JP2007268574A - Masking member and workpiece machining method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a masking member that increases working efficiency by reducing the number of processes for workpiece machining and that ensures quality of a screw hole drilled on the workpiece, and also to provide a workpiece machining method using this masking member. <P>SOLUTION: The masking member 2 is designed to mask the female screw part 33 of screw holes 32 drilled on a mounting plate 3. The masking member is formed in a columnar shape and is composed of a main body in which communicative hole 21 having a hexagonal cross section in the inner circumferential face and communicative hole 26 having a circular cross section in the inner circumferential face are drilled along the axial center C, and composed of a male screw part 22 which is threaded on the outer circumferential face of the main body. The masking member is screwed onto the screw hole 32, with the male screw part 22 closely fitted with the female screw part 33. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a masking member and a workpiece machining method using the same, and more particularly to a masking member for masking a female screw portion of a screw hole drilled in a workpiece and a workpiece machining method using the same.

  Conventionally, a configuration of an axle beam assembly in which various arms such as a trailing arm that supports left and right axles, a brake mechanism, and the like are assembled to both ends of the axle beam by welding or the like is known. In the assembly line for assembling the axle beam assembly, a welding process for welding workpieces and arms of various shapes to the axle beam, a painting process for coating by electrodeposition coating, and a workpiece and arm welded to the axle beam. And an assembly process for assembling other components (for example, a brake mechanism).

  By the way, since the workpiece | work used for the assembly line mentioned above usually has a screw hole drilled as a connection part (hole) with other parts, in a welding process or a painting process, a screw hole is sealed with a masking member. Or it is comprised so that it may coat | cover and a sputter | spatter and a coating material may penetrate | invade into a screw hole, and may adhere to a threaded part.

As a conventional masking member, for example, Patent Document 1 discloses a masking member configured to be screwed into a screw hole formed in a workpiece and to have a male screw portion in close contact with a female screw portion of the screw hole. It is disclosed (see Patent Document 1). Specifically, this Patent Document 1 discloses a screw member as a masking member composed of a shaft portion provided with a threaded portion and a head formed at an end portion of the shaft portion. The workpiece is subjected to a coating process in a state where the shaft portion of the screw member is screwed into the screw hole of the workpiece and the head is in close contact with the workpiece surface.
Japanese Patent Laid-Open No. 5-287592

  However, although the bolt-shaped masking member disclosed in Patent Document 1 described above has a high masking ability with respect to the threaded portion of the screw hole, its head protrudes from the workpiece surface in a state of being screwed into the workpiece. In some cases, the welding operation and the painting operation are hindered by interference with a jig or a workpiece. Therefore, in the conventional assembly line, the bolt-shaped masking member is removed from the screw hole according to the work contents during the process or in the process, for example, the screw hole is covered without sealing and the screw hole is sputtered. It was necessary to replace the masking member (jig cover) configured so as not to enter.

In this way, with the conventional masking member configuration, even if it is once attached to the workpiece and the screw hole is masked, it must be removed and replaced between processes or within the process, which increases the number of work processes on the assembly line. Work efficiency was bad.
In addition, the masking member configured to cover the screw hole has poor sealing performance against the screw hole, and it has not been possible to completely prevent the sputter from entering the screw hole. Therefore, after the welding process, it is necessary for the operator to remove spatters attached to the screw holes and tapping, and the quality of the screw holes cannot be maintained, and the operation rate of the assembly line is inferior.

  Therefore, the present invention relates to a masking member and a workpiece machining method using the same, and solves the above-described conventional problems. The number of workpiece machining steps is reduced to improve work efficiency and the workpiece is drilled. It aims at proposing the masking member which ensures the quality of a screw hole, and the workpiece processing method using the same.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, according to the first aspect of the present invention, the masking member masks the female thread portion of the screw hole formed in the workpiece, and is formed in a cylindrical shape, and a part or all of the inner peripheral surface is formed in a polygonal cross section. And a male threaded portion threaded on the outer peripheral surface of the main body, and the male threaded portion is in close contact with the female threaded portion. Thus, it is screwed into the screw hole.

  According to a second aspect of the present invention, the attachment hole is penetrated from one end surface of the main body portion to the other end surface.

