JP7750179B2 - Sealant nozzle - Google Patents

Description

The present invention relates to a nozzle device used with a sealant.

Workpieces such as automobile bodies have a variety of openings, such as holes for removing electrocoat paint and holes used to position components for welding. To prevent rainwater, dust, and noise from entering through these openings, elastically deformable sealing parts called plugs made of resin or rubber materials are used. The openings are sealed by forcing these sealing parts into the openings of the workpiece.

When using sealing members for openings of different diameters, it is necessary to prepare multiple types of sealing members in advance, which can lead to problems such as high component costs for the sealing members and the need to use different types of sealing members as the number of types increases. To address these problems, the inventors conducted extensive research into a technology for sealing openings by discharging a viscous sealant toward the opening in a workpiece. Being able to seal openings with a sealant eliminates the need to prepare multiple types of sealing members in advance for openings of different diameters, which has the advantage of keeping the construction costs required for sealing openings low. Automobile bodies are particularly well-shaped, and the ability to seal openings in a vehicle body with a sealant instead of a sealing member would be particularly advantageous.

Patent Document 1 below discloses a viscous liquid discharge nozzle relating to this type of technology. This viscous liquid discharge nozzle is designed to uniformly apply viscous liquid to a large flat surface such as a floor, and is equipped with a nozzle body having an inlet through which viscous liquid pressurized by a pump flows in, a cylindrical chamber located downstream of the inlet, and multiple holes spaced apart across the width of the chamber for allowing the viscous liquid to flow downward from the chamber. With this viscous liquid discharge nozzle, pressurized viscous liquid is discharged downward from the multiple holes in the viscous liquid discharge nozzle, thereby applying the liquid to the floor surface.

Japanese Utility Model Application Laid-Open Publication No. 3-119466

However, the above-mentioned viscous liquid discharge nozzle is designed to simply apply a viscous liquid to the surface of a workpiece without an opening. Therefore, when using this viscous liquid discharge nozzle to discharge a sealant such as a viscous liquid to seal an opening in a workpiece, the difference in the sealant discharge pressure between the area corresponding to each nozzle hole and the area between two adjacent holes makes it difficult to achieve a generally uniform discharge pressure across the same cross section of the sealant. When the discharge pressure is uneven in this way, the cross-sectional shape of the sealant after discharge cannot be maintained constant, and this can lead to the sealant adhering to the workpiece's applied surface and then peeling off, or the sealant penetrating the opening in the workpiece and forming a concave shape, or even breaking through the through-hole in the case of a through-hole. As a result, there are concerns that the appearance of the workpiece after the opening is sealed with the sealant may be poor, or that a decrease in the sealant's film thickness strength may reduce the sealing performance of the opening.

The present invention was made in consideration of these issues, and aims to provide a sealant nozzle device that has excellent sealing performance when sealing openings in workpieces with viscous sealant.

One aspect of the present invention is
A sealant nozzle device used to seal an opening of a workpiece with a viscous sealant,
a nozzle having an inlet through which the sealant flows, a wide discharge outlet having an opening width greater than the opening diameter of the opening, and an internal space through which the sealant flows from the inlet to the discharge outlet,
the internal space of the nozzle is a retention region having a flow path cross-sectional area greater than an opening area of the discharge port,
the nozzle has two inner wall surfaces that face each other across the internal space in an opening width direction of the discharge outlet and that form curved shapes that bulge outward in the opening width direction between the inlet and the discharge outlet, and two inner wall surfaces that face each other across the internal space in an opening height direction of the discharge outlet and that form linear shapes between the inlet and the discharge outlet,
the internal space of the nozzle expands in a curved convex shape outward in the opening width direction from the inlet side toward the outlet side when the nozzle is viewed from the opening height direction of the outlet;
is located.
Another aspect of the present invention is
A sealant nozzle device used to seal an opening of a workpiece with a viscous sealant,
a nozzle having an inlet through which the sealant flows, a wide discharge outlet having an opening width greater than the opening diameter of the opening, and an internal space through which the sealant flows from the inlet to the discharge outlet,
the internal space of the nozzle is a retention region having a flow path cross-sectional area greater than an opening area of the discharge port,
the nozzle has two inner wall surfaces that face each other in an opening height direction of the nozzle across the internal space, and the two inner wall surfaces are provided with outlet flat surfaces that are arranged parallel to each other,
the nozzle is configured so that one of the two inner wall surfaces at the discharge port protrudes more than the other in the discharge direction of the sealant;
is located.

In the sealant nozzle device of the above aspect, viscous sealant flows into the nozzle through the inlet. The sealant then flows through the internal space of the nozzle from the inlet side toward the outlet side, and is then discharged to the outside through the wide outlet. At this time, the internal space of the nozzle is configured as a retention area with a flow path cross-sectional area that exceeds the opening area of the outlet. Therefore, the sealant can be temporarily retained in the internal space of the nozzle, and then discharged in a state where its flow is narrowed at the outlet.

This allows the pressure of the sealant ejected from the nozzle outlet to be roughly uniform across the entire opening, stabilizing the ejection state of the sealant and making the cross-sectional shape of the sealant roughly consistent after ejection. Furthermore, by making the nozzle outlet wide, the opening of the workpiece can be sealed with a stable sealant film thickness. This allows the sealant to be evenly applied to the application surface around the opening of the workpiece, preventing the sealant from entering the opening of the workpiece and forming a dent.

As described above, the above-described aspect provides a sealant nozzle device that exhibits excellent sealing performance when sealing an opening in a workpiece with a viscous sealant.

1 is a side view showing the overall configuration of a sealing facility according to a first embodiment; FIG. 10 is a diagram for explaining the thixotropy of a sealing agent. FIG. 2 is a perspective view of the nozzle device according to the first embodiment. 3 as viewed from the direction of arrow A. FIG. 4 as viewed from the direction of arrow B. FIG. FIG. 2 is a perspective view of a nozzle according to the first embodiment. 6 as viewed from the direction of arrow C. FIG. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7 . FIG. 9 is an enlarged partial cross-sectional view showing the tip of the nozzle of FIG. 8 . 8 is a cross-sectional view taken along line X-X in FIG. 7 . 7 as viewed from the direction of arrow D. 12 is a cross-sectional view taken along line XII-XII in FIG. 10 . FIG. 10 is a partial cross-sectional view corresponding to FIG. 9 of a tip portion of a nozzle according to a second embodiment. FIG. 10 is a perspective view of a nozzle device according to a third embodiment.

