JP5593265B2 - Grinding method - Google Patents

Description

  The present invention relates to a grinding method for grinding a part of a bead.

  In butt welding, the bead protrudes from the base material. When it is necessary to improve the appearance, a part of the bead (protruding part) is often ground.

  Bead grinding may be performed with a grinding belt (see, for example, Patent Document 1 (FIG. 14)).

Patent document 1 is demonstrated based on the following figure.
FIG. 11 is a diagram for explaining the basic configuration of the prior art. The belt grinding apparatus 100 travels a grinding belt 104 stretched around pulleys 101, 102, and 103 by the driving force of an electric motor, and this grinding belt. This is a device for removing rust attached to the outer peripheral surface by applying 104 to the outer peripheral surface of the pipe 105 as shown by an arrow (1).
By the way, when the butt welding in the longitudinal direction is applied to the pipe 105, the protruding portion of the bead is ground in order to improve the appearance. The grinding method will be described next.

FIG. 12 is a diagram for explaining a conventional grinding method, in which the grinding belt 104 is caused to travel as indicated by an arrow (2) following the outer peripheral surface of the base material 106 of the pipe 105 and the bead 107.
When the grinding belt 104 is strongly pressed against the outer peripheral surface of the base material 106 and the bead 107 in this way, the width W1 at which the grinding belt 104 comes into contact with the outer peripheral surface of the base material 106 increases, and the base 107 is adjusted before the shape of the bead 107 is adjusted. Overcutting of the outer peripheral surface of the material 106 occurs. This leads to deterioration of the work quality.

  Accordingly, there is a need for a grinding technique that can prevent overcutting of the surface of the base material around the bead and that can reduce the cut width.

JP 2007-090498 A

  An object of the present invention is to provide a grinding method capable of preventing overcutting of the surface of the base material around the bead and reducing the cut width.

  The invention according to claim 1 is curved so as to be convex upward, the left and right centers are connected by welding, and a part of the bead protrudes upward from the base material so as to be the upper end of the inverted U-shaped cross section. A grinding method for grinding a part of the bead using a workpiece as a processing target, and a lifting frame that moves up and down relative to the workpiece, and a right and left of the lifting frame that are rotatably held via horizontal axes, respectively. The left and right pulleys, one of these left and right pulleys, or a drive source for driving a third pulley rotatably attached to the lifting frame at a position above the left and right pulleys, and the left and right pulleys and the third pulleys Grinding device preparation step for preparing a belt grinding device comprising a grinding belt having abrasive grains on the outer surface, and an upper portion of a part of the bead in a horizontal portion of the grinding belt that is run by the left and right pulleys A first grinding step for obtaining a flat surface by grinding horizontally; and lowering the left and right pulleys so that the grinding belt is applied to the flat surface so as to exhibit an inverted V shape, and a lower part of the bead is convex upward And a second grinding step for substantially matching the curvature of the upper surface of the bead with the curvature of the workpiece.

  In the invention which concerns on Claim 2, the press block which urges | biases the horizontal part of a grinding belt downward is provided in the belt grinding apparatus, and the grinding belt is made into the upper part of a part of bead by the said press block in a 1st grinding process. Grinding is carried out while urging the head.

  In the invention according to claim 1, the grinding method includes a grinding device preparation step, a first grinding step, and a second grinding step. In the first grinding step, the upper part of the bead is horizontally ground by the horizontal part of the grinding belt that is run by the left and right pulleys to obtain a flat surface. In the second grinding step, a lower part of the bead is ground upward while applying a grinding belt exhibiting an inverted V shape to the flat surface obtained by grinding, so that the upper surface of the bead The curve should be almost matched.

  In the second grinding step, when a grinding belt having an inverted V shape is applied to the flat surface obtained by grinding a part of the bead in the first grinding step, the contact portion of the grinding belt becomes horizontal, and the non-grinding belt Since the contact portion is easily separated from the curved base material, it is possible to prevent the base material surface around the bead from being excessively shaved. Further, in the second grinding step, the grinding belt grinds only the flat surface, so that the cutting width can be narrowed. Therefore, it is possible to provide a grinding method capable of preventing overcutting of the surface of the base material around the bead and narrowing the cut width.

