JP3523585B2 - Cylinder structure of vibration generator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic press-fitting method capable of constructing a tunnel such as a horizontal hole or a vertical hole in the ground by giving vibration in the axial direction to the ground like a pile driver. The present invention relates to a cylinder structure of a vibration generator used in a construction method.

[0002]

2. Description of the Related Art As a construction method for burying a pipe in the ground, a static press-fitting construction method is used in which a tip device is simply pressed by an extruding device installed in a shaft to press it into the ground without excavating the soil. An excavation method for excavating soil with an excavator and propelling the excavator in the ground while discharging the excavated soil, as shown in FIGS. 9 and 10 of the present application, by the method disclosed in Japanese Patent Laid-Open No. 60-148997. The vibration exciter a is operated to vibrate the front part c of the vibration generator b, and the soil d around the vibration generator b is vibrated to be fluidized, and the original pushing device f installed in the vertical shaft e. There is a dynamic press-fitting construction method in which the vibration generating device b is press-fitted by excavating the soil by pressing with.

Since the static press-fitting method is a method of pushing the tip end device by the original pushing device, when the soil is hard or the diameter of the pipe is large, the propulsion resistance at the time of press-fitting is large, and therefore the applicable soil is applicable. The N-value is limited to about 15 or less in a soft place, and the applicable pipe diameter is also limited to a small diameter pipe of about 350 mmφ or less. Even if the static press-fitting method can be applied, if the soil is hard, the propulsion speed will be slower, resulting in a longer construction period and higher construction costs. There is a problem that the promotion length is limited because it cannot be done.

The excavation method can be applied to a place where the static press-fitting method cannot be applied. However, since a soil excavation mechanism and an earth removal mechanism are required, the equipment cost of the tip device becomes high, and the construction work is also difficult. There are problems such as the need for soil removal, and the fact that it is an excavation type, so the propulsion speed is slow and construction costs are high.

In the case of the dynamic press-fitting method shown in FIGS. 9 and 10, it is possible to solve the problems of the static press-fitting method and the excavation method, but what kind of vibration is applied and how is it applied? Therefore, it is difficult to actually use it for construction, and since the vibration exciter a is housed in an independent vibration generator b, the outer diameter of the vibration generator b is There is a possibility that the device becomes large and the device becomes large.

Therefore, the inventor of the present application has examined a vibration generator which can be applied to an actual dynamic press-fitting method, has a small size, and has good operability and workability.
developed.

[0007]

[Summary of the developed vibration generator] This vibration generator is applied to the pipe burying device shown in FIG.
1 is a tip device. The tip device 1 vibrates the tip head 2 in the axial direction parallel to the device propulsion direction D1 to generate soil 3 in the ground.
The vibration generator 4 located on the front side of the device propulsion direction D1 so as to be able to apply vibration to the device, and connected to the rear of the device propulsion direction D1 of the vibration generator 4 and propelling the device during propulsion of the pipe burying device. A direction correcting device 6 including a center folding mechanism 5 for correcting the direction D1 is provided.

Reference numeral 7 denotes an insertion pipe arranged behind the direction correcting device 6 in the tip end device 1 in the device propelling direction D1, and 8 denotes a vertical shaft 9
It is an original pushing device such as a jack that is disposed inside and pushes the rear end of the insertion tube 7 via the pushing plate 10.

In the pipe burying device, the tip 3 of the vibration generator 4 is vibrated in a direction parallel to the device propulsion direction D1 to give vibration to the soil 3, thereby causing the soil 3 to flow. And the original pressing device 8 is extended to press the pressing plate 10.
The insertion tube 7 is press-fitted into the ground via the, and the tip device 1 is pushed by the insertion tube 7 to propel the tip device 1. When the soil 3 is fluidized, the shearing force is reduced, and thus the required propulsive force is reduced, so that the tip device 1 is easily pressed into the ground.

Details of the vibration generator 4 are shown in FIGS. 7 and 8. In the drawings, 11 is a cylindrical outer cylinder of the tip end portion. In the tip outer cylinder 11, a cylindrical tip inner cylinder is formed so that a space is formed between the inner circumference of the tip outer cylinder 11 and the inner periphery of the tip outer cylinder 11 in a portion other than the rear side of the device propelling direction D1. 12 are fitted concentrically, and the rear end of the tip inner cylinder 12 in the device propelling direction D1 is fitted and fixed to a mounting hole formed in the rear end of the tip outer cylinder 11 in the device propulsion direction D1. .

