JP4151167B2 - Tilt movable bit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inclined movable bit for cutting a natural ground at a front portion of a shield body.
[0002]
[Prior art]
The shield machine is constructed by attaching a cutter for cutting a natural ground to a shield body composed of a shield frame formed in a cylindrical shape and a partition wall that divides the inside of the shield frame back and forth so as to be able to rotate forward and backward. Yes. The cutter has a plurality of cutter spokes that extend radially from the rotating shaft portion, and is driven in a forward rotation direction or a reverse rotation direction by a drive motor. A cutter bit is attached to the cutter pork.
[0003]
An example of a conventional cutter bit is shown in FIG. As shown in the figure, the cutter pork 51 includes a forward rotation bit 52 having a blade portion in the forward rotation direction A of the cutter and a reverse rotation bit 53 having a blade portion in the reverse rotation direction B of the cutter. Attached along the direction.
[0004]
The forward rotation bit 52 and the reverse rotation bit 53 are swingably attached to both ends of a holder 54 extending forward from the cutter pork 51 via pins 55, respectively.
[0005]
[Problems to be solved by the invention]
However, in the above-described cutter bit, since the forward rotation bit 52 and the reverse rotation bit 53 are respectively attached to both ends of the holder 54, the distance between the bits 52 and 53 is large. Therefore, in order to secure the depth of cut, it is necessary to increase the backlash of the mounting seat for swinging the bits 52 and 53, so that the cutting earth and sand between the bits 52 and 53 and the holder 54 is increased. As a result, there is a problem that the bits 52 and 53 do not oscillate.
[0006]
In addition, when the earth and sand to be cut is a highly viscous soil layer, the earth and sand cut may adhere between the bits 52 and 53. However, if the distance between the bits 52 and 53 is large, the amount of earth and sand to be attached is large. For this reason, the area where the face surface comes in contact with the attached earth and sand becomes large, and large friction occurs. For this reason, a large amount of rotational torque is required for the drive motor, resulting in a problem that the excavation speed is reduced or the excavation is stopped.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides a holder provided on a cutter rotating body that rotates forward and backward, and each head provided on the holder so as to be swingable in the circumferential direction of the cutter rotating body via a pin. Are formed in a rocking direction at intervals in a double-headed shank, a pair of cemented carbide chips respectively provided on the heads of the shank, and a rocker abutting on the shank provided on the holder. A stopper for regulating the angle, and a sediment flow path for releasing the cut sediment that has entered between the shank and the stopper is formed in the holder .
[0008]
According to the said structure, the distance between each carbide | carbonized_material chip | tip can be made small by providing a pair of carbide | carbonized_material chip in each head of a double-headed type | mold shank. Therefore, since the cutting depth of the face can be secured by only slightly swinging the shank, the play of the holder can be reduced, and foreign matter such as cutting earth and sand can be prevented from entering. Further, since the amount of earth and sand adhering between the carbide bits is small, the friction with the face surface is small, and an increase in rotational torque can be prevented. Moreover, the cut earth and sand which entered between the shank and the stopper are released through the earth and sand channel.
[0009]
A recess having a V-shaped cross section is preferably formed between the cemented carbide chips of the shank .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment for carrying out the present invention will be described with reference to the accompanying drawings.
[0011]
1 is a radial side view showing an embodiment of a tilting movable bit according to the present invention, FIG. 2 is a circumferential side view showing an embodiment of a tilting movable bit according to the present invention, and FIG. 3 is a shield machine. It is side sectional drawing which showed the whole structure.
[0012]
First, the overall configuration of the shield machine will be described with reference to FIG.
[0013]
As shown in the figure, the shield machine 1 has a shield body 4 including a shield frame 2 formed in a cylindrical shape and a partition wall 3 that partitions the inside of the shield frame 2 back and forth. The shield frame 2 is provided with a propulsion jack 6 that takes the reaction force of the existing segment 5 and advances the shield body 4, and the partition 3 is attached with a screw conveyor 7 that conveys the cut earth and sand into the mine.
[0014]
A cutter rotator 9 that is driven in the forward rotation direction or the reverse rotation direction by switching the rotation direction of the drive motor 8 is attached to the partition wall 3. The cutter rotating body 9 includes a bearing 13 provided in the partition wall 3, a rotating shaft 10 supported by the bearing 13, a mounting seat 11 provided at the front end thereof, and a predetermined interval in the circumferential direction from the mounting seat 11. And a cut-out pork 12 extending radially outward with a gap therebetween.
[0015]
Next, the configuration of the tilting movable bit 14 according to the present invention will be described.
[0016]
As shown in FIGS. 1 and 2, the tilting movable bit 14 is provided with a holder 15 extending from the cutter pork 12 of the cutter rotating body 9 toward the front end side. The holder 15 is formed in a pair of brackets spaced at a predetermined interval in the radial direction, and is welded to the front surface of the cutter pork 12.
[0017]
Near the front end of the holder 15, a shank 17 is provided via a pin 16 so as to be swingable in the circumferential direction of the cutter rotating body. The shank 17 is integrally formed in a double-headed shape in which the heads 18a and 18b are spaced apart in the swinging direction.
[0018]
A pair of cemented carbide tips 19a and 19b for cutting the face are provided on the heads 18a and 18b of the shank 17, respectively. Each of these cemented carbide tips 19a, 19b is arranged so as to open toward the tip side and have a V shape, and a blade portion 21 is formed at the tip.
[0019]
