Liquid Coating Device

Abstract

To provide a liquid application device that can readily and evenly apply liquid to an outer periphery of a workpiece.SOLUTION: A liquid application device (oil application device) 1 includes: a rotary member 3; an electric motor 4 for rotating the rotary member 3; a recess part 6 which is provided in a shaft center of the rotary member 3 and into which a workpiece 10 is inserted; an oil container 2 for supplying oil P to the rotating rotary member 3; and a scraping member 5 for guiding the oil P adhering to the rotating rotary member 3 to the recess part 6.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid application device for applying a liquid such as oil to the outer periphery of a workpiece. [Background technology]

[0002] When two parts are fitted together to assemble, a rubber O-ring is sometimes placed between their mating surfaces. In this case, the O-ring is attached to the outer surface of one part, and then the two parts are assembled by elastically compressing and deforming the O-ring while pressing it into the inner circumference of the other part. At this time, oil is applied to the O-ring beforehand to prevent damage (galling) to the O-ring.

[0003] Oil can be applied to O-rings using a brush or by immersing them in oil stored in a container. However, applying oil to the entire circumference of an O-ring using a brush is extremely time-consuming. Furthermore, immersing an O-ring in oil results in oil adhering to unnecessary areas, requiring wiping after application, which increases the number of steps.

[0004] Patent Document 1 listed below shows an oil application device that applies oil to an O-ring. This oil application device has first and second plates that are stacked together, and a hole (oil application portion) that penetrates both plates is provided. An oil flow path that communicates with the hole is provided between the two plates. Oil is supplied to the inner circumferential surface of the hole from the oil flow path, and a part with an O-ring attached is inserted into the hole, thereby applying oil to the O-ring. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-237142 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the oil application device described above, it is difficult to uniformly apply oil to the inner circumferential surface of the hole. Therefore, if the amount of oil applied to the inner circumferential surface of the hole is too small, some parts of the O-ring along the circumference will not be coated with oil, which may cause damage to the O-ring during assembly. On the other hand, if too much oil is applied to the inner circumferential surface of the hole, excess oil will be applied to the O-ring, requiring the work of wiping off the oil after application, which increases the labor required. In particular, when an O-ring is used as an oil seal, if too much oil is applied to the O-ring, oil will adhere to areas where it should not be, which may be mistaken for an oil leak in a subsequent oil leak test.

[0007] The above-mentioned problems are not limited to when oil is applied to an O-ring, but can also occur when other liquids (for example, adhesive) are applied to the outer periphery of a workpiece.

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a liquid application device that can easily and uniformly apply a liquid to the outer periphery of a workpiece. [Means for solving the problem]

[0009] In order to solve the above problem, the present invention provides a liquid application device for applying a liquid to an outer periphery of a workpiece, comprising: A liquid application device is provided that includes a rotating member, a driving means for rotating the rotating member around its axis, a workpiece insertion section provided at the axis of the rotating member and into which the workpiece is inserted, a liquid supply section that supplies liquid to the rotating rotating member, and a liquid guide means that guides the liquid supplied to the rotating rotating member to the workpiece insertion section.

[0010] In this liquid supply device, liquid supplied to a rotating rotating member is guided by a liquid guide means to a workpiece insertion portion provided at the axis of the rotating member. In this way, by supplying liquid to the workpiece insertion portion provided at the axis while the rotating member is rotating, a uniform liquid film is formed on the inner peripheral surface of the workpiece insertion portion. By inserting a workpiece into this workpiece insertion portion and bringing the outer peripheral surface of the workpiece into contact with the uniform liquid film formed on the inner peripheral surface of the workpiece insertion portion, the liquid can be uniformly applied to the outer peripheral surface of the workpiece.

[0011] In the liquid supply device described above, the axis of the rotating member may be arranged horizontally. In this case, the liquid supply unit may be configured with a liquid container that stores liquid therein, and the rotating member may be rotated with the lower part of the rotating member immersed in the liquid stored in the liquid container, thereby supplying liquid to the outer periphery of the rotating member and its surroundings.

