JPS59118697A - Multistage jack - 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 The present invention relates to a hydraulically actuated multi-stage jack, and particularly to a multi-stage jack that is installed in a shaft and provides propulsion force from the shaft to pipes such as water and sewerage pipes, gas pipes, and cable-laying pipes. This invention relates to a multi-stage jack suitable for press-fitting the jack into the ground.

Conventionally, while excavating underground from a shaft using a shield type excavator, a pipe is press-fitted from behind the shield type excavator.

According to this, the shield type excavator is propelled together with the pipe through the pipe by a plurality of hydraulically operated jacks installed in the shaft.

The jack is usually a single stage jack. When the stroke of one operation of the jack is equal to or longer than the length of the propelled pipe, the pipe can be press-fitted from the inside of the shaft to the outside of the shaft with one action of the jack.

However, on the other hand, since the length of the jack is greater than the length of the pipe, the size of the shaft, that is, the distance between the reaction wall and the opposing wall, must be at least twice the length of the pipe. However, the construction of the shaft requires a great deal of labor and cost.

On the other hand, when the operating stroke of the jack is smaller than the pipe length, the size of the shaft can be made smaller than when the jack has an operating stroke that is greater than or equal to the pipe length. However, in this case, the pipe cannot be press-fitted into the ground unless a strut is interposed between the pipe and the jack. That is, after extending the rod of the jack and press-fitting a part of the pipe into the ground, the rod is retracted, and electricity is distributed to the strut between the end of the pipe and the rod end of each jack to operate the jack, thereby operating the strut. Depending on the size of the operating stroke, the rod 9 must be moved back and forth to press the pipe into the ground by adding struts.

Although this can reduce the labor and cost required for constructing a shaft, on the other hand, it involves the tedious work of arranging multiple struts, which inevitably lowers work efficiency.

Therefore, in order to reduce the size of the shaft and force the pipe into the ground without the intervention of struts, it is possible to use a multi-stage jack instead of the single-stage jack.

According to the conventional multi-stage jack, a plurality of cylinders are fitted together on one axis, with the cylinder having the largest diameter gradually decreasing at one end, so that the length when extended and the length when contracted are The difference can be increased. However, it is not possible to make the moving speed of each cylinder the same during expansion.

For this reason, it becomes difficult to adjust the excavation speed of the shield-type excavation shovel, which receives the propulsion force of the multi-stage jack, and the amount of excavated soil, which is closely related to this.As a result, the earth pressure balance at the face is disrupted, and the ground There is a risk that the ground may collapse or the ground may rise.

Further, a large number of the single-stage jacks are arranged in a basket shape at intervals in the circumferential direction between the propulsion filter tube and the reaction wall. For this reason, it is not possible to install and operate measurement equipment such as a propulsion error measuring device that uses a laser on the axis of the pipe between the jacks, and the pipes are sequentially press-fitted into the ground. This caused problems in measuring the direction of propulsion of the machine, and to compensate for this, the working space in the shaft was narrowed.
Another problem is that the shaft must be built large.

In order to solve the above-mentioned conventional problems, it is an object of the present invention to make the length when extended as large as possible and the length when contracted to be as small as possible, and to provide an operating speed of each cylinder when extended. The object of the present invention is to provide a hydraulically actuated multi-stage jack that is anti-identical.

The present invention provides a first cylinder constituting a multi-stage jack having a first liquid chamber and a second liquid chamber, and a second cylinder having a piston portion received in each liquid chamber, and a sixth cylinder having a piston portion received in each liquid chamber. A sixth cylinder is provided with cylinders disposed on the rear side and the front side of the first liquid chamber, and further receives the action of the pressurized liquid introduced from the extrusion port provided in the first cylinder. The pressure receiving surface of the cylinder and the fourth cylinder slidably fitted into the sixth cylinder have the same surface area.

In the multi-stage jack according to the present invention, the second cylinder can be fixedly installed on the reaction wall of the shaft, and the first cylinder is operated by introducing pressurized liquid from the extrusion hoard. When the first cylinder stops operating, the sixth cylinder starts operating, and when the sixth cylinder stops, the fourth cylinder starts operating.
cylinder operates. Thereby, the tube placed in the vertical shape against the front end of the fourth cylinder is propelled with a constant propulsion speed and constant thrust during the completion of one working stroke of the multi-stage jack, and is forced into the ground. Ru.

Therefore, by applying the multi-stage jack according to the present invention to pipe propulsion, it is possible to minimize the thickness of the shaft and to propel the pipe without the intervention of struts. The machine can always be propelled at a constant speed, which prevents subsidence or upheaval of the ground during excavation.