Preferred embodiments of the above aspects are described below.

In the sealant nozzle device of the above aspect, it is preferable that the internal space of the nozzle, when viewed from the opening height direction of the discharge outlet, expands in a curved convex shape outward in the opening width direction of the discharge outlet as it moves from the inlet side toward the discharge outlet side.

With this sealant nozzle device, by making both sides of the nozzle's internal space in the opening width direction curved convexly outward, it is possible to form a diffused flow of sealant in the internal space that diffuses the flow outward in the opening width direction, thereby minimizing the difference in flow speed of the sealant between the central part of the internal space in the opening width direction and the parts on either side.

In the sealant nozzle device of the above aspect, the nozzle preferably has two inner wall surfaces that face each other in the opening height direction across the internal space, and the two inner wall surfaces preferably have outlet planes that are arranged parallel to each other.

This sealant nozzle device provides flat outlet sections on two opposing inner wall surfaces in the nozzle's opening height direction, regulating and guiding the flow of sealant so that it is discharged linearly along the discharge direction. This acts to prevent the discharged sealant from diffusing in the opening height direction. As a result, the shape of the sealant can be maintained while improving the directionality of the sealant.

In the sealant nozzle device of the above aspect, the nozzle is preferably configured so that one of the two inner wall surfaces at the discharge port protrudes further in the direction of discharging the sealant than the other.

With this sealant nozzle device, the sealant ejected from the nozzle outlet flows only along the inner wall surface that is arranged to protrude in the protruding direction of the two inner wall surfaces. As a result, the sealant flows in a deflected direction that is biased away from its original ejection direction toward the relatively protruding inner wall surface. This means that the flow direction of the sealant ejected from the nozzle outlet can be changed from the ejection direction to the deflected direction.

In the sealant nozzle device of the above aspect, it is preferable that the nozzle has a plurality of flow straightening pieces provided in the internal space, each of which extends toward the discharge outlet and is arranged at intervals in the width direction of the opening of the discharge outlet.

This sealant nozzle device allows the flow of sealant generated within the internal space of the nozzle to be regulated by providing multiple flow straightening pieces within the internal space. Therefore, the sealant can be discharged from the nozzle outlet with a roughly uniform flow rate, making the discharge pressure of the sealant at the same cross section roughly uniform. As a result, once the sealant has adhered to the application surface of the workpiece, it is possible to prevent it from peeling off and dripping or getting into the opening in the workpiece, preventing the workpiece from looking unattractive after the opening has been sealed with the sealant.

Hereinafter, for convenience, a portion of the automobile body will be referred to as the workpiece, and one embodiment of a technology for sealing an opening in this workpiece will be described with reference to the drawings.

In the drawings used to explain this embodiment, unless otherwise specified, the horizontal first direction is indicated by arrow X, the vertical second direction perpendicular to the first direction X is indicated by arrow Y, and the third direction perpendicular to both the first direction X and the second direction Y is indicated by arrow Z.

(Embodiment 1)
1 , the sealing equipment 1 according to the first embodiment is for sealing an opening 4 formed in a horizontal surface of a workpiece 3 constituting a vehicle body 2. Here, the workpiece 3 is typically a base material such as a member or reinforcement constituting the underbody of the vehicle body 2.

When sealing the opening 4 with a sealant, the workpiece 3 is pre-positioned so that it extends generally horizontally in the first direction X. Typical openings 4 include apertures, through-holes, recesses, and spaces formed by steps or gaps (for example, a space defined by two step surfaces and a vertical surface connecting the two step surfaces). In this embodiment, the opening 4 is exemplified by a through-hole (opening diameter d) that is circular in plan view.

(Overall configuration of sealing equipment 1)
The sealing equipment 1 includes, as its constituent elements, a nozzle device 10, a pump 11, a supply pipe 12, a nozzle guide 40, a cylinder device 60, a robot 70, and a control device 80.

The nozzle device 10 of embodiment 1 is a sealant nozzle device used to seal the opening 4 of the workpiece 3 with a viscous sealant S, and is attached to and driven by a robot 70. The nozzle device 10 is connected to a pump 11 via a supply pipe 12. The sealant S is a fluid resin-based material. The pump 11 is a known fluid discharge pump configured to discharge the sealant S at high pressure. The pump 11 is electrically connected to a control device 80. The sealant S pressurized by the pump 11 is pumped through the supply pipe 12 to the nozzle device 10, from which it is discharged to the outside.

The nozzle device 10 has an inlet pipe section 20 and a nozzle 30. The inlet pipe section 20 is connected to the downstream end of the supply pipe 12. The inlet pipe section 20 has a flow path with a circular cross-section. The nozzle 30 is connected to the downstream end of the inlet pipe section 20. The nozzle 30 has an inlet 31 through which the sealant S flows, an outlet 32, and an internal space 33 through which the sealant S flows from the inlet 31 to the outlet 32. In this embodiment of the nozzle 30, the inlet 31 is circular, and the outlet 32 is shaped like a wide slit.

The nozzle guide 40 is attached to the nozzle 30. The nozzle guide 40 is provided with an adjustment mechanism 50 that can adjust its attachment position relative to the nozzle 30. The nozzle guide 40 is also fixed to the arm tip 72 of the robot arm 71 of the robot 70 via a cylinder device 60. Therefore, the nozzle device 10 is indirectly held by the robot arm 71 via the nozzle guide 40 and the cylinder device 60.

