JP2001082612A - Seal device for screwing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for preventing liquid leak from a screw part in a tool installation mechanism of a tool attached and detached by the screw part. SOLUTION: A first member 13 having a male screw part 13a, a second member 14 having a female screw part 14a to be screwed with the first member 13, and a seal member 21 protruded from an outer surface of the male screw part 13a or from an inner surface of the female screw part 14a to shield a spiral gap formed at a screwing part between the male screw part 13a and the female screw part 14a at least at one position for preventing liquid leak from the screwing part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing liquid leakage from a threaded portion of a threaded structure.

[0002]

2. Description of the Related Art Conventionally, in a threaded joint or the like, in order to prevent liquid leakage from a threaded joint portion, a seal tape is wound or a sealing material is applied to a threaded surface to eliminate a gap. I have. In addition, a seal portion or the like using an elastic O-ring is separately provided in a portion other than the screw portion, and sealing is performed to prevent liquid leakage.

[0003]

However, in the case where the attachment and detachment are repeatedly performed at the screwing portion between the main body of the chuck and the nut for exchanging the tool, like a tool holder, a seal tape is wound every time. It is troublesome to apply the sealing material. Further, in the case of the seal using the O-ring, since a portion for attaching the O-ring is required in addition to the screw portion, the device becomes large correspondingly, and it is difficult to apply the device to a small one.

Accordingly, the present invention relates to a threaded joint for preventing a liquid from leaking from a threaded portion with a simple structure in a screw joint such as a water distribution pipe or a nut and a main body of a collet chuck of a tool holder. It is an object to provide a sealing device.

[0005]

In order to achieve the above object, a sealing device in a threaded structure according to the present invention has a first member having a male screw portion and a female screw portion. A second member to be fitted, projecting from the outer surface of the male screw portion or projecting from the inner surface of the female screw portion, to form at least one helical gap formed at a screwing portion between the male screw portion and the female screw portion. And a seal member for shielding at different locations.

[0006] With this configuration, a gap formed spirally along the thread groove is blocked, and liquid leakage is prevented.

[0007] Preferably, the sealing member is an elastic member having a width longer than a half pitch of the male screw or the female screw in the axial direction of the screw.
The elastic member has a width longer than the pitch.

[0008] Preferably, at least the base of the seal member is a cylindrical elastic body.

Preferably, at least the tip of the seal member is formed so as to correspond to a substantially inclined angle of a screw thread or a screw groove of the screw. Thereby, the adhesion of the sealing member to the thread surface is enhanced.

[0010] Preferably, the seal member and the second member protruding from the inner surface of the female screw portion have a step or taper structure for preventing the seal member from falling from the female screw portion. This prevents the seal member from falling when the first and second members are separated from each other.

[0011] Preferably, the seal member includes a shape portion having alternately ridges and valleys corresponding to the threads of the thread portion and the threads, respectively. This makes it possible to seal at a plurality of locations.

[0012] Preferably, the seal member includes a resilient single-cell urethane or an equivalent thereof.

[0013] Preferably, the seal member is disposed longitudinally in the screw axis direction at a helical end of a male screw or a female screw.

[0014] Preferably, the above-mentioned screwing structure sealing device is applied to a tool holder.

Further, the tool device of the present invention has a chuck body having a male screw portion, a collet for holding a tool, and a female screw portion, and the collet is attached to the chuck body by screwing with the chuck body. Nuts,
A sealing member projecting from the outer surface of the male screw portion or projecting from the inner surface of the female screw portion to shield a helical gap formed at a threaded portion between the male screw portion and the female screw portion at at least one position; Is provided.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. First, an example of a device having a screw structure will be described.

FIG. 1 shows a tool device (or tool holder).
FIG. 2 is a perspective view showing a collet chuck as an example of FIG.
Is a front view of the collet chuck, and FIG. 3 is a sectional view of a mounting nut portion of the collet.

