JPS6168998A - Vibration absorber in vibration type excavator for method ofpropelling construction - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention particularly relates to a vibration absorbing device for a vibrating excavation device for a propulsion method for burying a very small diameter pipe of 200 mm or less in diameter.

[Prior art]

Currently, in order to bury ready-made pipes with a diameter of 800 mm or less, instead of the conventional cut-and-cover method, the mainstream is a propulsion method in which the buried pipe itself is propelled by a propulsion device, such as a hydraulic cylinder, installed in the starting shaft circle.

A vibrating excavation device is considered to be used in this propulsion method. Figure 5 is a diagram showing a conventional vibrating excavation device used in the propulsion method. In the figure, 1 is soil, 2 is a starting shaft provided within ±1, 3 is a propulsion cylinder provided within the starting shaft 2, 4 is a buried pipe, and the rear part of the buried pipe 4 is the propulsion cylinder 3.
is being pushed by 5 is a vibrating excavation device disposed at the top position of the buried pipe 4. This vibrating excavation device 5 is
It is composed of a head 6, a main body 7, and a vibration absorbing device 10 interposed between the head 6 and the main body 7. For example, an exciter 8 having a built-in eccentric weight 81 is provided in the head 6, and a drive motor 9 is installed at the rear of the exciter 8.
is provided, and the rotating shaft of the drive motor 9 and the shaft of the eccentric weight 81 of the exciter 8 are connected. As a result,
When the drive motor 9 is driven, the eccentric weight 81 rotates and centrifugal force is generated.

The centrifugal force causes the head 6 to vibrate (
transverse vibration) is given. The vibration absorbing device] 0 is composed of a plurality of small diameter rods 101 arranged on a concentric circle parallel to the propulsion shaft, and prevents the transverse vibration of the head 6 from being transmitted to the main body 7 and further to the buried pipe 4. The propulsion force is transmitted to the head 6, and it is flexible in the direction perpendicular to the propulsion direction and rigid in the propulsion direction. 11
Reference numeral 12 denotes a liquid supply device provided in the starting shaft, and 12 a liquid supply port provided at the head position of the head 6. The liquid supplied from the liquid supply device 11 can be supplied to the front surface of the head 6.

14 is a U-shaped elastic seal, for example, and the seal 14 prevents the slurry 13 from entering the inside of the apparatus.

In such a vibrating excavation device, when the drive motor 9 is driven to generate lateral vibration in the head 6 and liquid is supplied from the liquid supply port 12, ±1 in the vicinity of the front surface of the head 6 is mixed with the liquid due to the lateral vibration. - Stir to form a slurry. This slurry 13 passes through an annular gap between the buried pipe 4 and the ±1 provided by the hole expansion caused by the lateral vibration of the head 6, and is collected in the starting shaft. As a result, -, ±1 near the Rad6# plane
The strength of the buried pipe 4 is reduced, and the frictional force acting on the side surface of the buried pipe 4 is also reduced, making it possible to propel the excavation device 5 and the buried pipe 4 by simply applying a small propulsion force from the propulsion cylinder 3.

Some propulsion methods are progressing toward smaller diameters, and it is considered that the above-mentioned vibrating excavation device can be used to propel buried pipes 4 with a diameter of 200 mm or less (hereinafter referred to as extremely small diameter). There is. Therefore, the present inventor developed a vibrating excavation device for the propulsion method for burying the extremely small diameter pipe 4 (Japanese Patent Application No. 59-1082).
No. 81) was invented first.

As shown in Fig. 6, this vibrating excavation device is equipped with an exciter 8
constitutes the head 6 itself, and the head 6
(8) An eccentric weight 81 is built in the cylindrical portion 80, and the rear end shaft of the eccentric weight 81 is rotatably attached to the cylindrical portion 80 via a bearing 82. The inner diameter of this cylindrical portion 80 and the diameter of the eccentric weight 81 are made the same, and the eccentric weight 81 is configured to slide and rotate within the cylindrical portion. and eccentric weight 8
Even if the outer diameter of 1 is not the same, the eccentric weight 81 is
Any material that can slide within 0 is sufficient. - 10,000, the drive motor 9 that was attached to the exciter is attached to the main body 7, and between the rotational axis of the drive motor 9 and the axis of the eccentric weight 81, a spring is installed, for example, and the axis is perpendicular to the axis. A flexible coupling 16 that is soft and capable of transmitting rotational force is interposed in the direction. Liquid supply passages 15 and 15' are formed in the cylindrical portion 80 of the head 6 (8) and the outer surface of the main body 7.

A vibration absorbing device 10 composed of a plurality of small diameter rods 101 as shown in the previous example is interposed between the cylindrical portion 80 and the main body 7. Further, the head 6 and the main body 7 are provided with a seal 14 for preventing the intrusion of the slurry 13, and a seal 17 inside.The seal 17 follows the relative displacement between the head 6 and the main body 7 due to the lateral vibration of the head 6. The part sandwiched between the seals 14 and 17 is the liquid supply passage 1.
5, forms part of 15'.