In the invention which concerns on Claim 2, it grinds in a 1st grinding process, energizing a grinding belt toward the one part upper part of a bead with a press block.
When the grinding belt is urged to the upper part of the bead by the pressing block, the grinding belt is more closely attached to the upper part of the bead, so that the grinding time until a flat surface is formed can be shortened.

It is a perspective view of a workpiece. It is a front view of the belt grinding device for enforcing the grinding method concerning the present invention. It is a figure explaining a grinding device preparatory process and a 1st grinding process. It is a figure explaining a 2nd grinding process. It is a figure which shows the example of a change of FIG. It is a figure explaining the effect | action of a press part. It is a figure which shows the further example of a change of FIG. It is a figure explaining the grinding method using the belt grinding apparatus of FIG. It is a front view of another belt grinding apparatus for enforcing a grinding method. FIG. 10 is a sectional view taken along line 10-10 in FIG. 9; It is a figure explaining the basic composition of the conventional technology. It is a figure explaining the conventional grinding method.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, the workpiece will be described as the upper half of a motorcycle fuel tank.

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a tank upper half 10 of a motorcycle fuel tank includes a fuel filler port 11, the fuel filler port 11 as a front side, and the flange portion 12 as a rear side. The body right part 14 is connected by butt welding.

The tank upper half 10 is a member of the upper half of the fuel tank for motorcycles, and the tank lower half, which is a member of the lower half, is connected to the connection portion 15 provided in the tank upper half 10 by welding. .
A bead 16 obtained by butt welding is orthogonal to the oil filler port 11 and extends in the front-rear direction.

The structure of a belt grinding apparatus for grinding the bead 16 will be described with reference to FIG.
As shown in FIG. 2, the belt grinding apparatus 20 </ b> A includes an elevating frame 22 attached to the tip of the robot arm 21 and elevating with respect to the tank upper half 10, and a left arm portion 23 </ b> L extending from the elevating frame 22 to the lower left ( L is a subscript indicating left, and the same applies to the left pulley 25L that is rotatably held via the left horizontal shaft 24L, and a right arm portion 23R extending from the lifting frame 22 to the lower right (R is a subscript indicating right). A right pulley 25R that is rotatably held via a right horizontal shaft 24R and a third pulley 26 that is a drive pulley attached to the lifting frame 22 at a position above these left and right pulleys 25L, 25R. An electric motor 28 directly connected to the output shaft 27, and a grinding belt 29 spanned by the left and right pulleys 25L, 25R and the third pulley 26 and having abrasive grains on the outer surface thereof; Ranaru.

  Since the winding angle of the grinding belt 29 with respect to the third pulley 26 is secured, when the electric motor 28 is started, the grinding belt 29 can be run along the pulleys 25L, 25R, and 26 that rotate.

  In the embodiment, the third pulley 26 is disposed above the left and right pulleys 25L and 25R. However, the third pulley 26 may be disposed directly above the left pulley 25L or right pulley 25R. Further, although the electric motor is applied to the drive source of the third pulley 26, a hydraulic motor or an air motor may be applied. The third pulley 26 is directly connected to the output shaft 27 of the electric motor 28. However, the third pulley 26 is rotatably attached to the lifting frame 22, and the output shaft 27 of the electric motor 28 and the third pulley 26 are connected to the belt. It may be connected by a transmission mechanism such as a chain.

  A pressing cylinder 32, which is an urging means for a pressing block (described later), is attached to the flange portion 31 of the elevating frame 22 with a bolt 33, and a metal made to push the grinding belt 29 from the inside to the lower end of the piston rod 34 of the pressing cylinder 32. The pressing block 35A is attached. That is, the belt grinding device 20A is provided with a pressing block 35A that urges the horizontal portion 36 of the grinding belt 29 downward.

  The tank upper half 10 is curved so as to be convex upward in a cross-sectional view, the left and right centers are connected by welding, and a part of the bead 16 is an upper end of an inverted U-shaped cross section. Projecting upward from 37.

