JPH112086A - Rock bit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rock bit to excavate a rockbed by a transmitted force from rotation and strikes by a hammer device, whereby the bit replacing works can be simplified and the costs of excavating works can be suppressed. SOLUTION: A rock bit is inserted in a cylinder of a hammer device having a piston to make piston motions within the cylinder and excavates a rockbed with a rotational force and striking forces transmitted from the hammer device. The arrangement includes three parts dividedly, i.e., a transmission part 2f to transmit the torque of the hammer device, a shank 2 having a surface to be strucken 2c receiving strikes of the piston, and a head body 15 to perform excavation, and therein the head body 15 is removably mounted on the shank 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lock bit attached to a hammer device and used for drilling holes in rock or the like by rotation or impact.

[0002]

2. Description of the Related Art Conventionally, as a lock bit of this type, as shown in FIG. 5, a tip 3 of a carbide tip is provided on the lower surface and the outer periphery of a head 31 at the tip of a lock bit body 30 integrally formed.
3, ... used a large number of things.

The lock bit is inserted into the hammer device 25, and the lock bit main body 30 is rotated by the rotation of the hammer device itself via the transmission portion 32 of the lock bit main body 30, and at the same time, the lock bit of the hammer device 25 is rotated. The piston 28 provided inside repeats the vertical movement of the piston and strikes the struck surface 30a of the lock bit body 30, so that the lock bit body 30 transmits a striking force to the rock. That is, the rock bit body 30 excavates by hitting the rock while performing a rotary motion.

[0004] Here, the actual crushing and excavation of the rock mass is performed by using a chip attached to the head 31 of the lock bit body 30.
Since the chips 33,... Are made of a super-hard material, the rock having a lower hardness than the chips 33,.

The pulverized material, which has been pulverized and removed, is discharged upward by air pressure through a concave groove 34 vertically recessed on the outer periphery of the head 31, and the lock bit is moved downward by the pressing force of the hammer device. The drilling is continued by pushing into.

[0006]

However, no matter how the tip 33 is made of a super-hard material, the tip 33 is crushed and crushed by the impact reaction force from the rock and the friction with the rock.
Or, the wear may lead to a decrease in the excavating ability, and the head 31 without the excavating ability may be damaged and sometimes damaged by the pressing by the crushed rock and the friction by the crushed material.

Therefore, a lock bit having a reduced excavation ability has to be replaced, but the work of removing the lock bit itself from the hammer device requires a great deal of labor, and the lock bit itself requires material cost and transmission. Since the cost of processing the parts, heads, and the like is considerably expensive, there has been a problem that the cost for the excavation work is enormous.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and it is possible to simplify the removal work at the time of replacing a lock bit having a reduced excavation ability and to reduce the cost of excavation work. It is an object to provide a lock bit that can be used.

[0009]

In order to solve the above-mentioned problems, a lock bit according to the present invention comprises a cylindrical body of a hammer device 25 having a piston 28 which performs a piston motion inside a cylindrical body 26.
In a lock bit inserted into 26 and excavating the rock by the rotational force and the impact force transmitted from the hammer device 25, a transmitting portion 2f for transmitting the rotational force of the hammer device 25, and the piston 28 A shank 2 having an impact surface 2c to be hit and a head body 15 for excavation are provided separately, and the head body 15 is detachably attached to the shank 2. .

In the lock bit according to the present invention having the above-described structure, the rotation of the hammer device 25 causes the torque to be transmitted to the transmission portion 2f of the shank 2 and the piston to rotate.
By the impact of 28, the impact force is transmitted to the impacted surface 2c of the shank 2, and the transmission force of the rotational force and the impact force is also transmitted to the head body 15 attached to the shank 2. The head body 15 excavates rock.

When the excavating ability is reduced by using the head body 15 for a long time, only the head body 15 is removed and replaced without removing the lock bit itself from the hammer device 25. By attaching a new head body 15 to the shank 2 that is still inserted, the replacement operation can be simplified.

Further, even if the shank 2 is of one type, holes of various diameters can be excavated by attaching head bodies 15 of various diameters to the shank 2.

Further, in the lock bit according to the present invention, a first contact surface 2a is formed at an end of the shank 2 on the side of the head main body 15, and the first contact surface is formed. Face 2a
A hole 2e is formed in the hole, and a second contact surface 2b is formed at the bottom of the hole 2e.
The first contact surface 15a is formed on the shank 2 so as to contact the first contact surface 2a of the shank 2.
a from the fitting portion 15c fitted into the fitting hole 2e of the shank 2.
And the end of the fitting portion 15c is fitted with the first contact surface 2a of the shank 2 and the first contact surface 15a of the head body 15 in contact with each other. A configuration in which a second contact surface 15b is formed so as to contact the second contact surface 2b of the hole 2e may be employed.