1 to 3, a tool device 1 generally includes a tapered portion 1 mounted on a main shaft of a machine tool (not shown).
1. A gripper 12, which is gripped by a manipulator of an automatic tool changer (not shown), a chuck body 13, a nut 14, a hollow drill (tool body) 15, a collet 16 for gripping the drill 15, a thrust ball 17, and the like. ing.

The collet 16 has a plurality of slit-shaped cuts in the axial direction of the drill 15 and can be expanded and contracted in the radial direction. After inserting the drill 15 into the collet 16, the nut portion 14 is attached to the chuck body 13, and the female screw 14 a of the nut portion 14 is connected to the male screw 13 of the chuck body 13.
When the drill 15 is screwed and tightened, the drill 15 is gripped tightly by the tapered portion of the collet 16, and the drill 15 is mounted on the tool device 1.

A coolant (coolant (oil)) is supplied to the tool device 1 from the machine tool side to the tapered portion 11.
The coolant is further blown out of the drill tip from the rear end of the drill 15 through a passage inside the drill 15 to cool the cutting edge of the drill 15 and to blow off chips of a work (not shown). Some of the coolant passes through the gap between the collets 16 and
Further, a threaded portion (1) between the chuck body 13 and the nut portion 14 is formed.
3a, 14a) and may leak to the outside.

Therefore, studies were made to prevent this leakage. FIG. 4 shows an example of play (gap) between a male screw and a female screw. As shown in FIG. 4A, there is a slight play between the male screw 13a and the female screw 14a, which causes liquid leakage. Further, when the male screw 13a and the female screw 14a are tightened, as shown in FIG. 4B, the gap is offset in one direction, and a gap of about a half pitch is generated. This gap is spirally continuous along the slope of the thread. The coolant leaks along the spiral gap. FIG.
(C) shows the case of another combination of the male screw 13a and the female screw 14a having different thread shapes. Also in this example, a gap of about a half pitch is formed in a spiral shape.

FIG. 5 shows an embodiment of the present invention. In the figure, parts corresponding to those in FIG. 3 are denoted by the same reference numerals, and description of such parts is omitted. FIG. 6 is a cross-sectional view showing a cross section in the VI-VI ′ direction in FIG.

In the embodiment, a hole 20 is formed in the threaded portion of the nut portion 14 and a sealing member 21 and a screw 22 are provided in order to block the above-mentioned spiral gap. Hole 20
Is an opening (penetrating) at the center of the bottom and a stepped (stepped) hole in the middle. In the hole 20, a cylindrical base 21a
An elastic body including the sealing member 21b is inserted as the sealing member 21. The seal member base 21a is provided at the stepped portion of the hole 20.
The projections (or drops) of the seal member 21 are prevented by the engagement of the jaws. As the elastic body, for example, single-cell urethane can be used, and synthetic rubber having the same function may be used. The mounting screw 22 is attached to the thread groove on the inner periphery of the hole 20, and the sealing member 21 is pressed downward from above. The seal portion 21b protrudes from the inner periphery of the female screw and is in close contact with the male screw 13a, and interrupts a helical gap between the male screw 13a and the female screw 14a.

FIGS. 7 to 11 show a nut portion (female screw side).
14 shows various examples of formation of a seal member 21 provided on the 14 side.

The sealing member 21 shown in FIG.
a is cylindrical, and a prismatic seal portion 21b extends downward from the base. As shown in FIG. 2B, the seal portion 21b has a width corresponding to approximately one pitch of the thread (distance between adjacent threads or between thread grooves). The lower end side of the seal portion 21b is formed to have a dimension located below the valley of the male screw 13a, contracts and deforms by abutting against the outer surface of the male screw 13a, and closes the male screw 13a to shield the gap. Thereby, the valley of the male screw 13a and the ridge of the female screw 14a, the ridge of the male screw 13a and the valley of the female screw 14a, the male screw 1
The spiral gap generated between the inclined surface 3a and the inclined surface of the female screw 14a is interrupted in the middle of the spiral, so that coolant leakage is prevented.

