JPH0232519B2 - RYUTAIYOKAITENTSUGITE - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a technology that can be suitably applied to a rotary fluid pressure cylinder installed on the main shaft of a machine tool and used together with a chuck, and is a technology that can be suitably applied to a rotary fluid pressure cylinder or the like that is installed on the main shaft of a machine tool and is used with a chuck. This invention relates to the structure of a rotary joint for fluid used when supplying fluid.

The structure of the conventional rotary joint for fluids is
As is clear from No. 24803, it had a structure in which an annular flow path was interposed in the middle of the fluid passage when supplying pressurized fluid from a stationary body to a rotating body.
The drawback was that a large amount of pressurized fluid leaked from the wide micro gap created between the stationary part and the rotating part.

However, in order to further reduce the leakage of the pressurized fluid, it is necessary to make the minute gap smaller or to create a circular flow path for the pressurized fluid toward the consuming device and an annular flow path for the digestive fluid returning through the consuming device. There is no choice but to widen the interval between the two and separate them far apart, resulting in disadvantages such as an increase in heat generation, seizure, and an increase in the overall length of the fluid rotary joint.

Japanese Patent Laid-Open No. 131882/1982 proposes a structure that is effective in reducing the leakage of pressurized fluid, which is the disadvantage mentioned above, to some extent. However, regarding the arrangement positions of the pressurized fluid supply tact 19 and the digestion fluid recovery duct 20, there is no technology regarding the fact that the arrangement positional relationship between the two plays an extremely important role in preventing leakage of the pressurized fluid. Furthermore, there is no disclosure whatsoever regarding a technique for preventing the boss 23 from rotating under eccentric loading as a means to further drastically reduce the leakage of the pressurized fluid.

The present invention successfully eliminates the above-mentioned drawbacks, and is characterized by being formed of a stationary body, a rotating body that is rotatably supported by the stationary body, and a sleeve interposed between the two, A plurality of radially oriented fluid passages are bored in the sleeve, and the fluid passages are axially arranged in parallel and in a staggered arrangement, with one row being a pressurized fluid passage;
In addition to forming the other row as a digestive fluid passage, the stationary body is provided with a pressurized fluid inlet and a digestive fluid outlet, and the rotating body is provided with a pressurized fluid supply passage and a digestive fluid outlet. The purpose is to drill a discharge passage.

A specific example will be described in which the fluid is oil and the present invention is applied to a rotary hydraulic cylinder for opening and closing a chuck.

FIG. 1 is a partially cutaway perspective view of a rotary hydraulic cylinder consisting of a supply body A and a rotating body B provided with a pressurized oil consumption device, and FIG. 2 is a longitudinal sectional view of the cylinder.

In Figures 1 and 2, 1 is a cylinder, 2
is a piston rod; 3 is a piston fixed on piston rod 2;
It is fitted so that it can slide freely inside. Reference numeral 5 denotes a rotary valve into which the piston rod 2 is inserted, and a locking mechanism 6, 6 for regulating oil flow in only one direction is incorporated therein, and is connected to the cylinder 1 using a bolt 7. It will be done. 8, 9, and 10 are O-rings for keeping the cavity 4 airtight.

Reference numeral 11 denotes a guide pin fixed to the piston 3, and either end P or P' of the guide pin is always guided into a guide pin hole 12 provided in the cylinder 1 or the rotary valve 5 (in the illustrated example, toward the cylinder side). As a result, free rotation of the piston rod 2 is restricted.

On the other hand, one end of the piston rod 2 is threadedly connected to the draw tube to move the jaw of a chuck (not shown).

On the other hand, the rotary valve 5 is provided with two large and small key-shaped steps, one of which is a large-diameter key-shaped step K1, and the other is a small-diameter key-shaped step K2. A sleeve body 13 is provided in part K2. The sleeve 14 is press-fitted into the sleeve body 13 in the following manner. That is, the bearings 15, 15' fitted into both ends of the sleeve 14
One of the bearings (15 in the illustrated example) is in direct contact with the inner wall of the sleeve body 13, and the other bearing (15' in the illustrated example) is attached to the inner side of the sleeve cover 17, which is joined to the sleeve body 13 with bolts 16. It is fixed and integrated so that it comes into contact with the wall. Therefore, the inner periphery of the sleeve 14, which is stationary together with the sleeve body 13, is always in contact with the outer periphery of the rotating small-diameter key-shaped stepped portion K2 through a slight gap space, and the radial spacing of the gap space is usually This is a tiny gap of several tens of microns. Further, a stopper 18 is attached to the end edge of the small diameter key-shaped stepped portion K2.
It is attached using 9.