The cylinder device 60 is an air cylinder device that uses the pressure of air, which is a fluid, to drive the nozzle guide 40. This cylinder device 60 is electrically connected to the control device 80. Using this cylinder device 60, the relative position of the nozzle device 10 with respect to the nozzle guide 40 can be changed by raising and lowering the nozzle guide 40.

The robot 70 is configured as a multi-axis robot with multiple drive axes provided on the robot arm 71. The robot 70 is electrically connected to a control device 80. In the robot 70, the position and posture of the arm tip 72 of the robot arm 71 are controlled.

The control device 80 is composed of a known CPU, memory, input/output units, etc. This control device 80 has a robot control unit 81, a pump control unit 82, and a cylinder control unit 83.

The robot control unit 81 has the function of controlling the robot 70. This robot control unit 81 controls the robot 70 so that the arm tip 72 of the robot arm 71 moves according to a pre-taught movement trajectory. This adjusts the position and posture of the nozzle device 10 to the desired state.

The pump control unit 82 has the function of controlling the pump 11. This pump control unit 82 controls the supply flow rate of the sealant S supplied to the nozzle device 10.

The cylinder control unit 83 has the function of controlling the cylinder device 60. By controlling the cylinder device 60, the cylinder control unit 83 can adjust the relative position of the workpiece 3 and the nozzle device 10.

When using the sealing equipment 1 configured as described above, the robot control unit 81 of the control device 80 outputs a control signal to the robot 70 to adjust the position and posture of the arm tip 72 of the robot arm 71. This allows the nozzle device 10 to approach the workpiece 3 from below. At this time, the nozzle device 10 is positioned facing upward so that the discharge port 32 of the nozzle 30 faces the area surrounding the opening 4 of the workpiece 3.

(Characteristics of Sealant S)
As the sealant S, a resin-based sealant (for example, a resin such as vinyl chloride) is typically used, which has fluidity at room temperature and a static viscosity that allows it to maintain its shape after application at room temperature. This sealant S preferably has a viscosity of 120 [Pa.s] or more at a shear rate of 4.2 [s ^-1 ], which corresponds to the static viscosity at room temperature. Furthermore, this sealant S preferably has thixotropy to improve its fluidity at room temperature. The "room temperature" referred to here typically refers to a temperature in the range of 20 to 30 [°C].

As shown in Figure 2, the "thixotropy" of sealant S refers to the property of decreasing viscosity as the shear rate decreases. According to this thixotropy, the viscosity of sealant S decreases in regions where the shear rate of sealant S is relatively high, while the viscosity of sealant S increases in regions where the shear rate of sealant S is relatively low.

If the sealant S has thixotropy, the discharge pressure applied by the pump 11 when it is discharged from the nozzle device 10 causes the sealant S inside the nozzle device 10 to flow, increasing the shear rate of the sealant S. At this time, the viscosity of the sealant S temporarily decreases, allowing the sealant S to maintain a constant level of fluidity. This improves the discharge performance of the sealant S from the nozzle device 10.

Furthermore, when the sealant S is discharged from the nozzle device 10 and adheres to the workpiece 3, no external force acts on the sealant S, so the shear rate of the sealant S is lower than when it is discharged. At this time, the viscosity of the sealant S, which has thixotropic properties, increases, ensuring the desired adhesion and shape retention properties of the sealant S. In other words, once the sealant S has adhered to the workpiece 3, it is less likely to peel off or drip off the workpiece 3.

When the sealant S has a viscosity of 120 [Pa.s] or more at a shear rate of 4.2 [s ⁻¹ ] and further has thixotropy, it becomes possible to use a versatile and inexpensive pump 11 to discharge the sealant S. This makes it possible to keep the cost required for the sealing equipment 1 for carrying out the sealing method low.

By discharging the sealant S from the nozzle device 10, the worker can perform the sealing work without having to reach out to the opening 4 in the workpiece 3, reducing the burden on the worker. Furthermore, by changing the conditions for discharging the sealant S, sealing can be performed according to the position, size, shape, etc. of the opening 4 in the workpiece 3. Even if the workpiece 3 has uneven surfaces, the sealing work can be performed without being affected. Furthermore, since there is no need to prepare and use sealing parts such as plugs for each type of opening 4, multiple types of sealing parts are not required, and the cost of sealing parts can be reduced.

(Structure of nozzle guide 40)
3, the nozzle guide 40 is indirectly attached to the nozzle 30 via the connecting member 21 and the inlet pipe portion 20. The nozzle guide 40 has an extending portion 41 that extends toward the outlet 32 of the nozzle 30 when the nozzle 30 is attached. When the third direction Z is defined as the left-right direction, the extending portion 41 has two guide arms 42, a guide roller 43, and a connecting member 44 that are spaced apart in the left-right direction.

As shown in Figures 3 and 4, the guide rollers 43 are supported rotatably around a rotation axis 42b provided at the extended tip 42a of each guide arm 42. Each guide roller 43 has an outer periphery 43a as a protrusion that constantly protrudes in the discharge direction E1 beyond the discharge outlet 32 of the nozzle 30 when the nozzle guide 40 is attached to the nozzle 30. As a result, when the outer periphery 43a of the guide roller 43 is pressed against the coating surface 3a of the workpiece 3 when sealing the opening 4 of the workpiece 3 with sealant S, a constant distance L (see Figure 4) can be physically maintained between the coating surface 3a of the workpiece 3 and the tip 30a of the nozzle 30.

In this embodiment, the distance L is uniquely determined by pressing the outer periphery 43a of the guide roller 43 against the coating surface 3a of the workpiece 3, eliminating the need for labor such as fine-tuning the position of the arm tip 72 of the robot arm 71 to adjust the distance. Furthermore, this embodiment eliminates the need to use electronic device sensors to adjust the distance L. This has the advantage of improving maintainability compared to using electronic device sensors, and keeping device costs low due to the simple structure.

In this embodiment, the nozzle guide 40 is configured so that two guide rollers 43 are arranged on either side of the nozzle 30 in the third direction Z, sandwiching the nozzle 30 therebetween. This configuration stabilizes the movement of the nozzle 30 in the feed direction E2 (see Figure 5) while maintaining a constant physical distance L between the application surface 3a of the workpiece 3 and the tip 30a of the nozzle 30. This makes it possible to achieve the desired sealing quality of the opening 4 of the workpiece 3 with the sealant S using a simple structure.

