JPH0538009U - Road cutting bits - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] When cutting a road surface with a bit mounted on the peripheral surface of a rotating drum, the bit grounded on the road surface is attempted to rotate smoothly, and the carbide tip of the bit is biased. It is an object of the present invention to provide a technique for preventing wear, thereby making it easier to maintain the durability of the bit itself and also making it easier to maintain the cutting work efficiency of the bit. [Construction] In a bit 3 mounted on the peripheral surface of a rotary drum and supported so as to rotate by the cutting resistance of the road surface itself when cutting the road surface, the bit 3 is rotatably attached to the rotary drum. It is characterized in that it comprises a shank portion 8 to be supported and a cemented carbide tip 7 at the tip of the shank portion 8, and a plurality of spiral grooves 9 are formed in the cemented carbide tip 7.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a road cutting bit, and more particularly to a technique for allowing the bit itself attached to the peripheral surface of a rotary drum to rotate better.

[0002]

[Prior Art]

 As is well known, a bit is known which is attached to the peripheral surface of a rotary drum and is supported so as to rotate by the cutting resistance of the road surface itself when cutting the road surface. The bit is composed of a shank portion rotatably supported by the rotary drum and a cemented carbide tip made of cemented carbide at the tip of the shank portion. It was the type of.

[0003]

[Problems to be solved by the device]

 According to the above-mentioned prior art, the bit is attached to the peripheral surface of the rotating drum so that the bit itself rotates, so that when the rotating drum is rotated and the road surface is cut by the bit, the bit is cut from the road surface. Resistance causes itself to rotate, and the ground portion of the bit tip and the road surface constantly moves, thereby preventing uneven wear of the cemented carbide tip, and the cemented carbide tip made of cemented carbide at the tip of the bit. Was designed to maintain the durability of the.

However, in reality, there are some problems in the following points. That is, since the cemented carbide tip made of cemented carbide at the tip of the above-mentioned bit is in the shape of a bullet, it is possible that when the bit is actually used, it does not rotate due to cutting resistance. Many.

[0007] Specifically, although the bit is attached to the rotating drum so that the bit itself rotates, when the rotating drum is rotated to cut the road surface by the bit, cutting is performed on the carbide tip at the tip of the bit. If a portion of the cemented carbide chip wears flat due to the resistance from the road surface, that is, if uneven wear occurs on the curved surface of the bullet-shaped mold cemented carbide tip, The uneven wear part is always in contact with the road surface, which makes it difficult for the bit to rotate, and at the same time makes it difficult for the bit to rotate, which further increases uneven wear of the carbide tip and increases the durability of the bit itself. It was difficult to hold and maintain the cutting work efficiency with the bit.

Therefore, the object of the present invention is a bit which is attached to the peripheral surface of the rotary drum and which is supported so as to rotate by the cutting resistance on the road surface itself when cutting the road surface. By improving the cemented carbide tip made of cemented carbide at the tip of the bit above, when the road surface is cut by the bit, the bit grounded on the road surface tries to rotate smoothly and uneven wear of the carbide tip of the bit is caused. The purpose of this is to provide a technology that makes it easier to maintain the durability of the bit itself and the efficiency of cutting work by the bit.

[0007]

[Means for solving the problem]

 In order to solve the above object, the present invention has the following technical means. That is, to explain with reference to the reference numerals in the accompanying drawings corresponding to the embodiments, the present invention is attached to the peripheral surface 5 of the rotary drum 4, and when the road surface is cut, it itself rotates by the cutting resistance on the road surface side. In the supported bit 3, the bit 3 includes a shank portion 8 rotatably supported by a rotary drum 4 and a cemented carbide tip 7 at the tip of the shank portion 8. A road cutting bit having a plurality of spiral grooves 9 formed therein.

[0008]

[Action]

 According to the above configuration, by forming a plurality of spiral grooves 9 in the cemented carbide tip 7 at the tip of the shank portion 8 of the bit 3 which is rotatably supported by the rotary drum 4, when the road surface is cut by the bit 3 described above, The spiral groove 9 formed in the cemented carbide tip 7 receives a resistance from a road surface piece cut by the cemented carbide tip 7, and the cemented carbide chip 7 rotates in a direction in which the resistance escapes. The bit 3 rotatably supported by the rotary drum 4 is easily rotated.