[0012] The liquid guide means may be, for example, a scraping member that scrapes off the liquid adhering to the rotating member and guides it to the workpiece insertion section. In this case, by adjusting the position and angle of the scraping member, the liquid adhering to the surface of the rotating member can be scraped off by the scraping member and guided along the surface of the rotating member to the workpiece insertion section provided at the axis. [Effects of the Invention]

[0013] As described above, the liquid application device of the present invention makes it possible to easily and uniformly apply liquid to the outer periphery of a workpiece. [Brief explanation of the drawings]

[0014] [Figure 1] 3 is a cross-sectional view of the oil application device according to one embodiment of the present invention taken along line CC in FIG. 2. FIG. [Figure 2] FIG. 2 is a plan view of the oil application device. [Figure 3] FIG. 3 is a cross-sectional view taken along line DD in FIG. 2. [Figure 4] FIG. 3 is an axial cross-sectional view of the vicinity of a recess of a rotary member. [Figure 5] FIG. 2 is a cross-sectional view taken along the line AA in FIG. [Figure 6] 2 is a view of the rotating member and the scraping member as viewed from the direction B in FIG. 1. [Figure 7] FIG. 2 is a front view of the rotating member and the scraping member. [Figure 8] FIG. 2 is a front view of the rotating member and the scraping member. [Figure 9] FIG. 3 is an axial cross-sectional view of the vicinity of a recess of a rotary member. [Figure 10] FIG. 3 is an axial cross-sectional view of the vicinity of a recess of a rotary member. [Figure 11] FIG. 3 is an axial cross-sectional view of the vicinity of a recess of a rotary member. [Figure 12] FIG. 10 is an axial cross-sectional view of a portion near a recess of a rotary member according to another embodiment. [Figure 13] FIG. 10 is an axial cross-sectional view of a portion near a recess of a rotary member according to yet another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] 1 to 3 show an oil application device 1 as a liquid application device according to one embodiment of the present invention. The oil application device 1 has an oil container 2 as a liquid supply unit, a rotating member 3, an electric motor 4 as a drive means for rotationally driving the rotating member 3, and a scraping member 5 as a liquid guide means. In the following description, one side of the axial direction of the rotating member 3 (the front side of the paper in FIG. 1, the bottom side of FIG. 2, and the right side of FIG. 3) will be referred to as the "front side," and the other side of the axial direction of the rotating member 3 (the back side of the paper in FIG. 1, the top side of FIG. 2, and the left side of FIG. 3) will be referred to as the "rear side."

[0017] The oil container 2 stores oil P inside. In the illustrated example, the oil container 2 is a substantially rectangular box with an open top.

[0018] The rotating member 3 is made of metal or resin. In this embodiment, the rotating member 3 is disk-shaped and is disposed so that its axis is horizontal. The lower part of the rotating member 3 is immersed in oil P stored in an oil container 2. The rotating member 3 is driven to rotate about its axis by an electric motor 4. In the illustrated example, a rotating shaft 4a of the electric motor 4 is fixed to the axis of the end face 3b on the far side of the rotating member 3. By driving the electric motor 4, the rotating member 3 rotates in the direction of arrow R in FIG. 1 about its axis.

[0019] A recess 6 serving as a workpiece insertion portion is provided at the axis of the front end face 3a of the rotating member 3. The portion of the rotating member 3 below the recess 6 is immersed in oil P stored in the oil container 2. The recess 6 is provided at a position accessible from the front side of the oil application device 1, and in the illustrated example, the entire recess 6 is located above the oil container 2.

[0020] In this embodiment, as shown in FIG. 4, the recess 6 opens to the front end face 3a of the rotating member 3, but does not open to the rear end face 3b of the rotating member 3. The recess 6 has an introduction portion 6a provided at the front end and a cylindrical surface 6b provided on the rear side of the introduction portion 6a. The introduction portion 6a extends from the front end face 3a of the rotating member 3 to the rear side, and its diameter gradually decreases as it goes rearward. The introduction portion 6a in the illustrated example is a tapered surface coaxial with the axis of the rotating member 3. The cylindrical surface 6b is coaxial with the axis of the rotating member 3 and extends rearward from the rear end of the introduction portion 6a.