  According to a third aspect of the present invention, the main body portion is formed such that the length in the axial direction is shorter than or at least equal to the length in the width direction of the workpiece.

  According to a fourth aspect of the present invention, there is provided a workpiece processing method for performing welding processing and coating processing of a workpiece while masking a female screw portion of a screw hole drilled in the workpiece, the workpiece processing method being formed in a cylindrical shape, and having an inner peripheral surface A mounting hole having a part or all of which is formed in a polygonal cross section is formed along the axial center, and a male screw part that is threaded on the outer peripheral surface of the main body part and is in close contact with the female screw part A masking process in which a female screw part is masked by screwing a masking member provided in the screw hole, a welding process for welding the work, a painting process for coating the work, and the masking from the screw hole. And a masking process for removing the member.

  As effects of the present invention, the following effects can be obtained.

  Since it has the configuration shown in claim 1, it is not necessary to replace with another masking member during workpiece processing, the number of processes can be reduced, work efficiency can be improved, and spatter and paint can be reliably prevented from entering the screw holes. And the quality of the workpiece and the screw hole can be ensured.

  Since the structure shown in claim 2 is adopted, the paint entering the main body portion can be easily discharged from the attachment hole, the paint does not accumulate in the attachment hole, and a tool or the like cannot be inserted into the attachment hole. It is possible to prevent difficulty in detaching from the screw hole.

  Since it was set as the structure shown in Claim 3, during a workpiece | work processing, a masking member does not interfere with another jig | tool, a workpiece | work, etc., and this operation | work is not prevented.

  With the configuration shown in claim 4, there is no need to replace with another masking member during workpiece processing, the number of steps can be reduced, work efficiency can be improved, and spatter and paint entry into the screw hole can be reliably prevented. And the quality of the workpiece and the screw hole can be ensured.

Next, the best mode for carrying out the invention will be described.
FIG. 1 is a perspective view showing an overall configuration of an axle beam assembly using a masking member according to an embodiment of the present invention, FIG. 2 is a side view of a trailing arm in the axle beam assembly of FIG. 1, and FIG. FIG. 4 is a perspective view of the masking member, FIG. 5 is a central sectional view of the masking member, and FIG. 6 is a plan view of the masking member as viewed from the flat portion where the communication hole is opened. 7 is a plan view of the mounting plate, FIG. 8 is a cross-sectional view taken along arrow AA in FIG. 7, FIG. 9 is a flowchart showing the processing steps of the mounting plate, and FIG. 10 is a diagram of the mounting plate fixed to the jig. FIG. 11 is a cross-sectional view taken along the line BB in FIG.

  The masking member 2 of this embodiment is used in an assembly line for assembling the axle beam Assy1. As shown in FIG. 1, the axle beam Assy 1 of this embodiment has a trailing arm 11 welded to both ends of an axle beam 10 that supports left and right axles, and a brake mechanism 12 and a shock absorber at the end of the trailing arm 11. 15 and a suspension mechanism 13 composed of a coil spring 16 and the like are assembled. The axle beam Assy 1 is disposed on the rear axle, and the rear axle is supported via the left and right trailing arms 11.

  The axle beam 10 extends in a substantially horizontal direction, and trailing arms 11 are welded to both ends thereof. The trailing arm 11 is curved in a bow shape so as to have a substantially crescent shape when seen in a plan view, and is joined to the end of the axle beam 10 in the middle of the curved surface. Further, an end surface 11a having a horizontal surface is formed at one end portion of the trailing arm 11, and the mounting plate 3 described above is welded to the end surface 11a, and a back plate 14 constituting the brake mechanism 12 is assembled (FIG. 2).

  In the assembly line of the present embodiment, a welding process in which the trailing arm 11 is welded to the axle beam 10 or the mounting plate 3 is welded to the trailing arm 11, and the axle beam in which the trailing arm 11 is assembled. A painting process for painting 10 and an assembly process for assembling a brake mechanism or the like to the painted axle beam 10 are provided.