The seal member 21 shown in FIG.
Seal portion 21b extending downward from cylindrical base 21a
Is characterized by the shape of the tip. The tip shape is sharp, and the tip angle is determined to be an angle (screw angle) between the inclined surfaces of the threads of the substantially external thread 13a. As a result, the seal portion 21b is brought into close contact with the male screw.

FIG. 9A is characterized by a seal portion 21b extending downward from a cylindrical base portion 21a. The seal portion 21b is formed in a cylindrical shape. As a result, FIG.
As shown in (b), the seal portion 21b is designed to be in close contact with a male screw.

FIG. 10A is characterized by a distal end portion of a cylindrical seal portion 21b extending downward from a cylindrical base portion 21a. The shape of the tip is sharp, and the angle of the tip is determined so as to be an angle (screw angle) between the inclined surfaces of the threads of the substantially external thread 13a. As a result, FIG.
As shown in (b), the seal portion 21b comes into close contact with the male screw 13a with less deformation.

FIG. 11A is characterized by a seal portion 21b extending downward from a cylindrical base 21a. The width of the seal portion 21b is substantially equal to one pitch and a half, and
The tip shape of 1b is formed in a shape corresponding to the thread and valley of the male screw. As a result, as shown in FIG. 11B, the seal portion 21b adheres with a longer width along the shape of the threads and valleys of the male screw 13a, and the gap can be more reliably shielded.

The above-mentioned seal member 21 is provided with a female screw 14a.
Although it is provided on the side, it may be provided on the male screw side.

FIG. 12 shows this example. In the figure, parts corresponding to those in FIG. 5 are denoted by the same reference numerals, and description of such parts is omitted. Male thread portion 13a of chuck body
Is formed with a groove 13b, and a seal member 21 is provided in the groove 13b. The seal member 21 is a male screw 1
The helical gap formed by the 3a and the female screw 14a is blocked to prevent coolant leakage.

FIGS. 13 to 19 show various examples of the seal member 21 provided on the male screw 13a side.

FIG. 13A shows a prismatic seal member 21 arranged in a groove formed in the male screw 13a. This seal member 21 has a width corresponding to one pitch in the screw axis direction. As shown in FIG. 13B, a rectangular column-shaped groove 13b corresponding to the shape of the seal member is formed in the male screw 13a, and the seal member 21 is housed in the groove 13b. Thereafter, when the nut portion 14 is screwed into the male screw 13a, the seal member 21 is sandwiched between the male screw 13a and the female screw 14a and elastically contracts. Thereby, the male screw 13a and the female screw 14a
The gap between them is shielded.

FIG. 14A shows a prismatic sealing member 21.
Is formed so as to have a substantially thread angle (an angle formed by inclined surfaces on both sides of the thread). As shown in FIG. 14 (b), a prismatic groove 13b corresponding to the shape of the sealing member is formed in the male screw 13a.
The seal member 21 is accommodated in 3b. Nut part 1
When the screw 4 is screwed into the male screw 13a, the seal member 21 is sandwiched between the male screw 13a and the female screw 14a and elastically contracts. Thereby, the gap between the male screw 13a and the female screw 14a is shielded. Since the distal end side of the seal member 21 is inclined, there is less unreasonable deformation during contraction deformation than the columnar seal member 21 shown in FIG.

FIG. 15A shows a cylindrical sealing member 21.
Is shown. As shown in FIG. 15B, the male screw 13a has a cylindrical groove 1 corresponding to the shape of the sealing member.
3b is formed, and the seal member 21 is housed in the groove 13b. When the nut portion 14 is screwed into the male screw 13a,
The seal member 21 is sandwiched between the male screw 13a and the female screw 14a and elastically contracts. Thereby, the gap between the male screw 13a and the female screw 14a is shielded.