In the lock bit according to the second aspect of the present invention, the shank 2 and the head body 15 abut at two places, that is, the first contact surface 2a of the shank 2 and the first abutment of the head body 15. Contact with contact surface 15a and shank 2
The fitting portion 15 between the second contact surface 2b of the fitting hole 2e and the head body 15
c, the striking force transmitted to the shank 2 can be reliably transmitted to the head body 15, and the striking force of the piston 28 is evenly distributed on the two surfaces. It is possible to prevent the shank 2 from being damaged without generating excessive stress concentration on the shank 2.

In the lock bit according to the present invention, a female thread 7 is formed in the fitting hole 2e of the shank 2 and a fitting portion of the head main body 15 is formed.
15c is formed with a male thread portion 22 and the female thread portion 7 is formed.
And the external thread portion 22 can be configured to be tightened in the same direction as the rotation of the hammer device 25.

In the lock bit according to the third aspect of the present invention, the head body 15 is fixed to the shank 2 by screwing, and the head body 15 is inadvertently moved. The head body 15 can be securely fixed to the shank 2 without being detached from the shank 2 and with a stronger tightening force of the screw obtained by the rotating action of the hammer device.

Further, in the lock bit according to the present invention, the female thread portion 7 and the male thread portion 22
A screw configuration in which the peaks and valleys of the screw are curved can be employed.

[0018] In the lock bit according to the fourth aspect, the shank 2 and the head main body 15 are provided.
, And the thread is not damaged or broken by the impact force of the impact of the piston 28.

Further, the lock bit according to the present invention is characterized in that the shank 2 is provided with the shank 2.
An air hole 6 is formed along the axis of the head body 15 so that the head body 15 communicates with the air hole 6.
A configuration in which an air hole 19 is formed may be employed.

In the lock bit according to the fifth aspect of the present invention, the coolant air supplied from the hammer device is supplied to the lock bit excavation surface via the air hole 6 of the shank 2 and the air hole 19 of the head body 15. As a result, the head body 15 of the lock bit can be cooled and the crushed material can be discharged.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 or FIG. 3, reference numeral 1 denotes a lock bit body of the present embodiment, which comprises a shank 2 inserted into a hammer device and a head 15 body, and the head 15 body is detachably attached to the shank 2. I have.
Here, the shank 2 is made of a material having a higher hardness than the head body 15.

The shank 2 has an enlarged diameter portion 2d, a transmission portion 2f having an outer diameter smaller than the enlarged diameter portion 2d, and an outer diameter smaller than the transmission portion 2f in the axial direction from the mounting side of the head body 15. It is composed of a multi-stage cylindrical integrally formed member having a small holding portion 2g.

A first contact surface 2a is formed at an end of the enlarged diameter portion 2d, and a fitting hole 2e is formed in the first contact surface 2a. 2e is formed concentrically with the enlarged diameter portion 2d, and a second contact surface 2b is formed at the bottom of the fitting hole 2e. Further, a hole 8 for inserting a jig when the head body 15 is attached or detached is formed in the outer peripheral surface of the enlarged diameter portion 2d.

An internal thread 7 is formed in the fitting hole 2e, and the thread shape of the internal thread 7 is substantially the same as that of a circular screw in which the peaks and valleys of the screw are formed by curves. The thread of the thread is not an acute angle like a triangular thread.

A spline 3 is provided on the outer peripheral surface of the transmission portion 2f.
Are formed in the axial direction, and the rotation of the hammer device 25 is transmitted by the engagement of the spline 3 with the hammer device 25.

A keyway 4 for engaging with the hammer device 25 is formed in the holding portion 2g in the axial direction.
Further, a hit surface 2c is formed at an end of the holding portion 2g, and the piston 28 of the hammer device 25 is formed on the hit surface 2c.
Get hit by.

Reference numeral 5 denotes an abutment surface formed at a step portion between the enlarged diameter portion 2d and the transmission portion 2f, and the hammer device 25 is used when the lock bit body 1 is inserted into the hammer device 25.
This is for locking the end surface of the 25 cylindrical body 26.

At the center of the shank 2, an air hole 6 is formed as a passage for the coolant air, penetrating from the enlarged diameter portion 2 d to the holding portion 2 g, and the coolant passing through the air hole 6 is formed. The air is supplied to a head body 15 described later.