As shown in Figures 3 and 4, the connecting member 44 connects the two guide arms 42 of the extension portion 41. Therefore, the connecting member 44 is considered to be a member on the nozzle guide 40 side. This connecting member 44 is attached to the plate member 22 via the adjustment mechanism 50. The plate member 22 is connected to the inlet pipe portion 20 of the nozzle device 10 via the connecting member 21. Therefore, the plate member 22 is considered to be a member on the nozzle device 10 side that is integrated with the nozzle device 10.

As shown in FIG. 5, each guide roller 43 of the extension portion 41 is configured to roll on the coating surface 3a of the workpiece 3 as the nozzle guide 40 moves in the feed direction E2 across the opening 4 while pressed against the coating surface 3a. Therefore, the nozzle guide 40 is configured to maintain a constant distance L (see FIG. 4) between the nozzle outlet 32 of the nozzle 30 and the coating surface 3a as the guide rollers 43 roll on the coating surface 3a. This configuration prevents the tip 30a of the nozzle 30 from contacting the coating surface 3a of the workpiece 3 and minimizes resistance between the guide rollers 43 and the coating surface 3a, preventing the coating surface 3a of the workpiece 3 from being scratched by the nozzle 30 or nozzle guide 40. As an additional measure, a protective film may be attached to the guide rollers 43 to prevent scratches.

In addition, the nozzle guide 40 in this embodiment is configured to be rotatable in a rotation direction E3, which changes the discharge angle α of the discharge port 32 relative to the coating surface 3a, with the pressing portion 43b as a fulcrum, while each guide roller 43 of the extension portion 41 is pressed against the coating surface 3a of the workpiece 3. With this configuration, by rotating the nozzle guide 40 in the rotation direction E3, the discharge angle α of the discharge port 32 of the nozzle 30 can be changed as desired.

In this embodiment, it is preferable to fix the orientation of the nozzle 30 so that the discharge angle α of the discharge port 32 is within the range of approximately 70° to 90°. In this case, the discharge angle α is defined as the angle between the discharge direction E1 of the sealant S and the first direction X. If the nozzle 30 is fixed in an inclined state with respect to the opening plane of the opening 4 of the workpiece 3 and moved in this state in the feed direction E2, it becomes easier to adjust the supply balance of the sealant S as it adheres to the application surface 3a of the workpiece 3.

(Structure of adjustment mechanism 50)
As shown in Figures 3 and 4, the adjustment mechanism 50 allows the attachment position of the nozzle guide 40 relative to the nozzle 30 to be adjusted. The adjustment mechanism 50 includes guide holes 51 and 52 (see Figure 3), screw holes 53 and 54 (see Figure 4), and fastening members 55 and 56 (see Figures 3 and 4). These drawings illustrate the structure of the adjustment mechanism 50 for the purpose of conceptually explaining the function of adjusting the relative positions of the connecting member 44 and the plate member 22 in the second direction Y and in the third direction Z. For this reason, when actually designing the adjustment mechanism 50, it is preferable to appropriately refer to known position adjustment structures for the detailed structure.

As shown in FIG. 3, the guide holes 51, 52 are provided in the plate member 22, which is a component on the nozzle device 10 side. Both of the two guide holes 51 are horizontally elongated holes with the third direction Z as their longitudinal direction. These two guide holes 51 are arranged side by side in the third direction Z with a gap between them. In contrast, both of the two guide holes 52 are vertically elongated holes with the second direction Y as their longitudinal direction. These two guide holes 52 are arranged side by side in the third direction Z with a gap between them.

As shown in FIG. 4, the screw holes 53 and 54 are provided in the connecting member 44, which is the member on the nozzle guide 40 side. The two screw holes 53 are spaced apart and arranged side by side in the third direction Z. Similarly, the two screw holes 54 are spaced apart and arranged side by side in the third direction Z.

As shown in Figures 3 and 4, each of the two fastening members 55 has a screw shaft 55a that threads into the screw hole 53 of the connecting member 44 through the guide hole 51 of the plate member 22. Similarly, each of the two fastening members 56 has a screw shaft 56a that threads into the screw hole 54 of the connecting member 44 through the guide hole 52 of the plate member 22.

When adjusting the relative position of the connecting member 44 and the plate member 22 in the third direction Z in the adjustment mechanism 50 configured as described above, the two fastening members 56 are removed and only the two fastening members 55 are used. The connecting member 44 and the plate member 22 are moved relative to each other in the third direction Z using the two guide holes 51, and the screw shafts 55a of each fastening member 55 are then threaded into the corresponding screw holes 53 to fasten and fix the connecting member 44 and the plate member 22. This allows the relative position of the connecting member 44 and the plate member 22 in the third direction Z to be adjusted.

Furthermore, in the adjustment mechanism 50 configured as described above, when adjusting the relative position of the connecting member 44 and the plate member 22 in the second direction Y, only two fastening members 56 are used, without using two fastening members 55. The connecting member 44 and the plate member 22 are moved relatively in the second direction Y using the two guide holes 52, and the screw shafts 56a of each fastening member 56 are then threaded into the corresponding screw holes 54 to fasten and fix the connecting member 44 and the plate member 22. This makes it possible to adjust the relative position of the connecting member 44 and the plate member 22 in the second direction Y.

The adjustment mechanism 50 configured as described above makes it possible to arbitrarily adjust the distance L (see Figure 4) between the coating surface 3a of the workpiece 3 and the tip 30a of the nozzle 30, particularly by adjusting the relative position of the connecting member 44 and the plate member 22 in the second direction Y.

As a modification of the adjustment mechanism 50 configured as described above, screw holes 53 and 54 may be provided in the plate member 22, and guide holes 51 and 52 may be provided in the connecting member 44. Also, either the combination of guide hole 51, screw hole 53, and fastening member 55, or the combination of guide hole 52, screw hole 54, and fastening member 56 may be omitted. Furthermore, if necessary, a structure in which the adjustment mechanism 50 itself is omitted may be adopted.

