Waste Liquid Recovery Equipment

Abstract

To provide a waste liquid recovery device which is effective for improving a recovery rate of waste liquid produced by cleaning of a paint gun.SOLUTION: A waste liquid recovery device 101 is a device for recovering waste liquid produced during cleaning of a paint gun 1 and includes a cylindrical recovery hopper 10. One cylinder end side of the recovery hopper 10 is provided with an insertion hole 31 for inserting a jet head 2 of the paint gun 1 into a cylinder inner space 11. An inner periphery of the recovery hopper 10 is provided with collision wall surfaces 21, 34 with which the waste liquid jetted from the jet head 2 into the cylinder inner space 11 collides. The collision wall surfaces 21, 34 have a curved surface 34 which is curved so that a radial distance a from a center axis L1 of the recovery hopper 10 gradually increases in a direction away from the insertion hole 31 in an axial direction X.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a waste liquid recovery device that recovers waste liquid generated during cleaning of a paint gun. [Background technology]

[0002] Patent Document 1 below discloses this type of waste liquid recovery device. This waste liquid recovery device is used to clean a paint gun that has a bell cup at the tip. This waste liquid recovery device is equipped with a cylindrical box body that has an insertion hole into which the tip of the paint gun is inserted.

[0003] When cleaning the paint gun, first, the tip of the paint gun is inserted into the insertion hole of the box. Then, while supplying cleaning liquid to the paint gun with the bell cup rotated, shaping air is discharged from the shaping air discharge part provided on the outer periphery of the bell cup. As a result, the cleaning liquid flows inside the paint gun and is sprayed from the tip as atomized waste liquid, and the waste liquid is guided into the box along the discharge flow of the shaping air. The waste liquid then collides with the inner wall of the box and coagulates, where it is collected. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-223601 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the case of the waste liquid recovery device having the above configuration, the spray angle of the waste liquid from the tip of the paint gun changes depending on the processing conditions during cleaning, such as the rotation speed of the bell cup, the discharge amount of the waste liquid, and the discharge flow rate of the shaping air, and this changes the collision range where the waste liquid collides with the inner wall of the box. At this time, if the inner wall of the box extends vertically, the collision angle of the waste liquid with this inner wall becomes closer to vertical as it approaches the insertion hole, and the waste liquid at the time of collision is diverted to the insertion hole side and accumulates, and the amount of accumulation tends to increase. If the waste liquid accumulated in the area close to the insertion hole adheres to the spray head of the paint gun as droplets, it is assumed that these droplets will scatter from the box through the insertion hole at the timing of pressure fluctuations when the shaping air is discharged and stopped, etc., when it is turned on and off. As a result, the amount of condensed waste liquid decreases, and the recovery rate decreases.

[0006] SUMMARY OF THE PRESENT INVETION The present invention has been made in view of the above problems, and aims to provide a waste liquid recovery device that is effective in increasing the recovery rate of waste liquid generated during cleaning of paint guns. [Means for solving the problem]

[0007] One aspect of the present invention is A waste liquid recovery device for recovering waste liquid generated during cleaning of a paint gun, comprising: Equipped with a cylindrical collection hopper, an insertion hole for inserting the spray head of the coating gun into the space inside the cylinder is provided at one end of the recovery hopper, and a collision wall surface is provided on the inner periphery of the recovery hopper against which the waste liquid sprayed from the spray head into the space inside the cylinder collides; The collision wall surface has a curved surface that is curved so that the radial distance from the central axis of the recovery hopper gradually increases as the collision wall surface moves axially away from the insertion hole. death, The curved surface is provided with a collision angle maintaining region having a shape for maintaining the collision angle of the waste liquid constant even when the spray angle of the waste liquid varies. , waste liquid recovery device, is located. Effect of the Invention

[0008] In the waste liquid recovery device of the above aspect, when cleaning the paint gun, the spray head of the paint gun is inserted into the space inside the cylinder through an insertion hole provided at one end of the cylindrical recovery hopper. Therefore, the waste liquid sprayed from the spray head of the paint gun into the space inside the cylinder collides with a collision wall provided on the inner circumference of the recovery hopper. At this time, the mist-like waste liquid sprayed in an atomized state from the spray head collides with the collision wall, so that a portion of the mist is diverted toward the insertion hole side and the remainder coagulates into droplets and is recovered. The liquid then becomes droplets.