[0021] The diameter D1 of the cylindrical surface 6b of the recess 6 is approximately the same as the outer diameter of the workpiece to be inserted into the recess 6. In this embodiment, as shown in FIG. 11 , the workpiece 10 includes a cylindrical member 11 and a rubber O-ring 12 attached to its outer periphery. The diameter D1 of the cylindrical surface 6b of the recess 6 is equal to the outer diameter D2 of the O-ring 12 and is, for example, slightly smaller than the outer diameter D2 of the O-ring 12. The diameter D1 of the cylindrical surface 6b of the recess 6 is larger than the diameter D3 of the tip of the cylindrical member 11. The axial dimension L1 of the cylindrical surface 6b of the recess 6 is equal to the axial dimension L2 of the cylindrical member 11 on the tip side of the O-ring 12. In the illustrated example, the axial dimension L1 of the cylindrical surface 6b is slightly larger than the axial dimension L2 of the tip of the cylindrical member 11.

[0022] The scraping member 5 has a first scraping portion 5a arranged on the outer periphery of the rotating member 3 and a second scraping portion 5b arranged on the front side of the rotating member 3 (see FIGS. 1 to 3). In the illustrated example, the scraping member 5 is a generally L-shaped flat plate integrally having both scraping portions 5a and 5b. As shown in FIG. 5, the first scraping portion 5a is arranged with a small radial gap δ1 between it and the outer circumferential surface 3c of the rotating member 3. The second scraping portion 5b is arranged with a small axial gap δ2 between it and the front end face 3a of the rotating member 3. The scraping member 5 is arranged at a position facing the region of the rotating member 3 that is not immersed in the oil P (see FIG. 1). In the illustrated example, the scraping member 5 is arranged at a circumferential position upstream of the upper end of the region of the rotating member 3 that is not immersed in the oil P in the direction of rotation.

[0023] 6, when the rotating member 3 is viewed from the outer periphery (the direction of arrow B in FIG. 1), the first scraping portion 5a is slightly inclined with respect to the axis L of the rotating member 3. Specifically, the front portion (lower portion in the figure) of the first scraping portion 5a is disposed downstream (rightward in the figure) in the rotation direction R of the rotating member 3 relative to the rear portion (upper portion in the figure).

[0024] 1, the second scraping portion 5b extends from the outer peripheral end of the rotating member 3 toward the inner diameter side along the front end face 3a of the rotating member 3. In this embodiment, the second scraping portion 5b is inclined with respect to the radial direction of the rotating member 3. Specifically, the second scraping portion 5b extends in a direction gradually displacing downstream in the rotation direction R as it approaches the inner diameter side.

[0025] A method for applying oil to the outer periphery of the workpiece 10 using the above-described oil application device will be described below.

[0026] As shown in Figure 1, when the lower part of the rotating member 3 is immersed in oil P in the oil container 2 and the electric motor 4 is driven to rotate the rotating member 3 in the direction of arrow R, the oil P adheres to the entire circumference of the outer surface 3c of the rotating member 3 and the entire circumference near the outer edges of both end faces 3a, 3b (the radial areas immersed in the oil P in the oil container 2).

[0027] 5 and 6, the oil P adhering to the outer peripheral surface 3c of the rotating member 3 is scraped off by the first scraping portion 5a of the scraping member 5. In this embodiment, the first scraping portion 5a is inclined with respect to the axis L of the rotating member 3, so that the oil P scraped off by the first scraping portion 5a flows toward the front along the first scraping portion 5a and is supplied to the front end face 3a (see arrow M).

[0028] 5, oil P adhering near the outer peripheral edge of the front end face 3a of the rotating member 3 (including oil P scraped off by the first scraping portion 5a and supplied to the front end face 3a) is scraped off by the second scraping portion 5b. At this time, as shown in FIG. 7, because the second scraping portion 5b is inclined with respect to the radial direction of the rotating member 3, the oil P scraped off by the second scraping portion 5b flows toward the inner diameter along the second scraping portion 5b (see arrow N).