First, the structure of the masking member 2 and the mounting plate 3 of a present Example is demonstrated below.
As shown in FIGS. 2 and 3, the masking member 2 of this embodiment is used as a member for masking a screw hole 32 formed in a mounting plate 3 as a work member. The attachment plate 3 is welded to the end surface 11 a of the trailing arm 11, and the back plate 14 constituting the brake mechanism 12 is attached to the trailing arm 11 via the attachment plate 3. The masking member 2 is screwed into a screw hole 32 formed in the mounting plate 3 so that the screw hole 32 (the female screw portion 33) of the mounting plate 3 is welded and painted during the assembly line. Mask.

  As shown in FIGS. 3 to 6, the masking member 2 is formed in a columnar shape, and is threaded on the outer peripheral surface of the main body 20 having the communication hole 21 formed along the axial center C. And a male screw portion 22. The main body portion 20 is provided with a pair of plane portions 23 and 24 that face each other substantially in parallel as end surfaces, the communication hole 21 is opened in one plane portion 23, and the communication hole 26 is opened in the other plane portion 24. ing.

  The communication hole 21 is drilled from the flat portion 23 along the axial center C toward the center, and the inner peripheral surface 25 is drilled so as to have a hexagonal cross section. In the present embodiment, the communication hole 21 is formed in such a manner that the inner peripheral surface 25 has a hexagonal cross section, so that a mounting tool such as a general-purpose hexagon wrench or a rotating shaft portion of the mounting device formed in a hexagonal cross section is formed. Etc. can be inserted into the communication hole 21 from the flat surface portion 23 to rotate the main body portion 20 in the circumferential direction of the axial center C, and can be easily attached to and detached from the screw hole 32 of the mounting plate 3. Further, as will be described later, a positioning pin 51 provided on a jig 50 for fixing the mounting plate 3 is inserted into the communication hole 21 (see FIG. 11).

  The communication hole 26 is drilled from the flat surface portion 24 along the axial center C toward the central portion, and is continuous with the communication hole 21 at a substantially central portion of the main body portion 20. That is, the main body part 20 is penetrated from the flat part 23 to the flat part 24 by the communication holes 21 and 26. The communication hole 26 is formed so that the inner peripheral surface 27 has a circular cross section, and is smaller than the communication hole 21 in the radial direction. By forming the masking member 2 in this way, the thickness of the portion where the communication hole 26 is formed in the main body 20 is larger than the thickness of the portion where the communication hole 21 is formed. The rigidity of 2 is secured.

  The male screw portion 22 is threaded along the axial center C over the entire outer peripheral surface of the main body portion 20. The male screw portion 22 is in close contact with the female screw portion 33 of the screw hole 32 in a state where the masking member 2 is screwed into a screw hole 32 formed in the mounting plate 3 described later.

  As shown in FIGS. 3, 7, and 8, the mounting plate 3 is a plate-like work for fixing the back plate 14 to the trailing arm 11, and is formed in a substantially rectangular shape in plan view and in parallel. A pair of opposing mounting surfaces 30, 31 are formed, and a plurality of screw holes 32, 32... Are drilled through the mounting surfaces 30, 31. One mounting surface 30 is in contact with the back plate 14, and the other mounting surface 31 is in contact with the end surface 11a of the trailing arm 11 (see FIG. 2).

  In the present embodiment, the screw holes 32 are provided at four locations, and each is formed at a position where the distance from the center portion of the mounting plate 3 is equal. A female screw portion 33 is threaded on the inner peripheral surface of the screw hole 32 over the entire surface. The above-described masking member 2 is attached to each screw hole 32, and is screwed in a state where the male screw portion 22 of the masking member 2 is in close contact with the female screw portion 33 of the screw hole 32.

  A substantially circular opening 34 is formed in a substantially central portion in plan view of the mounting plate 3 so as to pass through the mounting surfaces 30 and 31, and the above-described screw hole 32 is provided near the periphery of the opening 34. -32 ... are drilled. When the attachment plate 3 is welded to the end surface 11a of the trailing arm 11, the clamp 52 provided on the fixing jig 50 is inserted into the opening 34 (see FIGS. 10 and 11).

  By the way, the masking member 2 of the present embodiment is formed so that both end portions do not protrude from the mounting surfaces 30 and 31 of the mounting plate 3 while being screwed into the screw holes 32. Specifically, the masking member 2 is formed so that the height (the length in the axial direction) of the main body 20 is shorter or equal to the length in the width direction of the mounting plate 3. In this embodiment, the masking member 2 is formed so that the height of the main body 20 is substantially the same as the length in the width direction of the mounting plate 3. Thus, by forming the masking member 2, when the mounting plate 3 to which the masking member 2 is attached is used in the assembly line, the masking member 2 does not interfere with other jigs, workpieces, etc. Does not interfere with work.