[0009] The collision wall surface of the recovery hopper has a curved surface that is curved so that the radial distance from the central axis of the recovery hopper gradually increases as the wall surface moves away from the insertion hole in the axial direction. With such a curved surface, even if the spray angle of the waste liquid relative to the curved surface changes, a collision angle maintaining region that can maintain the collision angle at the curved surface approximately constant can be continuously formed along the axial direction. Here, the collision angle at the curved surface is defined as the angle between the spray line of the waste liquid and the tangent at the collision point of the curved surface. In this way, if the collision angle maintaining region can be continuously formed on the curved surface, even if the spray angle of the waste liquid relative to the curved surface changes, it is possible to suppress the variation in the proportion of the diverted flow that flows toward the insertion hole after the waste liquid collides with the curved surface, which is effective in increasing the amount of flocculated waste liquid and increasing the recovery rate.

[0010] As described above, according to the above-mentioned aspect, it is possible to provide a waste liquid recovery device that is effective in increasing the recovery rate of waste liquid generated during cleaning of a paint gun. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an overall configuration of a waste liquid recovery device according to a first embodiment. [Diagram 2] FIG. 1A is a diagram showing a state where a workpiece is painted with a paint gun according to a first embodiment, and FIG. 1B is a diagram showing a state where a paint head is cleaned. [Diagram 3] FIG. 2 is a cross-sectional view of a recovery hopper of the waste liquid recovery device of the first embodiment. [Figure 4] FIG. 4 is a diagram for explaining the shape of a curved surface of the recovery hopper in FIG. 3. [Diagram 5] 6A and 6B are diagrams for explaining a state in which waste liquid collides with a collision wall surface of a recovery hopper. [Figure 6] FIG. 11 is a cross-sectional view showing a state in which waste liquid collides with a collision wall surface of a recovery hopper in a comparative example. [Figure 7] FIG. 4 is a cross-sectional view showing a state in which waste liquid collides with a curved surface of the recovery hopper of the embodiment. [Figure 8] FIG. 11 is a cross-sectional view of a recovery hopper module of the waste liquid recovery device of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A description will now be given of preferred embodiments of the above aspects.

[0013] In the waste liquid recovery device of the above aspect, it is preferable that the curved surface is formed following an elliptical arc of an ellipse whose major axis is in the axial direction of the recovery hopper.

[0014] According to this waste liquid recovery device, by forming the curved surface of the recovery hopper according to the elliptical arc of an ellipse whose major axis is in the axial direction of the recovery hopper, the impact angle maintaining region of the curved surface can be expanded in the axial direction. Furthermore, when designing the recovery hopper, the shape of the curved surface can be easily determined using the curvature of the elliptical arc of an ellipse that is suitable for the shape of the paint gun, the processing conditions during cleaning, etc.

[0015] In the waste liquid recovery device of the above-mentioned aspect, the recovery hopper has a main body cylindrical portion whose inner diameter is constant in the axial direction, and a lid portion attached to one end side of the main body cylindrical portion in the axial direction, and it is preferable that the lid portion is provided with the insertion hole and the curved surface.

[0016] According to this waste liquid recovery device, by making the main body cylindrical part and the lid part separate parts, it is possible to prepare a part having a desired shape of insertion hole and curved surface as the lid part, while preparing a part having a simple structure with a constant inner diameter as the main body cylindrical part. Therefore, it is possible to use an inexpensive general-purpose part for the main body cylindrical part, and to keep the cost of the device low. In addition, since the lid part can be removed from the main body cylindrical part to perform the inspection and cleaning work of the inside of the recovery hopper, the labor required for these work can be kept low.

[0017] In the waste liquid recovery device of the above aspect, the recovery hopper is preferably configured so that the dimensional ratio of the inner diameter of the main body cylindrical portion to the outer diameter of the injection head is a value within the range of more than 1.0 and not more than 3.0.

[0018] According to this waste liquid recovery device, the ratio of the inner diameter of the cylindrical body to the outer diameter of the spray head of the paint gun is kept to 3.0 or less, so that the radial distance from the spray head to the inner peripheral surface of the cylindrical body can be kept short. This allows the waste liquid sprayed in an atomized state from the spray head of the paint gun to collide with the curved surface over a short distance, and prevents the waste liquid from dispersing too much before colliding with the curved surface. As a result, this is effective in increasing the amount of condensed waste liquid and increasing the recovery rate. In addition, by keeping the radial dimension of the cylindrical body part small, the cylindrical body part itself can be designed to be compact, so that the recovery hopper can be made smaller and lighter.

[0019] The waste liquid recovery device of the above-mentioned embodiment is used in a twin coating gun in which two of the spray heads are arranged radially side by side, and is provided with a recovery hopper module in which the two recovery hoppers are radially adjacent and connected to each other, and it is preferable that the recovery hopper module is configured so that the inner diameter of the main body cylindrical portion in each recovery hopper is smaller than the center-to-center distance between the central axes of the two spray heads.