In the space between the tip outer cylinder 11 and the tip inner cylinder 12, the outer circumference slides on the inner circumference of the tip outer cylinder 11, and the inner circumference slides on the outer circumference of the tip inner cylinder 12. The obtained cylindrical piston 13 is fitted so as to reciprocate in the device propulsion direction D1, and the tip end of the piston 13 in the device propulsion direction D1 is in the device propulsion direction D rather than the tip end outer cylinder 11.
1 Projects forward. Thus, the cylinder structure of the vibration generator 4 is formed by the tip outer cylinder 11, the tip inner cylinder 12, and the piston 13, and the tip outer cylinder 11, the tip inner cylinder 12, and the piston 13 have the structure of the vibration generator 4. It also serves as a body.

An oil chamber 14 is formed in a rear portion of the inner circumference of the tip end outer cylinder 11, a midway portion of the outer circumference of the tip end inner cylinder 12 and a space surrounded by the rear end of the piston 13, and an oil chamber 14 is formed inside the rear end of the piston 13. An oil chamber 15 is formed in a space surrounded by the circumferential step portion and the outer circumferential step portion on the tip end side of the tip end inner cylinder 12. The front end outer cylinder 11 has an oil passage 11 whose front end opens to the oil chamber 14 and whose rear end opens to the rear surface of the front end outer cylinder 11.
The front end inner cylinder 12 is provided with an oil passage 12a whose front end opens to the oil chamber 15 and whose rear end opens to the rear surface of the front end inner cylinder 12.

A hollow disk-shaped seat 16 is attached to the tip of the piston 13 which projects from the outer cylinder 11 toward the front in the device propulsion direction D1, and the seat 16 is replaceable at the end of the device propulsion direction D1. A tip head 17 which is the same as the tip head 2 shown in FIG. In the illustrated example, the tip end head 17 has a frustoconical shape that is tapered toward the front in the device propelling direction D1.
The shape may be flat instead of frusto-conical depending on the soil quality of the soil to be pressed. When the oil is supplied to and discharged from the oil chambers 14 and 15, the tip head 17 is reciprocally excited through the piston 13 in a direction parallel to the device propulsion direction D1, and the soil in the soil with respect to the device propulsion direction D1. Vibrations in parallel directions can be applied.

In the figure, 18 is a stroke detector of the piston 13 and 19 is a device propulsion direction D1 of the tip outer cylinder 11.
A rear cylinder connected to the rear end, and inside the rear cylinder 19, various devices and controls such as an electromagnetic control valve 20 of a hydraulic circuit necessary for vibrating the front head 17 in a direction parallel to the device propulsion direction D1. It stores various system equipment.

When vibration is applied to the soil in order to press-fit the tip device 1 into the ground, the electromagnetic control valve 20 is switched at short time intervals to alternately supply and discharge oil in the oil chambers 14, 15. Therefore, the piston 13 reciprocates with a predetermined amplitude in a direction parallel to the device propulsion direction D1, and the tip head 17 is vibrated integrally with the piston 13 to give vibration to the ground.

[0016]

In the vibration generator 4, since the piston 13 vibrates in the soil, there is a possibility that soil particles may enter between the inner circumference of the tip outer cylinder 11 and the outer circumference of the piston 13. Therefore, the tip outer cylinder 11 and the piston 13 are
It is necessary to seal between and. Also, the piston 13
It is necessary to remove the oil from the inner circumference of this, and a seal is also required for this purpose.

However, since the piston 13 frequently slides with respect to the tip outer cylinder 11 and the tip inner cylinder 12 by vibrating operation, if a normal seal is used, the inner circumference of the tip outer cylinder 11 and the outer circumference of the piston 13 will be separated. Of the lubricating oil supplied between the outer circumference of the tip inner cylinder 12 and the inner circumference of the piston 13, and as a result, the contact surface between the tip outer cylinder 11 and the piston 13 and the tip inner cylinder 12 and the piston 13 There is a risk that seizure may occur or the seal may be damaged.

When the seal is damaged and the sealing performance against soil particles and oil deteriorates, the contact surface between the tip outer cylinder 11 and the piston 13 and the contact surface between the tip inner cylinder 12 and the piston 13 are abraded and vibrated. There is a risk that the generator 4 may not operate.

Further, since a large vibration load is applied to the front surface of the tip head 17 by vibrating the tip head 17, when the propulsion direction of the vibration generator 4 is changed, the piston 13 has a large vibration load. A radial load acts, which may also cause problems such as deterioration of sealing performance, seizure, and abrasion.