With such a configuration, the above-mentioned more advanced digging method is possible. In addition, by reducing the number of components of the head 6, which is the vibrating part, by using the vibrator 8 as the head 6 itself and attaching the drive motor 9 to the main body 7, the weight can be reduced and the eccentric weight 81 By making the outer diameter of the excavation device 5 as large as possible, the extreme decrease in the excitation force due to the smaller outer diameter of the excavation device 5 is compensated for. Thereby, sufficient vibration can be applied to the head 6 (8), and by increasing the vibration, digging efficiency is also improved.

However, in the case of a conventional vibrating excavation device with a large diameter as shown in FIG. 5, the exciter 8 and the vibration absorber 10 can be arranged coaxially and in parallel, whereas in the case of a conventional vibrating excavation device with a large diameter as shown in FIG. In the case of a vibrating excavation device, the cylindrical portion 80 of the head 6 (8) and the vibration absorbing device 10 are coaxially arranged in series in order to suppress the outer diameter of the excavation device 5 and to obtain an effective vibrational force. It has to be placed on top.

Here, the performance of the vibration absorbing device 10 configured with the small diameter rod lO1 will be considered. When the head 6 (8) is vibrating laterally, the small diameter rod 101 is deformed such that both ends thereof move in parallel, as shown in FIG. The deflection δ1 in this case is expressed as follows, and from equation (1), the spring constant in the direction perpendicular to the axis is
is 2πE d 1In K1-16t3 °゛°°°°°°゛°°°゛°°
°°°°°゛°°°°°°°°°“°°°°°” (2)
becomes. Also, 2 is the spring constant in the axial direction, πd2E k2= ......Mountain...
・・・・・・・・・・・・・・・・・・・・・・・・
...(3) It is expressed as t, and the ratio of both spring constants is as follows.9 If the diameter d of the small diameter rod 101 is made smaller and the length t is increased, it becomes easily rigid in the axial direction and perpendicular to the axis. Flexible properties can be obtained in the direction.

Partly focusing on the strength of the small diameter rod 101, the maximum stress σ1 due to displacement in the direction perpendicular to the axis is 6Wt 1 πd la...
・・・・・・・・・・・・・・・・・・・・・・・・
...If the amplitude YQ occurs in (5), 3πEdlIn w = k1yo = 16t570 ...
・・・・・・・・・・・・・・・・・・(6)
Substituting equation (6) into equation (5), Edn σ1"2")'O...hat...dan...
Mountain......Scream...+71, and on the other hand, the stress σ2 in the axial direction is F2-Ed2n ””′″°°°°゛°, where F is the driving force. °°°゛°
°°°゛°゛°°゛°°゛°゛°゛°°゛°°° (8)
becomes. From this, in order to suppress the stress in the axial direction and in the direction of extension to the axis, it is necessary to make the length L sufficiently larger than the diameter d of the small diameter rod 101. For example, diameter d=6111111
, n = vibration absorbing device 1 composed of six small diameter rods 101
0(7)% ratio U, thrust a force F ic vs. f le response force
2, 1.7 when dE 10 Kqf /rrm2
tonfi, but the deformation due to vibration has a half amplitude of 2. - When the occurrence occurs, the small diameter rod 101
When the length L f is 300 g, the stress σ2 is 8.9 K.
V f/'m2. From the above, it can be seen that the length of the small diameter rod 101 must be made sufficiently large in order to generate sufficiently large lateral vibrations in the head 6 and to improve the vibration absorption properties.

Therefore, in order to apply it to a vibration-type excavation device with a small diameter polarization, the length of the excavation device 5 becomes long. For example, even if the length of the buried pipe 4 is shorter than the excavation device 5, the starting vertical shaft is 2 and the problem of having to make the reaching shaft larger.

[Problem that the invention seeks to solve]

The present invention aims to provide a vibration absorbing device for a vibratory excavation device for propulsion construction method, which solves the above-mentioned problems.

[Means for solving problems]

The present invention, as a means for solving the above-mentioned problems,
Take the following steps. In other words, between the head and the main body,
It is equipped with a vibration absorbing device made by alternately laminating annular metal plates and annular elastic plates.

``Function'' By alternately laminating annular metal plates and annular elastic plates, it is possible to absorb head vibrations and transmit propulsion force to the head, while shortening the length in the direction of the propulsion axis. can do.

"Embodiment" Hereinafter, one embodiment of the vibration absorbing device in the vibratory excavation device for the propulsion method of the present invention will be described with reference to FIGS. 1 to 4.

Note that the same reference numerals as in FIGS. 5 and 6 indicate the same parts.