The head body 15 detachably attached to the shank 2 has a first contact surface 15 for contacting the first contact surface 2a of the shank 2 on the shank 2 side.
a is formed, and a fitting portion 15c for fitting into the fitting hole 2e of the shank 2 protrudes from the first contact surface 15a. The fitting portion 15c is provided concentrically with the head main body 15, similarly to the fitting hole 2e. With the head main body 15 attached to the shank 2, the shank 2 and the head main body 15 are concentric. It has become.

Further, at the end of the fitting portion 15c, the fitting hole is formed in a state where the first contact surface 2a of the shank 2 and the first contact surface 15a of the head body 15 are in contact with each other. A second contact surface 15b is formed so as to contact the second contact surface 2b of 2e.

Reference numeral 22 denotes a male thread portion engraved on the fitting portion 15c. The thread shape of the male thread portion 15 is such that the crests and valleys of the thread are curved like the female thread portion 7. , And are formed at substantially the same pitch as the female thread 7 so as to be screwed with the female thread 7.

Reference numeral 20 denotes an air escape groove recessed in the outer surface of the head body 15, and the air escape groove 20 is provided on the outer periphery of the head body 15 equally.
Reference numeral 20 denotes an outer peripheral surface of the head main body 15, which is formed in the axial direction, and is formed at its lower surface toward the axis, and has an L-shape in a central cross section.

The head body 15 is provided with an air hole 19 passing through the axis and branching and diffusing in the fitting portion 15c. The shape at the center cross section is an inverted Y-shape, and is configured to be connected to the air escape grooves 20, 20,.
The coolant air supplied through the air hole 6 of the shank 2 can blow through the air escape grooves 20, 20,... Through the air hole 19 communicating with the air hole 6, and the air pressure can be reduced. Thereby, the crushed material of the crushed bedrock is also discharged.

21 is the same as the air escape grooves 20, 20,.
Escape groove 2 recessed in the axial direction on the outer periphery of the head body 15
, And the escape grooves 21, 21, ... are the air escape grooves 2
Unlike 0, 20,..., It is not communicated with the air hole 19, and is exclusively for discharging the crushed material of the crushed rock. Are recessed in the middle between the air escape grooves 20, 20,....

Reference numeral 18 denotes a suspension screw, which is formed at the opening of an air hole 19 formed in the head main body 15 and is used to screw a suspension bolt used for transporting the head main body 15, for weight reduction. Conveying a certain head body 15, the head body 15
Is used for attachment to the shank 2 and the like.

Reference numerals 16 and 17 denote chips formed of a super hard material provided on the lower surface and the outer peripheral surface of the head main body 15, and are embedded in the head main body 15 so that a circular portion protrudes. As shown in FIG. 2, a large number of chips are arranged on the lower surface of the head body, and the excavating force of the chips 16, 17 is due to the rotational force of the hammer device 25 and the transmitting force of the striking force.

The present invention is configured as described above. The manner of fixing the shank 2 and the head body 15 will be described below with reference to FIG. When the fitting portion 15c of the head body 15 is fitted into the fitting hole 2e of the shank 2, the first contact surface 2a of the shank 2 and the first contact surface 15a of the head body 15 are provided. Abuts the shank
The second contact surface 2b of the second fitting hole 2e and the second contact surface 15b of the fitting portion 15c of the head main body 15 are in contact with each other, so that two surfaces are in contact.

Further, the shank 2 is formed by screwing the thread portion 7 formed in the fitting hole 2e of the shank 2 with the male thread portion 22 formed in the fitting portion 15c of the head body 15. And the head 15 are securely fixed and integrated.

Since the screw is cut so as to be tightened in the rotation direction of the hammer device 25, if the precision of machining is to be considered, the first abutting surface of the shank 2 is not used.
2a and the first contact surface 15a of the head body 15, and the second contact surface 2b of the shank 2 and the head body 15
For example, if any of the contact surfaces with the second contact surface 15b
Even if a gap of about 0.1 mm is generated, the shank 2 is elastically deformed by the pressing force from the head main body 15 due to the tightening force of the screwing of the screw portions 7 and 22, and the two contact surfaces are Close contact can be achieved without gaps.

During the excavation work, the rotation of the hammer device 25 causes the chips 16 and 1 of the head body 15 to rotate.
7 receives a rotational reaction force from the rock, and the rotational reaction force generates a torsional moment between the shank 2 and the head body 15, and the shank 2 and the head body 15 further act by the action of the torsional moment. It is tightened by a screwing action, and a contact between the first contact surface 2a of the shank 2 and the first contact surface 15a of the head body 15, and the shank 2
The second contact surface 2b of the head body 15
The head and the head body 15 are securely fixed to the shank 2 in a state of contact with the head body b.

