JP7836633B2 - Tip dresser blades - Google Patents

Description

This invention relates to a cutting tool for a tip dresser.

A tip dresser is a cutting device used to cut the tip of an electrode, such as one used for resistance welding, particularly spot welding. When a spot welding electrode is pressed against the cutting tool of a tip dresser and rotated to perform cutting, a protruding piece of material may remain at the center of the electrode tip. (Patent Document 1 [0002]). It is known that this material remains because the cutting speed becomes zero or near zero near the center of rotation of the cutting tool.

In other words, as shown in Figure 7, the shape of the cutting tools 101 and 102 of a typical tip dresser 100 is such that the approximately semicircular tips of a pair of opposing spot welding electrodes 103 and 104 can be approximately fitted onto the tip dresser's cutting tools.

Then, the cutting tool of the chip dresser is rotated using gears by a motor 105, etc. That is, when the rotation axis 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 chip dresser 100, driving the chip dresser 100. In other words, for example, the chip dresser 100 rotates its rotation axis 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 rotational center of the approximately circular cutting tools 101 and 102 of the tip dresser 100, the cutting speed becomes zero or close to zero, which can result in uncut material remaining on the spot welding electrodes 103 and 104.

Japanese Unexamined Patent Publication No. 7-009166

When the above-mentioned material residue occurs, it becomes difficult to apply the appropriate current and voltage to the welding area during resistance welding.

Therefore, the object of the present invention is to provide a tip dresser and its cutting tool that can apply an appropriate current and voltage to the area to be welded during resistance welding.

To achieve the above objective, the cutting tool for the chip dresser of the present invention comprises a single rod-shaped member having a constricted portion formed by narrowing the longitudinal center of the side surface of the rod, and means for causing the rod-shaped member to revolve around the constricted portion as the center of rotation, while rotating the rod-shaped member on an axis connecting both ends of the rod as the axis of rotation. This makes it possible to revolve and rotate the constricted portion, and the constricted portion is shaped to have a cutting tool for cutting, making it possible to cut the workpiece with the constricted portion.

Here, the constricted portion of the rod-shaped member may be made of a grinding wheel, allowing the workpiece to be cut at the constricted portion.

To achieve the above objective, the cutting tool for the chip dresser of the present invention has a single rod-shaped member having a constricted portion in the longitudinal center of the side surface of the rod. The constricted portion of the rod-shaped member is shaped to have a cutting tool for cutting, and the workpiece can be cut at the constricted portion.

To achieve the above objective, the cutting tool for the chip dresser of the present invention has a single rod-shaped member having a constricted portion formed by narrowing the longitudinal center of the side surface of the rod. The constricted portion of the rod-shaped member is made of a grinding wheel, and the workpiece can be cut at the constricted portion.

This invention provides a tip dresser and its cutting tool that can apply an appropriate current and voltage to the area to be welded during resistance welding.

This is an exploded perspective view of a chip dresser according to an embodiment of the present invention. This is a plan view of a chip dresser according to an embodiment of the present invention. This is a cross-sectional view taken along line C-C in Figure 2. This is a cross-sectional view taken along line D-D in Figure 2. This is a perspective view of a rod-shaped member of a chip dresser according to an embodiment of the present invention. This is a cross-sectional view taken along line E-E in Figure 5. This diagram shows the configuration of a conventional chip dresser. While this diagram is technically a cross-sectional view and should be hatched, it is presented schematically as a front view to avoid obscuring individual elements.

(Tip dresser configuration)
The configuration of the chip dresser of this embodiment will be described below with reference to Figures 1, 2, 3, and 4. First, the chip dresser 1 has a rod-shaped member 10. The rod-shaped member 10 has a constricted portion 11 formed by narrowing the central part of the side surface of the rod in the longitudinal direction. The cutting tool of the chip dresser 1 will be formed in this constricted portion 11. Details of the cutting tool will be shown in Figures 5 and 6, while Figures 1, 2, 3, and 4 only show the general shape of the constricted portion 11 without showing details such as the shape of the cutting tool.

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

First, the rod-shaped member 10 is placed in the through holes 13, 13 of the housing member 12, so that the constricted portion 11 is exposed through the window portion 14, which is the opening of the housing member 12. The window portion 14 of the housing member 12 is also formed on the side of the housing member 12 not shown in Figure 1, at a position opposite to the window portion 14.

