JP2007046439A - Rotating mechanism and excavator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanism forming a generally polygonal route while reducing the run-out and vibration of a drive system and the cost of the drive system. <P>SOLUTION: This rotating mechanism comprises a fixed bearing 31 having an annular inner peripheral part 311 around a predetermined fixed centerline P, an annular shaft 32 having an inner peripheral part 321 and an outer peripheral part 322 around a predetermined moving centerline G parallel with the fixed centerline and fitted into the bearing with the outer peripheral part in engageable contact with the inner peripheral part of the bearing, a rotating shaft 33 installed rotatably around the fixed centerline and having the outer peripheral part 331 in engageable contact with the inner peripheral part of the annular shaft, a holding member 37 fitted in the annular shaft in such a manner that is rotated around the moving centerline and supporting the rotating shaft to hold the engagement of the outer peripheral part of the rotating shaft with the inner peripheral part of the annular shaft, a drive part rotatingly driving the rotating shaft, and vane members 21 of a quantity reduced by one from the number of corners of the specified regular polygonal shape installed on the annular shaft, radially extending from the moving centerline by the same length at equal angular intervals in the regular polygonal shape around the fixed centerline. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotation mechanism that forms a substantially polygonal locus, and an excavator that excavates the ground and the like using the rotation mechanism.

  A general excavator is known in which a cutter head is rotated by a rotating mechanism and the ground is excavated by the cutter head. Such an excavator inevitably has a circular cross-section because the cutter head rotates about a predetermined center. However, tunnel use spaces such as railways and roads often have a substantially rectangular cross section, and a substantially rectangular space such as a railway or road is constructed within the circular excavation cross section. For this reason, since excavation more than utilization space is performed, in addition to requiring a lot of land area, there exists a problem that construction cost increases.

  2. Description of the Related Art Conventionally, there is a square drilling device for forming a square hole in a workpiece by providing a cutting tool on a roulau triangle rotating body, which is a roulau triangle, and rotating the roulau triangle rotating body (for example, Patent Documents). 1).

  In addition, there is an excavator in which a machining member is attached to a machining member rotation support device so as to be rotatable about its center, and the machining member rotation support device is attached to the machining member revolution support device. The processed member is provided with an excavation working surface by providing excavation blades at the apexes of substantially equilateral triangles concentric with the center and inward thereof. The processed member rotation support device is attached to the processed member revolving support device so that the center rotates at a radius ((1/2) / cos30 ° − (1/2)) times one side of the equilateral triangle. is there. And the drive means which revolves 3 times in the direction opposite to the rotation direction while rotating a process member is provided (for example, refer patent document 2).

  In addition, a circular arc centered on each vertex of the regular triangle and having the length of one side as a radius is drawn on the outside of each opposite side, and a cutter having an outline of a Rouleau triangle surrounded by these three circular arcs is defined as a rectangle. There is a rectangular shield method in which excavation is performed by rotating while revolving around the central axis of the shape skin plate. The eccentric distance of the rotation axis of the cutter with respect to the center axis of the skin plate is set so as to satisfy (L / 2) / cos 30 ° − (L / 2) (L: distance between vertices of the Rouleau triangle). Further, the revolution number of the cutter is three times the revolution number, and the revolution direction and the revolution direction are opposite directions (see, for example, Patent Document 3).

JP-A-11-267950 JP-A-1-158196 Japanese Patent No. 2926125

  By the way, when excavating into a substantially rectangular shape by using the Rouleau triangle, it is necessary to rotate the Rouleau triangle around its center of gravity and revolve the center of gravity of the Rouleau triangle around the center of the square.

  In the invention of Patent Document 1, a shaft for transmitting the torque of the motor and a shaft at the center of gravity of the Rouleau triangle rotating body are connected by a universal joint. However, in this configuration, rotational vibration and vibration are generated in the drive transmission system, and in an excavator that requires a larger torque, the universal joint is expensive and the manufacturing cost increases.

  In the invention of Patent Document 2, a revolution device is configured by transmitting torque from a motor to a machining member by a crankshaft. However, a shearing force and a bending moment are generated on the crankshaft, which causes rotational shake and vibration. Furthermore, in the invention of Patent Document 2, the Reuleaux triangle is revolved without using a square frame, but the radius of revolution of the Reuleaux triangle is ((1/2) / cos30 ° − (1 / 2)) It is set to double. However, in this case, each side of the substantially rectangular cross section to be excavated is formed in a concave shape toward the inside of the hole. The excavated hole thus excavated is not preferable because the strength is mechanically reduced.

  In the invention of Patent Document 3, a revolution drive board is provided at the center of a rectangular skin plate, and a cutter rotation shaft is provided on the revolution drive board. A motor for rotating the revolution drive board and a motor for rotating the cutter rotating shaft are provided. However, since the motor for rotating the cutter rotating shaft is provided on the revolution drive board, it is necessary to design the wiring and pipes after careful examination. Furthermore, it is necessary to synchronize by adjusting the rotation speed and rotation direction of each motor. As a result, the design cost increases. Furthermore, in the invention of Patent Document 3, the eccentric distance between the center of the cutter rotation shaft and the center of the revolution drive panel is (L / 2) / cos 30 ° − (L / 2). However, in this case, each side of the substantially rectangular cross section excavated in the same manner as the invention of Patent Document 2 described above is not preferable because it is formed in a concave shape toward the inside of the hole.

  As described above, although there is an application for a rotation mechanism that uses the principle of the Rouleau triangle to form a substantially rectangular locus, none of them realizes smooth driving. Further, in excavators that require a large torque, a square frame requires a large space in the excavation hole, so a mechanism without a square frame is desired. Furthermore, there is no realization of a rotating mechanism that forms a polygonal locus including a rectangular shape and an excavator using the rotating mechanism, not limited to rectangular excavation.

  In view of the above circumstances, the present invention reduces the rotational shake and vibration of the drive system without requiring a frame such as a square frame, and reduces the cost of the drive system, and forms a substantially polygonal trajectory. An object of the present invention is to provide an excavator that can realize excavation of a substantially polygonal cross section having mechanical strength using the rotating mechanism. Furthermore, the present invention uses the principle of the Rouleau triangle without requiring a square frame, reduces the rotational shake and vibration of the drive system, reduces the cost of the drive system, and has a substantially rectangular shape that is mechanically strong. An object of the present invention is to provide an excavator capable of realizing cross-section excavation.

  In order to achieve the above object, a rotating mechanism according to claim 1 of the present invention includes a fixed bearing having an annular inner periphery centered on a predetermined fixed center line, and a predetermined parallel to the fixed center line. An annular shaft having an inner peripheral portion and an outer peripheral portion centering on the moving center line, and formed in an annular shape, the outer peripheral portion being in contact with and engaging with the inner peripheral portion of the bearing; A rotation shaft that is rotatably provided with the fixed center line as a rotation center and that is in contact with and engages with the inner periphery of the annular shaft, and rotates about the movement center line. In the aspect, the inner peripheral portion of the bearing and the annular shaft are supported in the annular shaft and support the rotary shaft while maintaining the engagement between the outer peripheral portion of the rotary shaft and the inner peripheral portion of the annular shaft. A holding member that holds the engagement with the outer peripheral portion, a drive unit that rotationally drives the rotating shaft, and the fixed center line Within the contour of the desired regular polygonal shape as the center, the number of the regular polygonal shape reduced by one is provided on the annular shaft, and the same angle is equal while extending radially from the moving center line. And a blade member arranged in length.

  The rotating mechanism according to a second aspect of the present invention is the rotary mechanism according to the first aspect, wherein the radius of the inner peripheral portion of the bearing is [R], the radius of the outer peripheral portion of the annular shaft is [R ′], and the moving center line When the length of the blade member is [L] and a regular n-square shape is desired, n ≧ 3, R: R ′ = n: (n−1), L ≧ R × (n + 1) / n It is characterized by setting.

  An excavator according to a third aspect of the present invention uses the rotating mechanism according to the first or second aspect to support the bearing and to have a cylindrical body portion in which the driving portion is disposed, and the blade member And a drilling cutter provided with a cutter.

  In order to achieve the above object, an excavator according to a fourth aspect of the present invention includes a fixed bearing having an annular inner periphery centered on a predetermined fixed center line, and a predetermined moving center line. An annular shaft having an inner peripheral portion and an outer peripheral portion formed in an annular shape and abutting and engaging the outer peripheral portion with the inner peripheral portion of the bearing, and rotating the fixed center line A rotating shaft provided rotatably as a center and having its outer peripheral portion abuttingly engaged with an inner peripheral portion of the annular shaft; and provided on the moving center line with respect to the outer peripheral portion of the rotating shaft. A central axis that abuts and engages its outer peripheral part, and an outer peripheral part that has the same outer peripheral part as the rotary shaft, and abuts and engages the outer peripheral part with the inner peripheral part of the annular shaft and the outer peripheral part of the central axis A plurality of driven shafts, a drive unit that rotationally drives the rotating shaft, and a center provided on the moving center line provided on the annular shaft Characterized in that a drilling cutter disposed along the extension line connecting the at least the center and vertex within Reuleaux triangle ranging placed.

