JPS6024724Y2 - Structure of cutter bit mounting part - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the structure of a part for mounting a cutter bit in a cutting device used in civil engineering work.

A large number of blades (
A cutting device is often used in which a rotating drum equipped with a cutter bit is pressed against the surface to be cut.

In such cutting devices, the cutter bit is generally fitted into a cylindrical holder provided on the outer periphery of a rotating drum, and fixed with a pin passing through the side wall of the holder.

However, with the conventional fixing method described above, the inner surface of the holder rapidly wears out under severe usage conditions, reducing the support area of the cutter bit, and also leaves asphalt powder and rocks between the worn inner wall of the holder and the shank of the cutter bit. There is a problem in that dust from the workpiece accumulates, making it difficult to attach and detach the cutter bit.

This idea was made in view of the above circumstances,
The cutter bit mounting structure provides a structure that prevents wear and tear on the holder and allows the cutter bit to be easily attached and removed.

This will be explained below. The structure of the cutter bit mounting section according to this invention includes a cutter bit with a fixing recess on the side surface of the shank into which a fixing pin fits, a mounting hole into which the shank of the cutter bit fits, and a cutting device main body. The holder is installed by inserting a liner with a pin hole for protruding a fixed pin and the shank of the cutter bit into the hole so as to overlap each other. In addition, the holder is attached so that the cutter bit is held by fitting the tip of the fixing pin that protrudes from the large side through the pin hole of the liner into the shank 0 recess of the cutter bit. It is said that

Hereinafter, embodiments of this invention shown in the drawings will be described.

Fig. 1 is a plan view illustrating the cutter bit installation part according to this invention, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, Fig. 3 is a plan view of the liner, and Fig. 4 is FIG. 3 is a partially sectional view showing a state in which a cutter bit is attached.

In these figures, a rotating drum 1 forming the main body of the cutting device is shown.
A holder 2 is fixed (welded in the illustrated example) to.

The holder 2 is in the form of a cylinder with a hole 3 for fitting a cutter bit, and a through hole 4 is provided in the side wall of the holder 2.

A guide tube 6 having a guide hole 5 at its center along the longitudinal direction is fitted into the through hole 4 .

The guide tube 6 has a flange 7 having a diameter larger than the inner diameter of the through hole 4 at its rear end, and a male thread 8 at its tip.

The guide hole 5 of the guide tube 6 is shaped as a stepped through hole with a small diameter portion 5a at the tip side and an enlarged opening portion 5b at the rear. A spring 10 is held so that its tip 9a protrudes from the tip 6a of the guide tube.

The fixing pin 9 is shaped as a round bar with a collar 9b having a larger diameter than the inner diameter of the small diameter portion 5a of the guide hole 5 at the rear, and the body is slidably fitted into the small diameter portion 5a of the guide hole 5. The collar 9b is slidably fitted into the enlarged opening 5b.

That is, the fixing pin 9 is held within the guide hole 5 so as to be movable back and forth.

A screw 5c is provided on the inner surface of the rear end of the guide hole 5, and a bolt 11 is screwed onto the screw 5c.

The bolt 11 is for holding down the rear end of the spring 10, and the spring 10 is inserted into the guide hole 5 when the bolt 11 is pressed down.
and the fixing pin 9.

A washer 12 is provided between the flange 7 of the guide cylinder 6 and the side wall of the holder 2, if necessary.

When installing the holder 2, a steel material (for example, 355
A liner 13 made of C) or the like is inserted so as to be in close contact with the inner surface of the side wall.

The liner 13 is in the form of a plate with pin holes 14 drilled in portions corresponding to the positions of the through holes 4 of the holder 2.

A female thread 14a is provided on the inner wall of this pin hole 14, and a male thread 8 at the tip of the guide tube is screwed into this female thread 14a.

That is, in the illustrated example, the guide tube 6 is screwed onto the liner 13 so that the side wall of the holder 2 is pressed between the flange 7 and the liner 13 via the washer 12, and in this state, the fixing pin 9 is The tip 9a protrudes from the surface of the liner 13 into the mounting hole 3.