(Structure of cylinder device 60)
3, the cylinder device 60 is a device for driving the nozzle 30 by utilizing the pressure of air, which is a compressible fluid. The cylinder device 60 includes a cylinder 61 that houses a piston 61a so that the piston 61a can reciprocate in the second direction Y, a rod 62, and a movable member 63 that is joined to the plate member 22 and attached to the cylinder 61 via the rod 62. The cylinder device 60 is configured to drive the nozzle 30 together with the nozzle guide 40 in the second direction Y by controlling the air pressure in the cylinder 61 to move the piston 61a in the second direction Y.

The cylinder device 60 configured as described above allows the position of the nozzle 30's discharge port 32 relative to the coating surface 3a of the workpiece 3 to be adjusted appropriately. Furthermore, when the guide roller 43 of the nozzle guide 40 is pressed against the coating surface 3a of the workpiece 3, vibrations transmitted from the workpiece 3 can be absorbed by the compressibility of the air inside the cylinder 61 of the cylinder device 60. Therefore, the cylinder device 60 performs both its original function of driving the nozzle 30 using air pressure and its function as a vibration absorption mechanism that absorbs vibrations of the nozzle 30 using the compressibility of air.

In addition, the cylinder device 60 configured as described above may be configured to drive the nozzle 30 using a fluid other than air, such as hydraulic oil. Furthermore, an elastic member or cushioning material (shock absorber) capable of absorbing vibrations of the nozzle 30 may be provided separately from the cylinder device 60, or may be provided in place of the cylinder device 60. If necessary, the cylinder device 60 itself may be omitted, and a structure may be adopted in which the arm tip 72 of the robot arm 71 is fixed directly to the plate member 22.

(Sealing operation of opening 4)
When sealing the opening 4 of the workpiece 3, the robot arm 71 of the robot 70 is controlled to move the nozzle 30 of the nozzle device 10 in the feed direction E2. This makes it possible to automate and speed up the sealing operation of the opening 4 of the workpiece 3. At this time, the nozzle 30 moves in the feed direction E2 while maintaining constant the distance L between its discharge port 32 and the application surface 3a of the workpiece 3, the discharge angle α of the discharge port 32, and the discharge pressure of the sealant S.

For this reason, during the sealing operation of the opening 4 in the workpiece 3, the nozzle 30 discharges sealant S from its discharge port 32 in the discharge direction E1 at a fixed discharge angle α, causing it to adhere to the workpiece 3, and then moves in the feed direction E2 while maintaining this discharge state. This allows the sealant S extending from the initial adhesion point on the workpiece 3 to block the opening 4 and achieve good resin sealing. It is preferable to conduct a sealing test of the opening 4 in advance and then appropriately set the distance L, discharge angle α, and discharge pressure to values that will allow the opening 4 to be sealed well.

(Structure of the nozzle 30)
6, the nozzle 30 of the first embodiment is a wide nozzle, and has a wide discharge port 32 in which the opening width w in the opening width direction N2 exceeds the opening height h in the opening height direction N1. The discharge port 32 of the nozzle 30 is formed so that its opening height h is equivalent to or less than the target set film thickness, and its opening width w exceeds the opening diameter d (see FIG. 1) of the opening 4 in the workpiece 3. Here, the opening height direction N1 and the opening width direction N2 are both perpendicular to the longitudinal direction N3 of the nozzle 30.

For example, if the nozzle device 10 is positioned so that the outlet 32 of the nozzle 30 faces upward, the sealant S is continuously discharged from the outlet 32 in a band-like shape with a width sufficient to cover the opening 4 of the workpiece 3. After being discharged, the sealant S is affected by gravity and curves so that the tip of the discharged sealant S hangs down.

Since the opening height h of the nozzle 30's discharge port 32 roughly corresponds to the thickness of the ribbon-shaped sealant S after discharge, this is effective in controlling the seal thickness of the opening 4 of the workpiece 3 so that it remains roughly constant. By applying the sealant S evenly to the opening 4 and its surrounding area of the workpiece 3 without spreading it, the sealing performance of the opening 4 can be improved.

The value of the opening diameter d of the opening 4 is not particularly limited, but a typical vehicle body 2 is relatively often provided with openings 4 having opening diameters d ranging from φ10 to φ25, including openings 4 with opening diameters d of approximately φ10. The opening width w of the discharge port 32 of the nozzle 30 is determined according to the opening diameter d of the target opening 4. When the opening diameter d is smaller than the opening width w, the opening 4 can be sealed with sealant S.

The opening 4 may have a shape other than a circle in a plan view (for example, an oval or polygon). In this case, the opening diameter d can be interpreted as the maximum opening diameter of the opening 4, and the discharge port 32 of the nozzle 30 can be configured so that its opening height h is equivalent to or less than the target set film thickness, and its opening width w is equal to or greater than the maximum opening diameter.

As shown in FIG. 7 , the nozzle 30 has two inner wall surfaces 33a, 33b that define the opening width direction N2 of its internal space 33. The two inner wall surfaces 33a, 33b are wall surfaces that face each other in the opening width direction N2, separating the internal space 33. The two inner wall surfaces 33a, 33b have a curved shape that bulges outward in the opening width direction N2 between the inlet 31 and the outlet 32. By making the two inner wall surfaces 33a, 33b have such a curved shape, it becomes easier to retain the sealant S in a state where it is diffused in the opening width direction N2 within the internal space 33.

As shown in Figure 9, the nozzle 30 has two inner wall surfaces 34, 35 that define the opening height direction N1 of its internal space 33. The two inner wall surfaces 34, 35 are wall surfaces that face each other in the opening height direction N1, separating the internal space 33. The two inner wall surfaces 34, 35 form a straight line between the inlet 31 and the outlet 32.