Furthermore, according to the multi-stage jack according to the present invention, it is sufficient to apply thrust at at least two points at the ends of the tube in order to propel the tube.
This makes it easy to install measuring equipment in the space between the reaction wall and the tube end, and this space can be used as a work space.

The features of the invention will become clearer from the following description of the illustrated embodiments.

As shown in FIGS. 1 and 2, the hydraulically operated multi-stage jack 10 according to the present invention includes an annular first liquid chamber 12 and a first liquid chamber separated from the first liquid chamber by a partition wall '13. A first cylinder 16 having a cylindrical second liquid chamber 14 located inwardly, and a first piston located on the rear side of the first cylinder and received in the first liquid chamber 12. a second cylinder 20 having a section 18 and a third annular liquid chamber 22 located on the front side of the first cylinder 16;
A sixth cylinder 26 having a second piston portion 24 inserted into the 4Kl receiver, and a sixth piston having a cylindrical fourth liquid chamber 28 and inserted into the sixth liquid chamber 22. and a fourth cylinder 32 having a diameter of 0.

The second cylinder 20 is fixed to a further reaction support 64 of the reaction wall in the shaft.

The first cylinder 16 includes an extrusion port 36 for introducing pressure in order to eject the first cylinder 16, the sixth cylinder 26, and the fourth cylinder 62 to the front.
Each cylinder 16.26 has a port for pulling back the filter 2 (a first port 38 for pulling back and a second
40 is provided.

The first liquid chamber 12 is liquid-tightly partitioned by a first piston portion 18, and has spaces 12a and 1 on its front end side and rear end side.
2b is formed. Further, the second liquid chamber 14 is liquid-tightly partitioned by the second piston portion 24 to form spaces 14a and 14b on the rear end side and the front end side.
The liquid chamber 22 is also opened 41u by the sixth piston part 30
Spaces 22a and 22b are formed on the ll and front end sides.

The 7P-t 36 for extrusion is the space 1 of the first liquid chamber 12.
72a, and the space 12a communicates with the space 14a of the second liquid chamber 14 via the first liquid path 42 for extrusion passing through the partition wall 1. The space 14a also connects to the space 22a of the sixth liquid chamber 22 via a second liquid passage 44 for extrusion passing through the second piston portion 24 of the 66th cylinder 26.
It also communicates with the fourth liquid chamber 28 via a sixth liquid passage 46 for extrusion that passes through the center of the sixth cylinder 26 in the axial direction.

Further, the first port 68 and the second port 40 for pulling back communicate with the space 12b of the first liquid chamber 12 and the space 14b of the second liquid chamber 14, respectively. The space 14b is further connected to a space 22 of the sixth liquid chamber 22 via a pullback liquid passage 4B consisting of a linear passage provided in the sixth cylinder 24 and an annular passage intersecting the passage.
It communicates with b.

The first and second port filters 8.40 for pullback can be combined into one pullback port z-1, 52 by connecting them via the communication pipe 50. Moreover, instead of providing the second port filter 8 for pulling back in the first cylinder 16, it is also possible to provide it in the sixth cylinder 26 so as to open at its front end surface.

The surface area of the pressure-receiving surface that is introduced from the extrusion =f-) 36 and is subjected to its hydraulic pressure by the filtrate pressure liquid, that is, the surface area of the front end surfaces 18a and 18b of the first piston section 18, and the rear end surface of the second 2717 section. The surface area of 24a, 24b and the sixth
The sum of the surface area of the rear end surface 30a of the piston portion rotor 0 and the surface area of the front wall surface 32a in the fourth cylinder 62 defining the fourth liquid chamber 28 is set to be the same. This allows each cylinder 16, 26, 62 to be pushed forward at the same speed and with the same thrust.

The first piston part 18 differs from the other piston parts 24 and the filter 0 in that only its outer peripheral surface 18c is in contact with the outer side wall surface 16a defining the first liquid chamber 12. However, the first
The piston portion 18 can be shaped so as to come into contact with both the side wall surface 16a and the inner wall surface 16b (not shown), as long as the surface area of the front end surface which is the pressure receiving surface thereof does not change. However, inner Sen] wall surface 1
Pressure liquid is applied to the part in contact with 6b for extrusion (t-) 36
It is necessary to provide a flow path for the pressure liquid so that the pressure liquid flows from the liquid to the first liquid path for extrusion.

The first piston portion 18 also has a stepped front end;
The front end surface 18a protrudes forward, and a hole 54 is provided in the protruding portion. As a result, the front end surface 18a is aligned with the first liquid chamber 1.
2. When the pressure liquid is in contact with the filter front wall surface 16c, the pressure liquid can be introduced from the extrusion port filter 6 into the space 12a, and the introduced pressure liquid flows through the hole 54. do.