  The excavator according to claim 5 of the present invention is the excavator according to claim 4, wherein the distance from the center of the rotating shaft to the center of the central axis is [r], and the diameter of the inner peripheral portion of the bearing is [8r], The diameter of the outer peripheral portion of the annular shaft is set to [6r], the diameter of the inner peripheral portion of the annular shaft is set to [diameter of rotating shaft + 2r], and the outer width of the roulau triangle of the excavation cutter is set to [a]. As an extension line connecting the center and apex of the Rouleau triangle where the excavation cutter is arranged is set as [0.5a + r].

  The excavator according to a sixth aspect of the present invention is the excavator according to the fifth aspect, wherein the distance [r] from the center of the rotating shaft to the center of the central axis is equal to the outer width [a] of the rouleau triangle in the excavating cutter. The eccentricity is set as 6% to 8%.

  According to the present invention, by transmitting the driving force of the driving unit to the rotating shaft, the rotating shaft rotates about the fixed center line of the bearing. Then, the annular shaft engaged with the outer peripheral portion of the rotating shaft rotates in the same direction as the rotating shaft around the movement center line. In addition, since the outer peripheral portion of the annular shaft that rotates about the moving center line is engaged with the inner peripheral portion of the bearing, the rotary shaft rotates around the fixed center line of the bearing along the inner peripheral portion of the bearing. It will rotate in the opposite direction (revolution). For this reason, the tip of the blade member provided on the annular shaft moves as the annular shaft rotates. The tip of the moving blade member can form a substantially polygonal locus. And if it is set as the excavator provided with the excavation cutter which arrange | positioned the cutter to the blade member, it can excavate a substantially regular polygon-shaped excavation hole.

  The rotating shaft is driven to rotate about the fixed center line of the bearing, and the annular shaft rotates about the moving center line in a form held by the holding member as the rotating shaft rotates. As a result, the rotating shaft rotates on the fixed center line of the bearing without shifting its axis, so that rotational shake and vibration can be reduced. Further, since the annular shaft rotates around the moving center line in a form held by the holding member as the rotating shaft rotates, a conventional universal joint is not required between the rotating shaft and the annular shaft. Costs relating to the universal joint can be reduced.

  Further, the rotation mechanism has a positive n-angle, where [R] is the radius of the inner peripheral portion of the bearing, [R ′] is the radius of the outer peripheral portion of the annular shaft, and [L] is the length of the blade member from the moving center line. When the shape is desired, n ≧ 3, R: R ′ = n: (n−1), and L ≧ R × (n + 1) / n are set. As a result, a substantially regular polygonal locus can be formed in a convex shape with each side parallel or outward. Further, as the length of the blade member is increased, the locus of a regular polygonal shape close to a circle is obtained. And if this locus is excavated with an excavator, an excavation hole having mechanical strength can be obtained. When the moving center line, the fixed center line, and the tip of the blade member are aligned in this order, the tip of the blade member is at the center of one side of the regular polygon, and the side and the straight line are orthogonal to each other. To do.

  In the excavator according to the present invention, the rotary shaft is driven to rotate about the fixed center line of the bearing, and the annular shaft is supported by the rotary shaft, the central shaft and the driven shaft as the rotary shaft rotates. Rotate around the center line. As a result, the rotating shaft rotates on the fixed center line without shifting its axis, so that rotational shake and vibration can be reduced. Further, the annular shaft rotates around the movement center line in a form supported by the rotating shaft and the driven shaft as the rotating shaft rotates. For this reason, since a conventional universal joint is not required between the rotating shaft and the annular shaft, it is possible to reduce the cost of the universal joint, and further, without requiring a Rouleau triangle and a circumscribed square frame. Drilling holes with a substantially rectangular cross section can be drilled.

  In the excavator described above, the distance from the center of the rotating shaft (fixed center line) to the center of the center axis (moving center line) is [r], and the diameter of the inner peripheral portion of the bearing is [8r]. The diameter of the outer peripheral portion 322 is set to [6r], the diameter of the inner peripheral portion of the annular shaft is set to [diameter of the rotating shaft + 2r], and the outer width of the rouleau triangle in the excavation cutter (one side of the square section to be excavated) Is set to [0.5a + r], and the center of the rotation axis is located on this extension line. By making the direction of the extended line coincide with the direction of one side of the square, it is possible to excavate an ideal substantially rectangular section of the excavation hole.

  Further, in the excavator described above, the distance [r] from the center of the rotation axis (fixed center line) to the center of the center axis (movement center line) is 6% to the outer width [a] of the rouleau triangle in the excavation cutter. By setting the eccentric amount as 8%, the excavated excavation hole is mechanically strong because each side of the substantially rectangular cross section is formed in parallel or convex toward the outside of the excavation hole. It will be a thing. Further, by appropriately changing the amount of eccentricity, it is possible to obtain an excavation hole having a substantially rectangular cross section as required.

[Embodiment 1]
Exemplary embodiments of a rotating mechanism and an excavator according to the present invention will be explained below in detail with reference to the accompanying drawings. The present invention is not limited to the first embodiment.

  FIG. 1 is a schematic side view showing a first embodiment of an excavator using a rotating mechanism according to the present invention, FIG. 2 is a conceptual view of the rotating mechanism shown in FIG. 1 viewed from the axial direction (forward direction), and FIG. It is a disassembled perspective view of the rotation mechanism shown in FIG.

  As shown in FIG. 1, the excavator includes a trunk portion 1 and a excavation cutter 2. The trunk portion 1 drives the excavation cutter 2 while supporting the excavation cutter 2. The trunk portion 1 forms an outline of the excavator and includes a rotating mechanism 3 in a cylindrical shape.

  The rotation mechanism 3 includes a bearing 31, an annular shaft 32, a rotation shaft 33, a holding member 37, and a drive unit 36.

  The bearing 31 is fixed to the body part 1 and has an annular inner peripheral part 311 with a predetermined fixed center line P arranged along the front-rear direction of the body part 1 as a center.

  The annular shaft 32 has an inner peripheral portion 321 and an outer peripheral portion 322 centered on a predetermined movement center line G arranged along the front-rear direction of the body portion 1 in parallel with the fixed center line P, and is substantially annular. It is formed. The annular shaft 32 is housed inside the annular shape of the bearing 31, and the outer peripheral portion 322 is in contact with and engaged with the inner peripheral portion 311 of the bearing 31. The annular shaft 32 has a configuration in which an annular body integrally including an inner peripheral portion 321 and an outer peripheral portion 322, or a tubular body having the inner peripheral portion 321 and a tubular body having the outer peripheral portion 322 are combined. Can do.

  The rotary shaft 33 is supported on the body 1 so as to be rotatable about the fixed center line P of the bearing 31 as a rotation center. The rotating shaft 33 is provided inside the annular shaft 32, and a substantially cylindrical outer peripheral portion 331 is in contact with and engaged with the inner peripheral portion 321 of the annular shaft 32.

  The holding member 37 has a disk shape with a predetermined thickness and has substantially the same outer periphery as the inner periphery of the annular shaft 32, and is slidably contacted with the inner periphery of the annular shaft 32 and rotates around the movement center line G. It is mounted on the annular shaft in a moving manner. In addition, the holding member 37 is provided with an eccentric insertion hole 371 having an inner periphery substantially the same as the outer periphery of the rotation shaft 33 with the fixed center line P as the center. The rotation shaft 33 is inserted into and supported by the insertion hole 371 so as to be rotatable. That is, the holding member 37 is inserted through the rotary shaft 33 so as to be rotatable, and always holds the engagement between the outer peripheral portion 331 of the rotary shaft 33 and the inner peripheral portion 321 of the annular shaft 32.

  The drive unit 36 rotates the rotary shaft 33 and includes a drive source provided in the body 1 such as a motor. The drive unit 36 may have a speed reduction mechanism as appropriate between the drive source and the rotary shaft 33, although not shown in the figure.

  The engagement between the bearing 31 and the annular shaft 32 and the engagement between the annular shaft 32 and the rotary shaft 33 include, for example, engagement by gear meshing. Or the engagement by which contact slip was prevented via the high friction material etc. may be sufficient.

