JP2574190B2 - Seal structure of rotary fluid pressure cylinder device for chuck - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary fluid pressure cylinder device for a chuck which rotatably holds a fluid cylinder member for holding or releasing a chuck attached to a spindle of a machine tool by an externally inserted holding member. More specifically, the present invention relates to a seal structure for preventing oil leakage to the outside from a sliding contact surface to which a flow path for supplying a working fluid from a holding member to a fluid cylinder member is connected.

[0002]

2. Description of the Related Art Conventionally, a chuck for rotatably holding a fluid cylinder member actuated by a pressurized fluid by an externally inserted holding member has been used to hold or release a chuck attached to a main shaft of a machine tool. Rotary fluid pressure cylinder devices are known. (Japanese Patent Laid-Open No. 55-1
No. 44949) is a fluid cylinder member formed by slidably inserting a piston having a piston rod extending on both sides into a cylinder chamber formed therein. It is rotatably held by a holding member externally inserted into the end extension via a bearing. The cylinder chamber is separated into two left and right chambers by a piston, and the working fluid is supplied to one of the separated cylinder chambers and the working fluid in the other cylinder chamber is discharged to drive the piston forward and backward. The jaw of the chuck connected to the piston rod is gripped or released by the reciprocation.

A number of fluid passages for supplying a working fluid to the cylinder chamber or discharging the working fluid from the cylinder chamber are formed in the holding member side in a radial direction, and the fluid cylinder member side is formed in the holding member side passage. A passage groove formed at a predetermined depth corresponding to an outer peripheral position corresponding to an opening of a peripheral surface (sliding contact surface with a fluid cylinder member) is connected to a cylinder chamber by a passage formed in the fluid cylinder member. The fluid passage connecting portion allows the working fluid to flow through a sliding contact surface between the holding member and a fluid cylinder member that rotates relative to the holding member. is there. Bearings interposed between the fluid cylinder member and the holding member are disposed on both sides of the fluid passage connecting portion, and further, the inner periphery of an end outside the bearing of the holding member (the end in the longitudinal direction) is a fluid. The outer periphery of the cylinder member (or the outer periphery of the stopper member fixed to the end of the fluid cylinder member) is brought into non-contact and close proximity, where a labyrinth groove is formed and sealed, and sliding contact between the holding member and the fluid cylinder member is performed. The working fluid is prevented from leaking to the outside through the surface, and the intrusion of the fluid from the outside is also prevented.

[0004]

However, in the above-described conventional structure in which the space between the fluid cylinder member and the holding member is sealed by a labyrinth groove, the number of grooves is increased or the diameter of the groove is increased in order to improve the sealing performance. Is required, and as a result, there is a problem that the seal portion becomes long. Further, in the seal configuration using the labyrinth groove, air flows in either direction in the labyrinth groove, and the fluid in the labyrinth groove is atomized by being stirred by the rotating fluid cylinder member. As a result, the working fluid leaks to the outside or is mixed with the working fluid over a long period of use, and it is difficult to completely seal the working fluid. Was something.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a seal structure of a rotary fluid pressure cylinder device for a chuck which can obtain a complete sealing effect in a non-contact manner without increasing the length of a seal portion. With the goal.

[0006]

For this reason, the seal structure of the rotary fluid pressure cylinder device for a chuck according to the present invention is characterized in that the holding member on the end side of the connecting oil passage formed on the sliding contact surface between the fluid cylinder and the holding member is connected to the fluid. the opposing surface of the cylinder is provided with a labyrinth seal portion formed labyrinth groove above Ichijo, Raburin
The labyrinth is located at the front and rear ends of the
Husband diameter of fringe portion from the sealing portion outer diameter s providing the co
In addition , at least one labyrinth groove communicates with the outside air through the air hole, and the rotation of the fluid cylinder causes
Air flowing in from one side through the labyrinth seal
From the fringe to the inside of the fluid pressure cylinder device
Flow from the other fringe to the outside of the fluid pressure cylinder device
It is configured to flow toward the part . According to this configuration, when the fringe portion is rotated by the rotation of the fluid cylinder , the fringe portion is adjacent to the fringe portion by the pump action.
With air from the labyrinth grooves are attracted to the fringe portion which, in the labyrinth groove outside air flows through the vent holes, as a result, in the boundary the labyrinth grooves, one pretend
To the inside of the fluid pressure cylinder device from the
To the outside of the fluid pressure cylinder device
A flowing air stream results.