As shown in Figure 7, when the nozzle 30 is viewed from the opening height direction N1, the dimension of the internal space 33 in the opening width direction N2 gradually expands from the inlet 31 side toward the outlet 32 side. The internal space 33 expands in a curved, convex shape outward in the opening width direction N2 from the inlet 31 side toward the outlet 32 side. Also, as shown in Figures 8 and 9, when the nozzle 30 is viewed from the opening width direction N2, the dimension of the internal space 33 in the opening height direction N1 gradually contracts from the inlet 31 side toward the outlet 32 side.

For this reason, the nozzle 30 is configured so that its internal space 33 serves as a retention area with a flow path cross-sectional area greater than that of the discharge port 32. That is, as shown in FIG. 10, when comparing the opening area Pa of the discharge port 32 and the flow path cross-sectional area Pb of the internal space 33, the flow path cross-sectional area Pb is larger than the opening area Pa. Note that the flow path cross-sectional area Pb is the area of the flow path cross section normal to the discharge direction E1.

As shown in Figures 8 and 9, a plurality of flow straightening pieces 36, 37 are provided in the internal space 33 of the nozzle 30 on the tip end 30a side. Each of the plurality of flow straightening pieces 36, 37 is a plate-shaped portion whose thickness direction is the opening width direction N2, and extends toward the discharge port 32 along the longitudinal direction N3 (the flow direction of the sealant S). The number and shape of the flow straightening pieces 36, 37 are not particularly limited and can be changed as needed.

As shown in FIG. 11 , the flow rectifying pieces 36 protrude upward toward the inner wall surface 34, with the inner wall surface 35 as their base end, and are arranged so as to form a gap between them and the inner wall surface 34. In contrast, the flow rectifying pieces 37 protrude downward toward the inner wall surface 35, with the inner wall surface 34 as their base end, and are arranged so as to form a gap between them and the inner wall surface 35. The flow rectifying pieces 36 and 37 are arranged alternately in the opening width direction N2, with a gap 38 between them. By providing a gap between the flow rectifying pieces 36 and the inner wall surface 34 and a gap between the flow rectifying pieces 37 and the inner wall surface 35, it is possible to prevent the flow of sealant S in the internal space 33 from being split into multiple flows by the flow rectifying pieces 36 and 37. Furthermore, arranging the flow rectifying pieces 36 and 37 alternately is effective in preventing the flow of sealant S toward the discharge port 32 from being biased upward or downward in the opening height direction N1.

As shown in FIG. 9 , the two inner wall surfaces 34, 35 of the nozzle 30 are provided with outlet planes 34a, 35a arranged parallel to each other. The outlet plane 34a is a flat portion of the inner wall surface 34 formed in the boundary region with the discharge port 32. The outlet plane 35a is a flat portion of the inner wall surface 35 formed in the boundary region with the discharge port 32. By providing the outlet planes 34a, 35a on the nozzle 30, the flow of the sealant S can be regulated and guided so that the sealant S is discharged linearly along the discharge direction E1. This prevents the discharged sealant S from diffusing in the opening height direction N1. The provision of the outlet planes 34a, 35a is effective in maintaining the shape of the discharged sealant S and increasing the directionality of the sealant S.

Here, we will explain the flow of sealant S in the internal space 33 of the nozzle 30 with reference to Figure 12.

As shown in Figure 12, when the inlet 31 is circular, a first flow Fa is formed in the area of the internal space 33 directly below the inlet 31, with a high flow velocity in the central portion in the opening width direction N2. Furthermore, a second flow Fb is formed in the area directly below the first flow Fa, which is a diffusing flow of the sealant S diffusing outward in the opening width direction N2. This minimizes the difference in flow velocity of the sealant S between the central portion and both sides in the opening width direction N2 in the internal space 33 of the nozzle 30. The reason the second flow Fb is formed as a diffusing flow is because, as mentioned above, the internal space 33 is a retention area that expands outward in the opening width direction N2 in a curved, convex shape.

In this embodiment, multiple flow straightening pieces 36, 37 are provided in the internal space 33 of the nozzle 30. This causes the third flow Fc, which forms as a turbulent flow directly below the second flow Fb, to interfere with the multiple flow straightening pieces 36, 37 and then become a fourth flow Fd, which is a minute vortex, as it passes through the gap 38 between the flow straightening pieces 36, 37. This fourth flow Fd is then narrowed near the outlet 32 (see Figure 9), which has a shape with a gradually reduced dimension in the opening height direction N1, and is then discharged from the outlet 32 as a fifth flow Fe.

This allows the sealant S to be discharged from the discharge port 32 with a generally uniform flow rate across the entire opening of the discharge port 32, and the discharge pressure of the sealant S at the same cross section can be maintained generally uniform. Furthermore, if the discharge pressure can be maintained generally uniform, the cross-sectional shape of the sealant S after discharge can be maintained as a constant cross-sectional shape that corresponds to the opening shape of the discharge port 32, and the sealant S can be prevented from being continuously discharged in a twisted state from the discharge port 32 of the nozzle 30.

This prevents the occurrence of a phenomenon in which the sealant S cannot be evenly applied to the application surface 3a of the workpiece 3, causing part of the sealant S to peel off and droop from the application surface 3a (hereinafter referred to as the "first phenomenon"). Furthermore, the discharge pressure of the sealant S from the discharge port 32 can be reduced by the amount that the twisted state of the sealant S can be prevented, preventing the occurrence of a phenomenon in which the sealant S enters the opening 4 of the workpiece 3 due to its high discharge pressure (hereinafter referred to as the "second phenomenon").

By suppressing the occurrence of the second phenomenon, it is possible to prevent the film thickness of the sealant S from becoming unstable, which would reduce the sealing strength of the opening 4 in the workpiece 3. Furthermore, by suppressing the occurrence of the first and second phenomena, it is possible to prevent the appearance of the workpiece 3 from becoming poor after the opening 4 is sealed.