[0029] Thereafter, by continuing to rotate the rotary member 3 and continuing to supply the oil P from the oil container 2 to the rotary member 3, the oil P supplied to the front end face 3a of the rotary member 3 flows toward the inner diameter and reaches the edge of the opening of the recess 6 provided in the axial center (see FIGS. 8 and 9). By continuing to rotate the rotary member 3 further, the oil P enters the introduction portion 6a of the recess 6 of the rotary member 3 (see FIG. 10) and further enters the cylindrical surface 6b of the recess 6 (see FIG. 11). In this way, by providing the tapered introduction portion 6a at the open end of the recess 6, the oil P can easily enter the recess 6 from the front end face 3a.

[0030] Thereafter, even if the rotating member 3 continues to rotate and the oil P in the oil container 2 continues to be supplied to the rotating member 3, the film of oil P formed on the entire inner circumferential surface of the recess 6 is maintained at an appropriate thickness. In other words, each part of the oil application device 1 is adjusted so that the film of oil P formed on the inner circumferential surface of the recess 6, particularly on the inner end of the introduction portion 6a of the recess 6, is maintained at an appropriate thickness. Specifically, the following items are adjusted.

[0031] Angle θ1 between the first scraping portion 5a and the axis L of the rotating member 3 (see FIG. 6) If the angle θ1 is 0, the oil P scraped off by the first scraping portion 5a flows not only to the front side but also to the rear side, reducing the amount of oil P supplied to the front end face 3a. If the angle θ1 is too large, the radial gap between the rotating member 3 and the first scraping portion 5a at both axial ends of the rotating member 3 becomes excessively large, reducing the amount of oil P scraped off by the first scraping portion 5a. The angle θ1 is set in consideration of the above, and is set to, for example, about 1 to 5°.

[0032] Angle θ2 between the second scraping portion 5b and the radial direction of the rotating member 3 (see FIG. 1) If the angle θ2 is 0, the oil P scraped by the second scraping portion 5b flows not only to the inner diameter side but also to the outer diameter side, reducing the amount of oil P supplied to the recessed portion 6. If the angle θ2 is too large, the ability of the second scraping portion 5b to scrape the oil P decreases, reducing the amount of oil P supplied to the recessed portion 6. The angle θ2 is set in consideration of the above, and is set to, for example, about 5 to 20°.

[0033] A radial gap δ1 between the first scraping portion 5a and the outer peripheral surface 3c of the rotating member 3, and an axial gap δ2 between the second scraping portion 5b and the front end surface 3a of the rotating member 3 (see FIG. 5). The smaller the radial gap δ1 and the axial gap δ2 are, the higher the ability of the first scraping portion 5a and the second scraping portion 5b to scrape off the oil P. Therefore, the radial gap δ1 and the axial gap δ2 are set to as small a value as possible within a range in which the scraping member 5 and the rotating member 3 do not come into contact with each other.

[0034] The radial position of the inner diameter end of the second scraping portion 5b When the second scraping portion 5b is extended toward the inner diameter side (toward the axis of the rotating member 3) and brought closer to the recessed portion 6, the oil P is more easily supplied to the recessed portion 6. Therefore, the radial position of the inner diameter side end portion of the second scraping portion 5b is set so that an appropriate amount of oil P is supplied to the recessed portion 6.

[0035] Circumferential position of the scraping member 5 relative to the rotating member 3 According to the inventor's verification, when the scraping member 5 is disposed at the upper end of the rotating member 3, the oil P supplied to the front end face 3a of the rotating member 3 is not guided radially inward beyond the second scraping portion 5b and does not reach the recessed portion 6. In contrast, as shown in FIG. 1 , by arranging the scraping member 5 upstream of the upper end in the direction of rotation R in the region of the rotating member 3 that is not immersed in the oil P, the oil P is guided radially inward and reaches the recessed portion 6. Therefore, the scraping member 5 is set so that a film of oil P of an appropriate thickness is formed on the inner circumferential surface of the recessed portion 6 within the range upstream of the upper end in the direction of rotation R of the region of the rotating member 3 that is not immersed in the oil P.

