JP6330335B2 - Ceiling aren skin construction method - Google Patents

Description

  The present invention relates to a ceiling in which a ceiling round outer plate is bonded and bonded to the side of the ceiling portion of the skeleton frame that supports the outer plate of the bus along the vehicle length direction, and then the paint is baked and cured on the ceiling round outer plate. The present invention relates to a method of constructing the outer skin.

  The outer plate of the bus is applied by applying a baking paint after being joined to the skeleton frame. This outer plate includes a ceiling outer plate located at the center in the vehicle width direction of the skeleton frame constituting the roof portion of the bus, and a ceiling round outer plate located on both sides in the vehicle width direction of the skeleton frame. The ceiling round skin is configured by a horizontal portion that is adjacent to the ceiling skin, a vertical portion, and a round portion that connects the horizontal portion and the vertical portion.

JP 2008-195244 A JP 2010-36746 A JP 2012-214112 A

  By the way, when the paint is baked and cured, the outer plate becomes high temperature before the skeleton frame, and a temperature difference is generated between the skeleton frame and the outer plate. Further, the outer plate and the skeleton frame are thermally expanded due to a temperature rise, but due to the temperature difference, the thermal expansion amount of the outer plate is larger than the thermal expansion amount of the skeleton frame. In particular, since the ceiling round outer plate has a horizontal portion, a vertical portion, and a round portion as described above, different longitudinal in-plane compressive stresses act on each portion. As the temperature difference increases from zero, the in-plane stress in the longitudinal direction of the ceiling round skin transitions from a zero stress state to a compressive state, and when the compressive stress exceeds the limit, as shown in FIG. There existed a subject that it deform | transforms so that a part of R-shaped outer plate may become depressed in V shape.

  An object of the present invention is to provide a method for constructing a ceiling R-shaped outer plate that can prevent deformation of the ceiling R-shaped outer plate when a bake-hardening-type paint is baked and cured.

  In order to achieve the above-described object, the present invention attaches and joins a ceiling round outer plate along the vehicle length direction to the side of the ceiling portion of the skeleton frame that supports the outer plate of the bus, A method for constructing a ceiling round skin that prevents thermal deformation when a paint is baked and cured on a board, and when the ceiling round skin is joined to a side portion of the skeleton frame, the longitudinal direction of the ceiling round skin Are joined so that tensile stress is generated, and then the paint is baked and cured.

  When joining the above-mentioned ceiling R-shaped outer plate to the side of the skeleton frame, the ceiling R-shaped outer plate is bonded by applying a tensile force according to the linear expansion length of the ceiling R-shaped outer plate due to the temperature during bake hardening. May be.

  The ceiling portion of the skeleton frame extends in the vehicle width direction and is arranged at intervals in the vehicle length direction, and a vertical portion that extends along the vehicle length direction and connects the plurality of ceiling frames. The ceiling round skins may be joined in a state in which a tensile force is applied to each ceiling saddle member.

  When joining the ceiling round outer plate to the side part of the skeleton frame, the ceiling round outer plate may be joined in a state of being heated to a temperature corresponding to the temperature at the time of baking hardening.

  Bake hardening of the paint is performed by joining the ceiling outer skin to the side of the aggregate frame and then applying a bake hardening type paint. You may heat-harden at 10 degrees C or less for 10 minutes or more and 50 minutes or less.

  When the bake curable paint is heated and cured in a thermosetting furnace, all the outer plates are joined to the aggregate frame, and the bake curable paint is applied to the outer plates, and the bath is placed in the thermosetting furnace. The bake curable paint may be heat cured by putting a vehicle body.

  According to the method for constructing a ceiling R-shaped outer plate of the present invention, deformation of the ceiling R-shaped outer plate can be prevented when the bake-hardening type paint is baked and cured.