[0020] According to this waste liquid recovery device, the waste liquid sprayed from each of the two spray heads during cleaning of the twin coating gun can be recovered by using each of the two recovery hoppers of the recovery hopper module.

[0021] A structure for realizing the above-mentioned waste liquid recovery device will now be described with reference to the drawings.

[0022] In the drawings referred to in the description of this specification, unless otherwise specified, the axial direction of a recovery hopper constituting the waste liquid recovery device is indicated by arrow X, and the radial direction of this recovery hopper is indicated by arrow Y.

[0023] (Embodiment 1) 1, the waste liquid recovery device 101 of the first embodiment is a device that recovers waste liquid C generated during cleaning of a paint gun 1. This waste liquid recovery device 101 includes a recovery hopper 10 installed in a paint booth 102, and a recovery tank 106 and a transfer pump 107 installed in a tank room 103.

[0024] The paint booth 102 is installed indoors. The paint booth 102 has a first space 102a used for both painting the workpiece and cleaning the paint gun 1, a second space 102b provided below the first space 102a and in which the recovery pipe 14 is arranged, and a third space 102c provided below the second space 102b.

[0025] The painting booth 102 is provided with an exhaust duct 104 communicating with the third space 102c, and an intake blower 105 connected to the exhaust duct 104. In this painting booth 102, when the intake blower 105 is in operation, a downward flow is formed by the intake air in the first space 102a, and the air in the first space 102a is exhausted to the outdoors via the second space 102b, the third space 102c, and the exhaust duct 104 in this order.

[0026] 1 illustrates an example in which three recovery hoppers 10 are arranged in the first space 102a. Each recovery hopper 10 is a recovery container for recovering waste liquid C generated when cleaning the paint gun 1, and its bottom is connected to a recovery pipe 14 through a connection pipe 13. The connection pipe 13 extends vertically. The recovery pipe 14 extends in the second space 102b at an angle to the horizontal direction.

[0027] The waste liquid C collected in each collection hopper 10 flows by its own weight through the individual connecting pipes 13 and the shared collection pipe 14 in sequence, and enters the collection tank 106. The waste liquid C stored in the collection tank 106 is transferred to an appropriate destination by using a transfer pump 107 as necessary.

[0028] The number of recovery hoppers 10 is not particularly limited, and an appropriate number of recovery hoppers 10 can be installed in the coating booth 102 as necessary. Also, a pump may be connected to the connecting pipe 13, and the waste liquid C recovered in the recovery hoppers 10 may be pressure-transferred to the recovery tank 106 using this pump.

[0029] (Painting work) As shown in Fig. 2(a), when painting a workpiece W, the paint gun 1 is positioned so that its spray head 2 faces the surface to be painted of the workpiece W. At this time, the attitude and movement trajectory of the paint gun 1 are preferably controlled by a painting robot (not shown). The spray head 2 contains a bell cup 3 that is driven to rotate about an axis extending in the axial direction X. The bell cup 3 performs a spraying function by applying centrifugal force to the paint P by utilizing the rotation about its axis, thereby spraying the paint P in the form of fine particle mist.

[0030] The spraying function of the bell cup 3 allows the paint P to be sprayed in a mist (also called "atomized") state from the spray head 2 of the paint gun 1 toward the surface to be coated of the workpiece W by rotating about its axis. At this time, when shaping air A is sprayed in the axial direction X from the shaping air discharge part 4, the shaping air A gives directionality to the misted paint P. This allows the paint P to be sprayed radially to paint a desired range on the surface to be coated of the workpiece W.

[0031] (Cleaning work) As shown in FIG. 2(b), when cleaning the paint gun 1, the painting robot is controlled in the same manner as in the case of painting, and the paint gun 1 is positioned so that its spray head 2 is inserted inside the collection hopper 10.

[0032] Bell cup 3 is then rotated while cleaning liquid B is supplied to paint gun 1 instead of paint P. Cleaning liquid B is a solvent such as thinner that is suitable for cleaning paint P. At this time, paint P remaining inside paint gun 1 is replaced by cleaning liquid B over time, and waste liquid C is sprayed in a mist form from spray head 2. Note that some of the paint P remains in waste liquid C until cleaning of paint gun 1 is complete.

[0033] When the shaping air A is discharged from the shaping air discharge portion 4 in the axial direction X, the shaping air A imparts directionality to the mistified waste liquid C. This allows the waste liquid C to be sprayed radially into the inside of the recovery hopper 10.