Then, the bevel gears 16 and 17 are attached to the bevel gear mounting portions 15a and 15b at both ends of the rod-shaped member 10, respectively. The bevel gear mounting portion 15a and the bevel gear 16 are fixed together so that they can rotate, with a pin 18 positioned to pass through both the rotation axis of the bevel gear 16 and the rod-shaped member 10. The bevel gear mounting portion 15b and the bevel gear 17 are either integrally molded or fixed together so that they cannot rotate using adhesive or the like.

When the bevel gears 16 and 17 are installed, they are positioned outside the through holes 13 and 13. The rod-shaped member 10 is then fixed so that the bevel gears 16 and 17 can rotate; however, the bevel gear 17 rotates together with the rod-shaped member 10. Furthermore, the bevel gear 16 rotates freely and independently, without being affected by the rotation of the rod-shaped member 10.

The inner surface 19a of the annular bearing 19 is superimposed with the outer surface of the cylindrical wall portion 21 of the annular first cover member 20. This allows the outer surface 19b of the bearing 19 to rotate circumferentially along the circular shape of the wall portion 21, while 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 portion 23 formed on the edge of the hole 22 in the first cover member 20. The teeth of this gear portion 23 are oriented toward the center of the circular outer shape of the first cover member 20.

Furthermore, it has a circular gear portion 27 formed on the edge of the hole 26 of the annular second cover member 25, which has a cylindrical wall portion 24. The teeth of this gear portion 27 are oriented toward the center of the circular outer shape of the second cover member 25.

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

By doing so, the teeth of gear sections 23 and 27 can rotate while both bevel gears 16 and 17 mesh with each other. That is, by rotating the teeth of gear sections 23 and 27 while the bevel gears 16 and 17 mesh with each other, the rod-shaped member 10 can revolve around its constricted portion 11 as its center of rotation. When the rod-shaped member 10 is housed in the housing member 12, this revolve follows the arrow R2 in Figure 1. In this state, where the rod-shaped member 10 is housed in the housing member 12, the rotation of the housing member 12 along arrow R2 in Figure 1 means that the rod-shaped member 10 "revolves around its constricted portion 11 as its 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. This rotation is along the arrow R3 in Figure 1. The above describes one example of a means by which the tip dresser 1 revolves around the constricted portion 11 of the rod-shaped member 10 as the center of rotation, while simultaneously causing the rod-shaped member 10 to rotate around the axis connecting both ends of the rod.

As shown in Figures 5 and 6, the constricted portion 11 is shaped to have pointed portions 35a and 35b, which serve as the cutting tool 34. The constricted portion 11 is made to revolve and rotate, and the cutting tool 34 cuts the workpiece. Here, the number of non-cutting objects is not limited in principle; it can 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 pointed portions 35a and 35b extend in the longitudinal direction of the constricted portion 11. In other words, the tips of the two pointed portions 35a and 35b extend continuously and elongated in the longitudinal direction of the constricted portion 11.

(How the chip dresser 1 operates in this embodiment)
When operating the chip dresser 1, first the cutting tool 34 of the chip dresser 1 is made to revolve and rotate. Next, the cutting tool 34 is clamped with electrodes 103 and 104 shown in Figure 7. Then, electrodes 103 and 104 shown in Figure 7 are inserted into the two window portions 14 shown in Figure 2.

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

(Main effects obtained by this embodiment)
The tip dresser 1 of this embodiment has a means for rotating the rod on an axis connecting both ends while revolving around the constricted portion 11 where the cutting tool 34 is located. As a result, the cutting speed near the rotation center of the cutting tool 34 of the tip dresser 1 is never zero or close to zero, and no or very little cutting residue is left on the electrode for spot welding, etc. Therefore, it is possible to provide a tip dresser 1 that can apply an appropriate current and voltage to the area to be welded when performing resistance welding.

Furthermore, 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 an electrode, such as one used for spot welding, which has a rounded tip. This prevents excessive cutting and allows for cutting only what is substantially necessary.

Furthermore, the tip dresser 1 is less likely to subject electrodes 103 and 104, as shown in Figure 7, to eccentric load. Moreover, the tip dresser 1 can be structurally kept from becoming excessively large. As a result, in welding guns with narrow cuffs, interference from the cuff, preventing electrodes 103 and 104 from reaching the cutting tool 34, is avoided or minimized.