  The masking member 2 is attached to the attachment plate 3 in a state where the communication hole 21 is opened on one attachment surface 30 of the attachment plate 3. By attaching the masking member 2 in this manner, even if the attachment plate 3 is attached to the end surface 11a of the trailing arm 11, the communication hole 21 of the masking member 2 opens to the outside of the end surface 11a. The masking member 2 can be easily removed from the screw hole 32. A communication hole 26 of the masking member 2 is opened on one mounting surface 31 of the mounting plate 3.

Next, the process of processing the mounting plate 3 using the masking member 2 will be described below.
The masking member 2 of this embodiment masks the female screw portion 33 screwed into the screw hole 32 of the mounting plate 3, and the mounting plate 3 has the masking member 2 screwed into the screw hole 32. In this state, it is used in the assembly line of the axle beam Assy 1 and is subjected to welding and painting.

  As shown in FIG. 9, the mounting plate 3 is processed by a masking step (S100) in which the masking member 2 is screwed into the screw hole 32 and attached to the trailing arm 11 after the screw hole 32 is masked. A welding process (S101) in which welding is performed and the trailing arm 11 is welded to the axle beam 10, a coating process (S102) in which coating is performed by electrodeposition coating (ED coating), and the masking member 2 is a screw. It comprises a masking process (S103) for removing from the hole 32, an assembly process (104) for attaching the back plate 14 to the mounting plate 3 from which the masking member 2 has been removed, and the like.

  In the masking step (S100), the masking member 2 is screwed into the screw holes 32, 32... Of the mounting plate 3, and the masking member 2 is attached to the mounting plate 3. In this embodiment, the masking member 2 having the same shape is screwed into each screw hole 32.

  As shown in FIG. 3, when the masking member 2 is attached to the attachment plate 3, first, the attachment plate 3 is set so that the other attachment surface 31 is in contact with the mounting surface of the jig (not shown). Is done. The masking member 2 is in a state in which the rotating shaft portion of a mounting device (not shown) is inserted into the communication hole 21 and fixed to the one mounting surface 30 of the mounting plate 3 so as to face the flat surface portion 24, that is, the mounting member It waits in the state fixed in the perpendicular direction of the plate 3 so that one attachment surface 30 and the plane part 24 may become substantially parallel. Then, when the attachment device is operated, the masking member 2 is rotated and inserted into the screw hole 32, and the male screw portion 22 is screwed so as to be in close contact with the female screw portion 33 of the screw hole 32, and the attachment device is attached. It is attached to the plate 3.

In the welding step (S101), the mounting plate 3 is welded to a pair of end surfaces 11a formed at both ends of the trailing arm 11, respectively.
As shown in FIGS. 10 and 11, when the attachment plate 3 is attached to the trailing arm 11, the attachment plate 3 is attached to the jig 50 so that one attachment surface 30 contacts. At that time, one positioning pin 51 provided on the jig 50 is inserted into the communication hole 21 of the masking member 2, and a clamp 52 provided on the jig 50 is inserted into the opening 34 of the mounting plate 3. . By inserting the positioning pin 51 into the communication hole 21 of the masking member 2, the mounting plate 3 allows the clamp 52 to be easily inserted into the opening 34 while being positioned in the circumferential direction around the axis center C. be able to. In the state where the clamp 52 is inserted into the opening 34, the mounting plate 3 is attached to the jig 50 by the contact portion 52 a of the clamp 52 moving in the radial direction and contacting the inner wall of the opening 34. The position cannot be changed.
The mounting plate 3 is welded with the other mounting surface 31 in contact with the end surface 11 a of the trailing arm 11 while being fixed to the jig 50.

  As described above, the masking member 2 of the present embodiment is formed with the communication hole 21 opened in one of the mounting surfaces 30 in a state where the masking member 2 is screwed into the screw hole 32 of the mounting plate 3. , The mounting plate 3 can be easily positioned and fixed by inserting the positioning pin 51 into the communication hole 21. That is, when the processing step of the mounting plate 3 includes a positioning step with respect to a jig or the like, the masking member 2 can be applied as a positioning member for the mounting plate 3.