The present invention can be applied to an actual dynamic press-fitting method, and at the time of developing a small-sized vibration generator having good operability and workability, a piston for vibrating the tip head is used. A cylinder structure of a vibration generating device, which is capable of reliably sealing a space between a tip outer cylinder and a tip inner cylinder on which the piston slides, and also capable of supporting a large radial load acting on the piston. It is intended to be provided.

[0021]

A cylinder structure according to a first aspect of the present invention is characterized in that a cavity is formed between a tip outer cylinder and a tip inner cylinder fitted concentrically with the tip outer cylinder. First, a piston is fitted so that it can be vibrated in a direction parallel to, and the piston is operated between the rear end of the piston in the device propelling direction and the inner circumference of the outer cylinder of the tip portion and the outer circumference of the inner cylinder of the tip portion. And a second fluid chamber for operating the piston so as to retract the piston between the inner circumference of the piston and the outer circumference of the tip end inner cylinder, and a tip for vibrating the tip of the piston in the device propulsion direction into the ground. A cylinder structure of a vibration generator with a head attached, which removes soil particles adhering to the outer circumference of the piston between the inner circumference of the outer cylinder of the tip portion and the outer circumference of the piston from the front to the rear in the device propulsion direction. First scraper means adapted to , A first sealing means capable of preventing the working fluid from the first fluid chamber from leaking into the ground, and a predetermined direction in the apparatus propulsion direction so as to support a radial load acting on the piston. The first and second bearings are provided so as to be separated from each other.

According to a second aspect of the cylinder structure of the vibration generator, the working fluid adhered to the inner peripheral surface of the piston is directed between the inner circumference of the piston and the outer circumference of the tip end inner cylinder from the front to the rear in the apparatus propulsion direction. A second scraper means that can be removed, a second sealing means that can prevent the working fluid from leaking from the second fluid chamber to the second scraper side, and the second scraper means that acts on the piston. The third and fourth bearings capable of supporting a radial load, and the third and fourth bearings capable of preventing the working fluid from leaking between the second fluid chamber and the first fluid chamber. Sealing means and a fifth bearing adapted to support a radial load acting on the piston are arranged so that the third and fourth bearings sandwich the second fluid chamber.

According to a third aspect of the cylinder structure of the vibration generator, the tip outer cylinder, the piston, the first scraper means, and the first scraper means are provided between the first scraper means and the first sealing means of the tip outer cylinder. A drain groove for discharging the fluid in the space formed by the one sealing means through a drain fluid discharge passage formed in the outer cylinder of the tip end to a drain tank provided outside the fluid discharge passage is formed. .

In the cylinder structure of the vibration generator of the fourth aspect, the distance between the facing surfaces of the first scraper means and the first sealing means is formed to be equal to or greater than the full stroke of the piston.

In the cylinder structure of the vibration generator of the present invention, the first and second scraper means are formed by a resin-made annular scraper main body on the sliding side and are formed by an O-ring on the non-sliding side to form a combination. It is a seal.

In the cylinder structure of the vibration generator of the sixth aspect, the first, second and third sealing means are made of a resin-made annular seal body on the sliding side and an O-ring on the non-sliding side. And is a combination seal.

In the cylinder structure of the vibration generator of the seventh aspect, the materials of the third, fourth and fifth bearings are formed to have lower rigidity than the materials of the first and second bearings.

In the present invention, the fluid is alternately supplied to the first and second fluid chambers, and the piston is oscillated reciprocally with a predetermined amplitude in the direction parallel to the apparatus propulsion direction, whereby the tip head is moved to the piston. And vibrate it to give vibration to the soil in the ground.

At this time, the outer peripheral surface of the piston slides with respect to the first scraper means, the first sealing means, the first and second bearings, and the inner peripheral surface of the piston has the second scraper means.
The second seal means and the third bearing slide with respect to each other, and the fourth bearing and the third seal means slide with respect to the outer peripheral surface of the tip end inner cylinder.

In the inventions of claims 1 to 7, the radial load acting on the piston is supported by the first to fifth bearings. In this case, when the piston is tilted by receiving a moment due to the radial load, for example, when the piston is tilted so that the tip head side hangs the neck, the radial load is applied to the inner surface of the lower part of the first bearing and the upper part of the second bearing. It is supported by the inner surface and is also supported by the upper inner surface of the third bearing and the lower inner surfaces of the fourth and fifth bearings. Further, the soil particles adhering to the outer peripheral surface of the piston are removed by the first scraper means, the leakage of the fluid from the first fluid chamber is prevented by the first sealing means, and the fluid from the second fluid chamber is prevented. Leakage is prevented by the second and third sealing means.