Next, a grinding method carried out using the belt grinding apparatus 20A described above will be described.
In FIG. 3, (a) explains the grinding device preparation process, and (b) and (c) explain the first grinding process. As shown to (a), the belt grinding apparatus 20A is prepared, the electric motor 28 is started, and the grinding belt 29 is made to run as shown by the arrow (3). Next, the piston rod 34 of the pressing cylinder 32 is pushed out, and the pressing block 35A is lowered toward the grinding belt 29 as indicated by an arrow (4).

As shown in (b), the horizontal portion 36 of the grinding belt 29 pressed by the pressing block 35 </ b> A is applied to a part of the upper portion 38 of the bead 16.
When the upper portion 38 of a part of the bead 16 is ground by the horizontal portion 36 of the grinding belt 29, a flat surface 39 is obtained as shown in FIG. When the grinding belt 29 is urged to the upper part 38 of the bead 16 by the pressing block 35 </ b> A, the grinding belt 29 comes into close contact with the upper part 38 of the bead 16, thereby shortening the grinding time until the flat surface 39 is formed. it can.

  Next, the pressing block 35A is raised as indicated by an arrow (5), and in FIG. (A), the left and right pulleys 25L and 25R are lowered as indicated by an arrow (6) by the robot arm 21.

In FIG. 4, the second grinding process will be described with reference to (a) to (d). As shown to (a), the grinding belt 29 is applied to the one part flat surface (FIG.3 (c), code | symbol 39) of the bead 16 so that reverse V character may be exhibited.
As shown in (b), a part of the bead 16 is ground with the grinding belt 29 so that the grinding belt 29 follows the shape of the upper outer surface 41 of the tank upper half 10.

As shown in (c), a part of the lower portion 42 of the bead 16 is ground by the grinding belt 29 so as to be convex upward. Next, in (a), the robot arm 21 raises the belt grinding apparatus 20A as shown by the arrow (7).
As a result, as shown in (d), the curvature of the upper surface 43 of the bead 16 can be substantially matched with the curvature of the upper outer surface 41 of the tank upper half 10.

The grinding method of the present invention includes a grinding device preparation step (see FIG. 3A), a first grinding step (see FIGS. 3B and 3C), and a second grinding step.
In FIG. 3C, in the first grinding step, a flat portion 39 is obtained by horizontally grinding a part of the upper portion of the bead 16 with the horizontal portion 36 of the grinding belt 29 that is run by the left and right pulleys. In addition, even if the grinding belt 29 is not pressed by the pressing block 35A at the time of grinding, it can be expected that a flat surface is obtained only by the grinding belt 29.

  In FIG. 4C, in the second grinding step, a part of the lower portion 42 of the bead 16 is ground so as to be convex upward while a grinding belt 29 having an inverted V shape is applied to the flat surface obtained by grinding. Then, as shown in (d), the curvature of the upper surface 43 of the bead 16 is substantially matched with the curvature of the tank upper half 10.

  In the second grinding step, when the grinding belt 29 exhibiting an inverted V shape is applied to the flat surface 39 obtained by grinding a part of the bead 16 in the first grinding step, the contact portion of the grinding belt 29 becomes horizontal, Since the non-contact portion of the grinding belt 29 is easily separated from the curved base material, it is possible to prevent the surface of the base material 37 around the bead 16 from being excessively shaved. Further, since the grinding belt 29 grinds only the flat surface 39 in the second grinding step, the shaving width W2 can be reduced. Therefore, it is possible to provide a grinding method capable of preventing the surface of the base material 37 around the bead 16 from being excessively cut and reducing the cut width W2.

  In the grinding method described so far, the metal pressing block 35A provided in the belt grinding apparatus 20A is used. By the way, if the force applied to the tank upper half 10 can be reduced for the tank upper half 10 on the side receiving the pressing force, the external shape of the tank upper half can be maintained. An example in which the force applied to the tank upper half 10 can be reduced will be described next.

