JP7561930B2 - Tip dresser and cutting tool - Google Patents

Description

The present invention relates to a tip dresser and its cutting tool.

A tip dresser is a cutting device that cuts the tip of an electrode, for example for resistance welding, particularly for spot welding. When a spot welding electrode is pressed against the cutting tool of the tip dresser and rotated to perform cutting, a protruding cutting residue may be left in the center of the tip of the electrode. (Patent Document 1 [0002]) It is known that this cutting residue is caused by the cutting speed being zero or close to zero near the center of rotation of the cutting tool.

That is, as shown in FIG. 7, the cutting tools 101, 102 of a typical tip dresser 100 are shaped so that the roughly semicircular tips of a pair of opposing spot welding electrodes 103, 104 can roughly fit into the cutting tools of the tip dresser.

The cutting tool of the tip dresser is then rotated by a motor 105 or the like using gears. That is, when the rotating shaft 106 of the motor 105 is rotated in the direction of the arrow R, the first gear 107 rotates in the direction of the arrow R, and the first meshing portion 108 of the first gear 107 meshes with the second meshing portion 109 of the tip dresser 100, driving the tip dresser 100. That is, for example, the tip dresser 100 rotates the rotating shaft 110 in the direction of the arrow R1.

This rotation causes the cutting tool 101 of the tip dresser 100 to cut the tip of the spot welding electrode 103, and the cutting tool 102 of the tip dresser 100 to cut the spot welding electrode 104. However, near the center of rotation of the roughly circular cutting tools 101 and 102 of the tip dresser 100, the cutting speed is zero or close to zero, which can result in residual cutting on the spot welding electrodes 103 and 104.

Japanese Patent Application Publication No. 7-009166

If the above-mentioned cutting residue occurs, it becomes difficult to pass the appropriate current and apply the appropriate voltage to the area to be welded when performing resistance welding.

The object of the present invention is to provide a tip dresser and cutting tool that can pass an appropriate current and apply an appropriate voltage to the part to be welded when performing resistance welding.

To achieve the above object, the tip dresser of the present invention has a rod-shaped member having a constricted portion at the center of the length of the side of the rod, and a means for rotating the rod-shaped member about an axis connecting both ends of the rod while revolving the rod-shaped member around the constricted portion as the center of rotation, and the constricted portion has a cutting tool for cutting, and the cutting tool can cut the workpiece by revolving and rotating the constricted portion.

To achieve the above object, the tip dresser of the present invention has a single rod-shaped member and a means for revolving the rod-shaped member around the center of its length as the center of rotation while rotating the rod-shaped member around an axis connecting both ends of the rod. The center has a cutting tool for cutting, and the center is revolved and rotated to cut the workpiece with the cutting tool.

To achieve the above objective, the cutting tool for the tip dresser of the present invention has a single rod-shaped member with a constricted portion in which the center of the side of the rod in the longitudinal direction is constricted, and the constricted portion of the rod-shaped member is shaped to have a cutting tool for cutting, and the constricted portion can cut the workpiece.

To achieve the above objective, the cutting tool for the tip dresser of the present invention has a single rod-shaped member with a constricted portion formed by constricting the center of the side of the rod in the longitudinal direction, and the constricted portion of the rod-shaped member is made of a grinding wheel, and it is possible to cut the workpiece with the constricted portion.

The present invention provides a tip dresser and cutting tool that can pass an appropriate current and apply a voltage to the part to be welded when performing resistance welding.

1 is an exploded perspective view of a tip dresser according to an embodiment of the present invention; 1 is a plan view of a tip dresser according to an embodiment of the present invention; This is a cross-sectional view taken along the line CC of FIG. This is a cross-sectional view taken along the line D-D of FIG. FIG. 2 is a perspective view of a rod-shaped member of the tip dresser according to the embodiment of the present invention. 6 is a cross-sectional view taken along line E-E of FIG. 5. 1 is a diagram showing the configuration of a conventional tip dresser. Note that this diagram is actually a cross-sectional view and should be hatched, but since each element would be hidden by the hatching, it is drawn as a schematic front view.

