JP2017179882A - Road surface cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a road surface cutting tool capable of easily replacing the cutting tool.SOLUTION: A shank part 21 of a cutting tool 20 is inserted into a shank insertion hole 13 of a tool holder 10, and a seal groove 26 is provided on an outer diameter surface of its shank part 21, and an annular groove 14 is oppositely formed in the seal groove 26 on an inner diameter surface of the shank insertion hole 13. The shank part 21 is prevented from slipping out by incorporating an O ring 30 composed of rubber so as to straddle the seal groove 26 and the annular groove 14, and insertion-extraction of the shank part 21 to the shank insertion hole 13, is made possible by elastic deformation of the O ring 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a road surface cutting tool for cutting a surface layer portion of a road surface.

  In general, asphalt road surface becomes more fluid when the ambient temperature is higher, and unevenness surface is formed by running of the vehicle, flatness is lowered, and safe driving is hindered, so the surface layer part of the road surface is cut, Pavement repair is performed by laying an asphalt mixture on the cut surface and rolling with a roller.

  Here, a road surface cutting tool is used for cutting the surface layer portion of the asphalt road surface. As the road surface cutting tool, one described in Patent Document 1 below has been conventionally known.

  The road surface cutting tool described in Patent Document 1 includes a tool holder and a cutting tool that is detachably attached to the tool holder, and a part of the circumferential direction is cut off from the shank portion of the cutting tool. The sleeve is fitted, and a washer is fitted to the outside of the sleeve to hold the sleeve in a reduced diameter state. The retaining projection formed on the end of the sleeve and the outer diameter end of the shank are formed. In a state where the sleeve is prevented from being pulled out by engagement of the ring groove, the sleeve is inserted into a shank insertion hole formed in the tool holder, and the cutting tool is further pushed in from a state where the washer is in contact with the head side end surface of the tool holder. As a result, the sleeve and the shank are moved relative to each other in the axial direction to release the fitting, and the sleeve is pressed against the inner diameter surface of the shank insertion hole by expanding the sleeve inside the shank insertion hole. And a retaining of the cutting tool retaining tanning the sleeve, by engagement of the formed ring groove in the retaining projection and the shank portion Te.

  In the above-mentioned road surface cutting tool, a large number of tool holders are fixed to the outer diameter surface of the rotating drum, and the rotating drum is rotated with the cutting tool attached to each of the tool holders, and is fixed to the tip of the cutting tool. The surface layer portion of the road surface is cut with a cutting tip made of cemented carbide.

  At this time, if the cutting position at the cutting tip is constant, the cutting tip is unevenly worn and sharpness is deteriorated and cutting becomes impossible at an early stage. Therefore, the cutting tool is rotated by contact of the cutting tip with the road surface. However, even in that case, the cutting tip is worn at a relatively early stage and cannot be cut. At that time, the cutting tool is replaced.

  In winter, the temperature is low, and the asphalt road surface is hard. When cutting several tens of meters, the sharpness may deteriorate and the cutting tool may need to be replaced. Therefore, if the replacement takes time, the efficiency of the cutting work will be greatly reduced. In order to suppress the decrease in the work efficiency, it is necessary to replace the cutting tool in a short time.

JP 2009-536701 A

  By the way, in the road surface cutting tool of patent document 1, since a cutting tool rotates at the time of road surface cutting, abrasion arises in the contact part of a washer and the large diameter shaft part for washer removal prevention formed in the shank part. Since the gap formed by the wear communicates with the gap formed between the sleeve and the shank portion, foreign matter such as chips formed by cutting the road surface enters the gap formed between the sleeve and the shank portion. The foreign matter obstructs the diameter reduction of the sleeve and requires a large force and time for extracting the cutting tool, and there is a problem that it takes much time to replace the cutting tool.

  The subject of this invention is providing the road surface cutting tool which enabled it to replace | exchange a cutting tool easily.