Further, a recess 20 having a V-shaped cross section is formed between the carbide chips 19a and 19b of the shank 17. The V-shape of the recess 20 is shallower than the V-shape formed by the respective carbide tips 19a and 19b.
[0020]
The holder 15 is provided with a stopper 22 that abuts against the shank 17 and regulates its swing angle. The stopper 22 is composed of two rod bodies 23 spanned between the holders 15 at a predetermined interval rearward from the upper and lower ends of the rear end (right side in FIG. 1) of the shank 17.
[0021]
As a result, when the shank 17 rotates about the pin 16, the one abutting portion 24 at the rear end moves through the gap with the stopper 22 and is stopped by abutting against the one stopper 22. The swing angle is determined.
[0022]
In addition, a space between the rods 23 and a space between the pair of holders 15 form a sediment flow path 25 for escaping the cut sediment that has entered between the shank 17 and the stopper 22.
[0023]
A plurality of tilting movable bits 14 having the above-described configuration are provided on the cutter pork 12 at a predetermined interval in the radial direction.
[0024]
Next, the operation of the tilting movable bit 14 configured as described above will be described.
[0025]
As shown in FIG. 4, when the cutter rotating body 9 is driven in the normal rotation direction A (left side in the figure) with the tilting movable bit 14 in contact with the face surface 26, the carbide tip 19a on the left side in the figure becomes the face surface. 26, the shank 17 rotates around the pin 16 by the reaction force, and each of the carbide tips 19a and 19b tilts backward in the rotation direction (right side in the figure), and the carbide tip 19b on the right side in the figure becomes the face. It is forcibly and reliably spaced from the surface 26.
[0026]
At this time, the shank 17 comes into contact with the rod body 23 on the right side in the figure, the contact portion 24 of which is the stopper 22, and is fixed at an appropriate angle.
[0027]
Since the recess 20 is formed between the carbide tips 19a and 19b of the shank 17, the cutting earth and sand cut by the carbide tip 19a on the left side in the drawing is appropriately drawn by the negative pressure generated on the recess 20 side and cut. Efficiency is improved. The drawn cutting earth and sand escapes backward in the rotational direction (right side in the figure) from the gap between the carbide tip 19b on the right side and the face surface 26 in the figure. This makes it difficult for the cut soil to adhere between the carbide tips 19a and 19b.
[0028]
In the inclined movable bit 14, the distance between the carbide tips 19 a and 19 b can be reduced (specifically, about 160 mm) by integrally forming the shank 17 with a double-headed shape. As a result, even if cutting earth and sand adhere to the recess 20, the amount of earth and sand is small, so that friction with the face surface 26 is small, and an increase in rotational torque can be prevented. Accordingly, it is possible to prevent a decrease in the excavation speed and stop of the excavation.
[0029]
In addition, when the cut earth and sand are adhered between the cemented carbide chips 19a and 19b, most of them are adhered to the inner side of the line connecting the tips of the blade portions 21, but the cemented carbide behind the cutter rotating body 9 in the rotational direction. Since the tip 19b is separated from the face surface 26, a portion in contact with the face surface 26 can be further reduced, and friction can be further reduced.
[0030]
Furthermore, by providing the shank 17 in the vicinity of the front end portion of the holder 15 via the pin 16, the cutting depth s of the face surface 26 can be secured at a small swing angle. Therefore, the play of the holder 15 can be reduced, and the distance between the shank 17 and the stopper 22 is reduced (specifically, about 0.5 to 1.2 mm). Therefore, foreign matter such as cutting earth and sand can be prevented from entering between them, and the swinging of the shank 17 when the cutter rotating body 9 is reversed is not hindered.
[0031]
In addition, even if earth and sand having a small particle diameter enter between the shank 17 and the stopper 22, it can be released through the earth and sand channel 25 as shown by the arrow in FIG.
[0032]
Since the tilt movable bit 1 is formed integrally with the shank 17, the structure becomes simple, the number of parts can be reduced, the number of attachment steps can be reduced, and manufacturing labor and cost can be reduced.
[0033]
【The invention's effect】
In short, according to the present invention, by providing a pair of carbide tips on each head of the double-headed shank, the distance between each carbide tip can be reduced and the shank can be swung slightly. Since the cutting depth of the face can be ensured, the play of the holder can be reduced, and foreign matter such as cutting earth and sand can be prevented from entering. Moreover, since the amount of earth and sand adhering between the cemented carbide bits is small, the friction with the face surface is small, and an excellent effect of preventing an increase in rotational torque is exhibited.
[Brief description of the drawings]
FIG. 1 is a radial side view showing an embodiment of an inclined movable bit according to the present invention.
FIG. 2 is a circumferential side view showing an embodiment of an inclined movable bit according to the present invention.
FIG. 3 is a side sectional view showing the overall configuration of the shield machine.
FIG. 4 is an enlarged side view of an essential part showing a cutting state of an inclined movable bit.
FIG. 5 is a radial side view showing a conventional cutter bit.
[Explanation of symbols]
9 Cutter Rotating Body 15 Holder 16 Pin 17 Shank 18 Head 19 Carbide Tip 22 Stopper 25 Sediment Channel

Claims (2)

A holder provided on the cutter rotating body that rotates forward and backward, and a swingable movement in the circumferential direction of the cutter rotating body via pins on the holder, and each head is formed at intervals in the swinging direction. A double-headed shank, a pair of carbide tips provided on each head of the shank, and a stopper provided on the holder to abut against the shank and restrict its swing angle ;
An inclined movable bit characterized in that an earth and sand passage for escaping cutting earth and sand entering between the shank and the stopper is formed in the holder . The tilting movable bit according to claim 1, wherein a concave portion having a V-shaped cross section is formed between the cemented carbide chips of the shank .

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