JPH0242790Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Purpose of the invention Industrial application field This invention is applicable to the work of penetrating a penetrating body, especially a hollow pipe (casing) for construction such as a sand pile, into the ground.
The present invention relates to a fluid jet device for promoting penetration.

Conventional technology When constructing sand drain piles etc. on improved ground, a process of penetrating a casing into the ground is included, but generally, penetrating the casing involves installing an exciter, vibrator, etc. at the upper end of the pipe. Vibration is applied to the suspended casing, using the weight and vibration of the tube and vibrator. However, there may be cases where there is a hard layer in the ground that is being penetrated and the penetration action of the casing is too gradual, or there is a desire to complete the penetration work in a short time due to the schedule, or there is a desire to proceed with the penetration work efficiently. An additional operation is performed to assist the penetrating action of the casing. One method is to install multiple air jets near the outer periphery of the lower end of the casing, as shown in Figure 3, to inject compressed air into the ground as the pipe penetrates, loosening the tightness of the ground and reducing penetration resistance. There are means to weaken the casing and assist in the penetrating action of the casing. At this time, the ejected air is dispersed into the ground soil, and most of it is emitted upward through the outer periphery of the casing. However, since the injected fluid is air with a light specific gravity, the jet effect on the ground/soil is relatively mild. Another option is to apply a water jet nozzle. Water is more effective than air because it has a higher specific gravity. The above figure shows a schematic side view of the entire device, and in the figure, 1 is a casing, 2 is a penetrating end of the casing, 3 is a vibrator installed at the upper end of the casing 1, and a wire is connected to the vibrator 3. 4, and the entire penetrating device is suspended by a wire 4' via a buffer. Reference numeral 5 denotes a hopper for charging sand, aggregate, etc. into the casing 1, and is installed at the upper end of the casing 1. Reference numeral 6 denotes an air supply pipe which assists the action of increasing the pressure inside the casing when sand, etc. put into the casing is discharged from the pipe, and 7 a sand discharge/compaction member 8 installed around the penetrating end of the casing.
The operating cylinder/piston mechanism 9 is a pipe that supplies fluid to the tip jet device 10 . A plurality of tip jet devices 10 are installed near the penetration end 2 of the casing 1, and the jet injection direction thereof coincides with the penetration direction of the casing.

The detailed structure of the tip jet device 10 is shown in FIG.
As shown in the cross-sectional view, a conical valve seat 13 that opens outward at the opening edge of the center hole 12 of the nozzle body 11
A thread 14 for screwing into the fluid supply pipe 9 is cut on the outer peripheral surface of the other end. 15 is a mushroom valve having a conical surface that contacts the valve seat 13;
6 is the valve rod, and the rod 16 is the center hole 1 of the nozzle.
2, the other end passes through the support plate 18, and a helical spring 19 is interposed between the end 17 and the support plate 18, so that the valve body 15 is always pressed against the valve seat 13. is energized to form a check valve. The jet device with the above structure can be used with either air or water, and during casing penetration work,
By supplying pressure fluid from the supply pipe 9 as necessary, the check valve is opened against the bias of the helical spring 19, and the arrow is passed between the valve 15 and the valve seat 13 into the ground/soil. It is designed to eject a jet flow in the same direction.

As mentioned above, the direction of the nozzle in the jet device is the same as the direction of penetration of the casing 1, so it can be used when the casing penetrates into the ground without injecting fluid from the nozzle, or when the casing does not require injection of fluid. In the case of penetration work, there is a risk that the ground/soil will be forced into the nozzle hole 12 and clog the nozzle. For this reason, it is understood that the jet device of the conventional structure was provided with a check valve as described above at the opening end of the nozzle hole as a measure to prevent backflow of soil. By the way, the nozzle with the structure shown in Figure 4 should theoretically be able to completely prevent backflow of the ground/soil, but because the nozzle and valve seat are structurally too close to each other,
(1) Backflow materials tend to clog the valve seat, and the ability to prevent backflow to the ground/soil is poor.