The above-described first embodiment provides the following advantages:

In the nozzle device 10 of embodiment 1, viscous sealant S flows into the nozzle 30 through the inlet 31. The sealant S then flows through the internal space 33 of the nozzle 30 from the inlet 31 toward the outlet 32, and is then discharged to the outside through the wide outlet 32. At this time, the internal space 33 of the nozzle 30 is configured as a retention area having a flow path cross-sectional area Pb that exceeds the opening area Pa of the outlet 32. Therefore, the sealant S can be temporarily retained in the internal space 33 of the nozzle 30, and then discharged in a state where its flow is narrowed at the outlet 32.

This allows the pressure of the sealant S discharged from the outlet 32 of the nozzle 30 to be roughly uniform across the entire opening, stabilizing the discharge state of the sealant S and making the cross-sectional shape of the sealant S after discharge roughly consistent. Furthermore, by making the outlet 32 of the nozzle 30 wide, the opening 4 of the workpiece 3 can be sealed with a stable film thickness of the sealant S. This allows the sealant S to be uniformly applied to the application surface 3a around the opening 4 of the workpiece 3, preventing the sealant S from entering the opening 4 of the workpiece 3 and forming a recessed shape.

As described above, the first embodiment provides a nozzle device 10 with excellent sealing performance when sealing the opening 4 of the workpiece 3 with a viscous sealant S.

In the nozzle device 10 of embodiment 1, by making both sides of the internal space 33 of the nozzle 30 curved convexly outward in the opening width direction N2, a diffused flow of sealant S can be formed in the internal space 33, diffusing the flow of sealant S outward in the opening width direction N2, and the difference in flow speed of the sealant S between the central portion of the internal space 33 in the opening width direction N2 and the portions on either side of it can be kept small.

According to the nozzle device 10 of embodiment 1, by providing outlet flat surfaces 34a, 35a on two inner wall surfaces 34, 35 of the nozzle 30 that face each other in the opening height direction E1, the flow of the sealant S can be regulated and guided so that the sealant S is discharged linearly along the discharge direction E1. This makes it possible to prevent the sealant S from diffusing in the opening height direction N1 after discharge. As a result, the shape of the sealant S can be maintained and the directionality of the sealant S can be improved.

According to the nozzle device 10 of embodiment 1, by providing multiple flow straightening pieces 36, 37 in the internal space 33 of the nozzle 30, the flow of the sealant S generated in the internal space 33 can be straightened. Therefore, the sealant S can be discharged from the outlet 32 of the nozzle 30 with a generally uniform flow rate, and the discharge pressure of the sealant S at the same cross section can be made generally uniform. As a result, once the sealant S has adhered to the application surface 3a of the workpiece 3, it is possible to prevent the sealant S from peeling off and dripping or entering the opening 4 of the workpiece 3, and to prevent the appearance of the workpiece 3 from being impaired after the opening 4 is sealed with the sealant S.

In the nozzle device 10 of embodiment 1, the structure of the multiple flow straightening pieces 36, 37 can also be changed. For example, a structure in which either the flow straightening pieces 36 or the flow straightening pieces 37 are omitted, or a structure in which both the flow straightening pieces 36 and the flow straightening pieces 37 are omitted, can be adopted.

Next, other embodiments related to the above-described first embodiment will be described with reference to the drawings. In these other embodiments, elements that are the same as those in the above-described first embodiment will be assigned the same reference numerals, and descriptions of these same elements will be omitted.

(Embodiment 2)
13 , the nozzle device 110 of the second embodiment differs from the nozzle device 10 of the first embodiment in the structure of the tip portion 130a of the nozzle 130. The nozzle device 110 is configured such that the inner wall surface 34, which is one of the two inner wall surfaces 34, 35 at the discharge port 32 of the nozzle 130, protrudes further in the discharge direction E1 of the sealant S than the other inner wall surface 35. That is, the region of the tip portion 130a of the nozzle 130 on the inner wall surface 34 side protrudes further toward the tip than the region on the inner wall surface 35 side. In this embodiment, the tip portion 130a of the nozzle 130 is provided with a one-side facing region 39 that faces only the inner wall surface 34 of the two inner wall surfaces 34, 35 in the opening height direction N1.

Other configurations are the same as in embodiment 1.

According to the nozzle device 110 of embodiment 2, the sealant S discharged from the discharge port 32 of the nozzle 130 deviates from the inner wall surface 35 in the one-side facing region 39, and then flows along only the inner wall surface 34, 35, which protrudes further in the protruding direction E1 than the inner wall surface 35. Therefore, the sealant S changes direction from the original discharge direction E1 to a deflected direction E1' that is deflected toward the protruding inner wall surface 34 (upward in FIG. 13 ).

Therefore, by providing a one-sided facing region 39 at the tip 130a of the nozzle 130, the flow direction of the sealant S ejected from the ejection port 32 of the nozzle 30 can be changed from the ejection direction E1 to the deflected direction E1'.

Other than that, it has the same effects as embodiment 1.

As a modification of the nozzle 130 of embodiment 2, a structure can be adopted in which the outlet flat surfaces 34a, 35a of the two inner wall surfaces 34, 35 are replaced with outlet flat surfaces that are not parallel to each other.

(Embodiment 3)
As shown in Figure 14, the nozzle device 210 of embodiment 3 differs from the nozzle device 10 of embodiment 1 in the structure of the nozzle guide 140. The nozzle guide 140 has two guide arms 42, but does not have the guide roller 43 (see Figure 3) of embodiment 1. The extended tip 42a of each guide arm 42 is a protrusion that always protrudes in the discharge direction E1 beyond the discharge port 32 of the nozzle 30 when the nozzle guide 40 is attached to the nozzle 30. At this time, to prevent the extended tip 42a of each guide arm 42 from scratching the coating surface 3a of the workpiece 3, it is preferable to attach a protective film to the surface of the extended tip 42a to prevent scratching.

Other configurations are the same as in embodiment 1.

With the nozzle device 210 of embodiment 3, when the opening 4 of the workpiece 3 is sealed with the sealant S, the extended tip 42a of the guide arm 42 is pressed against the coating surface 3a of the workpiece 3, ensuring a constant distance L (see Figure 4) between the coating surface 3a of the workpiece 3 and the tip 30a of the nozzle 30. Furthermore, by omitting the guide roller 43, the structure of the nozzle guide 140 can be simplified.