It is a perspective explanatory view of a skeleton frame and a ceiling round outer plate according to an embodiment of the present invention. It is side surface explanatory drawing of the process of joining a ceiling round outer plate | board to a frame | skeleton frame. It is an isometric view explanatory drawing of the ceiling round outer plate joined to the skeleton frame. It is a principal part enlarged view of FIG. It is a diagram explaining the effect of the present invention. It is the diagram showing the deformation | transformation of the ceiling round outer plate in the conventional construction method by the relationship with a temperature difference. It is the diagram showing the deformation | transformation of the ceiling round outer plate in the construction method which concerns on this invention by the relationship with a temperature difference. It is side surface explanatory drawing of the ceiling round outer plate | board explaining the construction method which concerns on other embodiment. It is a side view of the bus explaining the deformation | transformation of the ceiling round outer plate in the conventional construction method.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Note that front, rear, left, and right in the embodiments described later are based on the traveling direction (vehicle length direction) of the vehicle. For example, the front in the vehicle traveling direction is simply referred to as the front, and the rear in the vehicle traveling direction is simply referred to as the rear, and refers to the left and right for the driver facing forward.

  First, the ceiling part of the skeleton frame of the bus and the ceiling round outer plate joined to the ceiling part will be described.

  As shown in FIG. 1, a ceiling portion 2 of a bus skeleton frame 1 includes a plurality of ceiling coverings 3 extending in the vehicle width direction and arranged at intervals in the vehicle length direction, and vehicle lengths arranged on both left and right sides. A longitudinal frame 4 that extends along the direction and connects the plurality of ceiling frames 3, and a plurality of longitudinal frames 4 that are arranged between the longitudinal frames 4 and extend along the vehicle length direction and that connect the plurality of ceiling frames 3. A beam 5.

  The ceiling covering 3 is made of a steel material formed in an arch shape. Both end portions 6 in the longitudinal direction of the ceiling covering 3 are formed with a larger curvature than the central portion 7, and the outer peripheral surface is formed so as to be close to the inner surface of a ceiling round outer plate 8 described later.

  The longitudinal aggregate 4 is made of a steel material that extends in a straight line, and is joined to both ends in the longitudinal direction of the ceiling covering 3 by welding or the like.

  The small beams 5 include left and right outer plate joining small beams 5 arranged at positions overlapping with side portions of a ceiling round outer plate 8 to be described later, and reinforcing small beams arranged between the outer plate joining small beams 5. There are beams (not shown). The outer plate joining beam 5 is made of a steel material extending linearly. The outer plate-joining beam 5 is disposed between the ceiling casings 3 adjacent to each other with a space therebetween, and both ends thereof are coupled to the ceiling casing 3 by welding or the like. Further, the outer plate joining beam 5 is arranged between the ceiling brazing members 3 and arranged on the same straight line so as to extend along the vehicle length direction. The outer plate joining beam 5 is formed such that its upper surface comes into contact with the inner surface of the ceiling round outer plate 8.

  Further, the ceiling round outer plate 8 is bonded and joined to the side portion of the ceiling portion 2 of the skeleton frame 1 along the vehicle length direction. The ceiling round outer plate 8 is made of a thin metal plate, and has a horizontal portion 8a formed on the inner side in the vehicle width direction, a vertical portion 8b formed on the outer side in the vehicle width direction, and a cross-sectional arc shape connecting the horizontal portion 8a and the vertical portion 8b. The round portion 8c is provided.

  Below, the construction method of the ceiling round outer plate 8 is demonstrated. In the construction of the ceiling round outer plate 8, the ceiling round outer plate 8 is first joined to the ceiling portion 2, and then the ceiling round outer plate 8 is coated.

  As shown in FIGS. 1 and 2, when the ceiling round outer plate 8 is joined to the ceiling 2, the ceiling portion 2 of the skeleton frame 1 is fixed to the work table 9, and the ceiling round outer plate 8 is fixed to the ceiling of the skeleton frame 1. Place on one side 10 of part 2. At this time, the ceiling portion 2 of the skeleton frame 1 is formed separately from other portions (not shown) of the skeleton frame 1.