Since the nozzle opening end has a conical structure that expands outward, (2) the jet jet is easily dispersed, and the jetting force is weaker than when the jet jet is converged.

Since the nozzle and check valve have an integral structure, (3) if one of the parts wears out, the entire system must be replaced, which is uneconomical.

There are other drawbacks.

Problems to be solved by this invention Therefore, the purpose of this invention is (1) to develop a nozzle device that prevents foreign matter from clogging the check valve seat, and (2) to make the injection jet as convergent as possible. (3) When the nozzle is worn out, it can be repaired with a new one by replacing only the nozzle member; (4) The nozzle member can be replaced to change the shape of the injection jet as necessary. (5) It is an object of the present invention to provide a fluid jet device having the following characteristics: (5) only the nozzle member can be heat-treated and it is easy to obtain a material that is resistant to wear.

(b) Means for solving the structural problems of the invention The jet device of the present invention consists of: In the injection nozzle, upstream of the fluid passing through the nozzle, the inner wall of the valve body forms a conical valve seat that expands downstream, and the conical valve in contact with the valve seat is always urged upstream to act as a check valve. On the other hand, the check valve body is sandwiched and concentrically assembled between the nozzle body adjacent to the downstream side and the fluid supply pipe on the upstream side, and can be removed when the nozzle body is attached or detached. A fluid jet device characterized in that it is provided in a fluid jet device.

The device having the configuration described below is also a modification of the jet device of the present invention described above, and can achieve the same purpose.

(2) The nozzle body installed on the downstream side of the check valve is heat-treated and screwed onto the end of the fluid supply pipe with a screw, and the valve body of the check valve is attached to the end of the fluid supply pipe with a screw. 2. The fluid jet device according to item (1) above, wherein the fluid jet device is energized by a fluid.

(3) The nozzle body has a spherical surface facing outward around the fluid injection port.
Fluid jet device described in (1) and (2).

(4) The fluid jet device as set forth in items (1) and (2) above, wherein the nozzle body is provided with a surface surrounding the fluid injection port that extends outward in a conical shape continuously from the port.

(5) The fluid jet device according to items (1) to (4) above, which uses compressed air or pressurized water as the jetting fluid.

The effects of the jet device having the above structure are as follows.

Function During the casing penetration work, when pressure water is supplied from the fluid supply pipe to promote the penetration action, the check valve opens against the spring pressure and penetration pressure, and the valve,
The pressurized water injected through the gap in the valve seat first overflows into the cylinder chamber provided at the base of the nozzle body downstream of it, and then passes through the nozzle hole where the flow path is narrowed, converting the pressure into flow velocity and controlling the injection direction. Since they are injected from the nozzle into the ground at the same time, a large injection force can be obtained compared to the flow rate.

Since the nozzle opening edge forms a spherical, parabolic, or conical surface that is open to the outside, the injected fluid easily leaves the nozzle and the injection direction is less dispersed, and the fluid injection can be stopped and the ground/soil can be removed easily. When external pressure from the nozzle is applied to the nozzle, the same surface produces an arch action effect and performs a primary blocking action against backflow due to earth pressure, first of all preventing the nozzle from clogging.

Furthermore, since the check valve structure is installed on the upstream side of the fluid passing through the nozzle, even after the injection of pressurized water is stopped, it is less likely to be subjected to backflow action due to earth pressure, and it is less likely to be affected by the backflow effect due to earth pressure. This way, there is no risk of foreign matter getting caught between the valve and the valve seat and impairing the effectiveness of the check valve. Moreover, the service life can be extended accordingly. The check valve is screwed between the end of the fluid supply pipe and the nozzle body to ensure a watertight fixation between the two, and can be disassembled as a whole, making it easy to repair and repair. When performing maintenance and inspection of the device, it is sufficient to replace only the target parts individually, which is economical.