[0009]

【Example】

 Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. That is, it is a bit 3 for cutting the asphalt 2 and the like on the surface of the road where the surface of the ground 1 is paved with the asphalt 2, and the bit 3 is rotatably supported by the rotating drum 4. ..

The rotary drum 4 has a cylindrical shape and is rotatable about a central axis. The rotation direction of the rotary drum 4 is a one-way rotation determined according to the position state of the bit 3 which will be described later and is supported by the rotary drum 4, and the rotation speed of the rotary drum 4 depends on the bit 3. It can be freely set according to the type and condition of the road surface to be cut.

Then, the bit 3 is attached to the peripheral surface 5 of the rotary drum 4. Looking at the mounting state of the bits 3 on the peripheral surface 5 of the rotating drum 4, a plurality of bits 3 are arranged in a zigzag pattern. Each bit 3 is cut on the road side when the road surface is cut. It is supported by a bit support member 6 provided on the peripheral surface 5 of the rotary drum 4 so as to rotate around the axis of the bit 3 by resistance.

Further, the mounting angle of the bit 3 with respect to the peripheral surface of the rotary drum 4 is such that the road surface is cut from the tip end portion of the bit 3 when the rotary drum 4 is rotated and the bit 3 comes in contact with the road surface. The angle B 2 between the axis of the bit 3 and the road surface is set to about 35 to 40 degrees. (See Figure 3)

Next, the bit 3 including the carbide tip 7 which is a feature of the present invention will be described. The bit 3 has a shank portion 8 rotatably supported by the rotary drum 4. And the cemented carbide tip 7 at the tip of the shank portion 8.

The shank portion 8 of the bit 3 is made of a ferrous metal, and the rear portion of the bit 3 opposite to the tip having the cemented carbide tip 7 is placed in the bit support member 6 provided on the rotary drum surface 5. The shank portion 8 is inserted by a predetermined length and is rotatably supported.

The cemented carbide tip 7 at the tip of the shank portion 8 is made of cemented carbide and is brazed to the tip of the shank portion 8. The cemented carbide tip 7 has a substantially bullet shape, and a plurality of spiral grooves 9 are formed on the surface thereof.

The spiral groove 7 formed on the surface of the cemented carbide tip 7 is a linear groove and has an inclination A of about 5 degrees with respect to a line of the shortest distance from the tip of the cemented carbide tip 7 to the periphery. And has a groove depth suitable for the cutting resistance from the road surface for rotating the bit 3 at the time of cutting the road surface to be properly applied to the spiral groove 9. Then, three spiral grooves 9 are formed.

Next, how to use the above configuration will be described. That is, in the case of a generally paved road, for example, a road in which the surface of the ground 1 is paved with asphalt 2, concrete, stones, or the like, if the surface of the paved road is damaged by a vehicle, etc. The need to do is required. At this time, in order to remove the damaged pavement part, specifically the asphalt 2 part and the concrete part, the bit 3 attached to the peripheral surface of the rotary drum 4 is used.

More specifically, the rotary drum 4 is rotated at a predetermined speed so that the bit 3 on the peripheral surface 5 of the rotary drum 4 is positioned to cut the road surface. Focusing on the bit 3 that cuts the road surface, the bit 3 cuts the road surface with the carbide tip 7 at the tip of the bit 3 by the rotational force of the rotary drum 4. At this time, the strip of the road surface cut by the cemented carbide tip 7 hits the spiral groove 9 formed in the cemented carbide tip 7, and the cemented carbide tip 7 receives resistance from the strip of the road surface cut by the spiral groove 9 portion.

Then, the cemented carbide tip 7 that has received the resistance is guided by the action of the spiral groove 9 having the inclination A so that the strip of the cut road surface is partially guided to the spiral groove 9. Since the spiral groove 9 is formed so as to have the inclination A, an initial movement is obtained in which the cemented carbide tip 7 is rotated by the resistance from the cut road surface strip.

After the initial rotational force of the cemented carbide tip 7, that is, the bit 3 is applied, the bit 3 continues its rotation during cutting to cut the road surface.

More specifically, referring to FIGS. 3 and 4, when the cemented carbide tip 7 is viewed from the front direction centering on the tip portion of the cemented carbide tip 7, it is formed on the cemented carbide tip 7. When the spiral groove 9 has a clockwise inclination A of about 5 degrees with respect to the shortest distance line drawn from the tip of the cemented carbide tip 7 to the surroundings, when the road surface is cut with the bit 3, The cemented carbide tip 7 that cuts the road surface receives cutting resistance from the road surface, and the cut road surface piece provides resistance to the spiral groove 9 and is guided to the spiral groove 9. At this time, since the spiral groove 9 has the inclination A in the clockwise direction, the resistance acting from the road surface strip to the spiral groove 9 becomes the resistance in the clockwise direction. That is, the bit 3 is rotated clockwise.