Next, the operation of the piston 3 within the cylinder 1 will be explained as follows. Pressurized oil from an external supply device (oil tank) (not shown) passes through the oil passage 25 through the oil filler port 24 of the sleeve body 13, and is led to the oil passage 26 and oil chamber 27 via the lock mechanism 6.
The piston 3 is moved by pressing. Digestion oil pushed out from the oil chamber 27' as the piston 3 moves passes through the lock mechanism 6', the oil passage 25', and the oil drain port 24'.
from there to an external supply device.

The forward stroke of the piston is completed due to the above action,
When moving to the return process, the aforementioned oil drain port 24' is changed to the oil fill port, and the oil fill port 24 is changed to the oil drain port by switching the switching valve (not shown). The reverse process is performed using a similar reverse path circuit. At this time, a small amount of pressurized oil is removed from the rotary valve 5.
It is supplied to the bearings 15, 15' on both sides through the small gaps T, T' between the sleeve 14 and the drain reservoir 2 after lubricating the bearings 15, 15'.
2 and then collected to an external supply device. At this time, a communication hole f is formed inside the sleeve 14, and the annular oil drain passages f1 and f2 are made to communicate with each other, so that the amount of oil supplied to both bearings 15, 15' is maintained in balance.

Through the operations detailed above, the chuck is opened and closed, a workpiece (not shown) is grasped, and the workpiece is machined while maintaining this state.

Next, regarding the ingenuity of the rotating joint structure, which is the main part,
This will be explained with reference to FIGS. 3 to 6. 3 is a Z-Z cross-sectional view of FIG. 2, FIG. 4 is a perspective view of the sleeve 14, FIG. 5 is a perspective view of the rotary valve 5, and FIG. 6 is a lubrication oil passage and drainage inside the sleeve 14. FIG. 3 is a partially enlarged view of a developed plan view showing the arrangement of oil passages. As is clear from the figure, annular oil passages 25a and 25'a are provided in parallel on the outer periphery of the sleeve 14 in the axial direction. Oil passages 2 (6 locations each in Figure 3)
5b and 25'b are drilled radially. On the other hand, on the outer periphery of the rotary valve 5, the oil passages 25b and 2
A plurality of oil passage reservoirs 25c are formed by cutting a part of the outer periphery of the rotary valve 5 into a bow-shaped shape so as to open corresponding to one or more of the openings of the rotary valve 5; 25c, ...... and 25'c, 2
5'c,... are arranged respectively, and the oil passage reservoir 2
5c includes the oil passage 25, and the oil passage reservoir 25'c.
The oil passages 25' are opened and communicated with each other (the example in FIG. 3 shows three oil passage reservoirs 25c (25'c) and two oil passages 25 (25')). Seat materials R1, R2, and R3 are oil passages 25a and 25'a.
This is an O-ring to prevent oil leakage from the
Further, the sleeve body 13 and the sleeve 14 are fixedly fixed in a non-rotatable state by a set screw U. When fixing the sleeve body 13 and sleeve 14 by shrink fitting, use the O-rings R1, R2, R3 and set screws U.
It is also possible to omit this to create a more compact structure. In addition, oil passages 25a, 25'a and sealing materials R1, R2,
A groove R3 may be provided on the sleeve body 13 side.

However, the pressurized oil supplied from the oil filler port 24 is
A large number of oil passages 25b, 25 pass through the annular oil passage 25a.
The oil passage reservoir 25c is distributed to either b,...
The oil is guided to the oil passage 25 and supplied to the consuming device. On the other hand, the oil passage 2
Digestion oil pushed out to the oil passage 5' is guided to the oil passage reservoir 25'c, and then returned to the annular oil passage 25'a through one of the many oil passages 25'b, 25'b, . . ., and is discharged. It is collected into the oil tank via the oil port 24'.

The fact that the pressurized oil is supplied from multiple locations while circulating within the sleeve body 13 and the sleeve 14 is effective in cooling the rotary joint, and also reduces the pressure of the pressurized oil on the rotary valve 5. The rotary valve 5 is superior in that it acts in a balanced manner in the radial direction, and the rotary valve 5 does not rotate under eccentric load conditions. Therefore, the oil passage 25b,
25b,... and the oil passages 25'b, 25'b... are preferably drilled in multiple radial arrangements that are equally divided if the weight of the rotary valve 5 is ignored, and the openings corresponding to these oil passages are It is also important that the oil passage reservoirs 25c and 25'c are provided at multiple locations on the oil passage valve 5 at equal intervals and formed in a structure that will not receive eccentric loads.

