-like member 31 of the recovery unit 3 has a circular cross section, the surface can be formed with minute irregularities, scratches, grooves, etc., and the surface assembly can be increased to prevent the recovery liquid from peeling. . For example, as shown in FIG. 10, it is preferable to form a shallow groove 312 having a certain length on the surface of the rod-shaped member 31 in the vertical direction because the recovered liquid can easily flow in the vertical direction along the shallow groove 312. The length of the shallow groove 312 is only an example, and the length of the shallow groove 312 may extend over the entire length of the rod-shaped member 31.

  In the above-described embodiment, the coating apparatus 2 is designed to improve productivity as a configuration in which the two spray nozzles N respectively apply the two workpieces W. The number of the injection nozzles N can be appropriately changed according to the size of the workpiece W and the housing H2 to be applied, the performance of the injection nozzles N, and the like. Moreover, although the collection | recovery apparatus arrange | positioned the rod-shaped member 31 in 3 rows in the collection | recovery part 3, what is necessary is just to set suitably so that desired collection | recovery efficiency may be obtained according to the spreading | diffusion path | route of a coating liquid. Other apparatus configurations can be arbitrarily changed.

  The coating liquid recovery apparatus of the present invention is not limited to a spark plug, but can be applied to an apparatus that uses an arbitrary product as a workpiece W and sprays the coating liquid on the surface thereof. And since coating liquids such as glaze liquid can be efficiently recovered using the recovery liquid and the contamination of the apparatus can be suppressed, it is used in the manufacturing process of various products to improve workability and productivity. It can contribute greatly.

W Work F Coating solution 1 Collection device 11 Collection chamber 2 Coating device 21 Coating chamber 22 Holding unit 3 Collection unit 31 Rod member 32 Collection solution tank 34 Plate member 36 Water supply hole (supply hole)
37 through holes

Claims (6)

A method of collecting a coating liquid that collects a coating liquid sprayed from a horizontal direction on a work surface by a spray nozzle,
A recovery chamber adjacent to the coating chamber for storing the workpiece is provided, and a bar-shaped member having a plurality of star-shaped cross sections is erected in the spreading direction of the coating liquid sprayed from the spray nozzle, and is formed on the outer peripheral surface of each bar-shaped member. A method for recovering a coating liquid, wherein the coating liquid is allowed to flow along the recovery chamber, and the coating liquid flowing into the recovery chamber is recovered in contact with the recovery liquid. A coating liquid collecting apparatus that is provided in a coating apparatus in which a work and a spray nozzle are arranged to face each other and collects a coating liquid sprayed from the horizontal direction by the spray nozzle on the work surface,
A recovery chamber adjacent to the coating chamber of the coating apparatus in which the workpiece is accommodated is provided, and a rod-shaped member having a plurality of star-shaped cross sections is provided in the recovery chamber in the spreading direction of the coating liquid sprayed from the spray nozzle. And a recovery unit having a recovery liquid tank for supplying recovery liquid to the outer peripheral surface of each bar-shaped member above the plurality of bar-shaped members, and the recovered liquid flowing down the outer peripheral surface of the plurality of bar-shaped members, An apparatus for recovering a coating liquid, wherein the coating liquid flowing into the recovery chamber is contacted and recovered.   The coating liquid recovery apparatus according to claim 2, wherein an air flow forming means for forming an air flow from the coating chamber side toward the recovery portion is provided in the recovery chamber.   4. The coating liquid according to claim 2, wherein the plurality of rod-shaped members are arranged in parallel across the spreading path of the coating liquid sprayed from the spray nozzle and are arranged in a plurality of rows in the spreading direction. Recovery device.   The said workpiece | work is rotatably supported by the holding part provided with the rotation mechanism provided in the said coating chamber, and a coating liquid is apply | coated to the surface exposed from this holding part. Coating liquid recovery device.   The upper end portions of the plurality of rod-shaped members are integrally fixed to a plate member disposed in the recovery liquid tank, and a plurality of through holes are inserted through the bottom surfaces of the recovery liquid tanks. 6. The coating liquid recovery apparatus according to claim 2, wherein a hole is provided, and a recovery liquid supply hole is formed between the through hole and each rod-shaped member.