(Tip dresser configuration)
The configuration of the tip dresser of this embodiment will be described below with reference to Figures 1, 2, 3, and 4. First, the tip dresser 1 has a rod-shaped member 10. The rod-shaped member 10 has a constricted portion 11 formed by constricting the center of the length direction of the side of the rod. The cutting tool of the tip dresser 1 will be formed in this constricted portion 11, but the details of the cutting tool will be shown in Figures 5 and 6, and only the general shape of the constricted portion 11 is shown in Figures 1, 2, 3, and 4 without showing the details of the shape of the cutting tool.

The tip dresser 1 has a means for rotating the rod-shaped member 10 around an axis connecting both ends of the rod, while revolving the rod-shaped member 10 around the constricted portion 11 as the center of rotation. This means is realized, for example, by the following configuration.

First, the rod-shaped member 10 is accommodated in the through holes 13, 13 of the accommodation member 12, so that the constricted portion 11 is exposed from the window portion 14, which is the hole portion of the accommodation member 12. The window portion 14 of the accommodation member 12 is also formed in a position facing the window portion 14 on the surface of the accommodation member 12 on the side not shown in FIG. 1.

Then, bevel gears 16 and 17 are attached to bevel gear attachment parts 15a and 15b on both ends of the rod-shaped member 10, respectively. The bevel gear attachment part 15a and the bevel gear 16 are fixed rotatably by arranging a pin 18 that passes through the rotation axis of the bevel gear 16 and the rod-shaped member 10. The bevel gear attachment part 15b and the bevel gear 17 are either molded as a single unit or fixed non-rotatably with an adhesive or the like.

When the bevel gears 16, 17 are attached, they are positioned outside the through holes 13, 13. The rod-shaped member 10 is fixed so that the bevel gears 16, 17 are rotatable, but the bevel gear 17 rotates together with the rod-shaped member 10. The bevel gear 16 rotates freely and independently, without being accompanied by the rotation of the rod-shaped member 10.

The inner surface 19a of the annular bearing 19 is then overlapped with the outer surface of the wall portion 21 formed on the cylinder of the annular first cover member 20, allowing the outer surface 19b of the bearing 19 to rotate circumferentially along the circular shape of the wall portion 21, and the inner surface 19a of the bearing 19 is fixed in position along the circular shape of the wall portion 21.

This bearing 19 uses a ball bearing 19c. It has a circular gear part 23 formed on the edge of the hole 22 of the first cover member 20. The teeth of this gear part 23 are oriented toward the center of the circle that defines the outer shape of the first cover member 20.

The second cover member 25 has a circular shape and a cylindrical wall 24. The second cover member 25 has a circular gear 27 formed on the edge of the hole 26. The gear 27 has teeth that face the center of the circle that defines the outer shape of the second cover member 25.

Then, the first cover member 20 is fitted to the second cover member 25. During this fitting, the annular outer surface 19b of the bearing 19 slides on the inside of the wall portion 24. During this fitting, the housing member 12 is positioned so that the gear portion 23 and the gear portion 27 mesh with the bevel gears 16 and 17. The bearing 19 plays a role in ensuring smooth rotation of the first cover member 20 and the second cover member 25.

By doing so, the teeth of the gear portion 23 and the gear portion 27 can rotate while meshing with both bevel gears 16, 17. In other words, by rotating the teeth of the gear portion 23 and the gear portion 27 while meshing with the bevel gears 16, 17, the rod-shaped member 10 can revolve around the constricted portion 11 as the center of rotation. When the rod-shaped member 10 is housed in the housing member 12, this revolution is along the arrow R2 in FIG. 1. When the rod-shaped member 10 is housed in the housing member 12, the rotation of the housing member 12 along the arrow R2 in FIG. 1 means that the rod-shaped member 10 "revolves around the constricted portion 11 as the center of rotation."