  The excavation cutter 2 includes a blade member 21 provided at the front end of an annular shaft 32 extending to the front side of the trunk portion 1. The blade member 21 is provided on the annular shaft 32 with a number obtained by subtracting one from the number of the regular polygonal shape within the contour of the desired regular polygon centered on the fixed centerline P. While extending in the radial direction, they are disposed at the same angle and at the same length. For example, when the desired regular polygonal shape is a regular square as shown in FIG. 2, the number of blade members is three, and the tip T is brought into contact with the contour of the regular square centered on the fixed center line P. Thus, they extend from the movement center line G in the radial direction and are arranged at the same angle and the same length. And the excavation cutter 2 is comprised by providing an excavation bit (not shown) in the front surface of a blade | wing member. Further, when the moving center line G, the fixed center line P, and the tip T of the excavation cutter 2 are arranged in a straight line in this order, the tip T of the excavation cutter 2 is at the center of one side of a desired regular polygon shape. This side and the straight line are orthogonal to each other.

  Here, the dimension setting which concerns on the said bearing 31, the annular shaft 32, the rotating shaft 33, and the excavation cutter 2 (blade member 21) is demonstrated. As shown in FIG. 2, the radius of the inner peripheral portion 311 of the bearing 31 is [R], the radius of the outer peripheral portion 322 of the annular shaft 32 is [R ′], and the length of the blade member 21 from the moving center line G is [L]. ], When a desired n-angle shape is desired, n ≧ 3, R: R ′ = n: (n−1), and L ≧ R × (n + 1) / n. The amount of eccentricity [r] from the fixed center line P to the moving center line G is r = R−R ′.

  The excavator having the above configuration transmits the driving force of the driving unit 36 to the rotating shaft 33 in the rotating mechanism 3, whereby the rotating shaft 33 rotates around the fixed center line P of the bearing 31 (for example, the clockwise direction in FIG. 2). ) Then, the annular shaft 32 that engages with the outer peripheral portion 331 of the rotating shaft 33 rotates in the same direction as the rotating shaft 33 (for example, the clockwise direction in FIG. 2) about the movement center line G. At this time, the holding member 37 rotates about the movement center line G and allows the rotation of the rotation shaft 33, thereby engaging the outer periphery 331 of the rotation shaft 33 and the inner periphery 321 of the annular shaft 32. Always hold the match. That is, the annular shaft 32 rotates around the movement center line G in a form held by the holding member 37 as the rotation shaft 33 rotates. Further, the annular shaft 32 that rotates about the movement center line G has an outer peripheral portion 322 engaged with an inner peripheral portion 311 of the bearing 31, and therefore, the bearing 31 extends along the inner peripheral portion 311 of the bearing 31. A rotary motion (revolution) is performed around the fixed center line P in the direction opposite to the rotation shaft 33 (for example, counterclockwise in FIG. 2). For this reason, the excavation cutter 2 (blade member 21) provided on the annular shaft 32 rotates and revolves as the annular shaft 32 rotates. The tip T of the excavating cutter 2 that moves moves in a desired regular polygonal shape (regular n-square shape).

  Specifically, as illustrated in FIGS. 4 to 8 for a regular quadrangular shape (n = 4), when the annular shaft 32 revolves around the fixed center line P, the annular shaft 32 moves toward the moving center line G. Rotate around 1/3. Accordingly, as shown by the movement position of the tip T (A, B, C) of the excavation cutter 2 in FIGS. 4 to 8, the excavation cutter 2 similarly revolves and rotates, and as shown in FIG. ). As a result, it is possible to excavate the excavation hole H having a substantially square cross section. Since this excavation hole H can be obtained by excavating only the use space without excavating unnecessary space, compared with a general excavation hole having a circular cross section, it does not require an unnecessarily large land area. Construction costs can be reduced.

  Furthermore, since the annular shaft 32 provided with the excavation cutter 2 is configured to revolve and rotate in a form held by the holding member 37, a Louro triangular shape is formed in a square frame having one side of the outer width of the Rouleau triangle as before. There is no need to support and rotate the shaft. That is, a square frame is not necessary. For this reason, it becomes possible to form the outline of the body part 1 of an excavator small in front view with respect to the cross-sectional shape of the excavated drill hole H. As a result, since the trunk portion 1 can pass through the excavation hole H that the excavation cutter 2 has excavated in advance, it is possible to obtain an excavator that excavates the excavation hole H having a substantially rectangular excavation cross section. Since the excavator excavates the excavation hole H having a substantially rectangular cross section with a simple mechanism as described above, the excavator is less likely to fail, has high reliability, and does not increase cost.

  The excavation hole H excavated by the excavator having the above-described configuration has rounded corners of a substantially rectangular cross section. The digging hole H having a rounded cross section and a substantially rectangular shape is suitable for excavation because stress concentration at the corner can be reduced as compared with a rectangular cross section.

  By the way, in the excavator having the above-described configuration, a plurality of rotating mechanisms 3 are provided so that the rotation shafts 33 are parallel to each other, and the trajectories of the excavation cutters 2 of the mutual rotating mechanisms 3 are adjacent to each other in an overlapping manner in front view. The position of the excavation cutter 2 is shifted in the axial direction of the rotary shaft 33. If comprised in this way, it becomes possible to obtain the excavation hole H of the substantially rectangular excavation cross section which continued the excavation cross section of the substantially square shape continuously. In addition, when a plurality of rotating mechanisms 3 are provided so that the rotation shafts 33 are parallel and the trajectories of the excavation cutters 2 of the respective rotation mechanisms 3 overlap in a front view, the adjacent excavation cutters 2 are the same. The adjacent rotating shafts 33 are rotated in the reverse direction while being arranged on the surface. Even if comprised in this way, it becomes possible to obtain the excavation hole H of the substantially rectangular excavation cross-section which continued the excavation cross-section of the substantially square shape continuously.

  In other words, it becomes possible to perform excavation of a substantially rectangular excavation section in which a plurality of excavation holes H having an approximately regular quadrangular excavation section are continuously connected. Further, by arranging the front surfaces of the excavation cutters 2 on the same plane, it becomes possible to excavate the excavated tip portion evenly without unevenness.

  Hereinafter, the eccentric amount [r], which is the distance from the fixed center line P to the movement center line G in the rotation mechanism 3 described above, will be described.

  As described above, when the rotating shaft 33 rotates, the annular shaft 32 that engages with the outer peripheral portion 331 of the rotating shaft 33 revolves and moves the movement center line G that is the center thereof along a predetermined trajectory. When excavating the excavation hole H having a substantially regular polygonal cross section, the movement locus of the center of the rotation shaft 33 (fixed center line P) with respect to the movement center line G that is the center of the annular shaft 32 including the excavation cutter 2 is It is substantially circular, and the eccentricity r = R−R ′ of the radius can be obtained from the following equation.

  That is, for example, the excavation cutter 2 (blade member 21) having a desired regular hexagonal shape (regular n-corner shape) is radially (n−1) = (6−6) from the movement center line G as shown in FIG. 1) = 5. The mutual angle of each excavation cutter 2 (blade member 21) is 2θ. This θ is expressed by the following formula 1.

  When the height of the regular n-corner is D and the length (G to T) of the excavation cutter 2 is L, the following formula 2 is obtained from the cosine theorem of an isosceles triangle with three sides L, L, D. It is done.

  That is, the height D of the regular n-corner shape is twice the length from the center (fixed center line P) of the regular n-corner shape to the center of the side, as shown in the following formula 3.

  Then, assuming that the center of the height D (fixed center line P) is the rotation center, the amount of eccentricity r = R−R ′ with respect to the movement center line G is obtained by the following equations 4 and 5.

  Note that L is set to be equal to or larger than the value obtained here so that the sides of the regular polygon are not recessed inward. Further, the length a of one side of the regular n-corner shape is obtained by the following formula 6.

  Further, the length (circumscribed circle radius) b from the apex to the center of the regular n-corner shape is obtained by the following formula 7.

  Thus, from the radius R of the inner peripheral portion 311 of the fixed bearing 31 and the radius R ′ of the outer peripheral portion 322 of the annular shaft 32 inscribed in the inner peripheral portion 311, the eccentricity r = R−R ′ is obtained. The length L of the excavation cutter 2 (blade member 21), the length a of one side of the regular n-corner shape, and the circumscribed circle radius b of the regular n-corner shape are obtained by Equations 5 to 7. On the contrary, when a and b are set, the eccentricity r is obtained from Equation 6 or Equation 7, L is obtained from Equation 1, and R and R 'are obtained from Equation 8, Equation 9, and Equation 10 below.