  Note that the positioning pin 51 of the present embodiment is formed in a substantially circular cross section and is not fitted to the inner peripheral surface 25 of the communication hole 21, so that the positioning pin 51 is attached in a state where the positioning pin 51 is inserted into the communication hole 21. The plate 3 can be supported rotatably about the axis center C. Moreover, you may comprise so that the positioning pin 51 penetrated by the communicating hole 21 may reach | attain the communicating hole 26 of the back | inner part. Furthermore, although the attachment location of the positioning pin 51 is not particularly limited, the positioning pin 51 is provided in at least one location as in the present embodiment, so that the positioning pin 51 and the clamp 52 can accurately correct the trailing arm 11. Positioning is possible, and the configuration of the masking member 2 and the jig 50 can be simplified.

  In the welding step (S101), not only the case where the attachment plate 3 is welded to the trailing arm 11, but also the step of welding other components to the trailing arm 11 to which the attachment plate 3 is attached, This includes a process of welding the trailing arm 11 to the axle beam 10 and the like. In this embodiment, the masking member 2 is not removed or replaced from the screw hole 32 of the mounting plate 3 during the welding process (S101).

  In the painting step (S102), the trailing arm 11 and the axle beam 10 to which the attachment plate 3 is attached are electrodeposited together. The mounting plate 3 is immersed in a tank (electrodeposition tank) in which a water-soluble paint is stored, and after the electrodeposition of the paint is performed on the surface of the member, the mounting plate 3 is pulled up from the tank and washed with water or baked. In this embodiment, the masking member 2 is not removed or replaced from the screw hole 32 of the mounting plate 3 during the painting step (S102).

  In addition, since the masking member 2 has the communication holes 21 and 26 (through holes) penetrating the flat surface portions 23 and 24 in the main body portion 20, when the mounting plate 3 is immersed in the tank described above, The paint that has entered from the communication hole 21 is discharged from the main body 20 through the communication hole 26. The end surface 11a of the trailing arm 11 of the present embodiment has a discharge hole (not shown) connected to the communication hole 26, so that the paint that has entered the main body 20 from the communication hole 21 is removed. Then, the toner is discharged from the trailing arm 11 through the communication hole 26 and the discharge hole, and does not accumulate inside the main body 20. That is, the masking member 2 of the present embodiment can discharge the paint that has entered the main body portion 20 through the communication holes 21 and 26 in the painting process, and the paint is deposited in the communication holes 21 and 26. Therefore, it is possible to prevent a tool or the like from being inserted into the communication hole 21 and detaching from the screw hole 32 becomes difficult.

  In the unmasking step (S103), the masking member 2 is removed from the screw hole 32 of the mounting plate 3. In order to remove the masking member 2 from the mounting plate 3, the above-described tool, the rotating shaft portion of the mounting device, or the like is inserted into the communication hole 21 opened in one mounting surface 30 of the mounting plate 3. 2 can be easily removed from the screw hole 32 by rotating it in the direction opposite to that when attaching 2 to the attachment plate 3.

  As shown in FIGS. 1 and 2, in the assembly step (S 104), the back plate 14 constituting the brake mechanism 12 is assembled to the mounting plate 3. That is, with the back plate 14 in contact with one mounting surface 30 of the mounting plate 3 and the support plate 40 in contact with the opposite direction of the back plate 14, the fixing bolt 41 is moved from the outside of the support plate 40. The back plate 13 is fastened to the mounting plate 3 by the fixing bolt 41 by being screwed into the screw hole 32 through a mounting hole (not shown). As the brake mechanism 12, a bearing housing, a brake shoe, a brake housing, and the like (not shown) are assembled to the back plate 14. Further, other members (such as a shock absorber 15 and a coil spring 16) are assembled to the axle beam 10 and the trailing arm 11 (see FIG. 1).