[0036] Rotation speed of rotating member 3 Increasing the rotation speed of the rotating member 3 increases the amount of oil P supplied from the oil container 2 to the rotating member 3, and slowing the rotation speed of the rotating member 3 decreases the amount of oil P supplied from the oil container 2 to the rotating member 3. Therefore, the rotation speed of the rotating member 3 is set so that a film of oil P of an appropriate thickness is formed on the inner circumferential surface of the recess 6.

[0037] The shape of the recess 6 of the rotating member 3 For example, changing the shape (angle) and size of the introduction portion 6a of the recess 6 changes the supply condition (ease of supply) of the oil P from the front end face 3a of the rotating member 3 into the recess 6. Therefore, the shape of the recess 6 is set so that a film of oil P with an appropriate thickness is formed on the inner circumferential surface of the recess 6.

[0038] As described above, after adjusting each part of the oil application device 1, oil P is supplied to the rotating member 3 while rotating the rotating member 3, thereby forming a uniform film of oil P all around the inner circumferential surface of the recessed portion 6 of the rotating member 3. In this state, as shown by the dotted line in Figure 11, the tip of the workpiece 10 is inserted into the inner circumferential surface of the recessed portion 6, and the O-ring 12 is brought into contact with the film of oil P formed on the inner circumferential surface of the recessed portion 6 (more specifically, the inner part of the introduction portion 6a), thereby uniformly applying oil P all around the outer periphery of the O-ring 12.

[0039] The O-ring 12 of the workpiece 10 of this embodiment is an oil seal. The area of ​​the workpiece 10 on the tip side of the O-ring 12 (left side in FIG. 11) is an area that comes into contact with oil (hereinafter referred to as the "oil contact area 13"), and the area on the base side of the O-ring 12 (right side in FIG. 11) is an area that does not come into contact with oil (hereinafter referred to as the "oil non-contact area 14"). The oil contact area 13 is inserted into the inner periphery of the cylindrical surface 6b of the recess 6, but the oil non-contact area 14 is not inserted into the inner periphery of the cylindrical surface 6b of the recess 6, so oil P is unlikely to adhere to the oil non-contact area 14. In particular, in this embodiment, a tapered introduction portion 6a is provided at the opening end of the recess 6, so that when the O-ring 12 is brought into contact with the innermost portion of the introduction portion 6a, the oil non-contact region 14 faces the middle portion of the introduction portion 6a (a portion with a larger diameter than the innermost portion), thereby separating the oil non-contact region 14 from the film of oil P and preventing the oil P from adhering to the oil non-contact region 14.

[0040] Furthermore, in this embodiment, the diameter D1 of the cylindrical surface 6b of the recess 6 is slightly smaller than the outer diameter D2 of the O-ring 12. Therefore, when the O-ring 12 is inserted into the inner periphery of the cylindrical surface 6b, the O-ring 12 interferes with the cylindrical surface 6b, causing resistance. This prevents the O-ring 12 and the oil-non-contact region 14 of the workpiece 10 from being inserted all the way into the recess 6 (cylindrical surface 6b), thereby preventing excessive oil P from adhering to the O-ring 12 or the oil-non-contact region 14. In particular, in this embodiment, the axial dimension L1 of the cylindrical surface 6b of the recess 6 is equal to the axial dimension L2 of the oil-contact region 13 of the workpiece 10. Therefore, the leading edge of the workpiece 10 hits the bottom surface of the recess 6 before the entire O-ring 12 of the workpiece 10 is inserted into the inner periphery of the cylindrical surface 6b of the recess 6. This reliably prevents the O-ring 12 and the oil-non-contact region 14 of the workpiece 10 from being inserted all the way into the recess 6.