Furthermore, the bevel gear 16 rotates together with the rod-shaped member 10, causing the rod-shaped member 10 to rotate around the axis connecting both ends of the rod. The rod-shaped member 10 rotates along the arrow R3 in FIG. 1. This is an example of a means for rotating the rod-shaped member 10 around the axis connecting both ends of the rod, while the tip dresser 1 revolves around the constricted portion 11 of the rod-shaped member 10 as the center of rotation.

As shown in Figures 5 and 6, the constricted portion 11 is shaped to have sharp points 35a and 35b to form a cutting tool 34, and the constricted portion 11 is caused to revolve and rotate on its axis to cut the workpiece with the cutting tool 34. Here, the number of non-cutting objects to be cut is not limited in principle, and may be one or more, or two or more. The overall shape of the cutting tool 34 is such that the cutting tool 34 has an S-shaped cross section and its sharp points 35a and 35b extend in the length direction of the constricted portion 11. In other words, the tips of the two sharp points 35a and 35b extend continuously and elongated in the length direction of the constricted portion 11.

(Operation of the tip dresser 1 in this embodiment)
When the tip dresser 1 is operated, first, the cutting tool 34 of the tip dresser 1 is revolved and rotated. Next, the cutting tool 34 is clamped by the electrodes 103 and 104 shown in Fig. 7. Then, the electrodes 103 and 104 shown in Fig. 7 are inserted into the two windows 14 shown in Fig. 2.

Then, this state is maintained for a predetermined time. Then, the clamps of the cutting tools 34 of the electrodes 103 and 104 shown in FIG. 7 are released. Then, the revolution and rotation of the cutting tool 34 of the tip dresser 1 are stopped.

(Major Effects Obtained by the Present Embodiment)
The tip dresser 1 of this embodiment has a means for rotating the rod around the axis connecting both ends while revolving around the constricted portion 11 where the cutting tool 34 is located. Therefore, the cutting speed near the rotation center of the cutting tool 34 of the tip dresser 1 does not become zero or close to zero, and there is no cutting residue on the electrode for spot welding, or even if there is, it is very small. Therefore, it is possible to provide a tip dresser 1 that can pass an appropriate current and apply a voltage to the welded part when performing resistance welding.

In addition, the constricted portion 11 of the rod-shaped member 10 is rounded as shown in the figure. Therefore, as the rod-shaped member 10 revolves and rotates, it can move along the tip shape of the electrode, which has a rounded tip, for spot welding, etc., and excessive cutting is not performed, and only the cutting that is approximately necessary can be performed.

In addition, the tip dresser 1 is less likely to apply an eccentric load to the electrodes 103 and 104 shown in FIG. 7. Furthermore, the tip dresser 1 can be designed not to be too large structurally. As a result, in a welding gun with a narrow bore, there is little or no interference with the bore, preventing the electrodes 103 and 104 shown in FIG. 7 from reaching the cutting tool 34.

(Other forms)
The tip dresser 1 according to the present embodiment described above is one example of a preferred embodiment of the present invention, but the present invention is not limited to this and various modifications can be made without departing from the spirit and scope of the present invention.

For example, the rod-shaped member 10 including the constricted portion 11 does not need to use the cutting tool 34. Here, cutting means using the cutting tool 34 and cutting means not using the cutting tool 34 are collectively referred to as "cutting tools." For example, the material of at least the constricted portion 11 of the rod-shaped member 10 can be a grindstone. A grindstone is a stone with a rough surface, and the roughness makes it possible to cut it into an electrode for spot welding, etc.

When using a grindstone without using the cutting tool 34 as described above, the tip dresser 1 in this embodiment can be operated in the following manner, in addition to the manner of operation when using the cutting tool 34.