[0007] Further, those labyrinth seal portion is configured with labyrinth grooves are formed plural rows in the fluid cylinder axial direction, a labyrinth groove and labyrinth seal outer lateral <br/> end communicating with a fluid outlet It is. Thereby, the fluid that has entered the labyrinth groove is discharged to the outside through the liquid discharge port. Further, in addition to the above configuration, at least one furin
A notch is formed in a side surface of the holding portion, which faces a wall surface of the holding member forming the labyrinth seal portion. to this
The rotation of the fringe due to the rotation of the fluid cylinder
Thus, a larger pump action can be generated.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a rotary oil pressure cylinder device using oil as a working fluid to which an embodiment of a seal structure of a rotary fluid pressure cylinder device for a chuck according to the present invention is applied, and FIG. 2 is a longitudinal sectional view thereof. is there. The illustrated rotary hydraulic cylinder has a disk-like shape in which a cylinder head 11 and a rotary valve 12 are joined together by bolts 13 and a cylinder chamber 14 is formed between the cylinder head 11 and a piston rod 15 on both surfaces thereof. A fluid cylinder 10 as a fluid cylinder member having a piston 16 fitted so as to be relatively slidable.
The piston 16 (i.e., the piston 16) is supplied by supplying pressurized oil to any one of the cylinder chambers 14a and 14b of the cylinder chamber 14 divided into two front and rear chambers by the piston 16 and discharging the oil from the other side. The rod 15) is moved in an arbitrary direction, and the jaws of the chuck are opened and closed via a draw tube (not shown).
The piston 16 is moved back and forth by a pair of guide rods 17 and 17 suspended and fixed to the cylinder head 11 and the rotary valve 12 so as to be parallel to the axial direction of the piston rod 15 at a position facing the piston 16 in the radial direction. You will be guided.

On the outer periphery of the rotary valve 12, a sleeve 2
1 are fitted at their axial ends so as to be relatively rotatable via bearings 22 and 22, respectively.
Through a bolt 26, a large-diameter front end 23 overlaps with the outer periphery of the cylinder head 11 and covers the sleeve body 20. The sleeve body 20 has a drain reservoir 25 having an external connection port 24 formed below. Positioning is fixed. In this embodiment, a holding member is constituted by the sleeve 21 and the sleeve body 20.
The sleeve 21 has a drain hole 2 facing the drain reservoir 25.
7.27 are formed as openings. Guide rod 17.1
7, a check valve mechanism A / A 'comprising a check valve which is biased by a spring (not shown) is provided, and a rotary valve 1 which supports the guide rods 17 is provided.
2, a pilot mechanism B / B 'for operating the check valve mechanism A / A' is provided therein.

The front and rear cylinder chambers 14a and 14b are formed with external connection ports 28a and 28b formed in the sleeve body 20.
And an oil passage 29a formed in the sleeve 21 in the radial direction.
29b and a hydraulic oil supply / discharge oil passage 18a / 18b drilled in the rotary valve 12, and the oil passages 29a / 29b and the hydraulic oil supply / discharge oil passage 18a
Hydraulic oil is supplied to the cylinder chambers 14a and 14b via 18b, and hydraulic oil is discharged from the cylinder chambers 14a and 14b. Oil passage 29 of sleeve 21
a. 29b and the connecting portion between the hydraulic oil supply / discharge oil passages 18a and 18b of the rotary valve 12 are connected to the oil passage 29a of the sleeve 21.
On the outer periphery of the rotary valve 12 corresponding to the 29b opening position,
Oil grooves 19a and 19b are formed at a predetermined depth, and hydraulic oil supply and discharge oil passages 18a and 1 are formed in the oil grooves 19a and 19b.
8b are connected to each other, so that hydraulic oil can flow between the non-rotating sleeve 21 and the rotating rotary valve 12. The hydraulic oil supply / discharge oil passages 18a and 18b are provided with the above-described check valve mechanisms A and A 'as shown in FIG. ′ Is the pilot passage 18
It is connected to the other pilot mechanism B, B 'via p.18p.