  In order to solve the above-described problems, in the present invention, a tool holder having a shank insertion hole, a shank portion inserted into the shank insertion hole of the tool holder, and a seat plate that regulates an insertion amount of the shank portion. A ring-shaped seal groove is formed on the outer diameter surface of the shank portion, and an annular groove is provided on the inner diameter surface of the shank insertion hole so as to face the seal groove. The ring has a structure in which the shank portion is prevented from being detached as an assembly extending over the annular groove and the seal groove.

  In the road surface cutting tool having the above configuration, when assembling the cutting tool, an O-ring is set in the seal groove of the shank portion, and the shank portion is inserted into the shank insertion hole of the tool holder in the set state of the O-ring. To do.

  When inserting the shank part into the shank insertion hole, the outer diameter of the O-ring is larger than the inner diameter of the shank insertion hole. Therefore, when the O-ring is inserted into the shank insertion hole, the inner diameter surface of the shank insertion hole The O-ring is elastically deformed by contact with. When the O-ring is inserted to a position facing the annular groove formed on the inner diameter surface of the shank insertion hole, the O-ring expands due to its own restoring elasticity and elastically contacts the inner diameter surface of the annular groove. The shank portion is prevented from being pulled out by the engagement of the O-ring with the groove, and the cutting tool is set. For this reason, a cutting tool can be easily set with respect to a tool holder.

  In the set state of the cutting tool, the O-ring is elastically in contact with the inner diameter surface of the annular groove and the outer diameter surface of the seal groove. Therefore, the O-ring functions as a seal ring, and the rear end surface of the shank from the seal groove. It is possible to prevent foreign matters such as chips from entering a gap formed between the outer diameter surface of the shank portion and the inner diameter surface of the shank insertion hole.

  Here, if the seal groove is provided at a position that is offset from the bisecting position of the shank portion in the axial direction toward the seat plate, the O-ring comes close to the contact surface between the head end surface of the tool holder and the seat plate. Since the part is sealed, the axial length of the gap formed between the outer diameter surface of the shank part and the inner diameter surface of the shank insertion hole between the seal groove and the seat plate is shortened, and foreign matter has entered. The trace amount of the shank is not hindered.

  Further, if the groove width of the annular groove is made larger than the wire diameter of the O-ring, wear occurs at the contact portion between the head side end surface of the tool holder and the seat plate, and the cutting tool is applied by an amount corresponding to the wear amount. Even when moved in the axial direction, the O-ring maintains the contact state with the inner diameter surface of the annular groove to ensure the sealing performance.

  When the road surface is cut by the cutting tool, the O-ring rotates integrally with the shank portion of the cutting tool, rotates in contact with the inner diameter surface of the annular groove, and rises in temperature. For this reason, the O-ring is preferably formed of rubber having excellent heat resistance. Examples of such rubber include silicone rubber, fluorine rubber, and acrylic rubber.

  When removing the cutting tool, insert the tip of the rod-shaped tool into the shank insertion hole from the end surface on the tail side of the tool holder, and apply axial force to the shank of the cutting tool by tapping the rear end of the tool. To do. Due to the load of the axial force, the O-ring is elastically deformed radially inward by contact with the axial end surface of the annular groove, the engagement with the annular groove is released, and the cutting tool can be easily extracted. .

  As described above, in the present invention, an O-ring made of rubber is incorporated across the seal groove formed on the outer diameter surface of the shank portion of the cutting tool and the annular groove formed on the inner diameter surface of the shank insertion hole of the tool holder. As a result, the shank part of the cutting tool can be easily inserted into and removed from the shank insertion hole of the tool holder, and the cutting tool that has become unable to cut can be easily replaced with a new cutting tool. It is possible to improve the work efficiency of road surface cutting.

Partially cutaway front view showing an embodiment of a road surface cutting tool according to the present invention Sectional drawing which expands and shows the incorporating part of the O-ring of FIG. 1 is an exploded perspective view showing the cutting tool and O-ring of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the road surface cutting tool according to the present invention includes a tool holder 10 and a cutting tool 20 that is detachably set on the tool holder 10.