  Thereafter, one end of the ceiling round outer plate 8 in the longitudinal direction is clamped by a clamp device 13 fixed to a fixing system 12 such as a wall, and the other end is fixed to the fixing system 14 by a hydraulic cylinder and a feed screw. Clamping is performed by a clamping device 13 connected via a tension generator 15 using a bolt / nut, gear, chain block, pulley, or the like. At this time, the ceiling round outer plate 8 is formed in advance to be clamped longer than the finished size. Thereby, it is possible to prevent the chamfering scratches and the like from being attached to the ceiling round outer plate 8 within the finished dimensions. Further, the clamping position by the clamping device 13 may be only the rounded portion 8c that is particularly easily deformed.

  After that, the tension generator is driven to pull both ends of the ceiling round outer plate 8 in the longitudinal direction to generate a predetermined tensile stress on the ceiling round outer plate 8. At this time, the force (tensile force) for pulling the ceiling radius outer plate 8 is determined according to the linear expansion length of the ceiling radius outer plate 8 due to the temperature at the time of bake hardening. Specifically, the tensile force is such that when the ceiling round skin 8 is brought to the temperature at the time of bake hardening, the ceiling round skin 8 is not deformed such as being depressed in a V shape, and the bus body is It is determined so that it can be sufficiently tolerated even if a stress due to thermal contraction is generated on the ceiling round outer plate 8 after being cooled in a cold district or the like.

  After that, as shown in FIG. 3, while applying a tensile force to the ceiling round outer plate 8, the ceiling round outer plate 8 is temporarily welded and temporarily fixed to the side portion of the ceiling portion 2 of the skeleton frame 1. The ceiling round outer plate 8 is joined to the side portion of the ceiling portion 2 of the skeleton frame 1 by spot welding. As shown in FIG. 4, spot welding is performed at a position X in the drawing. Thereby, the side part of the vehicle outer side in the vehicle width direction of the ceiling round outer plate 8 is joined to the longitudinal aggregate 4 along the vehicle length direction, and the side part of the ceiling round outer plate 8 on the inner side in the vehicle width direction is the outer plate. It is joined to the joining beam 5 along the vehicle length direction. Note that the joining of the ceiling round outer plate 8 to the skeleton frame 1 is not limited to spot welding, but may be other types of welding, and may be joining by rivets, bolts, or the like.

  When the ceiling round skin 8 is joined to the ceiling portion 2 of the skeleton frame 1 in this way, the tension to the ceiling round skin 8 is released by stopping the tension generator 15 or the like, The clamping device 13 is removed. Further, the portion clamped by the clamp device 13 is cut from the ceiling round outer plate 8 to form the ceiling round outer plate 8 to the finished size of the product. Further, the ceiling round outer plate 8 is joined to the other side portion 11 of the ceiling portion 2 of the skeleton frame 1 in the same procedure as described above.

  Thereafter, a bake curable paint is applied to the ceiling round outer plate 8, and the bake curable paint is heated and cured at 120 ° C. for 30 minutes in a thermosetting furnace (not shown). In addition, the temperature and time at the time of heat-curing may be the minimum necessary level for curing the paint. In general, when the heating temperature is set high, the baking time becomes short when the heating temperature is set high, and when the heating temperature is set low, the heating time becomes long. For example, at the time of heat curing, it may be in the range of 100 ° C. or more and 200 ° C. or less, and the heating time may be in the range of 10 minutes or more and 50 minutes or less.

  In the thermosetting furnace, the ceiling radius outer plate 8 becomes high temperature before the skeleton frame 1, and a temperature difference is generated between the skeleton frame 1 and the ceiling radius outer plate 8. Due to this temperature difference, the thermal expansion amount of the ceiling round outer plate 8 is larger than the thermal expansion amount of the skeleton frame 1.

  The stress generated in the ceiling round outer plate 8 at this time will be described with reference to FIG. FIG. 5 is a diagram showing the relationship between the stress generated in the ceiling round skin 8 and the temperature difference between the ceiling round skin 8 and the skeleton frame 1. A solid line shows the construction method which concerns on this Embodiment, and a broken line shows the conventional construction method (The tensile stress of the ceiling round outer plate 8 joined to the frame | skeleton frame 1 is zero).