For example, there is a method in which the grinding wheel is clamped (sandwiched) between the two electrodes 103, 104 shown in FIG. 7 and then rotated. There is also a method in which the grinding wheel is clamped (sandwiched) between the two electrodes 103, 104 shown in FIG. 7, rotated for a certain period of time, the rotation is stopped, and then the grinding wheel is released from the clamped state. Furthermore, a method in which the two paired electrodes 103, 104 are pressed against the grinding wheel one by one may be adopted. The last method is a method in which it is not necessary to clamp (sandwich) the grinding wheel between the two electrodes 103, 104.

Of course, the cutting tool for the tip dresser may have a rod-shaped member, the center of which may be made of a grindstone, and the center may cut the workpiece. In addition, this center made of a grindstone may have the shape of the constricted portion 11 at the position of the constricted portion 11. In addition, the cutting tool made of a grindstone may not be a grindstone except for the center of the rod-shaped member, or may be a grindstone.

Also, an example has been shown in which a constricted portion 11 is formed in the longitudinal center of the rod-shaped member 10. However, the shape of the electrodes of a resistance welding device such as a spot welding device can have various shapes other than a rounded shape. For example, if the tip shape of the electrode is flat, it is preferable to use a cylindrical shape for the rod-shaped member 10, as this "avoids excessive cutting" as mentioned above. This is also true when the longitudinal center of the rod-shaped member 10 is made of a grinding wheel.

Furthermore, if the tip of the electrode is concave, it is preferable for the rod-shaped member 10 to have a shape in which the center of the length is more bulging than the other parts, in order to avoid "excessive cutting" as described above. This "bulging shape" can be a rounded bulging shape, or the rod-shaped member 10 can be a rectangular bulging shape without being rounded. This is also true when the center of the length of the rod-shaped member 10 is made of a grinding stone.

In addition, the constricted portion 11 does not necessarily have to have the pointed portions 35a, 35b of the cutting tool 34. If the cutting tool 34 has a pointed portion, the number of pointed portions of the cutting tool 34 may be one, but this is also acceptable. Furthermore, the number of pointed portions of the cutting tool 34 may be three, four, five or more.

The overall shape of the cutting tool 34 has an S-shaped cross section as shown in FIG. 6. However, the overall shape of the cutting tool 34 does not have to be S-shaped, and can instead be rod-shaped, arc-shaped, L-shaped, W-shaped, etc.

In addition, the bearing 19 is not necessarily required, and can be removed from the configuration of the tip dresser 1. Of course, it is preferable to use the bearing 19 to ensure smooth rotation of the first cover member 20 and the second cover member 25, but if that smoothness can be ensured by other configurations, the bearing 19 is not necessary.

The pin 18 can also be removed from the configuration of the tip dresser 1. If there is another configuration for rotatably fixing the bevel gear mounting portion 15a and the bevel gear 16, the pin 18 is not necessary.

The tip dresser 1 of this embodiment also has a means for rotating the cutting tool 34 around the axis connecting both ends of the rod, while revolving around the constricted portion 11 where the cutting tool 34 is located. In this embodiment, the movement of the cutting tool 34 by meshing gears is selected as the method for achieving this revolution and rotation. However, instead of moving the cutting tool 34 by meshing gears, other moving means can be selected, such as moving the cutting tool 34 by rolling wheels.

10 Rod-shaped member 11 Narrowed portion 34 Cutting tool

Claims (2)

A single rod-shaped member having a narrowed portion formed by narrowing a central portion of a side surface of the rod in a longitudinal direction;
a means for rotating the rod-shaped member about an axis connecting both ends of the rod while revolving the rod-shaped member about the narrowed portion as a center of rotation,
The constricted portion has a cutting tool for cutting,
The constricted portion is caused to revolve and rotate, so that the workpiece can be cut by the cutting tool.
Tip dresser. A single rod-shaped member;
a means for rotating the rod-shaped member about an axis connecting both ends of the rod while revolving the rod-shaped member around a center of rotation in the longitudinal direction of the rod-shaped member,
The central portion has a cutting tool for cutting,
The central portion is caused to revolve and rotate, thereby cutting the workpiece with the cutting tool.
Tip dresser.