The lock bit according to the present embodiment has the above-described configuration. Next, an example of use will be described. As shown in FIG. 3, when the shank 2 and the head main body 15 are engaged with each other by screwing the female thread portion 7 and the male thread portion 15, a first contact surface of the shank 2 is engaged. 2a,
The first contact surface 15a of the head body 15 is in contact, and the second contact surface 2b of the shank 2 is in contact with the second contact surface 15b of the head body 15.

The state in which the shank 2 and the head body 15 are integrated is a lock bit body 1 as shown in FIG.
However, the lock bit 1 body is inserted into the hammer device 25 as shown in FIG.

That is, while the lock bit main body 1 is inserted into the open end of the cylindrical body 26 of the hammer device 25, the contact surface 5 of the shank 2 abuts on the open end surface of the cylindrical body 26 of the hammer device 25. Lock.

When the open end surface of the lock bit body 1 is in contact with the contact surface 5 of the shank 2, the groove provided at the tip inside diameter of the cylindrical body 26 of the hammer device 25 and the lock bit body 1 Spline 3 of transmission part 2f of shank 2
And the cylinder 27 provided inside the hammer device 25 clamps the clamping portion 2g of the shank 2, and the key attached to the cylinder 27 is engaged with the clamping portion 2g.
The lock bit main body 1 does not separate from the hammer device 25 and does not spin inside the hammer device 25 by fitting into the retainer ring.

Thereafter, the hammer device 25 with the lock bit main body 1 inserted therein is moved to a position where excavation is desired, and the hammer device 25 is rotated.

The hammer device 25 that has started rotating movement is
The rotational force is transmitted to the spline 3 of the transmitting portion 2f of the shank 2 of the lock bit main body 1 through the groove of the inner diameter of the housing 26 of the hammer device 25, and the rock bit main body 1 starts excavation while rotating.

The rotational force is transmitted to the lock bit main body 1 and, at the same time, the struck surface 2 c of the shank 2 of the lock bit main body 1 is moved to the cylinder 27 of the hammer device 25.
The striking force is transmitted to the lock bit main body 1 by being hit by the piston 28 which makes a vertical piston motion in the rock bit, and the rock bit main body 1 applies a striking force to the rock to crush the rock.

The crushed rock mass crushed by the rotational force and the impact force of the lock bit body 1 is removed by the hammer device.
Coolant air supplied from 25 pistons 28 is blown through the air holes 6 and 19, and the pulverized material flows through the air escape grooves 20, 20, ... and the escape grooves 21, 21, ... with the coolant air. The chips 16 and 17 will be continuously excavated with new rock.

The lock bit main body 1 used as described above, no matter how the tips 16 and 17 are made of a super hard material, the tip 16 and 17 may be formed by the reaction force against the rock and the friction with the rock. When the head body 15 without digging ability is damaged by the pressing by the crushed rock and the friction by the crushed material, The head body 15 must be replaced.To remove the head body 15, the shank 2 and the head body 15 can be removed by using a hydraulic device and rotating the head body 15 in a state where the shank 2 is fixed. And the head body 15 can be moved by using the hanging screw 18.

In the above-described state, the hammer device 25 is in a state in which only the shank 2 is inserted. Of course, the shank 2 can be used repeatedly, and another head body 15 is mounted. In this case, the hammer device 25 may be carried out while holding the shank 2 therebetween.

As described above, in this embodiment, since only the head body 15 can be easily attached and detached, the replacement work can be simplified and the excavation cost can be reduced.

During the excavation work, the lock bit main body 1 is provided with the shank 2 and the head main body 15 divided, but in the present embodiment, the head main body 15 is connected to the shank 2 and the two Since they are in close contact with each other, the impact force transmitted from the hammer device 25 to the shank 2, that is, the rotational force and the impact force, can be reliably transmitted to the head body 15.

Further, since the impact force is evenly distributed to the two contact surfaces, the expanded portion 2 of the shank 2
d) Concentration of internal stress at corners and corners of the inner diameter portion can be avoided, and breakage of the shank 2 can be prevented.

The thread shape of the female thread portion 7 and the male thread portion 22 is such that the thread and the groove are continuous in a circular shape, and is similar to a circular thread. Has a higher screw strength than triangular or trapezoidal shaped ones, and does not cause screw breakage due to impact force during excavation work.

The present invention is not limited to the above-described embodiment, and the design can be changed as appropriate. That is, in the embodiment of the present invention, the fixing between the shank 2 and the head main body 15 is performed by screwing the screws. However, with the head main body 15 attached to the shank 2, the shank 2 and the head main body 15 are fixed. A pin may be inserted into a hole communicating with the main body 15 to fix the same, or the shank 2 and the head main body 15 may be fixed with bolts or the like. Is the shank
The fixing means for fixing the shank 2 and the head main body 15 is not limited as long as the shank 2 is not separated from the shank 2.