  As indicated by a solid line in FIG. 5, when the temperature difference between the ceiling round outer plate 8 and the skeleton frame 1 is zero (before heating), a tensile stress is generated in the ceiling round outer plate 8 in advance. For this reason, it acts so that the tensile stress becomes small in the initial stage of heating, and after the tensile stress becomes zero, the compressive stress is generated, and the compressive stress increases as the temperature difference increases. For this reason, it is possible to shift the temperature difference when the ceiling round outer plate 8 is deformed to a larger temperature difference than the conventional construction method (broken line) in which compressive stress is generated by heating from a zero stress state. Thus, the deformation of the ceiling round outer plate 8 can be surely prevented.

  FIG. 6 shows the displacement in the Y direction (vehicle width direction) between the upper part of the driver's seat and the upper part of the central entrance / exit, which is particularly susceptible to deformation when the conventional construction method is performed, in relation to the temperature difference. In the figure, the solid line indicates the displacement of the upper part of the driver's seat, and the broken line indicates the displacement of the upper part of the central entrance / exit.

  FIG. 7 shows the displacement in the Y direction (vehicle width direction) between the upper part of the driver's seat and the upper part of the central entrance / exit when the construction method according to the present embodiment is performed in relation to the temperature difference. In the figure, the solid line indicates the displacement of the upper part of the driver's seat, and the broken line indicates the displacement of the upper part of the central entrance / exit.

  As shown in FIG. 6 and FIG. 7, the case where the construction method according to the present embodiment is performed is higher than the case where the conventional construction method is performed at any position of the upper part of the driver seat and the upper part of the central entrance / exit. It was confirmed that the ceiling round skin 8 can withstand a large temperature difference, and it was confirmed that deformation due to thermal expansion hardly occurs.

  When the bake-hardening paint is heat-cured in a thermosetting furnace, all the outer plates are joined to the skeleton frame 1 of all parts and the bake-hardening paint is applied to join the skeleton frame 1 of all parts. After assembling the bus body, the body of the bus is placed in a thermosetting furnace and the bake curable paint is heated and cured. Thereby, the bake curable coating material can be efficiently heat-cured.

  In this way, when the ceiling round outer plate 8 is joined to the side portion of the skeleton frame 1, it is joined so that tensile stress is generated in the longitudinal direction of the ceiling round outer plate 8, and then the paint is baked and cured. Therefore, the compressive stress of the ceiling round outer plate 8 when the temperature difference between the ceiling 2 of the skeleton frame 1 and the ceiling round outer plate 8 is opened can be reduced, and deformation due to thermal expansion of the ceiling round outer plate 8 can be prevented.

  Further, when the ceiling round skin 8 is joined to the side of the skeleton frame 1, a tensile force corresponding to the linear expansion length of the ceiling round skin 8 due to the temperature at the time of bake hardening is applied to the ceiling round skin 8. Therefore, it is possible to reliably generate a tensile stress on the ceiling round outer plate 8 joined to the ceiling portion 2 of the skeleton frame 1.

  The ceiling portion 2 of the skeleton frame 1 extends in the vehicle width direction and is connected to the plurality of ceiling frames 3 arranged at intervals in the vehicle length direction, and extends along the vehicle length direction and connects the plurality of ceiling frames 3 And the ceiling round skin 8 is joined to each ceiling brace 3 in a state in which a tensile force is applied to each ceiling brace 3. , And the deformation due to thermal expansion of the ceiling round outer plate 8 can be prevented.

  Bake hardening of the paint is done by joining the ceiling outer skin 8 to the side part of the aggregate frame, and then applying the bake hardening type paint, and then the bake hardening type paint at 100 ° C. or more and 200 ° C. or less in the thermosetting furnace. Since the heat curing is performed for 10 minutes or more and 50 minutes or less, the paint can be baked and cured without deforming the ceiling outer skin 8.

  When bake-hardening paint is heat-cured in a thermosetting furnace, all the outer plates are joined to the aggregate frame, and a bake-hardening paint is applied to these outer plates, and the bus body is placed in the thermosetting furnace. Since the bake curable paint is heated and cured, the bake curable paint can be baked and cured efficiently.

  Next, another embodiment in which a method for joining the ceiling round outer plate 8 is modified will be described. Since the process after the ceiling round outer plate 8 is joined is the same as described above, the description thereof is omitted.