According to the invention of claims 1 to 7, the second fluid chamber on the side for retracting the piston rearward in the device propulsion direction is formed between the inner circumference of the piston and the outer circumference of the inner cylinder of the tip portion, so that a normal hydraulic cylinder is used. In addition, it is not necessary to set the fluid chamber on the piston retracting side to the outside of the piston rod. Therefore, the diameter of the piston can be increased over the entire length, and the rigidity against a radial load can be improved. Further, since the outer diameters of the first and second bearings arranged between the outer cylinder of the tip portion and the piston can be increased, a large radial load can be received, which is advantageous in performance.

According to the third aspect of the present invention, the drain fluid accumulated in the internal drain groove between the first scraper and the first sealing means is discharged from the drain fluid discharge passage to the drain tank. In the unlikely event that soil particles enter the drain fluid, they are discharged into the drain tank together with the drain fluid.

According to the fourth aspect of the invention, since the distance between the facing surfaces of the first scraper means and the first sealing means is larger than the total stroke of the piston, the surface of the outer peripheral surface of the piston that comes into contact with the soil particles is the piston. The outer peripheral surface does not overlap the surface that comes into contact with the first sealing means. Therefore, even if the surface of the piston that contacts the soil particles is damaged, the surface that contacts the first sealing means is not damaged, and as a result, the fluid pressure sealing performance can be maintained.

In the invention of claim 5, since the first and second scraper means are in the form of a combined seal, the resistance at the time of sliding is low, the sliding is easy, and the sealing performance is also good. .

In the invention of claim 6, since the first, second and third sealing means are in the form of a combined seal, the sliding resistance is low and sliding is easy, and the sealing performance is high. Is also good.

In the invention of claim 7, the contact surfaces of the third, fourth, and fifth bearings can easily adapt to the opposing surface, so that the piston is placed between the outer cylinder of the tip and the inner cylinder of the tip. When fitting into the formed gap, the fitting tolerance can be loosened, and seizure may occur between the inner circumference of the outer cylinder of the tip part and the outer circumference of the piston, and between the inner circumference of the piston and the inner cylinder of the tip part. Can be prevented.

From the above, according to the present invention, the vibration generator can be applied to an actual dynamic press-fitting method, and a vibration generator having a small size and good operability and workability can be provided.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show an example of an embodiment for carrying out the present invention. In the drawings, the parts denoted by the same reference numerals as those in FIGS. The structure is the same as the conventional one shown in FIGS.

As shown in FIG. 1, in the inner circumference of the tip outer cylinder 11, a soil removing scraper 21 and an internal drain groove 2 are provided from the front side to the rear side in the device driving direction D1 of the vibration generator 4.
2, combination seal 23, bush-shaped bearings 24, 25,
26 and 27 are sequentially provided.

As shown in FIG. 2, the soil removing scraper 21 is fitted in a groove formed on the inner periphery of the front end of the front outer cylinder 11 in the device propelling direction D1 and is formed of a rubber O-ring 21a and an O-ring 21a. The scraper main body 21b made of resin and attached to the inner peripheral side has a thin ring shape, and the tip of the inner peripheral of the scraper main body 21b is in contact with the outer periphery of the piston 13.

The internal drain groove 22 is formed in a ring shape on the inner circumference of the tip outer cylinder 11 in order to prevent the clearance between the tip outer cylinder 11 and the piston 13 from becoming high pressure due to oil. A drain oil discharge passage 28 is formed in the outer cylinder 11 so that one end thereof opens at the upper end of the internal drain groove 22 and the other end thereof opens at the rear end of the front end outer cylinder 11. An oil drain pipe 29 is connected to the end of the drain oil discharge passage 28 on the rear cylinder 19 side, and the oil discharged from the internal drain groove 22 passes through the drain oil discharge passage 28 and the drain oil pipe 29 to drain the drain oil. Road 2
8 can be discharged to the drain tank 30 installed in the rear tubular body 19.

The combination seal 23 is fitted into a ring-shaped groove provided on the inner circumference of the middle portion of the tip outer cylinder 11 in the axial direction.
As shown in, a rectangular ring-shaped resin inner seal 23a and an O-ring 23b attached to the outer periphery of the inner seal 23a
The inner peripheral surface of the inner seal 23a is in contact with the outer peripheral surface of the piston 13. The inner seal 23a is made of resin in order to reduce the resistance force generated when the piston 13 reciprocally oscillates in a direction parallel to the device driving direction D1.