[0041] The present invention is not limited to the above-described embodiment. Other embodiments of the present invention will be described below, but redundant description of the same points as those in the above-described embodiment will be omitted.

[0042] The shape of the recess 6 provided at the axis of the rotating member 3 is not limited to the above. For example, as shown in FIG. 12, the introduction portion 6a of the recess 6 may be a convex curved surface (e.g., a convex curved surface with an arc-shaped cross section). Alternatively, as shown in FIG. 13, the introduction portion 6a may be configured to have a tapered surface 6a1 and a convex curved surface 6a2 (e.g., a convex curved surface with an arc-shaped cross section). The convex curved surface 6a2 smoothly connects the tapered surface 6a1 and the front end face 3a of the rotating member 3. Alternatively, a convex curved surface connecting the tapered surface 6a1 and the cylindrical surface 6b may be provided. Furthermore, the workpiece insertion portion is not limited to the recess 6, and may be, for example, a through hole penetrating the axis of the rotating member 3.

[0043] In the above embodiment, the scraping member 5 has the first scraping portion 5a and the second scraping portion 5b, but this is not limiting. For example, if the second scraping portion 5b alone is sufficient to form an appropriate film of oil P on the inner circumferential surface of the recess 6, the first scraping portion 5a may be omitted. On the other hand, if the oil P supplied by the first scraping portion 5a from the outer circumferential surface 3c of the rotating member 3 to the front end face 3a can be guided to the recess 6 without the second scraping portion 5b, the second scraping portion 5b may be omitted.

[0044] The liquid guiding means is not limited to the scraping member 5. For example, the liquid guiding means can also be configured by controlling the rotation speed of the rotating member 3. For example, the oil P can be guided to the recessed portion 6 by intermittently rotating the rotating member 3. Specifically, by temporarily reducing or stopping the rotation speed of the rotating member 3, the oil P adhering above the recessed portion 6 on the front end surface 3a of the rotating member 3 can be made to fall down the end surface 3a by its own weight and be guided to the recessed portion 6.

[0045] The liquid supply unit is not limited to the oil container 2. For example, the liquid supply unit may be configured by a nozzle that sprays liquid (oil) toward the rotating member 3, or a dripping unit that drips liquid (oil) onto the rotating member 3 from above.

[0046] In the above embodiment, the axis of the rotating member 3 is horizontal, but this is not limiting, and the axis of the rotating member 3 may be inclined relative to the horizontal direction. For example, the axis of the rotating member 3 may be vertical.

[0047] In the above embodiment, the liquid applied to the periphery of the workpiece is oil, but the present invention can also be applied to an apparatus that applies a liquid other than oil, such as an adhesive, to the periphery of a workpiece. [Explanation of symbols]

[0048] 1 Oil application device (liquid application device) 2 Oil container (liquid supply) 3 Rotating members 4. Electric motor (drive means) 5. Scraper (liquid guide means) 5a First scraping section 5b Second scraping section 6 Recess (workpiece insertion part) 6a Introduction 6b Cylindrical surface 10 Work 11 Cylindrical member 12 O-rings 13 Oil contact area 14 Oil-free area P Oil (liquid)

Claims

1. A liquid application device for applying a liquid to the outer periphery of a workpiece, A liquid application device comprising: a rotating member; a driving means for rotating the rotating member around its axis; a workpiece insertion portion provided at the axis of the rotating member and into which the workpiece is inserted; a liquid supply portion for supplying liquid to the rotating rotating member; and a liquid guide means for guiding the liquid supplied to the rotating rotating member to the workpiece insertion portion.

2. 2. The liquid application device according to claim 1, wherein the axis of the rotating member is disposed horizontally.

3. the liquid supply unit is a liquid container that stores liquid therein, 3. The liquid application device according to claim 2, wherein a lower portion of the rotating member is immersed in the liquid stored in the liquid container.

4. 4. The liquid application device according to claim 1, wherein the liquid guide means is a scraping member that scrapes off the liquid adhering to the rotating member and guides the liquid to the workpiece insertion portion.

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