In the above embodiment, the sleeve body 13 and the sleeve 14 are constructed as separate bodies, but the supply body 80 has an integral structure, and a large number of oil passages are directly provided in the supply body 80 in an equal arrangement. It may be.

Another idea is that the pressurized oil oil passages 25b, 2
5b,... column and digestion oil oil passages 25'b, 25'b,...
In relation to the rows, this is a technique in which the oil passages drilled in each row are arranged at intermediate positions of the other oil passages, forming a so-called staggered arrangement.

To explain this in more detail, the oil passage reservoir 25c is
Since the rotary valve 5 is arranged in a bow-string shape on a part of the outer circumference, the supplied pressurized oil flows out only through the small gap formed in the non-contact part with the lubrication oil passage 25b provided in the sleeve 14. It is the same thing.

Therefore, the leakage of pressurized oil from the annular oil drain paths f1 and f2 to the drain reservoir 22 is extremely small.

Furthermore, since the oil supply passage 25 and the oil drainage passage 25'b are arranged in a staggered manner as shown in FIG.
This also reduces the amount of oil that enters the drainage oil passage 25'b.

However, the effect obtained from the above configuration is that there is little leakage of pressurized oil, and the generation of conversion heat due to this can be extremely reduced. Furthermore, since the distance l between the annular oil passages 25a and 25'a can be made small, the shear heat of the pressurized oil in the minute gap is also extremely reduced. Therefore, it is very suitable for making the device smaller and more compact.

In particular, when comparing the present embodiment with the conventional one and assuming that the amount of leakage is the same, it is possible to select a large microgap, which is advantageous in terms of machining process accuracy and rough machining accuracy. Furthermore, since the shearing force caused by the pressurized oil is reduced, it also exhibits an extremely excellent effect in reducing torque resistance.

Furthermore, the bowstring-shaped notches S and S' provided in the oil passages 25b and 25'b cushion the impact when the pressurized oil flows, and prevent the deterioration phenomenon in which the pressurized oil becomes foamy. Alternatively, it exhibits excellent action and effect in preventing impact noise.

Furthermore, cutting oil passage reservoirs at equal intervals on the outer periphery of the rotating body is very effective in preventing vibration of the rotating joint during high-speed rotation.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a rotary hydraulic cylinder, FIG. 2 is a longitudinal sectional view of the entire cylinder, FIG. 3 is a Z-Z sectional view of FIG. 2, and FIG. 4 is a sleeve 1.
4, FIG. 5 is a perspective view of the rotary valve 5, and FIG. 6 is a partially enlarged view of a developed plan view showing the arrangement of the lubrication oil passage and the oil drainage oil passage in the sleeve 14. be. 1...Cylinder, 2...Piston rod, 3...
... Piston, 5 ... Rotary valve, 6, 6' ... Lock mechanism, 13 ... Sleeve body, 14 ... Sleeve, 22 ... Drain reservoir, 24 ... Oil filler port,
24'...Oil drain port, 25, 25'...Oil passage, 25
a, 25'a...Annular oil passage, 25b...Oil supply oil passage, 25'b...Oil drainage oil passage, 25c, 25'c...
...Oil passage reservoir, 27, 27'...oil chamber, A...supply body (stationary body), B...rotating body, K2...rotary valve bearing part, f1, f2...oil drain path.

Claims (1)

[Scope of Claims] 1. It is formed from a stationary body, a rotating body that is rotatably supported by the stationary body, and a sleeve interposed between the two, and the sleeve has a large number of fluid passages oriented in the radial direction. and provide the fluid passages in parallel in the axial direction in a staggered arrangement, with one row serving as a pressurized fluid passage and the other row serving as a digestive fluid passage. A rotary joint for fluid, characterized in that the rotary body is provided with a pressurized fluid inlet and a digestive fluid outlet, and the rotating body is provided with a pressurized fluid supply passage and a digestive fluid discharge passage. . 2. The fluid rotary joint according to claim 1, wherein the rotating body has a plurality of supply passages for pressurized fluid, and the passages are arranged at equal intervals.