The nozzle body can be easily changed to a different type of nozzle as needed, such as one with a small flow rate and high jet power, or one with a high flow rate and low jet power, or another nozzle with desired characteristics. It is possible to exchange it for Further, since the nozzle body is screwed to the center of the end face of the fluid supply pipe, the sliding contact with the ground/soil is relatively small, which is advantageous against wear.

Furthermore, by removing only the nozzle body and subjecting it to heat treatment, wear of the nozzle during use can be reduced.

Embodiment 1 FIG. 1 is a longitudinal cross-sectional view showing a part of the jet device of the present invention, in which 9 is a fluid supply pipe, 20 is a connecting tube welded to the end of the pipe, and the opening of the pipe is shown in FIG. The inner end wall is provided with a threaded groove 14 into which the nozzle body 21 is screwed, and a tapered surface that contacts and supports a conical surface portion formed on the check valve body 27. 2
Reference numeral 7 denotes a check valve main body, which has a conical surface on its outer periphery that opens downstream in the flow direction and seats on the tapered surface of the connecting cylinder 20, and has a hole in its center into which the valve rod 16 is fitted concentrically. A hollow portion 12 that guides fluid toward the valve seat 13 and a plurality of holes 26 that communicate the inside of the connecting cylinder 20 and the hollow portion 12 are provided on the upstream side. Also, adjacent to the previous hollow part 12,
On the downstream side thereof, a valve seat 13 having a conical surface open in the downstream direction is formed. Reference numeral 15 is the aforementioned mushroom valve having a conical surface that contacts and seats on the valve seat 13, and the valve rod 16 extends toward the upstream side through the valve body 27, and the end portion 17 and the valve body 27 are connected to each other. This is the same as the conventional device in that a helical spring 19 is interposed between the valve levers to urge the valve rod so as to press the mushroom valve 15 against the valve seat 13, thereby forming a check valve. However, in this embodiment, the check valve itself is a unit and is assembled so that it can be removed from the connecting cylinder 20 by itself.

21 is a nozzle body, and a connecting cylinder 2 is attached to the outer periphery of the nozzle body.
0 is provided with a thread groove 14 for screwing into the connecting cylinder 20, and the tip thereof is formed in the shape of a hexagonal nut, so that even if it is screwed into the connecting cylinder 20 with a spanner, tightened, or vibrated, it will not loosen unnecessarily. It is fixed so that it does not. At its center, a hollow portion 22 communicating with the downstream side of the check valve is bored, followed by a nozzle portion 23, and a spherical or parabolic surface 24 opening outward is formed at the periphery of the opening. It is continuous. The nozzle body 21 is heat-treated to impart wear resistance to the nozzle hole and outer peripheral surface.

When the nozzle body 21 is screwed onto the connecting tube 20, the check valve having the above-mentioned structure is assembled in advance at a predetermined position in the hollow part of the connecting tube 20, and then when the nozzle body 21 is screwed on, a check valve is formed on the upstream end surface of the nozzle body 21. The valve body 27 is pressed and crimped against the connecting cylinder 20 side to form a watertight seal and fix the space between the two. Therefore, when removing the nozzle body 21 from the device, the entire check valve unit can be removed from the connecting tube 20, allowing all parts to be disassembled and assembled. Furthermore, the nozzle body 2
1. By preparing models with various combinations of large and small nozzle diameters and long and short lengths, it is easy to replace nozzles with appropriate characteristic values depending on the construction ground. can. According to this embodiment, since the nozzle opening forms an outwardly open spherical or parabolic surface, an arch action effect against earth pressure is generated here even when the casing is penetrated with fluid injection stopped. In addition to primarily preventing foreign matter from being press-fitted into the nozzle, the check valve is located deep inside the nozzle on the upstream side, which secondarily prevents foreign matter from flowing backwards. There is almost no chance that foreign matter will go back to the point where it becomes clogged.