[0034] For further specific structure of the coating machine including the coating gun 1, reference can be made to, for example, the structure of the electrostatic atomization coating machine described in JP 2020-93195 A.

[0035] 3, the recovery hopper 10 of the waste liquid recovery device 101 is a cylindrical recovery container whose cylindrical axis direction is the axial direction X. The recovery hopper 10 has a main cylindrical portion 20 and a lid portion 30.

[0036] The main body tube portion 20 is configured as a cylindrical member whose inner diameter d2 in the radial direction Y is constant along the axial direction X. An internal space 20a is defined by a vertical surface 21 which is the inner peripheral surface of the main body tube portion 20. This vertical surface 21 is a surface which extends perpendicularly to the axial direction X, and is a collision wall surface against which the waste liquid C radially sprayed from the spray head 2 of the paint gun 1 into the in-tube space 11 collides. Therefore, in the following description, the vertical surface 21 is also referred to as the collision wall surface 21.

[0037] The lid portion 30 is configured as a separate lid member from the cylindrical main body portion 20. The lid portion 30 is attached to one end side of the cylindrical main body portion 20 in the axial direction X (the upper side of the recovery hopper 10 in FIG. 3 ) via a fixing means (not shown) such as a bolt member. On the other hand, when the fixing by the fixing means is released, the lid portion 30 can be removed from the cylindrical main body portion 20 to perform an inspection or cleaning operation on the inside of the recovery hopper 10.

[0038] The lid portion 30 is provided with an insertion hole 31, a flange portion 32, and an insertion portion 33.

[0039] The insertion hole 31 of the lid portion 30 is a circular insertion hole for inserting the circular spray head 2 of the coating gun 1 into the cylindrical space 11. The dimensions of this insertion hole 31 are set so that its inner diameter d3 exceeds the outer diameter of the tip side of the spray head 2, i.e., the outer diameter d1 of the tip side of the bell cup 3. This insertion hole 31 is preferably provided at the center position of the recovery hopper 10 in the radial direction Y of the lid portion 30.

[0040] The flange 32 of the lid 30 is supported by the opening edge of the tubular main body 20 when the insertion portion 33 is inserted into the internal space 20a of the tubular main body 20. As a result, the lid 30 is attached to the tubular main body 20 with its positioning in the axial direction X being determined. At this time, an internal space 30a is defined by the insertion portion 33 of the lid 30. This internal space 30a cooperates with the internal space 20a of the tubular main body 20 to form an in-cylinder space 11 for collecting the waste liquid C.

[0041] The inner peripheral surface of the insertion portion 33 of the lid portion 30 is a collision wall surface 34 against which the waste liquid C radially sprayed from the spray head 2 of the coating gun 1 into the cylindrical space 11 collides. That is, the collision wall surface 34 is provided on the inner peripheral surface of the recovery hopper 10. This collision wall surface 34 extends continuously from the insertion hole 31 along the axial direction X. Moreover, this collision wall surface 34 is a curved surface that is curved such that the radial distance a from the central axis L1 of the recovery hopper 10 gradually increases as it moves away from the insertion hole 31 in the axial direction X. Therefore, in the following description, the collision wall surface 34 is also referred to as the curved surface 34.

[0042] As described above, in the recovery hopper 10, the collision wall surface against the waste liquid C is composed of the collision wall surface 21 provided on the main body tubular portion 20 and the collision wall surface 34 provided on the lid portion 30. One of these collision wall surfaces 21, 34, that is, the collision wall surface 34, is a curved surface. In other words, the collision wall surfaces 21, 34 of the recovery hopper 10 have the curved surface 34.

[0043] It is preferable that the recovery hopper 10 is configured so that the dimensional ratio of the inner diameter d2 of the main body cylindrical portion 20 to the outer diameter of the injection head 2 (the outer diameter d1 at the tip side of the bell cup 3) is a value in the range of more than 1.0 and not more than 3.0.

[0044] According to this configuration, by keeping this dimensional ratio at 3.0 or less, the distance in the radial direction Y from the spray head 2 of the spray gun 1 to the vertical surface 21 of the main body tube 20 can be kept short. This allows the waste liquid C sprayed in an atomized state from the spray head 2 of the spray gun 1 to collide with the curved surface 34 over a short distance, and prevents the waste liquid C from dispersing too much before colliding with the curved surface 34. As a result, this is effective in increasing the amount of condensed waste liquid C and increasing the recovery rate. Note that if the waste liquid C disperses too much in the cylinder space 11, the waste liquid C becomes difficult to condense, making it difficult to recover the waste liquid C.