  As described above, the ratio of the radius R of the inner peripheral portion 311 of the bearing 31 to the radius R ′ of the outer peripheral portion 322 of the annular shaft 32 is R: R ′ = n: (n−1). Then, the position of the movement center line G is determined with the fixed center line P as the origin. An excavation cutter 2 (blade member 21) having a length L extends from the movement center line G. For example, in a coordinate system in which the horizontal side of the regular n-corner shape shown in FIG. 2 is the X coordinate and the vertical side is the Y coordinate, the coordinates of the tip T of the excavation cutter 2 are the fixed center line P, the moving center line G, Assuming that the rotation angle of the moving center line G from when the tip T of the cutter 2 is aligned on a straight line is φ, a substantially positive n-corner shape centered on the fixed center line P (see FIG. 2) In the case of a regular square).

  The following is a calculation example applying Formula 5, in which a regular polygonal locus is observed when the rotation mechanism 3 is rotated in a coordinate system in which the horizontal side is the X coordinate and the vertical side is the Y coordinate. FIG. 10 is a diagram showing a regular triangular trajectory, and the unit is m (meter). Here, R = 6 m, R ′ = 4 m, L = 8.4 m, and the eccentricity r = 2 m. Thereby, the excavation hole H of the equilateral triangle cross section shown in FIG. 10 is obtained. As a result, for example, a composite tunnel is used in which the upper part is used for a roadway (two lanes) and the lower part is used for sewerage. Moreover, by making the said shape upside down, it is possible to make it difficult for the excavated ground to collapse even in places where the earth covering is small.

  FIG. 11 is a diagram showing a regular tetragonal locus, and the unit is m (meter). Here, R = 4 m, R ′ = 3 m, L = 8 m, and eccentricity r = 1 m. Thereby, the excavation hole H of the regular square cross section shown in FIG. 11 is obtained. As a result, for example, an effective space such as a road / railway becomes a tunnel having an outer diameter smaller than the circular cross section.

  FIG. 12 is a diagram showing a regular hexagonal locus, and the unit is m (meter). Here, R = 3 m, R ′ = 2.5 m, L = 10 m, and the eccentricity r = 0.5 m. Thereby, the excavation hole H of the regular hexagonal cross section shown in FIG. 12 is obtained. As a result, for example, a honeycomb-shaped underground wall can be obtained by combining regular hexagonal holes constructed by a shaft excavator.

  FIG. 13 is a diagram showing a regular octagonal locus, and the unit is m (meters). Here, R = 2m, R '= 1.75m, L = 9.5m, and the eccentricity r = 0.25m. Thereby, the excavation hole H of a regular octagonal cross section shown in FIG. 13 is obtained.

  The rotating mechanism 3 has a regular polygonal shape in which the direction perpendicular to the straight line is desired in a mode in which the movement center line G, the fixed center line P, and the tip T of the excavation cutter 2 are arranged in a straight line in this order. It becomes the direction of one side. That is, the desired regular polygonal trajectory arrangement is determined by the position setting of the movement center line G, the fixed center line P, and the tip T of the excavation cutter 2. In the case of an excavator, the cross-sectional arrangement of the excavation holes H can be set by adjusting the installation angle according to the positions of the movement center line G, the fixed center line P, and the tip T of the excavation cutter 2.

  As described above, the rotation mechanism 3 described above is centered on the fixed bearing 31 having the annular inner peripheral portion 311 centered on the predetermined fixed center line P and the predetermined movement center line G parallel to the fixed center line P. An annular shaft 32 having an inner peripheral part 321 and an outer peripheral part 322 formed in an annular shape, the outer peripheral part 322 being in contact with and engaging with the inner peripheral part 311 of the bearing 31, A rotation shaft 33 that is rotatably provided with the fixed center line P as a rotation center and that abuts and engages the outer peripheral portion 331 with the inner peripheral portion 321 of the annular shaft 32, and a rotation center line G. The inner periphery of the bearing 31 is mounted on the annular shaft 32 in a moving manner, supports the rotating shaft 33 and maintains the engagement between the outer peripheral portion 331 of the rotating shaft 33 and the inner peripheral portion 321 of the annular shaft 32. Holding member 3 that holds the engagement between the portion 311 and the outer peripheral portion 322 of the annular shaft 32 And a drive unit 36 for rotationally driving the rotary shaft 33, and a number obtained by subtracting one from the number of corners of the regular polygon within the contour of the desired regular polygon centered on the fixed center line P. In addition, an excavation cutter 2 (blade member 21) is provided that extends in the radial direction from the movement center line G and is arranged at the same angle and the same length.

  Then, by transmitting the driving force of the driving unit 36 to the rotating shaft 33, the rotating shaft 33 rotates around the fixed center line P of the bearing 31. Then, the annular shaft 32 that engages with the outer peripheral portion 331 of the rotation shaft 33 rotates about the movement center line G in the same direction as the rotation shaft 33. In addition, the annular shaft 32 that rotates about the movement center line G has an outer peripheral portion 322 engaged with an inner peripheral portion 311 of the bearing 31, so that the bearing 31 extends along the inner peripheral portion 311 of the bearing 31. A rotary motion (revolution) is made around the fixed center line P in the direction opposite to the rotation shaft 33. For this reason, the tip T of the excavation cutter 2 (blade member 21) provided on the annular shaft 32 moves as the annular shaft 32 rotates. The tip T of the excavating cutter 2 that moves moves along a desired regular polygonal trajectory, and an excavation hole H having a substantially regular polygonal cross section is obtained.

  That is, the rotation mechanism 3 is driven in such a manner that the rotation shaft 33 is driven to rotate about the fixed center line P of the bearing 31 and the annular shaft 32 is held by the holding member 37 as the rotation shaft 33 rotates. Rotate around line G. As a result, the rotating shaft 33 rotates on the fixed center line P of the bearing 31 without shifting its axis, so that it is possible to reduce rotational shake and vibration. Further, since the annular shaft 32 rotates around the movement center line G in a form held by the holding member 37 as the rotating shaft 33 rotates, a conventional universal joint is provided between the rotating shaft 33 and the annular shaft 32. Since it does not need, it becomes possible to reduce the cost concerning a universal joint.

  Furthermore, since the annular shaft 32 is rotated around the movement center line G in the form of being held by the holding member 37, it is possible to form a substantially regular polygonal trajectory without requiring a conventional frame. For this reason, it becomes possible to form the outline of the body part 1 of an excavator small in front view with respect to the cross-sectional shape of the excavated drill hole H. As a result, since the trunk portion 1 can pass through the excavation hole H that the excavation cutter 2 has excavated in advance, it is possible to obtain an excavator that excavates the excavation hole H having a substantially polygonal cross section.

  The rotation mechanism 3 has a radius of the inner peripheral portion 311 of the bearing 31 [R], a radius of the outer peripheral portion 322 of the annular shaft 32 [R ′], and the length of the blade member 21 from the moving center line G. [L] is set such that n ≧ 3, R: R ′ = n: (n−1), and L ≧ R × (n + 1) / n when a regular n-corner shape is desired. As a result, the excavated excavation hole H is mechanically strong because each side of the substantially regular polygonal cross section is formed parallel or convex toward the outside of the excavation hole H. Further, if necessary, by adjusting the eccentric amount r = R−R ′ to be small or by adjusting the length L of the blade member 21 to be long, each side of the substantially polygonal cross section is rounded outward. It is possible to obtain an excavation hole H having a different cross-sectional shape.

  Further, since the rotary shaft 33 is rotationally driven at the fixed center line P, it is possible to extend the front end of the rotary shaft 33 to the front side of the excavation cutter 2 and to equip another excavation cutter. As a result, a circular auxiliary excavation hole can be excavated before excavating the excavation hole H having a substantially regular polygonal cross section, or a part of the excavation cross section can be formed into a substantially regular polygonal cross section and the tip can be a circular cross section. it can. Further, if a drilling drill is provided at the front end of the rotary shaft 33, rock drilling can be performed before the drilling hole H is drilled, and the load of drilling can be reduced.

  In addition, when making the middle part of a digging cross section into a substantially regular polygonal cross section and making the tip into a circular cross section, for example, only the pile head of a cast-in-place concrete pile is made into a substantially square cross section, and the remaining lower part is made circular. By doing this, as shown in FIG. 14, only the pile head with a large stress joined to the foundation is made into a substantially square cross section, and interference with the foundation beam and the mat reinforcement arranged in the X and Y directions is prevented. While avoiding, it becomes possible to arrange a large amount of main bars on the pile head. In addition, since it has a substantially square cross section, not only the outer peripheral hoop 100 but also a core hoop 102 having hooks 102a at both ends while securing a space for the tremy tube 101 in the center of the cross section is easily added to increase the shear strength. It is possible to prevent shear failure at the pile head. The conventional pile head with a circular cross section had some increase in yield strength even with the expanded section, but there was a problem of interference with the foundation reinforcement due to the fact that the main reinforcement of the pile heads were lined up on the circumference, to ensure the shear strength. In many cases, the cross-sectional area of the pile head is excessively large, and in the first embodiment, these are fundamentally solved.