Other than that, it has the same effects as embodiment 1.

If necessary, the structure of the nozzle guide 140 in embodiment 3 can also be applied to the structure of the nozzle guide 40 in embodiments 1 and 2.

The present invention is not limited to the exemplary embodiments 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 embodiments described above.

In the above embodiment, an example was given of a nozzle 30 equipped with a nozzle guide 40, but if necessary, a structure in which the nozzle guide 40 is omitted can also be adopted.

In the above embodiment, an example was given of using the robot arm 71 to move the nozzle device 10, 110, 210 in the feed direction E2, but instead, a drive device can be used that slides the nozzle device 10, 110, 210 in the feed direction E2 along a slide rail (not shown).

In the above embodiment, an example was given of the case where sealant S is ejected upward from the bottom surface of a horizontally extending workpiece 3 using an upward-facing nozzle device 10, 110, 210. However, alternatively, a structure in which sealant S is ejected downward from the top surface of a horizontally extending workpiece 3 using a downward-facing nozzle device 10, 110, 210, or a structure in which sealant S is ejected sideways from the side surface of a vertically extending workpiece using a horizontally facing nozzle device 10, 110, 210. In this case, the surface of the workpiece 3 to which sealant S is applied may be a horizontal or vertical surface.

The above embodiment illustrates a technique for sealing the opening 4 of the workpiece 3 that constitutes the underbody of the vehicle body 2 with sealant S, but the sealing location is not limited to this. This technique can also be applied to a technique for sealing the opening of a part that constitutes an element of the vehicle body 2 other than the underbody with sealant S, or a technique for sealing the opening of a part that constitutes an object other than an automobile with sealant S.

In light of the above-mentioned embodiments and various modifications, the present invention can take the following forms:

(Aspect 1)
A sealant nozzle device used to seal an opening of a workpiece with a viscous sealant,
a nozzle having an inlet through which the sealant flows, a wide discharge outlet having an opening width greater than the opening diameter of the opening, and an internal space through which the sealant flows from the inlet to the discharge outlet,
the internal space of the nozzle is a retention region having a flow path cross-sectional area greater than an opening area of the discharge port,
the nozzle has two inner wall surfaces that face each other in the opening height direction across the internal space, and the two inner wall surfaces are provided with outlet flat surfaces that are arranged parallel to each other,
The nozzle has a plurality of straightening pieces provided in the internal space, and the plurality of straightening pieces all extend toward the discharge outlet and are arranged at intervals in the opening width direction of the discharge outlet.

(Aspect 2)
A sealant nozzle device used to seal an opening of a workpiece with a viscous sealant,
a nozzle having an inlet through which the sealant flows, a wide discharge outlet having an opening width greater than the opening diameter of the opening, and an internal space through which the sealant flows from the inlet to the discharge outlet,
the internal space of the nozzle is a retention region having a flow path cross-sectional area greater than an opening area of the discharge port,
the nozzle has two inner wall surfaces that face each other in the opening height direction across the internal space, and one of the two inner wall surfaces protrudes more than the other at the discharge port in the discharge direction of the sealant,
The nozzle has a plurality of straightening pieces provided in the internal space, and the plurality of straightening pieces all extend toward the discharge outlet and are arranged at intervals in the opening width direction of the discharge outlet.

3 Workpiece 4 Opening 10, 110, 210 Nozzle device (sealant nozzle device)
30, 130 Nozzle 31 Inlet 32 Outlet 33 Internal space (retention area)
34, 35 Inner wall surface 34a, 35a Outlet flat surface d Opening diameter E1 Discharge direction N1 Opening height direction N2 Opening width direction Pa Opening area Pb Flow path cross-sectional area S Sealant w Opening width

Claims (5)

A sealant nozzle device used to seal an opening of a workpiece with a viscous sealant,
a nozzle having an inlet through which the sealant flows, a wide discharge outlet having an opening width greater than the opening diameter of the opening, and an internal space through which the sealant flows from the inlet to the discharge outlet,
the internal space of the nozzle is a retention region having a flow path cross-sectional area greater than an opening area of the discharge port,
the nozzle has two inner wall surfaces that face each other across the internal space in an opening width direction of the discharge outlet and that form curved shapes that bulge outward in the opening width direction between the inlet and the discharge outlet, and two inner wall surfaces that face each other across the internal space in an opening height direction of the discharge outlet and that form linear shapes between the inlet and the discharge outlet,
A sealant nozzle device, wherein the internal space of the nozzle expands in a curved convex shape outward in the opening width direction as it moves from the inlet side toward the outlet side when the nozzle is viewed from the opening height direction of the outlet. 2. The sealant nozzle device according to claim 1, wherein the internal space of the nozzle, when viewed from the opening width direction, has a dimension in the opening height direction that gradually decreases from the inlet toward the outlet . 3. The sealant nozzle device according to claim 1, wherein the two inner wall surfaces facing each other in the opening height direction are provided with outlet flat surfaces arranged parallel to each other. 4. The sealant nozzle device according to claim 3, wherein the nozzle is configured such that one of the two inner wall surfaces facing each other in the opening height direction at the discharge port protrudes in the discharge direction of the sealant more than the other. A sealant nozzle device used to seal an opening of a workpiece with a viscous sealant,
a nozzle having an inlet through which the sealant flows, a wide discharge outlet having an opening width greater than the opening diameter of the opening, and an internal space through which the sealant flows from the inlet to the discharge outlet,
the internal space of the nozzle is a retention region having a flow path cross-sectional area greater than an opening area of the discharge port,
the nozzle has two inner wall surfaces that face each other in an opening height direction of the nozzle across the internal space, and the two inner wall surfaces are provided with outlet flat surfaces that are arranged parallel to each other,
The nozzle is configured so that one of the two inner wall surfaces at the discharge port protrudes more than the other in the discharge direction of the sealant .