[0045] Furthermore, by reducing the dimension of the cylindrical main body portion 20 in the radial direction Y, the cylindrical main body portion 20 itself can be designed to be compact, so that the recovery hopper 10 can be made smaller and lighter.

[0046] 4, the recovery hopper 10 is preferably configured such that the curved surface 34 of the lid portion 30 is formed following the elliptical arc 43 of the imaginary ellipse 40. In other words, the shape of the curved surface 34 is approximated using the shape of the elliptical arc 43 of the ellipse 40.

[0047] Here, the ellipse 40 is an ellipse with the long axis 41 directed along the axial direction X. In the cross-sectional structure of the cover portion 30 in FIG. 4, the curved surface 34 on the right side in the figure is formed following a first elliptical arc 43a which is a part of the ellipse 40, and the curved surface 34 on the left side in the figure is formed following a second elliptical arc 43b which is a part of the ellipse 40. At this time, the elliptical arcs 43a and 43b are elliptical arcs whose curvature gradually increases as they move away from the insertion hole 31. Therefore, both of the left and right curved surfaces 34 and 34 are elliptical arcs whose curvature gradually increases as they move away from the insertion hole 31, in accordance with the shapes of the elliptical arcs 43a and 43b.

[0048] Next, a state in which the mist-like waste liquid C collides with the collision wall surface 34 will be described with reference to Figures 3 and 5 to 7. For the sake of convenience, only a part of the collision wall surface 34 is shown in these figures.

[0049] 5, the mist-like waste liquid C is sprayed at a spray angle M with respect to a vertical line V of the axial direction X, and its original flow Ca flows obliquely downward and collides with the collision wall surface 34 at a collision angle N at a collision point S. The collision angle N is defined as the angle (>90°) between the spray line F of the original flow Ca and the collision wall surface 34. At this time, the waste liquid C collides with the collision wall surface 34 and is separated into a main flow Cb and a branch flow Cc.

[0050] The main flow Cb is formed so as to flow away from the lid portion 30, and is a downward flow along the collision wall surface 34. The waste liquid C that aggregates on the collision wall surface 34 and turns into droplets flows down the collision wall surface 34 toward the bottom due to its own weight. In contrast, the branch flow Cc is formed so as to approach the lid portion 30, and is an upward counterflow to the main flow Cb.

[0051] If the ratio of the diverted flow Cc to the original flow Ca is high, the waste liquid C will accumulate and coagulate in the area of ​​the cylinder inner space 11 close to the insertion hole 31 of the lid portion 30, and will tend to adhere as droplets to the spray head 2 of the coating gun 1. Then, when the pressure fluctuates when the shaping air A is discharged and stopped, the amount of coagulated waste liquid will decrease, and this can lead to a problem of a decrease in the recovery rate of the waste liquid C.

[0052] In particular, when a structure is adopted in which the waste liquid C sprayed from the spray head 2 of the paint gun 1 is caused to collide with the collision wall surface 34 over a relatively short distance, the progress of dispersion of the waste liquid C in the cylindrical space 11 can be suppressed, but on the other hand, the amount of liquid pool formed on the insertion hole 31 side increases as the waste liquid C collides with the collision wall surface 34, making this problem more pronounced.

[0053] Here, the ratio of the diverted flow Cc to the original flow Ca decreases as the collision angle N increases, whereas the ratio of the diverted flow Cc to the original flow Ca increases as the collision angle N decreases. Also, the collision angle N generally tends to change with changes in the spray angle M. Therefore, in order to increase the recovery rate of the waste liquid C, it is preferable to set the collision angle N to be large and to adopt a structure in which this collision angle N is not easily affected by changes in the spray angle M.

[0054] An embodiment employing this structure will be described below in comparison with a comparative example.

[0055] (Comparative Example) As shown in Fig. 6, the recovery hopper 10' of the comparative example has a structure in which the collision wall surface 34' of the lid portion 30 extends perpendicularly to the axial direction X. The collision wall surface 34' is different from the curved surface 34 shown in Fig. 3 in that it is a surface that extends perpendicularly. In this structure, the case where the spray angle of the waste liquid C with respect to the perpendicular line V is different will be considered.

[0056] The waste liquid C ejected from the bell cup 3 at the ejection angle Ma collides with the collision wall surface 34' at the collision point Sa along the ejection line Fa. At this time, the collision angle formed by the ejection line Fa and the collision wall surface 34' is Na. Also, the waste liquid C ejected from the bell cup 3 at the ejection angle Mb (< Ma) collides with the collision wall surface 34' at the collision point Sb along the ejection line Fb. At this time, the collision angle formed by the ejection line Fb and the collision wall surface 34' is Nb (> Na). Furthermore, the waste liquid C ejected from the bell cup 3 at the ejection angle Mc (< Mb) collides with the collision wall surface 34' at the collision point Sc along the ejection line Fc. At this time, the collision angle formed by the ejection line Fc and the collision wall surface 34' is Nc (> Nb).