  A plurality of rotation mechanisms 3 are provided so that the rotation shafts 33 are parallel, and the positions of the adjacent excavation cutters 2 are rotated in such a manner that the trajectories of the excavation cutters 2 of the rotation mechanisms 3 overlap each other in front view. The shaft 33 is shifted in the axial direction. Alternatively, the adjacent rotary shafts 33 are driven to rotate in opposite directions while the adjacent excavation cutters 2 are arranged on the same plane. If comprised in this way, it is possible to obtain the excavation hole H of the continuous excavation cross section by combining the excavation cross section of a substantially regular polygon shape. Further, by combining the rotation mechanism 3 and the conventional circular excavation rotation mechanism, it is possible to obtain a continuous excavation hole H by combining a polygonal excavation section and a circular excavation section. It is. If the front surfaces of the excavation cutters 2 are arranged on the same plane, the excavated tip portions between the rotary mechanisms 3 can be dug flatly without any unevenness.

  Moreover, since the rotating shaft 33 is positioned and fixed to the fixed center line P, the excavator can be easily obtained by changing the configuration of the front end of the rotating shaft of a conventional excavator to the above-described mechanism. Is possible.

  By the way, in Embodiment 1 mentioned above, the outer peripheral part of the inner peripheral part 311 of the bearing 31 and the outer peripheral part of the annular shaft 32 is always maintained while the engagement between the outer peripheral part 331 of the rotating shaft 33 and the inner peripheral part 321 of the annular shaft 32 is maintained. The holding member 37 that always holds the engagement with the 322 is configured to slidably contact with the inner periphery of the annular shaft 32 and rotate around the movement center line G, and the rotation shaft 33 is inserted and supported to be rotatable. Not only this but the holding member 37 comprised, for example with the center axis | shaft 34 and the driven shaft 35 as shown in FIG. 15 may be sufficient. The central shaft 34 is provided on the movement center line G of the annular shaft 32 and is provided in the annular shape of the annular shaft 32, and the substantially cylindrical outer peripheral portion 341 with respect to the outer peripheral portion 331 of the rotating shaft 33. Abutment engagement. The driven shaft 35 has an outer peripheral portion 351 having the same diameter as that of the rotating shaft 33 and is provided in parallel with the rotating shaft 33. The driven shaft 35 is provided inside the annular shaft 32 and has a substantially cylindrical outer peripheral portion 351. The inner peripheral portion 321 of the annular shaft 32 and the outer peripheral portion 341 of the central shaft 34 are in contact with and engaged with each other. A plurality (two in FIG. 15) of the driven shafts 35 are provided, and the rotation shafts 33 are arranged at intervals of 120 ° with the rotation axis 33 as the center. That is, the annular shaft 32 rotates around the movement center line G in a form held by the rotation shaft 33, the center shaft 34 and the driven shaft 35 as the rotation shaft 33 rotates. Although not clearly shown in the drawing, the rotating shaft 33 is supported and supported by the holding member being engaged between the inner peripheral portion 311 of the bearing 31 and the outer peripheral portion 322 of the annular shaft 32. The engagement between the inner peripheral portion 311 of the bearing 31 and the outer peripheral portion 322 of the annular shaft 32 is maintained while the engagement between the outer peripheral portion 331 of the annular shaft 32 and the inner peripheral portion 321 of the annular shaft 32 is maintained. Such a form may be sufficient. In this case, the holding member (not shown) has a disk shape with a predetermined thickness having substantially the same outer periphery as the inner periphery of the bearing 31, and is in sliding contact with the outer periphery of the annular shaft 32. The bearing 31 is housed in such a manner that it rotates around the center. The holding member (not shown) is eccentrically provided with a through hole having an inner periphery substantially the same as the outer periphery of the annular shaft 32 around the movement center line G. Of course, both the holding member (not shown) and the holding member 37 shown in FIGS. 1 and 15 may be used in combination.

  In the first embodiment described above, an example in which the rotation mechanism 3 is applied to an excavator has been described. However, the rotation mechanism 3 is not limited to an excavator. For example, as another use of the rotating mechanism 3 having a substantially polygonal trajectory, the ground can be used for excavation of a polygonal cross section in an underground continuous wall or by improving the ground by injecting a hardening material such as cement into the ground. Various uses are conceivable, such as when used for kneading and stirring together with a hardener, or for use in cutting polygonal shapes of workpieces, or for stirring for manufacturing kneaded materials other than the ground. That is, when the rotation mechanism 3 is used for ground improvement or kneading and stirring, the blade member 21 is a stirring blade. When the rotating mechanism 3 is used for cutting, the blade member 21 is provided with a cutting blade to form a cutting cutter. Therefore, the excavation in Embodiment 1 of the present invention is used in the meaning including stirring and cutting.

[Embodiment 2]
Hereinafter, a preferred embodiment 2 of an excavator according to the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the second embodiment.

  16 is a schematic side view showing a second embodiment of the excavator according to the present invention, and FIG. 17 is a conceptual view of the excavator shown in FIG. 16 viewed from the axial direction. In the second embodiment, the same reference numerals are given to the same parts as those in the first embodiment.

  As shown in FIG. 16, the excavator includes a trunk portion 1 and an excavation cutter 2 (blade member 21 in the first embodiment). The trunk portion 1 drives the excavation cutter 2 while supporting the excavation cutter 2. The trunk portion 1 forms an outline of the excavator and includes a drive mechanism (the rotation mechanism in the first embodiment) 3 therein. .

  The drive mechanism 3 includes a bearing 31, an annular shaft 32, a rotation shaft 33, a central shaft 34, a driven shaft 35, and a drive unit 36.

  The bearing 31 is fixed to the body part 1 and has an annular inner peripheral part 311 with a predetermined fixed center line P arranged along the front-rear direction of the body part 1 as a center.

  The annular shaft 32 has an inner peripheral portion 321 and an outer peripheral portion 322 centered on a predetermined movement center line G arranged along the front-rear direction of the body portion 1 in parallel with the fixed center line P, and is substantially annular. It is formed. The annular shaft 32 is housed inside the annular shape of the bearing 31, and the outer peripheral portion 322 is in contact with and engaged with the inner peripheral portion 311 of the bearing 31. The annular shaft 32 has a configuration in which an annular body integrally including an inner peripheral portion 321 and an outer peripheral portion 322, or a tubular body having the inner peripheral portion 321 and a tubular body having the outer peripheral portion 322 are combined. Can do.

  The rotary shaft 33 is supported on the body 1 so as to be rotatable about the fixed center line P of the bearing 31 as a rotation center. The rotating shaft 33 is provided inside the annular shaft 32, and a substantially cylindrical outer peripheral portion 331 is in contact with and engaged with the inner peripheral portion 321 of the annular shaft 32.

  The central shaft 34 is provided on the movement center line G of the annular shaft 32. The central shaft 34 is provided inside the annular shaft 32, and a substantially cylindrical outer peripheral portion 341 is in contact with and engaged with the outer peripheral portion 331 of the rotating shaft 33. The central shaft 34 constitutes the holding member 37 in the first embodiment.

  The driven shaft 35 has an outer peripheral portion 351 having the same diameter as the rotating shaft 33 and is provided in parallel with the rotating shaft 33. The driven shaft 35 is provided in the annular shape of the annular shaft 32, and a substantially cylindrical outer peripheral portion 351 is in contact with and engaged with the inner peripheral portion 321 of the annular shaft 32 and the outer peripheral portion 341 of the central shaft 34. . Further, a plurality of driven shafts 35 (two in the second embodiment) are provided, and are arranged at intervals of 120 ° around the movement center line G together with the rotation shaft 33. The driven shaft 35 constitutes the holding member 37 in the first embodiment.

  The drive unit 36 rotates the rotary shaft 33 and includes a drive source provided in the body 1 such as a motor. The drive unit 36 may have a speed reduction mechanism as appropriate between the drive source and the rotary shaft 33, although not shown in the figure.

  The engagement between the bearing 31 and the annular shaft 32, the engagement between the annular shaft 32 and the rotation shaft 33 and the driven shaft 35, and the engagement between the center shaft 34 and the rotation shaft 33 and the driven shaft 35 are, for example, gears. There is engagement by meshing. Or the engagement by which contact slip was prevented via the high friction material etc. may be sufficient.