In FIG. 5, the same structure as that of FIG. The main change is that an elastic material is provided at the lower end of the pressing block.
A pressing portion 44 is provided at the lower end of the piston rod 34 of the pressing cylinder 32. The pressing portion 44 is configured by a pressing block 35B attached to the piston rod 34 with a bolt 45 and an elastic material attached to the lower end of the pressing block 35B with an elastic material and absorbs the pressing force from the pressing cylinder 32. The absorbing member 46 includes an absorbing member cover 48 that is attached to the left and right of the pressing block 35B with two bolts 47 and is made of an elastic material and covers the pressing force absorbing member 46.

  Pocket portions 49 are provided between the left and right sides of the pressing force absorbing member 46 and the lower left and right sides of the absorbing member cover 48. The pocket portion 49 is a portion where a force is applied to the pressing force absorbing member 46 from the outside and a part of the compressed pressing force absorbing member 46 enters.

  A sponge or soft rubber is suitable for the pressing force absorbing member 46, but a soft resin or other elastic material may be applied. Further, a soft resin is suitable for the absorbing member cover 48, but soft rubber or other elastic material may be applied.

The effect | action of the press part 44 is demonstrated based on FIG.
As shown in FIG. 6A, the horizontal portion 36 of the grinding belt 29 pressed by the pressing portion 44 is applied to a part of the upper portion 38 of the bead 16.
When the piston rod 34 of the pressing cylinder (FIG. 5, reference numeral 32) is pushed out as shown by the arrow (8), as shown in (b), the pressing force absorbing member 46 absorbs the pressing force of the pressing cylinder, The height H1 is compressed compared to (a). As a result, the left and right portions 51 of the pressing force absorbing member 46 enter the pocket portion 49.

  Thus, since the pressing force of the pressing cylinder is absorbed by the pressing force absorbing member 46, the force applied to the tank upper half 10 can be reduced, and the external shape of the tank upper half can be maintained. Therefore, it contributes to improving the quality of the tank upper half 10.

  By the way, since the plate thickness of the fuel tank of the motorcycle may change according to the size of the vehicle, the bead width of the tank upper half 10 also changes with the size of the vehicle. It is preferable that the bead width can be easily changed at low cost. An example of this will be described next.

In FIG. 7, the same structure as that of FIG. The main change is that the pressing block is eliminated and the third pulley is supported so as to be movable.
The belt grinding apparatus 20B includes a substantially inverted V-shaped lifting frame 52 attached to the tip of the robot arm 21, and a left pulley 25L rotatably held at the lower left end of the lifting frame 52 via a left horizontal shaft 24L. A right pulley 25R that is rotatably held at the lower right end of the lifting frame 52 via a right horizontal shaft 24R, and a pair of left and right rails 54L, 54R attached to the central portion 53 of the lifting frame 52, a left and right slider 55L, An electric motor 28 slidably provided via 55R, and a puller having a ring portion 57 attached to the central portion 53 and inserted into the piston rod 56 so as not to disturb the rotation of the output shaft 27 of the electric motor 28. A cylinder 65, a third pulley 26 attached to the output shaft 27 and disposed above the left and right pulleys 25L, 25R, and a pulley 25L 25R, made from the grinding belt 29 for abrasive grains are attached to over passed the outer surface 26.

  When the piston rod 56 of the pulling cylinder 65 is pulled, the third pulley 26, the electric motor 28, and the sliders 55L and 55R move along the rails 54L and 54R, so that the tension of the grinding belt 29 can be relaxed.

  As shown in FIG. 8A, the horizontal portion 36 of the grinding belt 29 in a tensioned state is applied to a part of the bead 16 of the tank upper half 10.

  Here, for example, when the workpiece is changed to a large fuel tank, the bead width of the upper half of the tank also increases. Correspondingly, when the third pulley 26 is lowered as shown by the arrow (9) and the left and right pulleys 25L and 25R are lowered as shown by the arrow (10), the grinding belt 29 is moved as shown in (b). Since the tension is relaxed, the shaving width is increased and the bead 59 of the tank upper half 58 can be ground. Although the bead width is larger than that of (a), it is only necessary to loosen the tension of the grinding belt 29, and the change of the bead width can be easily and inexpensively handled.