In the embodiment of the present invention, the female screw 7
The thread shape of the external thread portion 22 is such that the crests and valleys of the thread are curved, and has a shape similar to a circular screw, but the thread shape is a triangle, a trapezoid, or the like. But it can be adopted.

[0057]

As described above, in the lock bit according to the present invention, the head main body having the shank and the tip is provided separately, and the lock main body is used by fitting the head main body to the shank. It is not necessary to remove the lock bit itself, and only the head body needs to be replaced, so that the replacement operation can be simplified and the cost can be reduced. Also, holes of various diameters can be excavated by mounting head bodies of various diameters, and rocks of various hardness can be excavated by mounting head bodies provided with chips of different materials.

According to the lock bit of the present invention, the head body can be securely brought into close contact with the shank on two surfaces, and the striking force from the piston can be transmitted at the same time as the striking force from the piston. Can be evenly distributed on the two surfaces, without causing excessive stress concentration on the shank,
No breakage of the shank can occur.

Further, the lock bit according to claim 3 is
A screw portion is provided, and by screwing the screw portion, the head main body can be securely fixed to the shank, and the screw portion is configured such that the screw portions are tightened in the rotation direction of the hammer device. Therefore, the shank and the head main body can be securely fixed by the rotation of the hammer device, and the head main body does not accidentally come off from the shank.

According to a fourth aspect of the present invention, in the lock bit, the screw portion has substantially the same shape as a circular screw, and a strong tightening force between the shank and the head main body and an impact due to the impact of the piston. The thread will not be damaged or broken by the force.

Furthermore, the lock bit according to claim 5 is
In the fixed state of the shank and the head main body, since the air holes communicate with each other, the coolant air supplied from the hammer device reaches the lock bit excavation surface, and the cooling of the head main body of the lock bit and the discharge of the crushed material are performed. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention and including a partial cross section of a lock bit main body.

FIG. 2 is a bottom view of the head body according to the embodiment.

FIG. 3 is an essential part cross-sectional view showing a state where the head main body is fitted to the shank of the embodiment.

FIG. 4 is a partial cross-sectional front view showing a use state of the lock bit body of the embodiment.

FIG. 5 is a front view including a partial cross section of a conventional lock bit main body.

[Explanation of symbols]

1 ... lock bit body, 2 ... shank, 7 ... female thread,
15… Head body, 16,17… Tip, 22… Male thread, 25…
Hammer equipment

Claims (5)

[Claims] 1. A rotary force transmitted from the hammer device (25), which is inserted into a cylinder (26) of a hammer device (25) having a piston (28) performing a piston motion inside the cylinder (26). A rock bit for excavating rock with a striking force, comprising a transmitting portion (2f) for transmitting the rotational force of the hammer device (25), and a struck surface (2c) to be struck by the piston (28). A lock characterized in that a shank (2) and a head body (15) for digging are provided separately, and the head body (15) is detachably attached to the shank (2). bit. 2. The head body (1) is attached to the shank (2).
5) A first contact surface (2a) is formed at the side end, and a fitting hole (2e) is formed in the first contact surface (2a). )
A second contact surface (2b) is formed on the bottom, and the head body (15) has a first contact surface that contacts the first contact surface (2a) of the shank (2). Surface (15a) is formed,
From the first contact surface (15a) to the fitting hole (2e) of the shank (2)
The fitting portion (15c) that fits into the
5c), the first contact surface (2a) of the shank (2)
The second contact surface (15b) that contacts the second contact surface (2b) of the fitting hole (2e) with the first contact surface (15a) of the head body (15) in contact with the second contact surface (15b). The lock bit according to claim 1, wherein the lock bit is formed. 3. A female thread (7) is formed in a fitting hole (2e) of the shank (2), and a female thread (7c) is formed in a fitting part (15c) of the head body (15). A screw part (22) is engraved, and the female screw part (7) and the male screw part (22) are hammered (2).
The lock bit according to claim 2, wherein the lock bit is configured to be tightened in the same direction as the rotation of (5). 4. The female thread (7) and the male thread (22).
The lock bit according to claim 3, wherein the lock bit is a screw in which the ridges and valleys of the screw are formed in a curved shape. 5. The shank (2) includes the shank (2).
An air hole (6) is formed along the axis of the head body (15), and an air hole (19) is formed in the head body (15) so as to communicate with the air hole (6). Item 5. The lock bit according to items 1 to 4.