  The excavation cutter 2 is provided at the front end of the annular shaft 32 extending to the front side of the body portion 1, and is within a range of a virtual roulau triangle having a center (center of gravity) on the movement center line G, They are arranged along an extension line connecting the center (moving center line G) and the vertex (T). Although not shown in the drawing, a drill bit is provided on the front surface of the drill cutter 2. The rouleau triangle has a shape formed by drawing an arc connecting the other vertices with each vertex of the regular triangle as the center as shown by a dashed line in FIG. 17, and the outer width (passing width) is constant. is there.

  Here, the dimension setting of the bearing 31, the annular shaft 32, the rotary shaft 33, the central shaft 34, and the excavation cutter 2 will be described. FIG. 18 is a conceptual diagram showing the dimension setting of the excavator shown in FIG. As shown in FIG. 18, the distance (eccentricity) from the center (fixed center line P) of the rotating shaft 33 to the center (moving center line G) of the center shaft 34 is [r]. The diameter is set to [8r], the diameter of the outer peripheral portion 322 of the annular shaft 32 is set to [6r], and the diameter of the inner peripheral portion 321 of the annular shaft 32 is set to [h (diameter of rotating shaft) + 2r]. And, with the outer width of the roulau triangle of the excavation cutter 2 as [a], an extension line L connecting the center (movement center line G) of the roulau triangle on which the excavation cutter 2 is arranged and the apex T is [L = 0.5a + r]. And set.

  The excavator having the above configuration transmits the driving force of the driving unit 36 to the rotating shaft 33 in the driving mechanism 3 so that the rotating shaft 33 rotates around the fixed center line P of the bearing 31 (for example, the clockwise direction in FIG. 17). ) Then, the center shaft 34 that engages with the outer peripheral portion 331 of the rotation shaft 33 rotates about the movement center line G in the direction opposite to the rotation shaft 33 (for example, counterclockwise in FIG. 17). Further, the driven shaft 35 engaged with the outer peripheral portion 341 of the central shaft 34 rotates in the same direction as the rotating shaft 33 (for example, the clockwise direction in FIG. 17). At the same time, when the rotating shaft 33 rotates, the annular shaft 32 engaged with the outer peripheral portion 331 of the rotating shaft 33 and the outer peripheral portion 351 of the driven shaft 35 is the same as the rotating shaft 33 and the driven shaft 35 around the movement center line G. It rotates in a direction (for example, clockwise direction in FIG. 17). That is, the annular shaft 32 rotates around the movement center line G in a form supported by the rotation shaft 33 and the driven shaft 35 as the rotation shaft 33 rotates. In addition, the annular shaft 32 that rotates about the movement center line G has an outer peripheral portion 322 engaged with an inner peripheral portion 311 of the bearing 31, so that the bearing 31 extends along the inner peripheral portion 311 of the bearing 31. The rotary motion (revolution) is performed around the fixed center line P in the direction opposite to the rotation shaft 33 (for example, counterclockwise in FIG. 17). For this reason, the excavation cutter 2 provided on the annular shaft 32 moves the vertex T of the Rouleau triangle, which is the tip of the excavation cutter 2, as the annular shaft 32 rotates. The tip (vertex T) of the moving excavation cutter 2 forms a substantially rectangular locus close to a square centered on the fixed center line P of the bearing 31 with the outer width of the Rouleau triangle as one side.

  Since the above-described dimension setting is set to “diameter [6r] of outer peripheral portion 322 of annular shaft 32”: “diameter [8r] of inner peripheral portion 311 of bearing 31”, that is, 3: 4, FIG. As shown in FIG. 23, when the annular shaft 32 makes one rotation around the movement center line G, the annular shaft 32 revolves around the fixed center line P by 1/3 rotation. Accordingly, as shown by the movement positions of the tips A, B, and C of the excavation cutter 2 in FIGS.

  As a result, as shown in FIG. 17, it becomes possible to dig up the excavation hole H having a substantially rectangular cross section. Since this excavation hole H can be obtained by excavating only the use space without excavating unnecessary space, compared to the excavation hole having a circular cross section, in addition to not requiring more land area than necessary, the construction cost is reduced. It becomes possible to reduce.

  Further, since the annular shaft 32 provided with the excavation cutter 2 is configured to rotate in a form supported by the rotary shaft 33 and the driven shaft 35, the loop shaft 32 is formed in a square frame with the outer width of the Rouleau triangle as one side as before. There is no need to support and rotate the triangular shaft. That is, a square frame is not necessary. For this reason, it becomes possible to form the outline of the body part 1 of an excavator small in front view with respect to the cross-sectional shape of the excavated drill hole H. As a result, since the trunk portion 1 can pass through the excavation hole H that the excavation cutter 2 has excavated in advance, it is possible to obtain an excavator that excavates the excavation hole H having a substantially rectangular excavation cross section. Since the excavator excavates the excavation hole H having a substantially rectangular cross section with a simple mechanism as described above, the excavator is less likely to fail, has high reliability, and does not increase cost.

  The excavation hole H excavated by the excavator having the above-described configuration has rounded corners of a substantially rectangular cross section. The digging hole H having a rounded cross section and a substantially rectangular shape is suitable for excavation because stress concentration at the corner can be reduced as compared with a rectangular cross section.

  By the way, in the excavator having the above-described configuration, a plurality of excavation cutters 2 are adjacent to each other by the drive mechanism 3 provided with a plurality of rotating shafts 33 in parallel, and the trajectories of the excavation cutters 2 are adjacent to each other in an overlapping manner in front view. The position of the excavation cutter 2 is shifted in the axial direction of the rotary shaft 33. If comprised in this way, it becomes possible to obtain the excavation hole of the substantially rectangular (substantially rectangular shape) excavation cross section which continued the excavation cross section of substantially square (substantially rectangular shape) in series.

  In addition, when a plurality of excavation cutters 2 are adjacent to each other by the drive mechanism 3 provided with a plurality of rotation shafts 33 in parallel, and the trajectories of the excavation cutters 2 are overlapped in front view, the adjacent excavation cutters 2 are The rotating shafts 33 adjacent to each other are rotationally driven in opposite directions while being arranged on the same plane. If comprised in this way, it becomes possible to obtain the excavation hole of the substantially rectangular (substantially rectangular shape) excavation cross section which continued the excavation cross section of substantially square (substantially rectangular shape) in series.

  That is, it becomes possible to perform excavation of a substantially rectangular (substantially rectangular) excavation cross-section in which a plurality of excavation holes H that are substantially square (substantially rectangular) excavation cross-sections are continuously arranged. Further, by arranging the front surfaces of the excavation cutters 2 on the same plane, it becomes possible to excavate the excavated tip portion evenly without unevenness.

  Hereinafter, the distance [r] from the center of the rotating shaft 33 (fixed center line P) to the center of the center axis 34 (moving center line G) in the excavator described above will be described.

  As described above, when the rotating shaft 33 rotates, the annular shaft 32 that engages with the outer peripheral portion 331 of the rotating shaft 33 revolves, and the center of the center shaft 34 (movement center line G) that is the center thereof is predetermined. Move in orbit. Then, when excavating a substantially square excavation hole H, the rotation with respect to the center (moving center line G) of the central axis 34 that is the center (center of gravity) of the rouleau triangle on the virtual rouleau triangle forming the excavation cutter 2. The movement locus of the center of the axis 33 (fixed center line P) is almost circular, and its radius [r] is about 7.7% to 8.2% of the outer width [a] of the virtual rouleau triangle. Is known geometrically.

  That is, as shown in FIG. 24, the Rouleau triangle is rotated in a form inscribed in the square in the coordinate system in which the horizontal side of the square with the outer width [a] of the Rouleau triangle as one side is the X coordinate and the vertical side is the Y coordinate. The locus of the center position of the square (the center of the rotation axis 33 (fixed center line P)) on the Rouleau triangle is observed. In FIG. 24, the trajectory indicated by a broken line is a distance 0 [r] (the amount of eccentricity) between the center of the rotating shaft 33 (fixed center line P) and the center of the center axis 34 (moving center line G). It is constant at 0774a.

  However, the locus shown by the broken line coincides with the locus (shown by the solid line in FIG. 24) of the center position of the square (the center of the rotation axis 33 (fixed center line P)) on the actual Rouleau triangle. There are only three places. And in the case of the locus | trajectory shown with a broken line, each side of the cross section of the substantially rectangular excavation hole H excavated will be formed in a slightly concave shape toward the inner side of the hole. The excavated hole thus excavated is not preferable because the strength is mechanically reduced.

  The locus shown by the solid line includes 0.0816a shown by the following formula 14, and the distance [r] (eccentricity) between the center of the rotating shaft 33 (fixed center line P) and the center of the center axis 34 (moving center line G). Amount) is 0.0774a to 0.0816a.