  Conventional belt grinding apparatuses are provided with one third pulley (drive pulley) and two left and right pulleys (driven pulleys). In order to realize a cheaper belt grinding apparatus, an example of a belt grinding apparatus having a single driven pulley will be described below.

In FIG. 9, the same structure as that of FIG. The main change is that the pulleys on the left and right are combined into one.
The belt grinding device 60 includes a substantially inverted V-shaped lifting frame 61 attached to the tip of the robot arm 21, an electric motor 28 attached to the lower left end of the lifting frame 61, and an output shaft of the electric motor 28. 27, a right pulley 25R that is rotatably held at the lower right end of the lifting frame 52 via a right horizontal shaft 24R, and pulleys 25R and 26. The grinding belt 29 attached, the pressing cylinder 32 attached to the central portion 62 of the lifting frame 61, and the metal pressing attached to the lower end of the piston rod 34 of the pressing cylinder 32 to push the grinding belt 29 from the inside. It consists of block 35A.

As shown in FIG. 10, the pressing block 35 </ b> A includes an extension portion 64 that extends forward from the piston rod 34 so as to protrude forward from the center line 63 of the pressing cylinder 32. When the piston rod 34 of the pressing cylinder 32 is pushed out, the extended portion 64 pushes the grinding belt 29 from the inside, so that the grinding belt 29 can be pushed against the bead.
In FIG. 9, since the belt grinding apparatus 60 includes one third pulley 26 and one right pulley 25R, the belt grinding apparatus 60 that is less expensive than the case of including a third pulley and a pair of left and right pulleys is provided. realizable.

Although the work according to the present invention is applied to the upper half of a tank for a motorcycle fuel tank in the embodiment, the work is also applied to the upper half of a tank for a household kerosene tank and the upper half of a tank for a vehicle fuel tank. It is applicable and can be applied to the upper half of general canning equipment.
In addition, although the urging means of the pressing block according to the present invention has been described by applying a cylinder in the embodiment, a spring mechanism or a diaphragm using expansion and contraction of a spring may be applied.

  The grinding method of the present invention is suitable for grinding a bead provided in a tank upper half of a motorcycle fuel tank.

  DESCRIPTION OF SYMBOLS 10 ... Work, 16 ... Bead, 20A ... Belt grinding apparatus, 22 ... Elevating frame, 24L, 24R ... Horizontal axis, 25L, 25R ... Left and right pulleys, 26 ... Third pulley, 28 ... Drive source, 29 ... Grinding belt, 35A ... Pressing block, 36 ... Horizontal part, 37 ... Base material, 38 ... Upper part, 39 ... Flat surface, 42 ... Lower part, 43 ... Upper surface.

Claims (2)

Curved so as to be convex upward, the left and right centers are connected by welding, and the workpiece protruding upward from the base material so that a part of the bead is the upper end of the inverted U-shaped cross section, A grinding method for grinding a part of a bead,
The lifting frame that moves up and down with respect to the workpiece, the left and right pulleys that are rotatably held on the left and right sides of the lifting frame, respectively, and the lifting and lowering at one of these left and right pulleys or at a position above the left and right pulleys. Grinding for preparing a belt grinding device comprising a driving source for driving a third pulley rotatably attached to a frame, and a grinding belt having abrasive grains on the outer surface thereof spanned between the left and right pulleys and the third pulley. Equipment preparation process;
A first grinding step of obtaining a flat surface by horizontally grinding an upper part of the bead at a horizontal portion of the grinding belt that is run by the left and right pulleys;
While lowering the left and right pulleys and applying the grinding belt to the flat surface so as to exhibit an inverted V shape, the lower part of the bead is ground so as to be convex upward, and the bead of the bead is curved to the workpiece. A second grinding step for substantially matching the curvature of the upper surface;
A grinding method comprising: The belt grinding device is provided with a pressing block for biasing the horizontal portion of the grinding belt downward,
2. The grinding method according to claim 1, wherein in the first grinding step, the grinding is performed while the grinding belt is urged toward an upper part of the bead by the pressing block. 3.

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