The liner has a fixed pin (or guide tube) that fits into it.
Since it is supported by the holder, it will not fall off during use.

Note that it is advantageous for fixing the guide tube to screw the liner onto the guide tube as shown in the illustrated example.

The side surface of the shank 15a of the cutter bit 15 has a recess 16 for fitting into which the tip end 9a of the fixing pin 9 fits.
is provided.

As shown in FIG. 4, the cutter bit 15 is attached to the rotating drum 1 rotating in the direction of arrow X by inserting the rear part of the shank 15a into the hole 3 of the holder 2. Since the fixing pin 9 fits into the recess 16 provided for attachment, it is prevented from falling off from the holder during use.

For mounting, it is preferable that the recess 16 be in the form of a groove or a conical space.

Further, as shown in FIG. 5, the fixing pin 9 is formed as a long rod whose rear part protrudes from the guide tube 6, and its rear end can be pulled out against a spring 10 disposed around the outer periphery of its middle part. If the tip part 9a can be moved back, the cutter bit 15 can be installed in the hole 3.
An advantage arises in that the fixing pin 9 can be kept out of the way when it is fitted into the housing.

However, even if the structure is not such that the fixing pin can be retracted from the outside, the inner wall of the recess 16 for attachment to the shank of the cutter bit can be shaped as an inclined surface at an appropriate angle. If the tip of the fixing pin 9 is chamfered or rounded and the strength of the spring 10 is set to an appropriate level, the cutter bit itself can be easily attached and detached by simply pushing and pulling it.

In the cutter bit installation according to this invention, a plate-shaped liner is disposed between the inner wall of the holder and the shank of the cutter bit, so that wear and tear on the inner wall of the holder during use is effectively prevented.

The liner gradually wears out with use, in which case only the liner needs to be replaced.

Compared to holders, liners are much cheaper to manufacture;
Moreover, since it is easy to attach and detach, the liner can be replaced frequently.

Therefore, the gap formed by wear and tear of the cutter bit support portion is filled with asphalt, thereby effectively preventing an accident in which the cutter bit becomes difficult to attach and detach.

As explained above, the cutter bit mounting part according to this invention has a structure in which the cutter bit fitted into the cylindrical holder is held by a fixing pin, but it is designed so as not to impair the function of the fixing pin. Since the liner is interposed between the shank of the cutter bit and the inner wall of the holder, there is little wear and tear on the holder, and the cutter bit can be easily attached and detached, making it extremely practical and excellent.

[Brief explanation of the drawing]

Fig. 1 is a plan view illustrating the cutter bit installation part according to this invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1,
FIG. 3 is a plan view illustrating the liner, FIG. 4 is a partial sectional view illustrating a state in which a cutter bit is attached, and FIG. 5 is a sectional view showing a different embodiment. 1...Rotating drum, 2...Holder
3... Mounting is through hole, 4... Through hole, 6...
...Guide tube, 9...Fixing pin, 10...
... Spring, 11 ... Bolt, 13.
...Liner, 14...Pin hole, 15
""Cutter bit, 16... recess.

Claims (3)

[Scope of utility model registration request] (1) The cutter bit, which has a cutting edge at the tip and a recess for fitting a fixing pin on the side of the shank, is attached to the main body of the cutting device. For installation, a cylindrical holder with a hole is installed in the main body of the cutting device.
To install the holder, insert the liner with a pin hole for protruding the fixing pin and the shank of the cutter bit into the hole so as to overlap each other, and install the holder by penetrating the pin hole of the liner from the hole side chamber. The cutter bit mounting structure is characterized in that the cutter bit is held by fitting the tip of the protruding fixing pin into the recess of the shank of the cutter bit. (2) A hollow guide tube is fitted into the pin hole, and a fixing pin is held in the guide tube by a spring and the fixing pin is pressed in the direction of protruding into the hole.Claim 1 of Utility Model Registration The cutter bit installation described in section is the structure of the part. (3) The cutter bit mounting structure according to claim 2, wherein the tip of the guide tube is screwed into a pin hole provided in the liner.