  As described above, the masking member 2 of the present embodiment is a member for masking the female screw portion 33 of the screw hole 32 formed in the mounting plate 3 and is formed in a cylindrical shape, and the inner peripheral surface 25 is a cross-section. A communication hole 21 formed in a hexagonal shape is provided with a main body portion 20 that is formed along the axial center C, and a male screw portion 22 that is threaded on the outer peripheral surface of the main body portion 20. Is configured to be screwed into the screw hole 32 so as to be in close contact with the female screw portion 33.

  By adopting such a configuration, the masking member 2 is screwed into the screw hole 32 of the mounting plate 3 and masked, so that the masking member 2 can be replaced with another masking member 2 during processing of the mounting plate 3. The number of processes in the assembly line can be reduced to improve the work efficiency, and it is possible to reliably prevent spatter from entering the screw holes 32 in the welding process and paint from entering the screw holes 32 in the painting process. And the quality of the screw hole 32 can be ensured.

In the masking member 2 of the present embodiment, the inner peripheral surface 25 of the communication hole 21 formed in the main body portion 20 is formed in a hexagonal cross section, but the cross sectional shape is not limited to this, and the cross sectional square It is formed in a polygonal shape such as a shape. Thus, by making the inner peripheral surface 25 have a polygonal cross section, the masking member 2 can be easily inserted into and removed from the screw hole 32.
In addition, the main body 20 has through holes made of communication holes 21 and 26, but the communication hole 21 in which the inner peripheral surface 25 is formed in a hexagonal cross section penetrates from the flat part 23 to the flat part 24. May be provided. That is, it is preferable that the main body 20 of the present embodiment is provided with a communication hole 21 (or a communication hole 26) formed so that a part of the inner peripheral surface or the front part has a polygonal cross-sectional shape.

  The configuration of the mounting plate 3 is not limited to the above-described embodiment as long as at least one screw hole 32 is formed. That is, the position and number of the screw holes 32, the overall shape of the mounting plate 3, and the like can be applied within the intended range of this embodiment. The processing steps of the mounting plate 3 are not limited to the above-described embodiments, but preferably include at least a welding step and a painting step.

  The masking member 2 of the present embodiment is used in an assembly line for assembling the axle beam Assy1. However, the masking member 2 only needs to mask the screw holes 32 during the processing of the mounting plate 3. The application range is not limited to the assembly line shown in the present embodiment.

The perspective view which showed the whole structure of the axle beam Assy using the masking member which concerns on one Example of this invention. The side view of the trailing arm in the axle beam Assy of FIG. The perspective view which showed a mode that the masking member was attached to an attachment plate. The perspective view of a masking member. The center sectional view of a masking member. The top view of the masking member seen from the plane part by which the communicating hole was opened. The top view of a mounting plate. AA arrow sectional drawing in FIG. The flowchart which showed the manufacturing process of the attachment plate. The top view of the attachment plate fixed to the jig | tool. BB arrow sectional drawing in FIG.

Explanation of symbols

2 Masking member 3 Mounting plate (workpiece)
20 Body 21 Communication hole (Mounting hole)
22 Male thread 26 Communication hole (Mounting hole)
32 Screw hole 33 Female thread part C-axis center

Claims (4)

A masking member for masking a female screw portion of a screw hole drilled in a workpiece,
A mounting hole formed in a columnar shape, and a part or all of the inner peripheral surface is formed in a polygonal cross-section, a main body portion drilled along the axis center,
A male threaded portion threaded on the outer peripheral surface of the main body, and
A masking member, wherein the male screw portion is screwed into the screw hole so as to be in close contact with the female screw portion.   The masking member according to claim 1, wherein the attachment hole is penetrated from one end surface of the main body portion to the other end surface.   3. The masking member according to claim 1, wherein the main body portion is formed so that a length in an axial direction is shorter than or at least equal to a length in a width direction of the workpiece. A workpiece processing method for performing welding processing and coating processing of a workpiece while masking a female screw portion of a screw hole drilled in the workpiece,
A mounting hole that is formed in a cylindrical shape and a part or all of the inner peripheral surface is formed in a polygonal cross-section, is threaded on the outer peripheral surface of the main body portion that is drilled along the axial center, A masking step of masking the female screw part by screwing a masking member provided with a male screw part closely attached to the female screw part into the screw hole;
Welding process for welding the workpiece;
A painting process for painting the workpiece;
A workpiece machining method comprising: a masking process for removing the masking member from the screw hole.

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