[0057] Here, in the recovery hopper 10' of the comparative example, because the collision wall surface 34' extends vertically, when the ejection angle of the waste liquid C changes, the collision position with respect to the collision wall surface 34' changes, and the collision angle of the waste liquid C with respect to the collision wall surface 34' changes. At this time, due to the influence of the change in the collision angle of the waste liquid C, the ratio of the diverted flow Cc to the original flow Ca (see Fig. 5) fluctuates greatly and is not stable, so it is difficult to increase the recovery rate of the waste liquid C.

[0058] Also, according to the recovery hopper 10' of the comparative example, when the waste liquid C is ejected at a position close to the insertion hole 31 like the ejection line Fa, for example, compared with the case where the waste liquid C is ejected along the ejection line Fc, the ratio of the above-mentioned diverted flow Cc increases, so the mist-like waste liquid C after diversion is likely to aggregate and scatter outward from the recovery hopper 10' through the insertion hole 31. For this reason, it can be a factor that reduces the amount of the aggregated liquid of the waste liquid C and lowers the recovery rate of the waste liquid C.

[0059] (Example) As shown in Fig. 7, the recovery hopper 10 of the example is proposed to solve the above problems of the recovery hopper 10' of the comparative example, and has a structure in which a curved surface 34 serving as a collision wall surface is provided on the lid portion 30. In this structure, consider the case where the ejection angle of the waste liquid C with respect to the vertical line V is different.

[0060] When the waste liquid C sprayed from the bell cup 3 at a spray angle Ma collides with the curved surface 34 at the collision point Sa along the spray line Fa, the collision angle between the spray line Fa and the tangent line Ta at the collision point Sa of the curved surface 34 is Na'. When the waste liquid C sprayed from the bell cup 3 at a spray angle Mb collides with the curved surface 34 at the collision point Sb along the spray line Fb, the collision angle between the spray line Fb and the tangent line Tb at the collision point Sb of the curved surface 34 is Nb'. When the waste liquid C sprayed from the bell cup 3 at a spray angle Mc collides with the curved surface 34 at the collision point Sc along the spray line Fc, the collision angle between the spray line Fc and the tangent line Tc at the collision point Sc of the curved surface 34 is Nc'.

[0061] Here, in the recovery hopper 10 of the embodiment, the curved surface 34 is curved so that the radial distance a (see FIG. 3) gradually increases as it moves away from the insertion hole 31 in the axial direction X. In this case, even if the spray angle of the waste liquid C changes and the collision position with the curved surface 34 changes, a collision angle maintaining region 35 can be formed that can maintain the collision angle of the waste liquid C with the curved surface 34 at approximately the same value. The collision angle maintaining region 35 is formed continuously along the axial direction X by a part or the whole of the curved surface 34. By forming the collision angle maintaining region 35, it is possible to suppress the ratio of the diverted flow Cc to the original flow Ca from fluctuating even if the spray angle of the waste liquid C changes, which is effective in increasing the recovery rate of the waste liquid C.

[0062] According to the recovery hopper 10 of the embodiment, the collision angle can be increased even if the injection angle is the same as that of the comparative example. For example, when the collision angle Na corresponding to the injection angle Ma in the comparative example is compared with the collision angle Na' corresponding to the injection angle Ma in the embodiment, the collision angle Na' is larger than the collision angle Na. In addition, even if the waste liquid C is injected at a position close to the insertion hole 31 as in the injection line Fa, the ratio of the diverted flow Cc to the original flow Ca can be suppressed, and even if the diverted mist-like waste liquid C aggregates on the insertion hole 31 side, it is difficult for it to scatter from the recovery hopper 10 to the outside through the insertion hole 31. Therefore, it is possible to suppress the amount of aggregated liquid of the waste liquid C from decreasing, and it is possible to prevent the recovery rate of the waste liquid C from decreasing.