The rear end surface of the second piston part 24 is formed in a step shape for the same reason as described for the first piston part 18.

Further, the rear part of the first liquid chamber 12, the front part of the second liquid chamber 14, and the front part of the sixth liquid chamber 22 are respectively arranged such that the first 4-) 38 for pulling back and the second 4-) 38 for pulling back It is formed in a step shape near the openings of the RF port 40 and the liquid path 4B for pulling back. As a result, when the first piston part 18, the second piston part 24, and the sixth piston part filter 0 are each pulled back, they engage with the stepped portions and the port filter by each piston part. 8.40 and occlusion of said opening is prevented.

The locations where the cylinders 16, 20, 26, 62 come into contact with each other include the locations where the outer circumferential surface Ob of the sixth piston portion 60 and the outer wall surface 26a defining the sixth liquid chamber 22 are in contact with each other. A ring-shaped gasket is arranged to prevent liquid leakage.

In order to extend the multi-stage jack 1D, in which the rear end of the second cylinder 20 is fixed to the reaction support 34, from the state shown in FIG.
Pressure liquid is introduced into the space 12a of No. 2. When hydraulic pressure is applied to the front end surface 18b of the first piston portion 18 by introducing the pressure fluid, the first cylinder 16 is pushed forward by the reaction.

As the first cylinder 16 moves slightly, the hydraulic pressure also reaches the front end 18a, thereby causing the first seven cylinders 16 to move at a constant speed a. During this time, the first liquid path 4 for extrusion
The hydraulic pressure of the pressurized liquid is applied to the second piston portion 24 through the cylinder 2, and this applies a force to the third cylinder 26 to move it forward. However, pressure liquid has a property that the pressure of the liquid decreases as it moves away from the port filter 6, which is its introduction port, and therefore, when an appropriate load is applied to the fourth cylinder filter 2, A thrust sufficient to overcome the load is not generated in the lower cylinder 26. Further, while the first cylinder 16 is operating, the liquid in the space 12b of the first liquid chamber 12 is discharged through the pullback port 52.

When the first cylinder 16 completes one stroke of movement, hydraulic pressure is applied to the rear end surfaces 24a and 24b of the second piston part 24 by the pressure liquid introduced from the extrusion liquid path 42, and the third cylinder 26 is pushed forward at the same speed a as the first cylinder 1-6. At this time as well, for the same reason as described above, the fourth cylinder 62 does not operate until one stroke of movement of the sixth cylinder 26 is completed. During this time, the liquid in the space 14b of the sixth liquid chamber 14 is discharged via the pull-back hole 52.

Thereafter, the third piston part 30 is
'& end surface 30a and front wall surface 32 of the fourth cylinder 32
A hydraulic pressure is applied to the cylinder a, and the cylinder is pushed forward at the same speed as the moving speed a of the first and sixth cylinders 16 and 26.

During this time, the liquid in the space 22b of the third liquid chamber 22 is discharged via the liquid path 48 for pulling back, the space 14b, and the $-t 52 for pulling back. Further, the fifth piston portion 60 is
While sliding in the third liquid chamber 22, the liquid in the space 22c of the third liquid chamber 22 is compressed as it moves, and the pressure exceeds the pressure exerted on the rear end surface 30a of the sixth piston part 60. At this time, the liquid flows into the space 22a through between the outer circumferential surface 30b of the sixth piston portion 60 and the wall surface 26a. First, as will be described later, when the first piston portion 60 moves rearward, the liquid in the space 22a flows between the outer circumferential surface 3Db and the wall surface 26a and into the space between the walls 22c. This provides lubrication between the third piston portion 60 and the wall surface 26a.

In addition, each piston portion 18.2 in the state shown in FIG.
4.30, the end surfaces 18a, 24a and 30a are
A front wall surface 16c defining a first liquid chamber, a rear wall surface 16d defining a second liquid chamber 14, and a sixth liquid chamber 22, respectively.
It is in contact with the rear wall surface 26b that defines the. Therefore, when pushing each cylinder forward, it may take a short time for the action of the pressure fluid to reach the entire surface of each piston portion. Therefore, in order to avoid this, for example, each piston portion 18.
24.60 stops immediately before contacting the wall surfaces 16c, 16a, '26b, or the shape of the end surfaces 18a, 24a, 30a of each piston part or the wall surfaces 16c, 16d, 26b defining each liquid chamber. It is desirable that a slight gap exists between the end surface of each piston portion and the wall surface defining each liquid chamber by changing the .