  The tool holder 10 has a configuration in which a columnar portion 12 is provided at an upper portion of a pedestal portion 11 fixed to the outer diameter surface of the rotating drum A by means such as welding, and a shank is formed along the inclination of the columnar portion 12. An insertion hole 13 is provided. The shank insertion holes 13 are opened at both end surfaces of the head side end surface 12a that is separated from the outer diameter surface of the rotating drum A of the columnar portion 12 and the tail side end surface 12b that is close to the outer diameter surface of the rotating drum A.

  As shown in FIGS. 1 and 3, the cutting tool 20 has a shank portion 21 that is inserted into the shank insertion hole 13 of the tool holder 10, and a seat plate 22 is provided at the tip of the shank portion 21. A head portion 24 is provided on the surface of the seat plate 22 via a conical neck portion 23, and a cutting tip 25 made of a super steel alloy is provided on the head portion 24.

  The shank portion 21 is provided with a ring-shaped seal groove 26 at a position that is offset from the bisecting position of the axial length to the seat plate 22 side. On the other hand, as shown in FIGS. 1 and 2, an annular groove 14 is provided on the inner diameter surface of the shank insertion hole 13 in the tool holder 10 so as to face the seal groove 26, and between the annular groove 14 and the seal groove 26. The O-ring 30 is incorporated in the.

  The O-ring 30 is made of rubber having excellent heat resistance. Examples of such rubber include silicone rubber, fluorine rubber, acrylic rubber, chlorosulfonated polyethylene rubber, and epichlorohydrin rubber.

  The O-ring 30 is incorporated so as to straddle the annular groove 14 and the seal groove 26, and the outer peripheral portion elastically contacts the inner diameter surface of the annular groove 14. The shank portion 21 is prevented from being pulled out by elastic contact with each other, and at the same time, the space between the opposed surfaces of the shank insertion hole 13 and the shank portion 21 is sealed.

  As shown in FIG. 2, when the groove width of the annular groove 14 is W and the wire diameter of the O-ring 30 is d, the groove width W of the annular groove 14 is larger than the wire diameter d of the O-ring 30 (W> d). ing.

  The road surface cutting tool shown in the embodiment has the above-described structure. When the cutting tool 20 is assembled, the O-ring 30 is set in the seal groove 26 of the shank portion 21, and the shank is inserted from the head side end surface 12a of the tool holder 10. The shank part 21 is inserted into the hole 13.

  When the shank portion 21 is inserted into the shank insertion hole 13, the outer diameter of the O-ring 30 is larger than the inner diameter of the shank insertion hole 13. Therefore, when the O-ring 30 is inserted into the shank insertion hole 13, The O-ring 30 is elastically deformed and inserted into the shank insertion hole 13 by contact with the inner diameter surface of the shank insertion hole 13.

  When the shank portion 21 is inserted to a position where the seat plate 22 abuts against the head-side end surface 12a of the tool holder 10, the O-ring 30 faces the annular groove 14 formed on the inner diameter surface of the shank insertion hole 13, The ring 30 expands by its own restoring elasticity and elastically contacts the inner diameter surface of the annular groove 14, and the shank portion 21 is retained by the engagement of the O-ring 30 with the annular groove 14, so that the cutting tool 20 is in the set state. Is done.

  Thus, since the cutting tool 20 is attached by inserting the shank portion 21 into the shank insertion hole 13, the cutting tool 20 can be easily set on the tool holder 10.

  When the rotary drum A is rotated with the cutting tool 20 attached to the tool holder 10, the cutting tip 25 cuts the road surface. At this time, the cutting tool 20 rotates around the axis of the shank portion 21 by the contact of the cutting tip 25 with the road surface.

  When the cutting tool 20 is rotated, the seat plate 22 rotates while being in contact with the head-side end surface 12a of the columnar portion 12 of the tool holder 10, so that wear occurs at the contact portion. The cutting tool 20 can move in the axial direction by an amount corresponding to the amount of wear.