Propulsion direction D of the scraper 21 for removing soil
The distance S1 between the 1 rear end and the front end of the combination seal 23 in the device propelling direction D1 is slightly larger than the total stroke S2 of the piston 13, but this is used as a double propulsion mechanism instead of the original pushing device 8. When the piston 13 is reciprocated over the entire stroke S2 due to reasons such as
This is to prevent the portion of the outer peripheral surface to which the soil particles adhere from coming into contact with the inner peripheral surface of the combination seal 23.

The bearings 24, 25, 26 and 27 are pistons 1.
3, which is for supporting a radial load acting on 3, and is formed of a metal material or resin having high rigidity, and is fitted into a ring-shaped groove provided on the inner circumference of the middle portion of the tip outer cylinder 11 in the axial direction. At the same time, it is in contact with the outer peripheral surface of the piston 13.

Further, the soil removing scraper 21, the internal drain groove 22, the combination seal 23, the bearings 24 and 25 are arranged close to each other, and the bearings 26 and 27 are arranged close to each other. , Are separated from each other. In this way, the group of the bearings 24 and 25 and the group of the bearings 26 and 27 are arranged apart from each other so that the moment acting on the piston 13 when the piston 13 is subjected to a radial load can be easily supported. This is because.

A vibration generator 4 is provided on the outer circumference of the inner cylinder 12 at the tip.
In the apparatus propulsion direction D1 from the front side to the rear side, an oil removing scraper 31, a combination seal 32, and a bush-shaped bearing 33 are sequentially provided relatively close to each other.

As shown in FIG. 4, the oil removing scraper 31 is fitted in a groove formed on the outer periphery of the front end portion of the front inner cylinder 12 in the device propelling direction D1 and is attached to the O ring 31a and the outer peripheral side of the O ring 31a. The scraper body 31b made of resin and having a tongue-shaped cross section is provided, and the outer peripheral end of the scraper body 31b is in contact with the inner peripheral surface of the piston 13.

The combination seal 32 is fitted in a ring-shaped groove provided on the outer periphery of the middle portion of the inner tube 12 in the axial direction,
As shown in FIG. 3, a rectangular ring-shaped outer seal 32a made of resin and a rubber O-ring 32b attached to the inner circumference of the outer seal 32a are provided, and the outer peripheral surface of the outer seal 32a contacts the inner peripheral surface of the piston 13. Is ready to go. The outer seal 32a is made of resin in order to reduce the resistance force generated when the piston 13 reciprocally oscillates in a direction parallel to the device driving direction D1.

The bearing 33 is for supporting a radial load acting on the piston 13, is made of a metal material or a resin material, and is formed in a ring-shaped groove provided on the outer periphery of the distal end inner cylinder 12 in the axial middle direction. While being fitted, the outer peripheral surface of the bearing 33 is in contact with the inner peripheral surface of the piston 13.

A bearing 34, a combination seal 35, and a bush-shaped bearing 36 are sequentially provided relatively close to each other on the inner periphery of the piston 13 in the rear side of the device propulsion direction D1 from the upstream side to the downstream side of the device propulsion direction D1. ing.

The bearings 34 and 36 are for supporting a radial load acting on the piston 13 and are made of a metal material or a resin material, and are formed in a ring-shaped groove provided on the inner periphery of the rear portion in the axial direction of the piston 13. It is fitted and is in contact with the outer peripheral surface of the tip end inner cylinder 12. Therefore,
The oil chamber 15 formed on the inner circumference of the piston 13 and the outer circumference of the tip end inner cylinder 12 is sandwiched by the bearings 33 and 34 in a direction parallel to the device propulsion direction D1.

The bearings 33 and 34 are arranged apart from each other so that the moment acting on the piston 13 when a radial load is applied to the piston 13 can be easily supported.

The rigidity of the bearings 33, 34 and 36 is the same as that of the bearing 2.
It is lower than the rigidity of 4, 25, 26, 27,
This is for the following reasons. That is, the tip outer cylinder 1
Even when the piston 13 is fitted in the space between the inner cylinder 1 and the inner cylinder 12 at the tip end, the bearings 33, 34, 36 slide due to the reciprocating motion of the piston 13, and the piston 13 of the bearing 33. This is because the contact surfaces with respect to and the contact surfaces of the bearings 34 and 36 with respect to the inner cylinder 12 at the tip end are adapted to eliminate the misalignment between the outer cylinder 11 at the tip end and the inner cylinder 12 at the tip end and the piston 13. In other words, this is to loosen the fitting tolerance of the piston 13 with respect to the space formed between the tip outer cylinder 11 and the tip inner cylinder 12.

The combination seal 35 has the same structure as the combination seal 23, although the dimensions are different, and has a rectangular ring-shaped inner seal made of resin and an O-ring made of hard rubber attached to the outer periphery of the inner seal. The inner seal is made of resin for the same reason as the inner seal 23a of the combination seal 23.