Here, the check valve mechanisms A and A 'act to prevent the flow of the pressure oil from the cylinder chambers 14a and 14b when the supply hydraulic pressure is reduced, and to maintain the work holding force of the chuck. The pilot mechanisms B and B 'open the check valve mechanism (A') on the other side when supplying pressure oil to one cylinder chamber (e.g., 14a).
b) works so that the oil inside can be discharged. An annular stopper 30 is fastened to the rear end (left end in the figure) of the rotary valve 12 via a flinger 31 by a bolt 32, so that the outer periphery of the stopper 30 does not come into contact with the rear end of the sleeve body 20. And are formed in a concavo-convex shape that exhibits a labyrinth seal structure with each other.
A disc-shaped fringe portion 33 is formed at the outer end of the stopper 30. That is, a labyrinth seal portion 40 is formed between the outer periphery of the stopper 30 and the rear end portion of the sleeve body 20, and a fringe member 31 and a fringe portion 33 as fringe members are provided on both sides of the labyrinth seal portion 40.
Are provided adjacent to each other, and the diameter of the rotating member (stopper 3) constituting the labyrinth seal portion 40 is
0) is formed larger than the diameter of the adjacent part. In the labyrinth seal portion 40, three labyrinth grooves 41, 42, 43 continuous in the circumferential direction are formed adjacent to the outer periphery of the stopper 30 in the axial direction.
Reference numerals 42 and 43 communicate with the outside through intake holes 41a, 42a and 43a formed in the upper position of the sleeve body 20, respectively. Also, as shown in FIG.
The labyrinth groove 41 on the outer end portion is located outside the sleeve body 20, and the inner labyrinth groove 43 is located inside the sleeve body 20 via oil drain holes 41b and 43b formed at lower positions in the sleeve body 20, respectively. Are in communication.

According to the above-described configuration, when the rotary valve 12 rotates, the stopper 30 is rotated with the rotation.
Of the sleeve body 2 with the fringe portion 33 and the fringer 31
0, the air between the fringe portion 33 and the wall surface of the sleeve body 20 forming the fringe portion 31 and the labyrinth seal portion 40 is radially blown outward from the rotation center side by the pump action. It will be. Air can be supplied to the respective labyrinth grooves 41, 42, and 43 from the outside via the intake holes 41a, 42a, and 43a. As a result, as shown by arrows in the drawing, the labyrinth grooves 41 on the outer end side have Air is sleeve body 20
The air in the inner labyrinth groove 43 generates an air flow to be sucked out inside the sleeve body 20, and the air flow is generated outside the labyrinth seal portion 40 with the central labyrinth groove 42 interposed therebetween. Oil in the form of a mist due to the rotation of the rotary valve 12, the fringe portion 33, and the fringer 31 does not pass through the labyrinth seal portion 40 in the air flow, and high sealing performance is obtained. It is. The labyrinth seal part 4
As described above, the oil in the liquid state that has reached 0 is discharged from the labyrinth groove 41 through the oil drain hole 41b.
Hydraulic oil leaking from the inside is discharged from the labyrinth groove 43 through oil drain holes 43b, respectively, and the hydraulic oil discharged through the oil drain holes 43b is collected in the drain reservoir 25 in the sleeve body 20. Things.