  Further, the cross section of the substantially rectangular excavation hole H that is excavated as the distance [r] (the amount of eccentricity) between the center of the rotation shaft 33 (fixed center line P) and the center of the center axis 34 (movement center line G) increases. Each side is formed in a concave shape toward the inside of the hole. Therefore, if the distance [r] is 6% to 8% of the outer width [a] of the virtual rouleau triangle, the cross-sectional shape of the excavation hole H to be excavated becomes an ideal substantially rectangular shape.

  Specifically, when the rouleau triangle (excavation cutter 2) rotates 120 ° clockwise from the state shown in FIG. 17, the movement center line G, which is the center of the excavation cutter 2 and the center of gravity of the rouleau triangle, It rotates 360 ° counterclockwise around a fixed center line P that is the center of the rotating shaft 33. Therefore, when the center of the annular shaft 32 (movement center line G) rotates φ with respect to the center (fixed center line P), the excavation cutter 2 rotates −φ / 3 with respect to the center (movement center line G). That is, in the X and Y coordinates of the square, the locus of the tip of the excavation cutter 2 (the vertex of the rouleau triangle) is obtained by the following equations 15 and 16.

  And the locus | trajectory of the front-end | tip of the excavation cutter 2 calculated | required by said Formula 15 and Formula 16 is shown in FIGS. FIG. 25 shows the excavation cutter 2 when the distance [r] (the amount of eccentricity) between the center of the rotating shaft 33 (fixed center line P) and the center of the center shaft 34 (moving center line G) is 0.1a (10%). It can be seen that each side of the cross section of the substantially rectangular excavation hole H is formed in a concave shape toward the inside of the hole.

  FIG. 26 shows the trajectory of the tip of the excavation cutter 2 when the distance [r] (the amount of eccentricity) is 0.09a (0.9%), and each of the cross sections of the substantially rectangular excavation hole H is also excavated. It can be seen that the sides are formed concave toward the inside of the hole.

  FIG. 27 shows the trajectory of the tip of the excavation cutter 2 when the distance [r] (the amount of eccentricity) is 0.085a (0.85%), and each of the cross sections of the substantially rectangular excavation hole H excavated. It can be seen that the sides are formed concave toward the inside of the hole.

  FIG. 28 shows the trajectory of the tip of the excavation cutter 2 when the distance [r] (the amount of eccentricity) is 0.08a (0.8%), and each of the cross sections of the substantially rectangular excavation hole H is also excavated. It can be seen that the sides are formed concave toward the inside of the hole.

  FIG. 29 shows the locus of the tip of the excavation cutter 2 when the distance [r] (the amount of eccentricity) is 0.075a (0.75%), and each side of the cross section of the substantially rectangular excavation hole H is shown. It turns out that it forms substantially parallel.

  FIG. 30 shows the locus of the tip of the excavation cutter 2 when the distance [r] (the amount of eccentricity) is 0.07a (0.7%). Each side of the cross section of the excavated substantially rectangular excavation hole H is shown in FIG. It turns out that it forms in convex shape toward the outer side of a hole.

  FIG. 31 shows the trajectory of the tip of the excavation cutter 2 when the distance [r] (the amount of eccentricity) is 0.065a (0.65%), and each of the cross sections of the substantially rectangular excavation hole H is also excavated. It can be seen that the sides are formed in a convex shape toward the outside of the hole.

  FIG. 32 shows the trajectory of the tip of the excavation cutter 2 when the distance [r] (the amount of eccentricity) is 0.06a (0.6%), and each of the cross sections of the substantially rectangular excavation hole H is excavated. It can be seen that the sides are formed in a convex shape toward the outside of the hole.

  FIG. 33 shows the locus of the tip of the excavation cutter 2 when the distance [r] (the amount of eccentricity) is 0.055a (0.55%), and each side of the cross section of the substantially rectangular excavation hole H is shown. It can be seen that it is formed convex toward the outside of the hole, and the entire excavation hole H is slightly rounded.

  Therefore, in order to obtain a drilling hole H having an ideal cross-sectional shape as shown in FIGS. 25 to 33, the center of the rotating shaft 33 (fixed center line P) and the center of the center axis 34 (moving center line G) It is understood that the distance [r] is preferably 6% to 8% of the outer width [a] of the virtual Rouleau triangle and set as the eccentric amount.

  As described above, the excavator described above includes the fixed bearing 31 having the annular inner peripheral portion 311 centered on the predetermined fixed center line P, the inner peripheral portion 321 and the outer periphery centered on the predetermined moving center line G. An annular shaft 32 which is formed in an annular shape having a portion 322 and whose outer peripheral portion 322 is in contact with and engaged with the inner peripheral portion 311 of the bearing 31 and the fixed center line P of the bearing 31 is The rotary shaft 33 is provided on the rotational center line G of the annular shaft 32 and the rotational shaft 33 provided so as to be rotatable as a center of rotation and abutting and engaging the outer peripheral portion 331 with the inner peripheral portion 321 of the annular shaft 32. The central shaft 34 that abuts and engages its outer peripheral portion 341 with the outer peripheral portion 331 of the rotary shaft 33, and the outer peripheral portion 351 that is the same as the rotary shaft 33. A plurality of followers that are in contact with and engaged with the outer peripheral portion 341 of the portion 321 and the central shaft 34 35, a drive unit 36 that rotationally drives the rotating shaft 33, and an annular shaft 32 provided at least on the center (moving center) within a range of a Rouleau triangle centered on the moving center line G of the annular shaft 32. The excavation cutter 2 is provided along an extension line connecting the line G) and the vertex T.

  Then, by transmitting the driving force of the driving unit 36 to the rotating shaft 33, the rotating shaft 33 rotates around the fixed center line P of the bearing 31. Then, the center shaft 34 that engages with the outer peripheral portion 331 of the rotation shaft 33 rotates about the movement center line G in the direction opposite to the rotation shaft 33. Further, the driven shaft 35 that engages with the outer peripheral portion 341 of the central shaft 34 rotates in the same direction as the rotating shaft 33. At the same time, when the rotating shaft 33 rotates, the annular shaft 32 engaged with the outer peripheral portion 331 of the rotating shaft 33 and the outer peripheral portion 351 of the driven shaft 35 is the same as the rotating shaft 33 and the driven shaft 35 around the movement center line G. Rotate in the direction. In addition, the annular shaft 32 that rotates about the movement center line G has an outer peripheral portion 322 engaged with an inner peripheral portion 311 of the bearing 31, so that the bearing 31 extends along the inner peripheral portion 311 of the bearing 31. A rotary motion (revolution) is made around the fixed center line P in the direction opposite to the rotation shaft 33. For this reason, the excavation cutter 2 provided on the annular shaft 32 moves the vertex T of the Rouleau triangle, which is the tip of the excavation cutter 2, as the annular shaft 32 rotates. The tip (vertex T) of the moving excavation cutter 2 forms a substantially rectangular locus close to a square centered on the fixed center line P of the bearing 31 with the outer width of the Rouleau triangle as one side. As a result, the excavation hole H having a substantially rectangular cross section can be advanced.

  That is, the rotation center 33 is driven to rotate about the fixed center line P of the bearing 31 and the annular shaft 32 is supported by the rotation shaft 33 and the driven shaft 35 as the rotation shaft 33 rotates. It consists only of a rotation mechanism that rotates around G. As a result, the rotating shaft 33 rotates on the fixed center line P of the bearing 31 without shifting its axis, so that it is possible to reduce rotational shake and vibration. Further, since the annular shaft 32 rotates around the movement center line G in a form supported by the rotating shaft 33, the central shaft 34 and the driven shaft 35 as the rotating shaft 33 rotates, the rotating shaft 33 and the annular shaft 32 Since a conventional universal joint is not required, the cost related to the universal joint can be reduced.

  Further, since the annular shaft 32 rotates around the movement center line G in a form supported by the rotating shaft 33, the central shaft 34, and the driven shaft 35 as the rotating shaft 33 rotates, a square frame is not required. The excavation hole H having a rectangular cross section can be excavated.

  Further, since the rotary shaft 33 is rotationally driven at the fixed center line P, if the front end extends to the front side of the excavation cutter 2, it is possible to equip the front end with another excavation cutter. For example, a circular auxiliary excavation hole can be excavated by the excavation cutter provided at the front end of the rotating shaft 33 before excavating the excavation hole H having a substantially rectangular cross section.

  Moreover, since the rotating shaft 33 is positioned and fixed to the fixed center line P, the excavator can be easily obtained by changing the configuration of the front end of the rotating shaft of a conventional excavator to the above-described mechanism. Is possible.