Next, the operation of the illustrated example will be described. Also in the illustrated example, when vibration is applied to the soil in order to press the tip device 1 into the ground, the electromagnetic control valve 2 shown in FIGS.
By switching 0 at short time intervals, oil is alternately supplied to and discharged from the oil chambers 14 and 15, and the piston 13 is oscillated and reciprocally moved in a direction parallel to the device propulsion direction D1 with a predetermined amplitude, whereby the tip head 17 is moved. It vibrates integrally with the piston 13 and gives vibration to the soil in the ground.

At this time, the outer peripheral surface of the piston 13 has a soil removing scraper 21, a combination seal 23, bearings 24, 25,
26 and 27, the inner peripheral surface of the piston 13 slides on the oil removing scraper 31, the combination seal 32, and the bearing 33, and the bearings 34 and 36 and the combination seal 35 are the outer peripheral surface of the tip inner cylinder 12. Slide against.

The radial load acting on the piston 13 is supported by the bearings 24, 25, 26, 27, 33, 34 and 36, and the piston 13 receives a moment by the radial load so that the piston 13 is Corresponding to the clearance between the circumference and the outer circumference of the piston 13, or the clearance between the outer circumference of the bearing 33 and the inner circumference of the piston 13, or the clearance between the inner circumference of the bearings 34 and 36 and the outer circumference of the tip inner cylinder 12. When tilted, for example, when the piston 13 is tilted so that the tip head 17 side hangs down in FIG. 1, the radial load is supported by the upper side of the bearings 26 and 27 and the lower side of the bearings 24 and 25 in FIG. Together with the upper side of the bearing 33 and the bearing 3
It is supported by the lower side of 4, 36.

The soil particles adhering to the outer peripheral surface of the piston 13 are removed by the scraper body 21b of the soil removing scraper 21, and the oil leakage from the oil chamber 14 is prevented by the combination seal 23.
The leakage oil is prevented by the drainage oil, and the drain oil accumulated in the internal drain groove 22 between the soil removing scraper 21 and the combination seal 23 is discharged from the drain oil discharge passage 28 to the drain tank 30 via the oil discharge pipe 29, and is appropriately drained. Tank 30
The leakage of oil from the oil chamber 15 is prevented by the combination seals 32 and 35.

In this illustrated example, since the oil chamber 15 on the side for pulling the piston 13 rearward in the device propulsion direction D1 is formed between the inner circumference of the portion of the piston 13 that functions as a piston rod and the tip end inner cylinder 12, It is not necessary to make the oil chamber on the piston retracting side outside the piston rod, unlike the hydraulic cylinder of. Therefore, the diameter of the portion of the piston 13 corresponding to the piston rod can be increased, and the rigidity against a radial load can be improved. Further, since the outer diameters of the bearings 24, 25, 26, 27 arranged between the tip end outer cylinder 11 and the piston 13 can be increased, a large radial load can be applied, which is advantageous in performance.

A distance S1 between the facing surfaces of the soil removing scraper 21 and the combination seal 23 arranged outside the piston 13.
Is larger than the total stroke S2 of the piston 13, the surface of the outer peripheral surface of the piston 13 that contacts the soil particles is
The outer peripheral surface does not overlap the surface that comes into contact with the combination seal 23. Therefore, even if the surface of the piston 13 that contacts the soil particles is damaged, the surface that contacts the combination seal 23 is not damaged, and as a result, the hydraulic sealing performance can be maintained.

An internal drain groove 22 is provided between the soil removing scraper 21 and the combination seal 23 so that the oil accumulated in the gap between the soil removing scraper 21 and the internal drain groove 22 is discharged. Therefore, even if the soil particles intrude into the gap between the soil removing scraper 21 and the internal drain groove 22, the soil particles are appropriately collected together with the drain oil in the drain tank 30. There is little risk of trouble.

Further, the bearings 24, 25, 26, 27 are arranged on the oil chamber 14 side of the combination seal 23, the bearings 33, 34 are arranged on the oil chamber 15 side of the combination seals 32, 35, and the combination seal 35. Since the bearing 36 is arranged closer to the oil chamber 14 than the oil chamber 14, the bearings 24, 25, 26, 27 and 36 are lubricated by the oil from the oil chamber 14, and the bearings 33 and 34 are lubricated by the oil from the oil chamber 15. To be done. Therefore, the bearing 24,
25, 26, 27, 33, 34, 36 can be used for a long time even if the piston 13 slides repeatedly.