On the other hand, the stopper 3 described above is also provided at a portion where the front end 23 of the sleeve body 20 and the cylinder head 11 are opposed to each other.
A labyrinth seal portion 50 substantially similar to the labyrinth seal portion 40 formed between the sleeve body 20 and the sleeve body 20 is formed. That is, two labyrinth grooves 51 and 52 continuous in the circumferential direction are formed on the inner periphery of the front end portion 23, and the fan 60 is mounted on the outer periphery of the cylinder head 11 adjacent to the front side of the front end portion 23. A flinger 53 is mounted on the outer periphery 12 a of the rotary valve 12 having the same diameter as the cylinder head 11 adjacent to the rear surface of the front end 23. The labyrinth grooves 51 and 52 are communicated with the outside through intake holes 51a and 52a formed at upper positions of the sleeve body 20. The labyrinth groove 51 on the rotary valve 12 side communicates with the inside of the sleeve body 20 via an oil drain hole 51b formed at a lower position of the sleeve body 20. The fan 60 is set so as to blow the air on the front side to the rear side by the rotation of the cylinder head 11 mounted thereon, and the outer periphery of the fan 60 is formed on the outer periphery of the sleeve body 20 at the rear end. Is covered by a substantially columnar cover 61 attached to the
Air is allowed to flow in between the fan head 60 and the outer periphery of the cylinder head 11 on the front end side, and an exhaust hole 62 is formed at the rear end of the mounting portion to the sleeve body 20.

With the above configuration, the cylinder head 1
When the rotary valve 1 and the rotary valve 12 rotate, the fan 60 and the flinger 53 rotate relative to the sleeve body 20 with the rotation, and the fan 60 sucks air into the cover 61 from the front side and discharges air from the exhaust hole 62. A flow is generated, and the air between the fan 60 and the wall surface of the sleeve body 20 is radially sucked outward from the rotation center side by the same pumping action as the flinger by the fan 60, and the air is sucked out of the flinger 53 and the sleeve. The air between the wall of the body 20 and the center of rotation is also blown radially outward. The labyrinth grooves 51 and 52 have suction holes 5
Air can be supplied from outside through 1a and 52a,
As a result, as shown by the arrow in the figure, the front labyrinth groove 5
2, the air in the labyrinth groove 51 on the rear side is inside the sleeve body 20.
Air flows in the opposite directions to be sucked out are generated, so that the atomized oil does not ride on the air flow and pass through the labyrinth seal portion 50, so that high sealing performance is obtained. The liquid hydraulic oil leaking from the inside is discharged from the labyrinth groove 51 on the rear side through the oil discharge hole 51b, and is collected in the drain reservoir 25 in the sleeve body 20.

Here, the flinger 31 in the above embodiment is used.
And the labyrinth seal portions 40 and 50 of the flinger 53
By forming a notch C having a concave shape on the surface opposite to the wall surface of the notch C as shown in FIG. -The sealing effect can be further improved by strengthening the airflow from between the 53 and the wall surface. The same applies to the fringe portion 33 of the stopper 30. It goes without saying that the number of the notches C can be set to any number. The labyrinth seal portion 40 according to the present invention is used.
The number of fifty labyrinth grooves is not limited to the above-described embodiment. For example, one labyrinth groove can function effectively, and three or more labyrinth grooves may be used and may be changed as appropriate. Also, not all labyrinth grooves need to communicate with the outside air side, it is only necessary to communicate at least one labyrinth groove to the outside air side, and which of the plurality of labyrinth grooves communicates with the outside air side is also optional. It is selectable. Further, instead of the fringe members (fringe portion 33, fringer 31, fringer 53) in the above embodiment, as shown in FIG. 7, a sealing material formed by projecting the lip 71 obliquely with an elastic material such as rubber or the like. 70 is provided on the rotating member 90 with the tip of the lip 71 abutting against the adjacent wall surface 81 of the labyrinth seal portion 80. When the rotating member 90 rotates, the tip of the lip 71 is
It may be configured to function as a fringe member apart from the main body. According to this configuration, when the rotating member 90 is not rotating, the lip 71 is sealed by contact with the wall surface 81.