(Other forms)
The chip dresser 1 according to the above-described embodiment is an example of a preferred form of the present invention, but is not limited thereto, and various modifications can be made without changing the gist of the present invention.

For example, the rod-shaped member 10 including the constricted portion 11 does not necessarily require the use of a 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 grinding wheel. Since a grinding wheel is a stone with a rough surface, its roughness allows for cutting into electrodes for spot welding, etc.

Furthermore, when using a grinding wheel instead of the cutting tool 34 as described above, the operation of the chip dresser 1 in this embodiment can be performed in addition to the operation method when using the cutting tool 34, for example, the following operation methods can be applied.

For example, one method involves clamping the grinding wheel with the two electrodes 103 and 104 shown in Figure 7, and then rotating the grinding wheel. Another method involves clamping the grinding wheel with the two electrodes 103 and 104 shown in Figure 7, rotating the grinding wheel for a certain period of time, stopping the rotation, and then releasing the grinding wheel from the clamp. Furthermore, a method of pressing one electrode at a time against the grinding wheel is also possible. The last method does not require clamping the grinding wheel with the two electrodes 103 and 104.

Of course, the cutting tool for the chip dresser may have a rod-shaped member, with the central part of the rod-shaped member being made of a grinding stone, and the workpiece being cut at the central part. Furthermore, this central part made of a grinding stone may have the shape of the constricted portion 11 at the position of the constricted portion 11. Also, the parts of this cutting tool made of a grinding stone other than the central part of the rod-shaped member may or may not be made of a grinding stone.

Furthermore, an example was 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 resistance welding devices such as spot welding devices can be various shapes other than rounded shapes. For example, if the tip shape of the electrode is flat, it is preferable to adopt a cylindrical shape for the rod-shaped member 10 in order to "avoid excessive cutting" as described above. This is also true when the longitudinal center of the rod-shaped member 10 is made of a grinding wheel.

Furthermore, if the electrode tip is concave, it is preferable for the rod-shaped member 10 to have a shape where the central part in the longitudinal direction is more bulging than other parts, in order to avoid the aforementioned "excessive cutting." This "bulging shape" can be a rounded bulge, or the rod-shaped member 10 can have a rectangular bulge without being rounded. This is also true when the central part in the longitudinal direction of the rod-shaped member 10 is made of a grinding wheel.

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

Furthermore, the overall shape of the cutting tool 34 is S-shaped in cross-section, as shown in Figure 6. However, the overall shape of the cutting tool 34 can be other than S-shaped in cross-section, such as a rod-shaped, arc-shaped, L-shaped, or W-shaped cross-section.

Furthermore, since the bearing 19 is not necessarily required, it can be omitted from the configuration of the tip dresser 1. While it is preferable to use the bearing 19 to ensure smooth rotation between the first cover member 20 and the second cover member 25, if that smoothness can be ensured by other components, the bearing 19 is unnecessary.

Furthermore, pin 18 can also be removed from the configuration of the chip dresser 1. If there is another configuration for rotatably fixing the bevel gear mounting portion 15a and the bevel gear 16, pin 18 is unnecessary.

Furthermore, the chip dresser 1 of this embodiment has a means for revolving around the constricted portion 11 where the cutting tool 34 is located as the center of rotation, while simultaneously rotating on an axis connecting both ends of the rod as the axis of rotation. In this embodiment, the movement of the cutting tool 34 is achieved by the meshing of gears. However, other means of movement, such as the movement of the cutting tool 34 by the rolling of wheels, can be selected instead of the movement of the cutting tool 34 by the meshing of gears.

10 Rod-shaped member 11 Constricted portion 34 Cutting tool

Claims (2)

A single rod-shaped member having a constricted portion formed by narrowing the longitudinal center of the side surface of the rod,
The rod-shaped member has means for revolving around the constricted portion of the rod-shaped member as the center of rotation, while also rotating the rod-shaped member on an axis connecting both ends of the rod.
The constricted portion can be made to revolve and rotate,
The constricted portion is shaped to have a cutting tool for cutting, and the constricted portion is capable of cutting the workpiece.
Cutting tools for tip dressers. A cutting tool for a tip dresser according to claim 1,
The constricted portion of the rod-shaped member is made of a grinding wheel, and the constricted portion is capable of cutting the workpiece.
Cutting tools for tip dressers