JP2531823B2 - Swivel for rotating water jet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to demolition of concrete structures, cutting and crushing of concrete and / or rock, excavation of ground, metal working,
The present invention relates to a swivel for a rotary water jet used in various construction methods such as cleaning the surface of concrete or metal and removing paint.

[Prior Art] In recent years, as a new technology for performing various construction methods such as cutting, crushing, excavation, and processing on reinforced concrete, rock, ground, metal, etc., the abrasive jet has rapidly spread in the construction industry. .

The abrasive jet has the characteristics of low noise, no vibration, no dust, and excellent remote controllability, and when performing the dismantling method of existing structures or the various methods described above,
It can be a promising basic technology for achieving automation of work and reduction of pollution. On the other hand, due to the fact that the construction cost is higher than other cutting methods, and the ability to cut thick members decreases, it has not been generalized as a construction method, and it has not been used as a method for housing remodeling or reactor biological shielding walls. It is only used under special conditions such as dismantling.

A rotary water jet can be considered as one of the methods that can solve the problems of cost and capacity in the abrasive jet. This technique has been mainly studied for drilling and cutting hard rock, and is characterized in that the cutting width is widened by rotating the nozzle body, and the nozzle can be inserted into the groove as the cutting progresses. Therefore, there is an advantage that even a thick member can be constructed with a constant ability. Further, since no abrasive is used, the running cost is lower than that of the abrasive jet.

[Problems to be Solved by the Invention] Here, there are a packing seal and a mechanical taper seal as a sealing method of a swivel (rotating joint) generally used in a rotary water jet. When used at high speed for a long time under the pressure of, the packing will generate heat due to friction on the sealing surface, wear will occur, or rotational load will occur due to frictional resistance, so there is a problem in durability of the seal part. there were. Along with this, there is a problem in that the entire device (including the rotary power unit) is downsized.

An object of the present invention is to provide a swivel for a rotary water jet, which can improve the durability of a seal portion and can make the entire apparatus compact.

[Means for Solving the Problems] In a swivel for a rotary water jet of the present invention, a seal inner cylinder is fitted into an inner hole of a rotating shaft that rotates a nozzle body provided with a nozzle, and the seal inner cylinder is provided with an outer periphery thereof. A seal outer cylinder that forms a clearance is provided, and the seal outer cylinder is supported by a connector connected to a high-pressure pump via an elastic ring.

It is preferable that both the seal inner cylinder and the outer cylinder are made of a cemented carbide (for example, tungsten carbide) and have a true cylindrical shape.

The clearance is preferably 1 to 6 microns, the length of the sealing surface is 20 to 50 mm, and the outer diameter of the inner cylinder is preferably 5 to 15 mm.

Further, although it is preferable that the nozzle body is provided with a pair of nozzles, one or a plurality of nozzles can be provided depending on the layout.

In addition to this, it is possible to connect the seal inner cylinder to another member via an elastic ring.

[Operation] In the rotary water jet swivel of the present invention configured as described above, since water leaks to the outside through the clearance, the inner cylinder and the outer cylinder are kept in non-contact with each other. Therefore, the friction between the two cylinders is reduced, and therefore the wear of the member due to the friction and the rotational load due to the frictional resistance are greatly reduced. As a result, the durability of the rotary water jet swivel is greatly improved.

Further, since the outer cylinder is supported by the connector via the elastic ring, the axis of the outer cylinder has a degree of freedom with respect to the axis of the connector. Therefore, when the axes of both cylinders do not match with an accuracy of, for example, 1 micron or more (it is usually extremely difficult to match with an accuracy of 1 micron or less), the outer cylinder has a water pressure balance. Due to the presence of the above degrees of freedom, the outer cylinder follows the inner cylinder, and the axes of both cylinders coincide. If the axes of both cylinders coincide with each other, it is possible to prevent a large stress from occurring between both cylinders.

According to the present invention, it is possible to reduce the size of the entire swivel for a rotary water jet as the durability is greatly improved.

Here, instead of balancing only the outer cylinder,
Both the inner cylinder and the outer cylinder can be configured to be hydraulically balanced.

Further, since both cylinders are formed in a true cylinder shape, neither radial load nor thrust load is generated in both cylinders.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 and 2, the rotary water jet nozzle assembly is provided with a rotary swivel R. A spur gear 14 is provided on the insertion tube 2 which is the rotation shaft of the swivel R, and a spur gear fixed to the output shaft of a stepping motor 17 mounted on the swivel R via a fixing base 16 is mounted on the spur gear 14. 15 meshed.
A nozzle body B having a nozzle N is attached to the end of the insertion tube 2.

In FIG. 3, a connector 4 connected to a high pressure pump (not shown) is screwed into one end of the body 1 of the rotary swivel R, and a boss 3 with a flange is screwed into the other end.