[0016]

According to the seal structure of the rotary fluid pressure cylinder device for a chuck according to the present invention as described above, the fringe member having a diameter larger than the outer diameter of the labyrinth seal forming portion is provided on both sides of the labyrinth seal portion of the fluid cylinder member. Is provided close to the wall surface of the holding member forming the labyrinth seal portion, and the labyrinth groove of the labyrinth seal portion is configured to communicate with the outside air through the vent hole, so that the fringe member due to the rotation of the fluid cylinder member is formed. The air is sucked from the adjacent labyrinth groove to the fringe member side by the pumping action generated by the rotation, and outside air flows into the labyrinth groove through the ventilation hole. As a result, each of the fluid entry sides is separated from the labyrinth groove as a boundary. The mist oil rides on the air flow and passes through the labyrinth seal. Rukoto can be prevented, without lengthening the seal portion, in which it is possible to obtain a perfect sealing effect in a non-contact.

[Brief description of the drawings]

FIG. 1 is a perspective view of a rotary hydraulic pressure cylinder device using oil as a working fluid to which an embodiment of a seal structure of a rotary fluid pressure cylinder device for a chuck according to the present invention is applied.

FIG. 2 is a longitudinal sectional view of FIG.

FIG. 3 is a conceptual configuration circuit diagram of a check valve mechanism and a pilot mechanism.

FIG. 4 is an enlarged cross-sectional view of a rear end side seal portion of a sleeve body.

FIG. 5 is an enlarged sectional view of a front end side seal portion of a sleeve body.

FIG. 6 is a perspective view of a fringe.

FIG. 7 is a sectional view showing another embodiment of a fringe.

[Explanation of symbols]

10 fluid cylinder (fluid cylinder member) 18a / 18b (connection oil passage) 19a / 19b (connection oil passage) 20 ... sleeve body (holding member) 21 ... sleeve (holding member) 29a / 29b (connection oil passage) 31 · 53 · · · Fringer (fringe member) 33 · · · Fringe portion (fringe member) 40 · 50 · labyrinth seal portion 41 · 42 · 43 · 51 · 52 · labyrinth groove 41a · 42a · 43a · 51a · 52a · intake hole ( Vent holes) 41b, 43b, 51b: Oil drain holes (fluid discharge holes) C: Notches

Claims (3)

(57) [Claims] 1. A rotary fluid pressure cylinder device for a chuck for rotatably holding a fluid cylinder for gripping or releasing gripping of a chuck attached to a main shaft of a machine tool by an externally inserted holding member, wherein the holding member is provided. And the fluid
A working fluid is supplied from the holding member to the fluid cylinder through the connection flow path formed on the sliding contact surface of the cylinder ,
The holding member on the end side from the connection oil passage and the fluid
Labyrinth seal portion formed one or more strips of the labyrinth grooves on the facing surface of the Sunda At a what is provided, the fluid cylinder axial front and rear ends of the labyrinth seal portion
In the labyrinth seal portion outer diameter than the diameter of the fringe portion
Respectively provided with, at least Article labyrinth grooves of the labyrinth seal portion is communicated with the outside air through the vent hole, by rotation of said fluid cylinder, it flows from the vent holes
The air that has flowed through the labyrinth seal part causes one free
From inside the fluid pressure cylinder device
Flow from the other fringe section to the fluid pressure cylinder device
The seal structure of the rotary fluid pressure cylinder device for a chuck, wherein the seal structure is configured to flow toward the outside of the chuck. 2. The labyrinth seal portion is formed by forming a plurality of labyrinth grooves in an axial direction of a fluid cylinder , and the labyrinth groove at a lateral end is communicated with the outside of the labyrinth seal portion via a fluid discharge port. 2. The seal structure for a rotary fluid pressure cylinder device for a chuck according to claim 1, wherein: According to claim 3 wherein at least one of the fringe portion, the wall facing the side face of the holding member forming the labyrinth seal portion, the notch is formed, according to claim 1 or 2, characterized in Seal structure of rotary fluid pressure cylinder device for chuck.