  In the excavator described above, the distance from the center (fixed center line P) of the rotation shaft 33 to the center of the center axis (movement center line G) is [r], and the diameter of the inner peripheral portion 311 of the bearing 31 is [8r]. ], The diameter of the outer peripheral portion 322 of the annular shaft 32 is set to [6r], the diameter of the inner peripheral portion 321 of the annular shaft 32 is set to [diameter of the rotating shaft + 2r], and the outer width of the rouleau triangle of the excavating cutter 2 [A], an extension line connecting the center (movement center line G) of the Rouleau triangle where the excavation cutter 2 is arranged and the apex T was set to [0.5a + r]. As a result, it is possible to excavate an ideal borehole H having a substantially rectangular cross section.

  In the excavator described above, the distance [r] from the center of the rotating shaft 33 (fixed center line P) to the center of the center axis (moving center line G) is set to the outer width [a] of the rouleau triangle in the excavating cutter 2. The eccentric amount was set as 6% to 8%. As a result, the excavated excavation hole H is mechanically strong because each side of the substantially rectangular cross section is formed in parallel or convex toward the outside of the excavation hole H. Further, by appropriately changing the amount of eccentricity, it is possible to obtain an excavation hole H having a substantially rectangular cross section as required.

  In the second embodiment described above, the excavator mainly excavating the ground or the like has been described. However, the above configuration is not limited to the excavator. For example, other applications of the rotating mechanism that has a nearly rectangular trajectory are used for rectangular excavation on underground continuous walls, etc., or the ground is mixed with the hardener by improving the ground by injecting a hardener such as cement into the ground. It can be used for various purposes such as kneading and stirring, rectangular cutting of workpieces, and kneading for manufacturing kneaded materials other than the ground. That is, when using the rotation mechanism for ground improvement or kneading and stirring, the excavator and excavation cutter 2 serve as a stirrer and a stirring blade. Moreover, when using the said rotation mechanism for cutting, the said excavator and excavation cutter 2 become a cutting machine and a cutting cutter. Therefore, in Embodiment 2 of the present invention, excavation is used in the meaning including stirring and cutting.

It is a schematic side view which shows Embodiment 1 of the excavator using the rotation mechanism which concerns on this invention. It is the conceptual diagram which looked at the rotation mechanism shown in FIG. 1 from the axial direction (front direction). It is a disassembled perspective view of the rotation mechanism shown in FIG. It is a conceptual diagram which shows operation | movement of the rotation mechanism shown in FIG. It is a conceptual diagram which shows operation | movement of the rotation mechanism shown in FIG. It is a conceptual diagram which shows operation | movement of the rotation mechanism shown in FIG. It is a conceptual diagram which shows operation | movement of the rotation mechanism shown in FIG. It is a conceptual diagram which shows operation | movement of the rotation mechanism shown in FIG. It is a conceptual diagram for calculating the amount of eccentricity. It is a figure which shows the locus | trajectory of an equilateral triangle shape. It is a figure which shows a regular tetragonal locus. It is a figure which shows the locus | trajectory of a regular hexagon shape. It is a figure which shows the locus | trajectory of a regular octagon shape. It is a conceptual diagram which illustrates the pile head made into the substantially square-shaped cross section. It is a conceptual diagram which shows another holding member. 1 is a schematic side view showing an embodiment of an excavator according to the present invention. It is the conceptual diagram which looked at the excavator shown in FIG. 16 from the axial direction. It is a conceptual diagram which shows the dimension setting of the excavator shown in FIG. It is a conceptual diagram which shows operation | movement of the excavator shown in FIG. It is a conceptual diagram which shows operation | movement of the excavator shown in FIG. It is a conceptual diagram which shows operation | movement of the excavator shown in FIG. It is a conceptual diagram which shows operation | movement of the excavator shown in FIG. It is a conceptual diagram which shows operation | movement of the excavator shown in FIG. It is a figure which shows the locus | trajectory of the center position of the square on a virtual roulau triangle. It is a figure which shows the locus | trajectory of the front-end | tip of a digging cutter. It is a figure which shows the locus | trajectory of the front-end | tip of a digging cutter. It is a figure which shows the locus | trajectory of the front-end | tip of a digging cutter. It is a figure which shows the locus | trajectory of the front-end | tip of a digging cutter. It is a figure which shows the locus | trajectory of the front-end | tip of a digging cutter. It is a figure which shows the locus | trajectory of the front-end | tip of a digging cutter. It is a figure which shows the locus | trajectory of the front-end | tip of a digging cutter. It is a figure which shows the locus | trajectory of the front-end | tip of a digging cutter. It is a figure which shows the locus | trajectory of the front-end | tip of a digging cutter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 trunk | drum 2 excavation cutter 21 blade | wing member 3 rotation mechanism (drive mechanism)
31 Bearing 311 Inner peripheral portion 32 Annular shaft 321 Inner peripheral portion 322 Outer peripheral portion 33 Rotating shaft 331 Outer peripheral portion 34 Center shaft 341 Outer peripheral portion 35 Driven shaft 351 Outer peripheral portion 36 Drive portion 37 Holding member 371 Insertion hole 100 Outer peripheral hoop 101 Tremy tube 102 Core hoop 102a Hook a Outer width b Outer circle radius r Eccentricity G Movement center line H Drilling hole L Length of blade member from movement center line P Fixed center line R Radius of inner circumference of bearing R ' Radius of the outer periphery T Tip of the blade member (vertex)

Claims (6)

A fixed bearing having an annular inner periphery centered on a predetermined fixed center line;
An inner peripheral portion and an outer peripheral portion centered on a predetermined movement center line parallel to the fixed center line are formed in an annular shape, and the outer peripheral portion is brought into contact with and engaged with the inner peripheral portion of the bearing. An annular shaft built in the bearing;
A rotating shaft provided rotatably about the fixed center line as a center of rotation and having its outer peripheral portion abuttingly engaged with the inner peripheral portion of the annular shaft;
While being mounted on the annular shaft so as to rotate around the movement center line, the rotating shaft is supported and the engagement between the outer peripheral portion of the rotating shaft and the inner peripheral portion of the annular shaft is maintained. A holding member that holds the engagement between the inner periphery of the bearing and the outer periphery of the annular shaft;
A drive unit that rotationally drives the rotary shaft;
Within the contour of the desired regular polygon centered on the fixed center line, a number obtained by subtracting one from the number of corners of the regular polygon shape is provided on the annular shaft and extends radially from the moving center line. And a vane member arranged at the same angle and at the same length.   A desired n-square shape is desired, where the radius of the inner peripheral portion of the bearing is [R], the radius of the outer peripheral portion of the annular shaft is [R '], and the length of the blade member from the moving center line is [L]. The rotation mechanism according to claim 1, wherein n ≧ 3, R: R ′ = n: (n−1), and L ≧ R × (n + 1) / n are set. Using the rotation mechanism according to claim 1 or 2,
A cylindrical body portion that supports the bearing and has the driving portion disposed therein;
An excavator comprising: an excavation cutter in which a cutter is disposed on the blade member. A fixed bearing having an annular inner periphery centered on a predetermined fixed center line;
An annular shaft having an inner peripheral portion and an outer peripheral portion centered on a predetermined movement center line, which is formed in an annular shape, the outer peripheral portion being in contact with and engaging with the inner peripheral portion of the bearing When,
A rotating shaft provided rotatably about the fixed center line as a center of rotation and having its outer peripheral portion abuttingly engaged with the inner peripheral portion of the annular shaft;
A central axis provided on the moving center line and abutting and engaging with the outer peripheral portion of the rotary shaft;
A plurality of driven shafts having the same outer peripheral portion as the rotating shaft and abutting and engaging the outer peripheral portion with the inner peripheral portion of the annular shaft and the outer peripheral portion of the central shaft;
A drive unit that rotationally drives the rotary shaft;
A drilling cutter provided on the annular shaft and disposed along an extended line connecting at least the center and the apex within a range of a Rouleau triangle centered on the moving centerline. Machine.   The distance from the center of the rotating shaft to the center of the central axis is [r], the diameter of the inner peripheral portion of the bearing is [8r], the diameter of the outer peripheral portion of the annular shaft is [6r], and the annular shaft The diameter of the inner periphery is set to [diameter of rotating shaft + 2r], and the outer width of the roulau triangle of the excavation cutter is set to [a] and the extension connecting the center and apex of the roulau triangle where the excavation cutter is arranged The excavator according to claim 4, wherein the line is set to [0.5a + r].   The distance [r] from the center of the rotation axis to the center of the center axis is set as an eccentric amount as 6% to 8% of the outer width [a] of the Rouleau triangle in the excavation cutter. 5. The excavator according to 5.

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