Bearing 3 arranged on the inner peripheral side of piston 13
Since the hardness of 3, 34, and 36 is lower than the hardness of the bearings 24, 25, 26, and 27 arranged on the outer peripheral side of the piston 13, the piston 13 is provided in the gap between the tip outer cylinder 11 and the tip inner cylinder 12. , The contact surfaces of the bearings 33, 34, and 36 with respect to the piston 13 can be easily adjusted by the piston 1 of the 36.
You can get used to 3. Therefore, the fitting tolerance between the piston 13 and the gap formed between the tip outer cylinder 11 and the tip inner cylinder 12 can be loosened.

Since the bearings 24, 25, 26, 27, 33, 34, 36 are arranged on the outer circumference and the inner circumference of the piston 13, even if the piston 13 is tilted, the piston 13 will be attached to the tip end outer cylinder. 11 and the tip end inner cylinder 12, and therefore, the seizure between the tip outer cylinder 11 inner peripheral surface and the piston 13 outer peripheral surface, and the piston 13 inner peripheral surface and the tip inner cylinder 1
2 Seizure with the outer peripheral surface is prevented.

Therefore, in the illustrated example, the vibration generator 4 can be applied to an actual dynamic press-fitting method, and at the same time, the vibration generator 4 which is small in size and has good operability and workability can be provided.

In the illustrated example of the present invention, the case where the scraper and the seal are combined seals has been described.
Needless to say, various changes can be made without departing from the scope of the present invention.

[0067]

As described above, in the cylinder structure of the vibration generator of the present invention, I) According to claims 1 to 6, the vibration generator can be applied to an actual dynamic press-fitting method. It is possible to provide a vibration generator that is small and has good operability and workability. II) In claim 3, the drain accumulated in the internal drain groove between the first scraper and the first sealing means. The fluid is discharged from the drain fluid discharge path to the drain tank, and in this case, if soil particles invade the drain fluid, the fluid is discharged to the drain tank together with the drain fluid. III) Claim 4 Since the distance between the facing surfaces of the first scraper means and the first sealing means is equal to or greater than the full stroke of the piston, the surface of the piston outer peripheral surface that contacts the soil particles contacts the first sealing means. Therefore, even if the surface of the piston that contacts the soil particles is damaged, the contact surface with the first sealing means is not damaged, and as a result, the fluid pressure sealing performance can be maintained. IV) In claim 5, the first and second scraper means are:
The resistance at the time of sliding can be lowered and the sealing performance is also good. V) In claim 6, the first, second and third sealing means are:
The resistance during sliding can be reduced and the sealing performance is also good. VI) In claim 7, when the piston is fitted in the space between the outer cylinder of the tip and the inner cylinder of the tip, the third and fourth Since the fifth bearing can be easily fitted to the sliding surface, it is possible to loosen the fitting tolerance between the piston and the space formed between the outer cylinder of the tip and the inner cylinder of the tip, and moreover, the tip. It is possible to achieve various excellent effects such as preventing the seizure from occurring on the inner peripheral surface of the outer cylinder and the outer peripheral surface of the piston, and the inner peripheral surface of the piston and the outer peripheral surface of the inner cylinder of the tip portion.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an example of an embodiment of a cylinder structure of the present invention.

FIG. 2 is a partial cross-sectional view of a soil removing scraper applied to the cylinder structure of the present invention.

FIG. 3 is a cutaway perspective view showing an example of a combination seal applied to the cylinder structure of the present invention.

FIG. 4 is a partial cross-sectional view of an oil removing scraper applied to the cylinder structure of the present invention.

FIG. 5 is a perspective view showing another example of the combination seal applied to the cylinder structure of the present invention in a broken manner.

FIG. 6 is a side view of a pipe burying device to which the cylinder structure of the present invention is applied.

FIG. 7 is a vertical cross-sectional view of a tip device developed to which the cylinder structure of the present invention can be applied.

8 is a VIII-VIII direction arrow view of FIG. 7. FIG.

FIG. 9 is a side view showing an outline of a vibration generator used in a conventional press-fitting method.

10 is a side view showing an outline of a pipe burying device to which the vibration generating device shown in FIG. 9 is applied.