During the extension movement of the multi-stage jack 10, each cylinder 16.2
6.62 moves forward at the same speed and generates the same amount of thrust during each operation, as described above.

Next, in order to reduce the multi-stage jack 10 from the state shown in FIG.
b and the space 22b of the sixth liquid chamber 22 via the liquid path 48 for pulling back.

As a result, each cylinder (ne) is pulled back backwards at the same time,
At this time, the liquid in the fourth liquid chamber 28, the liquid in the space 22a of the sixth liquid chamber 22, and the liquid in the space 14a of the second liquid chamber 14 reverse the movement path of the liquid at the time of the extension operation. The liquid is collected in the space 1'2a of the first liquid chamber 12, and is discharged from the extrusion port 36 together with the liquid in the space 12a.

According to the present invention, the surface area of the front end surface of the first piston section, the surface area of the rear end surface of the second piston section, the surface area of the rear end surface of the second piston section, and Since the sum of the surface areas of the front walls in the fourth cylinder defining the fourth liquid chamber is the same, each cylinder can be moved forward at the same speed, and the thrust generated by each cylinder can be They can be the same.

Therefore, when the pipe is propelled from behind under the guidance of the shield type 9 excavator, when the pipe is propelled by the multi-stage jack according to the present invention, the propulsion speed of the pipe and the shield type excavator is kept constant. You can move them while maintaining them. As a result, it becomes easy to control the amount of soil excavated by the shield type excavator, and it is possible to prevent ground subsidence and ground uplift during excavation by the shield type excavator.

Further, according to the present invention, since the second cylinder is arranged behind the first cylinder, the length when expanded can be made as large as possible and the length when contracted can be made as small as possible. Therefore, when using the multi-stage jack according to the present invention for propulsion of a pipe from a shaft, the size of the shaft can be minimized without impairing the characteristics that each cylinder advances at the same speed and generates the same thrust. However, the pipe can be press-fitted into the ground outside the vertical structure without the use of struts.

Furthermore, according to the multi-stage jack according to the present invention, sufficient thrust can be applied to the pipe. Therefore, the distance between the multi-stage jacks can be increased, which makes it easier to install equipment for measuring the direction of propulsion of the pipe between the multi-stage jacks, and allows the space between the multi-stage jacks to be used as a working space in a narrow shaft. can.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a multi-stage jack according to the present invention in an extended state, and FIG. 2 is a vertical cross-sectional view of the multi-stage jack in a contracted state. 10: Multi-stage jack, 12: First liquid chamber, 14: Second liquid chamber, 16: First cylinder, 18: First piston part, 20: Second cylinder, 22: Sixth liquid chamber , 24: second piston section, 26: sixth cylinder, 28: fourth liquid chamber, 60: sixth piston section, 62
: Fourth cylinder, 64: Reaction force support, 66: Hoard for extrusion, filter 8.40.52: First port, second port and port for pulling back, 42.44.46: For extrusion 48: Liquid path for pulling back. Agent Patent Attorney Nobuyuki Matsunaga

Claims (2)

[Claims] (1) A first cylinder having a first liquid chamber and a second liquid chamber, and a first piston portion located on the rear side of the first cylinder and received in the first liquid chamber. and a sixth cylinder located on the front side of the first cylinder.
a second liquid chamber having a liquid chamber and a receiver placed in the second liquid chamber;
a sixth cylinder having a piston portion, a fourth cylinder having a fourth liquid chamber and a sixth piston portion received in the sixth liquid chamber, and the first cylinder a first port for extrusion and a first port for retraction that communicate with the first liquid chamber at the front end side and the rear end side of the first piston portion, respectively; a second port for pulling back that is provided in the cylinder and communicates with the second liquid chamber on the front end side of the second piston portion, and the second port of the second liquid chamber
The rear end side of the piston part, the front end side of the first piston part of the first liquid chamber, the rear end side of the sixth piston scoop of the third liquid chamber, and the fourth liquid chamber are respectively The front end side of the second piston part of the second liquid chamber and the front end l111 of the sixth piston part of the sixth liquid chamber communicate through a liquid path for pushing out, and a liquid path for pulling back. communicates through the first
the surface area of the front end face of the histostone part, the surface area of the rear end face of the second piston part, the surface area of the rear end face of the sixth piston part, and the front side of the fourth cylinder defining the fourth liquid chamber. A multi-stage jack whose surface area is equal to the sum of the inner wall surfaces. (2) The multi-stage jack according to claim (1), wherein the second cylinder is fixed to a reaction support.