Example 2 Figure 2 shows the nozzle body 2 of the jet device of the present invention.
In the figure, 21 is a nozzle body, the outer periphery of which is provided with a threaded groove 14 for screwing into the connecting cylinder, and the tip thereof is It is formed in the shape of a hexagonal nut and is screwed onto the connecting tube using a spanner or wrench to ensure that it does not loosen unnecessarily even against vibrations. At its center is a hollow section 2 that communicates with the downstream side of the check valve.
2, and a nozzle part 2 adjacent to this.
3 are connected to each other, and furthermore, a conical surface 25 expanding outward is formed on the opening edge thereof. The apex angle of the conical surface is
Since any angle in the range of 30° to 120° is adopted, and the length of the generatrix on the side surface of the truncated cone can be varied in length or short, the shape of the nozzle opening edge can be of various types. As in Example 1, the nozzle diameter and length can also be changed to various types depending on the characteristics of the ground, and the functions and effects are also the same as those described in Example 1. be.

In this embodiment as well, the check valve and other structures are the same as in the first embodiment, so these parts will not be described again.

(c) Effects Since the jet device of the present invention is configured as described above, compared to conventional jet devices, (1) the check valve is installed deep on the upstream side of the nozzle; Therefore, even during penetration operation when fluid injection is not performed or stopped, the backflow of foreign matter due to earth pressure will not reach the check valve, and the valve seat will not be clogged with foreign matter.

(2) An independent and removable nozzle is installed downstream of the check valve, so the nozzle shape can be freely selected.
By simply replacing the nozzle body, it is possible to converge the jet stream as much as possible to enhance the jet effect, or to diffuse it as necessary.

(3) The nozzle body can be removed from the jet device and replaced without leaving the device as it is, and the check valve unit can also be disassembled, making it possible to repair and maintain the jet device by simply replacing parts. It is economical.

(4) By forming the nozzle opening edge into an outward-opening spherical, parabolic, or conical surface, the shape of the jet flow is adjusted, and the nozzle is created by the earth pressure when the jet device penetrates the ground with the jet stopped. The backflow into the nozzle is prevented by the arch action effect of the surface, thereby preventing foreign matter from clogging the nozzle or the check valve.

(5) The nozzle body protrudes and the fluid is injected from there, which reduces wear on the entire device.Also, since the nozzle body is fixed to the device and the material can be heat treated, the nozzle body It can also reduce wear on itself.

etc., it will produce special effects.

[Brief explanation of the drawing]

FIG. 1 is a partially cut away vertical cross-sectional view of one embodiment of the jet device of the present invention, FIG. 2 is a cross-sectional view of another embodiment of only the nozzle body, and FIG.
The figure is a schematic side view of a known casing penetrating device equipped with a jet device, and FIG. 4 is a longitudinal sectional view of a conventional jet device. 12...Hollow part, 13...Conical valve seat, 14...
...Screw, 15...Valve body (mushroom valve), 16...Valve rod,
17... Valve rod end, 19... Hanging spring, 20
...Connecting tube, 21... Nozzle body, 22... Hollow part, 23... Nozzle hole, 24... Nozzle opening,
26...Communication hole, 27...Check valve body.

Claims (1)

[Scope of utility model registration request] In a fluid injection nozzle installed near the tip of a hollow pipe for creating sand piles, etc., facing the direction of penetration of the hollow pipe, the inner wall of the valve body has a conical surface that expands downstream at the upstream side of the fluid passing through the nozzle. A conical valve that forms a valve seat and is in contact with the valve seat is always urged upstream to constitute a check valve, while the check valve body is connected to a nozzle body adjacent to the downstream side thereof and a nozzle body adjacent to the upstream side. 1. A fluid jet device, which is assembled concentrically between a fluid supply pipe and is detachable when a nozzle body is attached or detached.