[Explanation of symbols]

11 Tip outer cylinder 12 Tip inner cylinder 13 pistons 14 Oil chamber (first fluid chamber) 15 Oil chamber (second fluid chamber) 17 Tip head 21 Soil removal scraper (first scraper means) 21a O-ring 21b scraper body 22 Drain groove 23 Combination seal (first sealing means) 23a Inner seal (seal body) 23b O-ring 24 bearings (first bearing) 25 bearings (first bearing) 26 Bearings (second bearing) 27 Bearings (second bearing) 28 Drain oil discharge passage (drain fluid discharge passage) 30 drain tank 31 Oil removal scraper (second scraper means) 31a O-ring 31b scraper body 32 Combination seal (second sealing means) 32a Outer seal (seal body) 32b O-ring 33 bearings (third bearing) 34 bearings (fourth bearing) 35 Combination seal (third sealing means) 36 bearings (fifth bearing) S1 distance (interval) S2 full stroke D1 device propulsion direction

─────────────────────────────────────────────────── ─── Continued Front Page (72) Yuichi Miura, Inventor Yuichi Miura, 1-1-15 Toyosu, Koto-ku, Tokyo Ishikawa Shima Harima Heavy Industries, Ltd. Tokyo Engineering Ring Center (72) Minor Tanaka, Otemachi, Chiyoda-ku, Tokyo 3-3-1 Nihon Telegraph and Telephone Corporation (72) Inventor Toshihiko Takanashi 2-3-1 Otemachi, Chiyoda-ku, Tokyo 3-3-1 Nihon Telegraph and Telephone Corporation (Inventor) Hidenori Hino 2-Otemachi, Chiyoda-ku, Tokyo (3) Nihon Telegraph and Telephone Corporation (56) References JP-A-60-148997 (JP, A) Fukukaihei 3-83251 (JP, U) (58) Fields investigated (Int.Cl. ⁷⁾ , DB name) B06B 1/00-3/04

Claims (7)

(57) [Claims] Claim: What is claimed is: 1. A piston formed in a space formed between a tip outer cylinder and a tip inner cylinder fitted concentrically with the tip outer cylinder so that a piston can be vibrated in a direction parallel to the apparatus propulsion direction. A first fluid chamber is formed between the rear end of the piston in the device propelling direction and the inner circumference of the tip outer cylinder and the outer circumference of the tip inner cylinder. A cylinder structure of a vibration generator in which a second fluid chamber for actuating a piston is formed between the tip inner cylinder and the outer periphery of the cylinder, and a tip head for applying vibration to the ground is attached to the tip of the piston in the device propulsion direction. In between the inner circumference of the outer cylinder of the tip portion and the outer circumference of the piston, from the front to the rear of the device propelling direction, a first scraper means capable of removing soil particles attached to the outer circumference of the piston, The working fluid from the first fluid chamber is ground To prevent leakage to the first seal means and first and second seal means provided to be separated and opposed in the apparatus propelling direction for a predetermined period so as to support a radial load acting on the piston. A cylinder structure of a vibration generator, characterized in that a bearing is provided. 2. A second scraper between the inner circumference of the piston and the outer circumference of the inner cylinder of the tip portion, which can remove the working fluid adhering to the inner peripheral surface of the piston from the front to the rear in the device propelling direction. Means, a second sealing means capable of preventing the working fluid from leaking from the second fluid chamber to the second scraper side, and a first sealing means capable of supporting a radial load acting on the piston. Third and fourth bearings, a third sealing means capable of preventing the working fluid from leaking between the second fluid chamber and the first fluid chamber, and a radial acting on the piston. The cylinder structure of the vibration generator according to claim 1, wherein a fifth bearing adapted to support a load is arranged so that the third and fourth bearings sandwich the second fluid chamber. 3. A space formed between the first scraper means and the first sealing means of the tip outer cylinder by the tip outer cylinder, the piston, the first scraper means and the first sealing means. The cylinder of the vibration generator according to claim 1 or 2, further comprising: a drain groove for discharging the fluid present in (4) to a drain tank provided outside the fluid discharge path through a drain fluid discharge path formed in the outer cylinder of the tip portion. Construction. 4. The cylinder structure of the vibration generator according to claim 1, wherein the distance between the facing surfaces of the first scraper means and the first sealing means is equal to or greater than the full stroke of the piston. 5. The first and second scraper means are made of a resin-made annular scraper body on the sliding side and are formed by an O-ring on the non-sliding side to form a combined seal. The cylinder structure of the vibration generator according to 2, 3 or 4. 6. The first, second, and third sealing means are combination seals in which a sliding side is made of a resin and is formed by an annular seal body, and a non-sliding side is formed by an O-ring. The cylinder structure of the vibration generator according to 2, 3, 4 or 5. 7. The material of the third, fourth and fifth bearings is first,
The rigidity of the second bearing is lower than that of the material of the second bearing.
The cylinder structure of the vibration generator according to 4, 5, or 6.