A nozzle body B is screwed into one end of the insertion tube 2 and sealed by an O-ring 22, and the other end is rotatably supported by the main body 1 and the boss 3 via ball bearings 8, 8. It is sealed by a ring 19, a stopper ring 6 and an oil seal 7. A thrust bearing 9 is interposed between the flange portion 2a and the boss 3. The spur gear 14 is fixed to the insertion tube 2 with a key 20.

An inner hole 2b is formed in the insertion tube 2, and a clearance seal inner cylinder 10 is attached to a large diameter portion 2c of the insertion tube 2 by a holding bolt 5 screwed to an end portion of the insertion tube 2 and is sealed by an O-ring 21. ing.

The inner cylinder 10 has an inner hole 10 having a smaller diameter than the inner hole 2b of the insertion tube 2.
A is formed, and the connector 4 side of the inner hole 10a is formed as a tapered hole 10b having a diameter slightly larger than the inner hole 4a of the connector 4.

A clearance seal outer cylinder 11 that forms a clearance C is provided on the outer periphery of the inner hole 10, and the outer cylinder 11 is fixedly supported on the small diameter portion 4b of the connector 4 by an O ring 12 and a backup ring 13 which are elastic rings. There is.

Both the inner cylinder 10 and the outer cylinder 11 are made of a cemented carbide (for example, tungsten carbide) in a true cylindrical shape, and their sealing surfaces are finished with extremely high precision. And both 1
The clearance C of 0 and 11 is, for example, 1 to 6 microns, the length L of the sealing surface is, for example, 20 to 50 mm, and the outer diameter D of the inner cylinder 10 is
Is formed in a size selected from the range of 5 to 15 mm, for example.

For example, when cutting a concrete structure, the motor 17 is operated to rotate the nozzle body B via the insertion tube 2, and the high-pressure water from the high-pressure pump is jetted from the rotating nozzle N while the nozzle body B is horizontally moved. Moving. As a result, a cutting groove having a relatively large width dimension is formed.

At the time of cutting, as shown by an arrow in FIG. 3, water leaks through the clearance C, so that the inner cylinder 10 and the outer cylinder 11 are kept in no contact. Therefore, the wear due to the friction of the two cylinders 10 and 11 and the rotational load due to the frictional resistance are greatly reduced. In addition, according to the experiment, the rotation load is extremely smaller than that of the taper seal (about 1/20 when the pressure is 196Mpa), and the leak amount is as low as 50cc / min (passage flow rate 50 liters / min 0.1%). It is a value. Regarding the durability, when measured after 50 hours, it was found that the change in the clearance C was as small as 0.1 micron or less, and the durability was significantly improved.

Further, since the outer cylinder 11 is supported by the connector 4 by the O-ring 12 and the backup ring 13 which are elastic rings, the axis of the outer cylinder 11 is, for example, 10 mm relative to the axis of the connector 4.
It has a degree of freedom of a few millimeters. Therefore, both cylinders 10, 11
If the axes of the two do not match with an accuracy of 1 micron or more (it is usually extremely difficult to match with an accuracy of 1 micron or less), the outer cylinder 1 follows the inner cylinder 10 and both cylinders The axes of 10 and 11 are aligned with each other, and it is suppressed that a large stress is generated between the two cylinders 10 and 11.

Further, since both cylinders 10 and 11 are formed in a true cylindrical shape, neither radial load nor thrust load is generated in both cylinders 10 and 11.

FIG. 4 shows another embodiment of the present invention. In the embodiment shown in FIGS. 1 to 3, the outer cylinder 11 is balanced and the inner cylinder 10 is
However, in the embodiment shown in FIG. 4, both the outer cylinder 11 and the inner cylinder 10 are balanced. In FIG. 4, members corresponding to those in the embodiment of FIGS. 1 to 3 are designated by the same reference numerals. However, reference numerals 21 and 22 indicate O-rings for sealing.

EFFECT OF THE INVENTION Since the present invention is configured as described above,
The durability of the seal part can be improved. Along with that
The entire rotary water jet nozzle assembly can be made compact.

[Brief description of drawings]

FIGS. 1, 2 and 3 are a front view, a top view and a side sectional view showing a rotary water jet nozzle assembly equipped with a swivel according to an embodiment of the present invention, and FIG. It is a partially expanded side view which shows other Examples of this. B ... Nozzle body, C ... Clearance, N ... Nozzle, R ... Rotary swivel, 1 ... Main body, 2 ... Insertion tube, 2c ... Large inner diameter part, 4 ... Connector, 10 ... Clearance Seal inner cylinder, 11 …… Clearance seal outer cylinder, 12
…… O ring, 13 …… Backup ring

Claims (1)

(57) [Claims] 1. A seal inner cylinder is inserted into an inner hole of a rotating shaft for rotating a nozzle body having a nozzle, and a seal outer cylinder is provided on the outer circumference of the seal inner cylinder to form a clearance. A swivel for a rotary water jet, wherein the seal outer cylinder is supported by a connector connected to a high-pressure pump.