[0063] Furthermore, when a structure is adopted in which the waste liquid C sprayed from the spray head 2 of the coating gun 1 is caused to collide with the collision wall surface 34 over a relatively short distance (a structure in which the dimensional ratio of the inner diameter d2 of the main body tube 20 to the outer diameter d1 of the spray head 2 is greater than 1.0 and is equal to or less than 3.0), the amount of liquid pool formed on the insertion hole 31 side increases, but by using the curved surface 34 to suppress the ratio of the diverted flow Cc to the original flow Ca, even if the amount of liquid pool increases, it is possible to prevent the waste liquid C coagulated on the insertion hole 31 side from scattering outside the recovery hopper 10 through the insertion hole 31. As a result, the progress of dispersion of the waste liquid C in the cylindrical space 11 before collision can be suppressed, and the ratio of the diverted flow Cc to the original flow Ca can be suppressed, which has the effect of further increasing the recovery rate of the waste liquid C.

[0064] Next, the effects of the first embodiment will be described.

[0065] In the waste liquid recovery device 101 of the first embodiment, when the paint gun 1 is washed, the spray head 2 of the paint gun 1 is inserted into the cylindrical space 11 through an insertion hole 31 provided on one cylindrical end side of a cylindrical recovery hopper 10. Therefore, the waste liquid C sprayed from the spray head 2 of the paint gun 1 into the cylindrical space 11 collides with the collision wall surfaces 21, 34 provided on the inner circumference of the recovery hopper 10. At this time, the mist-like waste liquid C sprayed in an atomized state from the spray head 2 collides with the collision wall surfaces 21, 34, so that a part of the waste liquid C is diverted to the insertion hole 31 side and the remainder coagulates into droplets and is recovered.

[0066] The collision wall surfaces 21, 34 of the recovery hopper 10 have a curved surface 34 that is curved so that the radial distance a from the central axis L1 of the recovery hopper 10 gradually increases as it moves away from the insertion hole 31 in the axial direction X. With such a curved surface 34, even if the spray angle of the waste liquid C with respect to the curved surface 34 changes, a collision angle maintaining region 35 that can maintain the collision angle at the curved surface 34 approximately constant can be continuously formed along the axial direction X.

[0067] In this way, if the collision angle maintenance region 35 can be continuously formed on the curved surface 34, even if the spray angle of the waste liquid C relative to the curved surface 34 changes, it is possible to suppress fluctuations in the proportion of the diverted flow that flows toward the insertion hole 31 after the waste liquid C collides with the curved surface 34, which is effective in increasing the amount of condensed liquid of the waste liquid C and improving the recovery rate.

[0068] Therefore, according to the above-described first embodiment, it is possible to provide the waste liquid recovery device 101 that is effective in increasing the recovery rate of the waste liquid C generated during cleaning of the paint gun 1.

[0069] According to the waste liquid recovery device 101 of the first embodiment, by forming the curved surface 34 of the recovery hopper 10 following the elliptical arc 43 of the ellipse 40 whose major axis 41 is oriented in the axial direction X of the recovery hopper 10, it is possible to expand the collision angle maintaining region 35 of the curved surface 34 in the axial direction X. Furthermore, when designing the recovery hopper 10, the shape of the curved surface 34 can be easily determined using the curvature of the elliptical arc 43 of the ellipse 40 that is suitable for the shape of the paint gun 1, the processing conditions during cleaning, and the like.

[0070] According to the waste liquid recovery device 101 of the first embodiment, by making the main body tubular portion 20 and the lid portion 30 separate members, it is only necessary to prepare a part having a desired shape of the insertion hole 31 and the collision wall surface 34 as the lid portion 30, while preparing a part having a simple structure with a constant inner diameter d2 as the main body tubular portion 20. Therefore, it is possible to use an inexpensive general-purpose part for the main body tubular portion 20 and to keep the device cost low. In addition, since the lid portion 30 can be removed from the main body tubular portion 20 to perform the inspection and cleaning work of the inside of the recovery hopper 10, the man-hours required for these work can be kept low.

[0071] Hereinafter, other embodiments related to the above-mentioned embodiment 1 will be described with reference to the drawings. In the other embodiments, the same elements as those in embodiment 1 are given the same reference numerals, and the description of the same elements will be omitted.

[0072] (Embodiment 2) As shown in FIG. 8, the waste liquid recovery apparatus 101A of the second embodiment differs in structure from the waste liquid recovery apparatus 101 of the first embodiment in that the waste liquid recovery apparatus 101A of the second embodiment includes two components equivalent to the recovery hoppers 10. As shown in FIG.