Next, a modification of the above embodiment will be described. In this example, substantially the same parts as those in the above-mentioned embodiment are omitted, and only different parts will be described. That is, the number of spiral grooves 9 formed in the cemented carbide tip 7 at the tip of the bit 3 is four. Furthermore, by increasing the number of the spiral grooves 9 described above, the spiral formed in the cemented carbide tip 7 of the present modification is higher than the cutting resistance from the road surface received by the spiral groove 9 formed in the cemented carbide tip 7 of the above-described embodiment. Since it is considered that the cutting resistance from the road surface that the groove 9 receives will be large, the depth of the spiral groove 9 formed in the carbide tip 7 of this modification is the same as that of the carbide tip of the embodiment described above. The depth of the spiral groove 9 formed in No. 7 is shallower than that of the spiral groove 9. The cutting resistance from the road surface for rotating the bit 3 at the time of cutting the road surface is appropriately set to the spiral groove 9 as well. The groove depth is suitable for this.

In the above-described embodiment, the shank portion 8 of the bit 3 is made of iron-based metal and the cemented carbide tip 7 is made of cemented carbide. However, the shank portion 8 and the cemented carbide tip 7 are It is conceivable to integrally mold the material and make it a cemented carbide. Further, the spiral groove 9 formed on the cemented carbide tip 7 at the tip of the bit 3 is a linear groove, but it may be a curved groove and the spiral groove 9 has an inclination A in the clockwise direction. Although the spiral groove 9 is provided, the spiral groove 9 may have a counterclockwise inclination A. Furthermore, the number of spiral grooves 9 formed in the cemented carbide tip 7 can be freely set according to the type and condition of the road surface to be cut.

As described above, the cemented carbide tip 7 attached to the peripheral surface 5 of the rotary drum 4 and supported at the tip of the bit 3 which is supported by itself by the cutting resistance on the road surface side when the road surface is cut By forming a plurality of spiral grooves 9, cutting resistance from the road surface acts on the spiral grooves 9 when cutting the road surface, and a resistance force to rotate the bit 3 is generated, so that the initial movement of the rotation of the bit 3 is obtained. It is what is done.

[0025]

【effect】

 As described above in detail, the present invention has a bit attached to the peripheral surface of a rotary drum, which is supported at the tip of the bit so as to rotate by cutting resistance on the road surface itself when cutting the road surface. By forming multiple spiral grooves on the carbide tip, the bit that cuts the road surface rotates smoothly when cutting the road surface, and the cutting surface of the carbide chip is grounded evenly with the road surface. It is easy to prevent uneven wear of the insert, which makes it easier to maintain the durability of the bit itself and also to maintain the cutting work efficiency of the bit.

[Brief description of drawings]

FIG. 1 is a front view schematically showing a working state of a road cutting bit according to the present invention.

FIG. 2 is a side view schematically showing a working state of the road cutting bit of the present invention.

FIG. 3 is a view showing a road surface grounding state in the road cutting bit of the present invention.

FIG. 4 is a front view of a cemented carbide tip in a road cutting bit according to the present invention.

FIG. 5 is a cross-sectional view of the cemented carbide tip of the road cutting bit of the present invention cut perpendicularly to the axis.

FIG. 6 is a view showing a modification of the cemented carbide tip in the road cutting bit of the present invention.

[Explanation of symbols]

 1 Ground 2 Asphalt 3 Bit 4 Rotating Drum 5 Circumferential Surface of Rotating Drum 6 Bit Supporting Member 7 Carbide Tip 8 Shank 9 Spiral Groove A Spiral Groove Inclination B Angle between Bit and Road

Claims (1)

[Scope of utility model registration request] 1. Attached to a peripheral surface 5 of a rotary drum 4,
Further, in the bit 3 which is itself supported to rotate by the cutting resistance on the road surface when cutting the road surface, the bit 3 includes the shank portion 8 rotatably supported by the rotary drum 4 and the shank portion. A bit for road cutting, comprising a cemented carbide tip 7 having 8 tips, and a plurality of spiral grooves 9 formed in the cemented carbide tip 7.