  As shown in FIG. 8, when the ceiling round outer plate 8 is joined to the ceiling portion 2, the ceiling portion 2 of the skeleton frame 1 is fixed to the work table, while the ceiling round outer plate 8 is heated to a predetermined temperature. Thermally expand.

  Next, the thermally expanded ceiling radius outer plate 8 is placed on one side portion of the ceiling portion 2 of the skeleton frame 1, and the ceiling radius outer plate 8 is temporarily welded to the side portion of the ceiling portion 2 of the skeleton frame 1 and temporarily attached. Stop. Thereafter, the ceiling round outer plate 8 before being cooled is joined to the side portion of the ceiling portion 2 of the skeleton frame 1 by spot welding. At this time, the ceiling round outer plate 8 is kept in a high temperature state lower than the temperature at the time of bake hardening or the temperature at the time of bake hardening. That is, the ceiling round outer plate 8 is joined to the ceiling portion 2 of the skeleton frame 1 while being heated to a temperature corresponding to the temperature at the time of bake hardening (for example, a temperature directly proportional to the temperature at the time of bake hardening).

  After joining the ceiling round skin 8, the ceiling round skin 8 is naturally cooled to room temperature. If necessary, the end of the ceiling round outer plate 8 is cut according to the finished dimensions. By cutting the ceiling round outer plate 8 in a state where the ceiling round outer plate 8 has returned to room temperature, the ceiling round outer plate 8 can be formed in an accurate finished size.

  As described above, when the ceiling round outer plate 8 is joined to the side portion of the skeleton frame 1, the ceiling round outer plate 8 may be joined in a state where the ceiling round outer plate 8 is heated to a temperature corresponding to the temperature at the time of bake hardening. The compressive stress of the ceiling round outer plate 8 generated when the temperature difference between the rounded outer plate 8 and the skeleton frame 1 is opened can be reduced, and deformation due to thermal expansion of the ceiling round outer plate 8 can be prevented.

DESCRIPTION OF SYMBOLS 1 Skeletal frame 2 Ceiling part 3 Ceiling gutter 4 Longitudinal aggregate 8 Ceiling round skin 10 Side part 11 Side part

Claims (6)

A ceiling round skin is attached to the side of the ceiling of the skeletal frame that supports the outer skin of the bus along the vehicle length direction, and then heat deformation when the paint is baked and cured on the ceiling round skin is performed. It is a construction method of the ceiling arek outer plate to prevent,
When the ceiling round skin is joined to the side of the skeleton frame, the ceiling round skin is joined so that a tensile stress is generated in the vehicle length direction, and then the paint is baked and cured. Construction method of ceiling areal skin.   When joining the ceiling round skin to the side of the skeleton frame, the ceiling round skin is joined by applying a tensile force according to the linear expansion length of the ceiling round skin due to the temperature during bake hardening. The construction method of the ceiling round outer plate | board of Claim 1.   The ceiling portion of the skeleton frame extends in the vehicle width direction and is arranged at intervals in the vehicle length direction, and a vertical portion that extends along the vehicle length direction and connects the plurality of ceiling frames. The ceiling round skin according to claim 2, wherein the ceiling round skin is joined in a state where a tensile force is applied to each ceiling collar.   2. The outside of the ceiling radius according to claim 1, wherein when the ceiling radius outer plate is joined to the side portion of the skeleton frame, the ceiling radius outer plate is joined in a state of being heated to a temperature corresponding to a temperature at the time of baking hardening. Construction method of the board.   Bake hardening of the paint is performed by joining the ceiling outer skin to the side of the aggregate frame and then applying a bake hardening type paint. The method for constructing a ceiling round skin according to any one of claims 1 to 4, wherein the method is heat-cured at 10 ° C or lower for 10 minutes to 50 minutes.   When the bake curable paint is heated and cured in a thermosetting furnace, all the outer plates are joined to the aggregate frame, and the bake curable paint is applied to the outer plates, and the bath is placed in the thermosetting furnace. 6. The method for constructing a ceiling round outer panel according to claim 5, wherein the body is put and the bake curable paint is heated and cured.