Therefore, the addition of the vibration absorbing device of the present invention in this embodiment is as follows:
As shown in FIG. 2, an annular metal plate 201 with an inner diameter d and an outer diameter, and an annular elastic plate such as a rubber plate 202 with an inner diameter d and an outer diameter h and a thickness h are alternately attached to the metal plate 201. It is made by laminating layers such that they are located at both ends. The metal plates 201 at both ends of the vibration absorbing device of the present invention are respectively fixed to the head 6 (8) and the main body 7 of the vibrating excavation device for the propulsion method, and the vibration absorbing device silver of the present invention is attached to the head 6 (8) and the main body 7. It is inserted between the main body 7.

Next, the performance of the vibration absorbing device 20 of the present invention will be explained using FIGS. 2 to 4. As shown in FIG. The apparent longitudinal elastic modulus Eap in the X direction (propulsion axis direction) of 2021 sheets is ``ap = Eo (S2 to 1 + 2)
・・・・・・・・・・・・・・・　　　　　　　　(a
). In addition, the spring constant kx in the X direction of the S suction device consisting of n layers is k=E,, A=:・p" (p2.12)...
・・・・・・・・・(a)・xnh 2nh Substituting the above formula (a) into this (a)′, we get the following.

On the other hand, the spring constants in the y and z directions are determined as follows. First, when a force W acts in two directions, the rubber plate 202 undergoes shear deformation as shown in FIG. 3(a) and as shown in FIG.
A deformation (referred to as parallel deformation) as shown in a) occurs. In the case of n-layer rubber, the deflections δI and δ for each deformation are determined by the following equations.

7°(nh)' ・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・(4
)δ””12EI Therefore, the total deflection δ for the force W is,
From this, the spring constant ky, 2 in the y and z directions is (nh)3,ky...=7=(2.12)"i□8k1-1
゛−°−=−(f). E is E. and E3p.

Therefore, try substituting numerical values into the above formula (b) + (o formula. However, G = 5.1 K da f 7 cm", K
O = 10Kff/m2+ = 0.85 rubber plate 202
The outer diameter D of the rubber plate 202 is 10 cm.
, inner diameter d = 5 crll, thickness h = 0.15
m and the number of sheets n=8, kX=5844 Kff/ran ky, 2=24.8 to 25 Kqf/m, which is sufficient in terms of strength. As described above, the annular metal plate 201
By laminating the rubber plate 202 and the rubber plate 202, it is possible to have a property of V'i, which is rigid in the direction of the propulsion axis and flexible in the direction perpendicular thereto.

Therefore, by providing the vibration absorbing device 20 having this laminated structure between the head 6 and the main body 7, it is possible to transmit the propulsive force and prevent the lateral movement of the head 6 from being transmitted to the main body 7 and further to the buried pipe 4. I can do it. In addition, the small diameter rod 101 of the conventional vibration absorber 10 required a sufficient length of about 300 mm, but by using the vibration absorber silver according to the present invention, the length in the axial direction can be reduced even in the above calculation example. 30m
The desired performance can be achieved to a certain degree. That is, the length of the excavation device in the direction of the propulsion shaft can be shortened, and the weight of the device can also be reduced by an amount corresponding to the shortened length of the entire device.

〔Effect of the invention〕

As explained above, the vibration absorbing device in the vibrating excavation Kn of the present invention has properties that are rigid in the direction of the propulsion shaft and flexible in the direction perpendicular to it even if the vibration absorbing device is shortened by the length of the vibration absorbing device. The length of the device can be shortened, and both the starting shaft and the arriving shaft can be small-scale for propulsion.

In addition, since the length of the excavation device is shortened, the weight of the vibrating part can be reduced compared to conventional ones, and a larger driving force can be generated with the same excitation force, improving excavation efficiency. In addition, machining is easier than with conventional vibration absorbers that use small-diameter rods.

[Brief explanation of drawings]

1 to 4 show an embodiment of the vibration absorbing device of the present invention, FIG. 1 is a sectional view of a small-diameter vibrating excavation device equipped with the vibration absorbing device of the present invention, and FIG. 2 is a perspective view. , FIG. 3(a) and FIG. 4(a) are explanatory diagrams showing the deformed state of the rubber plate,
FIG. 3(b) and FIG. 4(b) are diagrams simulating the deformed state of the rubber plate. FIG. 5 is an explanatory diagram showing the construction state of the propulsion method. FIG. 6 is a sectional view of a small-diameter vibrating excavation device using a conventional vibration absorbing device, and FIG. 7 is an explanatory diagram of the operating state of the conventional vibration absorbing device. 6 (8)...Head, 7...Main body, 9...Drive motor, 12...Liquid supply port, Addition...Vibration absorber, 201...
・Metal plate, 202...Rubber plate.

Claims (1)

[Claims] A head, a main body, a vibration absorbing device interposed between the head and the main body, an eccentric weight slidably and rotatably supported within the head, and a drive motor attached to the main body. A vibratory excavation device for a propulsion method in which an annular metal plate and an annular elastic plate are alternately laminated. Vibration absorber in equipment.