  At this time, since the groove width W of the annular groove 14 is larger than the wire diameter d of the O-ring 30, the O-ring 30 maintains a state of elastic contact with the inner diameter surface of the annular groove 14. The sealing property between the 26 opposing portions is ensured.

  For this reason, a gap is formed between the seat plate 22 and the head-side end surface 12a of the columnar portion 12 of the tool holder 10 by the movement of the cutting tool 20 in the axial direction, and the road surface is cut into the shank insertion hole 13 from the gap. Even if foreign matter such as chips enters, it is prevented from entering from the position of the O-ring 30 toward the tail side end face 12b.

  Here, since the seal groove 26 in which the O-ring 30 is set is a position that is offset toward the seat plate 22 from the bisected position of the axial length of the shank portion 21, the O-ring 30 is the head of the tool holder 10. The part close to the contact surface between the side end face 12a and the seat plate 22 is sealed. Therefore, the axial length of the gap formed between the outer diameter surface of the shank portion 21 and the inner diameter surface of the shank insertion hole 13 between the seal groove 26 and the seat plate 22 is short, and even if a foreign object enters the gap. The trace amount does not hinder the extraction of the cutting tool 20.

  Since the O-ring 30 has a higher contact pressure with respect to the seal groove 26 than a contact pressure with respect to the annular groove 14, the O-ring 30 rotates integrally with the shank portion 21 of the cutting tool 20 and is heated by contact rotation with respect to the inner diameter surface of the annular groove 14. However, since it is formed of rubber having excellent heat resistance, it is not damaged, and the set state of the cutting tool 20 is reliably maintained.

  When the sharpness is deteriorated due to wear of the cutting tip 25, the cutting tool 20 is extracted and replaced with a new cutting tool 20.

  When the cutting tool 20 is extracted, the tip end of a rod-shaped tool is inserted into the shank insertion hole 13 from the end surface on the tail side of the tool holder 10, and the shank portion 21 of the cutting tool 20 is struck by tapping the rear end of the tool. Apply axial force. Due to the load of the axial force, the shank portion 21 starts to move in the axial direction.

  In the initial stage of the movement, the O-ring 30 is elastically deformed radially inward by abutting against the axial end surface of the annular groove 14 and the engagement with the annular groove 14 is released. It moves toward the head-side end surface 12a while maintaining a state of elastic contact with the inner diameter surface. At this time, even if foreign matter such as chips enter the shank insertion hole 13, the amount is very small, so that the cutting tool 20 is not obstructed and can be easily extracted.

  Thus, since the cutting tool 20 can be easily attached to and detached from the tool holder 10, it can be easily replaced, and the efficiency of the road surface cutting operation can be improved.

DESCRIPTION OF SYMBOLS 10 Tool holder 13 Shank insertion hole 14 Annular groove 20 Cutting tool 21 Shank part 22 Seat plate 24 Head part 25 Cutting tip 26 Seal groove 30 O-ring

Claims (4)

A tool holder in which a shank insertion hole is formed;
A cutting tool detachably attached to the tool holder,
The cutting tool is provided with a seat plate that abuts against the head side end surface of the tool holder at the tip of the shank portion that is inserted into the shank insertion hole of the tool holder, and the head portion is formed on the seat plate. The head is configured to have a cutting tip,
A ring-shaped seal groove is formed on the outer diameter surface of the shank portion,
An annular groove is formed on the inner diameter surface of the shank insertion hole so as to face the seal groove,
A road surface cutting tool in which the shank portion is retained by a rubber O-ring that is incorporated over the annular groove and the seal groove and elastically contacts the inner diameter surface of the annular groove and the outer diameter surface of the seal groove.   2. The road surface cutting tool according to claim 1, wherein the seal groove is provided at a position that is offset from a bisecting position of an axial length of the shank portion toward the seat plate.   The road surface cutting tool according to claim 1 or 2, wherein a groove width of the annular groove is larger than a wire diameter of the O-ring.   The road surface cutting tool according to any one of claims 1 to 3, wherein the O-ring is made of rubber having excellent heat resistance.

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