[0073] The waste liquid recovery device 101A is used for a twin coating gun 1A in which the spray heads 2 of two coating guns 1 are arranged side by side in the radial direction Y. This waste liquid recovery device 101A is equipped with a recovery hopper module 10A. The recovery hopper module 10A has a structure in which two recovery hoppers 10 are adjacent to each other in the radial direction Y and connected to each other by a connecting member 15. This recovery hopper module 10A is configured so that the inner diameter d2 of the main body cylindrical portion 20 of each recovery hopper 10 is smaller than the center-to-center distance D between the central axes L2 of the two spray heads 2. With this configuration, the recovery hopper module 10A can be suitably used for cleaning a twin coating gun 1A in which two coating guns 1 are arranged close to each other.

[0074] The other configurations and the method of use during cleaning are the same as those in the first embodiment.

[0075] According to the waste liquid recovery device 101A of embodiment 2, the waste liquid C sprayed from each of the two spray heads 2 when cleaning the twin coating gun 1A can be recovered by using each of the two recovery hoppers 10 of the recovery hopper module 10A.

[0076] In addition, the same effects as those of the first embodiment are achieved.

[0077] The present invention is not limited to the exemplary embodiment described above, and various applications and modifications are possible without departing from the scope of the present invention. For example, the following embodiments can be implemented by applying the above-described embodiment.

[0078] In the above embodiment, the curved surface 34 of the recovery hopper 10 is formed to follow the elliptical arc 43 of the ellipse 40, but the shape of the curved surface 34 is not limited to this and can be appropriately changed as necessary. For example, the curved surface 34 may be formed to follow a circular arc.

[0079] In the above embodiment, the case where only one of the collision wall surfaces 21, 34 of the recovery hopper 10, the collision wall surface 34, is a curved surface has been illustrated. However, instead of this, both of the collision wall surfaces 21, 34 may be curved surfaces.

[0080] In the above-described embodiment, a recovery hopper 10 having a main body cylindrical portion 20 and a lid portion 30 that is separate from the main body cylindrical portion 20 has been exemplified. However, instead, the recovery hopper 10 may be formed from an integrated part in which the portion corresponding to the main body cylindrical portion 20 and the portion corresponding to the lid portion 30 are integrated together.

[0081] In the above-described embodiment, an example was given of an injection head 2 having a bell-shaped structure that houses a bell cup 3, but this injection head 2 need only be configured to be able to inject waste liquid C, and its structure is not limited to a bell-shaped structure. [Explanation of symbols]

[0082] 1 Paint gun 1A Twin Paint Gun 2 Jet head 10 Collection Hopper 10A Collection Hopper Module 11 Cylinder space 21 Collision wall surface (vertical surface) 31 Insertion hole 34 Collision wall (curved surface) 40 Oval 41 Long axis 43,43a,43b Elliptical arc 101,101A Waste liquid recovery device a Radial distance C. Waste liquid D Center distance d1 Outer diameter of the jet head d2 Inner diameter of the main body L1 Collection hopper central axis L2 Center axis of the jet head X-axis direction Y radial direction

Claims

1. A waste liquid recovery device for recovering waste liquid generated during cleaning of a paint gun, comprising: Equipped with a cylindrical collection hopper, an insertion hole for inserting the spray head of the coating gun into the space inside the cylinder is provided at one end of the recovery hopper, and a collision wall surface is provided on the inner periphery of the recovery hopper against which the waste liquid sprayed from the spray head into the space inside the cylinder collides; The collision wall surface has a curved surface that is curved so that the radial distance from the central axis of the recovery hopper gradually increases as the collision wall surface moves axially away from the insertion hole, The curved surface is provided with a collision angle maintaining area having a shape for maintaining the collision angle of the waste liquid constant even when the spray angle of the waste liquid varies.

2. 2. The waste liquid recovery device according to claim 1, wherein the recovery hopper is configured so that the curved surface is formed following an elliptical arc of an ellipse whose major axis is in the axial direction.

3. The waste liquid recovery device of claim 1 or 2, wherein the recovery hopper has a main cylindrical portion whose inner diameter is constant in the axial direction, and a lid portion attached to one end side of the main cylindrical portion in the axial direction, and the insertion hole and the curved surface are provided in the lid portion.

4. 4. The waste liquid recovery device according to claim 3, wherein the recovery hopper is configured so that a dimensional ratio of an inner diameter of the main cylindrical portion to an outer diameter of the injection head is a value within a range exceeding 1.0 and not exceeding 3.

0.

5. 4. The waste liquid recovery device according to claim 3, which is used in a twin coating gun in which two of the spray heads are arranged side by side in the radial direction, and which includes a recovery hopper module in which two of the recovery hoppers are adjacent to each other in the radial direction and connected to each other, and the recovery hopper module is configured such that the inner diameter of the main body cylindrical portion of each recovery hopper is smaller than the center-to-center distance between the central axes of the two spray heads.

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