FIG. 16A shows a cylindrical sealing member 21.
Is formed so that the tip of the thread has a substantially thread angle.
As shown in FIG. 16B, a cylindrical groove 13b corresponding to the shape of the seal member is formed in the male screw 13a, and the seal member 21 is accommodated in the groove 13b. When the nut portion 14 is screwed into the male screw 13a, the seal member 21 is sandwiched between the male screw 13a and the female screw 14a and elastically contracts.
Thereby, the gap between the male screw 13a and the female screw 14a is shielded. Since the end of the seal member 21 has an angle, excessive deformation is less likely to occur than the seal shown in FIG. Note that the tip of the cylindrical seal member may have a conical or truncated cone shape.

The seal member 21 shown in FIG. 17 (a) has a width of a plurality of pitches (two pitches in this example) in the axial direction of the screw, and has a shape corresponding to the shape of the prismatic base 21a and the female screw 14a. Shaped (or rack-shaped) seal portion 21b
Consists of As shown in FIG. 17B, the male screw 13a is formed with a prismatic groove 13b corresponding to the shape of the base 21a, and the seal member 21 is accommodated in the groove 13b. When the nut portion 14 is screwed into the male screw 13a, the seal member 21 is sandwiched between the male screw 13a and the female screw 14a and elastically contracts. Thereby, the male screw 13a and the female screw 14a
Each of the plurality of gaps therebetween is shielded. Therefore, liquid leakage is more reliably prevented.

The seal member 21 shown in FIG. 18A is a horizontal columnar elastic body having a width of a plurality of pitches (two pitches in this example) in the axial direction of the screw. Male screw 13a
As shown in FIG. 18B, a semi-cylindrical groove 13b extending in the screw axis direction is formed in a part of the male screw 13a, and the cylindrical seal member 21 is accommodated in the groove 13b.
When the nut portion 14 is screwed into the male screw 13a, the seal member 21 is sandwiched between the male screw 13a and the female screw 14a and elastically contracts. Thereby, a plurality of gaps (two places in this example) existing in the axial direction between the male screw 13a and the female screw 14a are shielded.

The sealing member 21 shown in FIG. 19A also has a width of a plurality of pitches (two pitches in this example) in the axial direction of the screw, but the upper half of the horizontal columnar elastic body corresponds to the female screw. To form a thread-like (or rack-like) shape. As shown in FIG. 18B, the male screw 13a has
A semi-cylindrical groove 13b extending in the screw axis direction is formed in a part of the male screw 13a, and the seal member 21 is accommodated in the groove 13b. When the nut portion 14 is screwed into the male screw 13a,
The seal member 21 is sandwiched between the male screw 13a and the female screw 14a and elastically contracts. Thereby, a plurality of gaps (two places in this example) existing in the axial direction between the male screw 13a and the female screw 14a are shielded. In this case, the sealing member 21
The shape of the upper part is in conformity with the shape of the female screw 14a, so that the seal easily adheres.

The sealing member 21 shown in FIG. 20A also has a width of a plurality of pitches (two pitches in this example) in the axial direction of the screw, and has a screw shape corresponding to the shape of the prismatic base 21a and the female screw 14a. (Or a rack-shaped) seal portion 21b. In this example, a columnar elastic member is cut out in a columnar shape in a direction perpendicular to the center axis thereof, and a curved surface of the cutout member is formed in a rack shape. FIG. 20 shows the external thread 13a.
As shown in (b), a prismatic groove 13b corresponding to the shape of the base 21a is formed, and the seal member 21 is accommodated in the groove 13b. When the nut portion 14 is screwed into the male screw 13a, the sealing member 21 is formed into a male screw 13a and a female screw 14a.
It is sandwiched between and elastically contracts. Thereby, the male screw 13a
A plurality of gaps (two locations in this example) existing in the axial direction between the female screw 14a and the female screw 14a are shielded. The edge of the rack-shaped portion is a curved surface (a column). Therefore, the elastic contraction of the seal member 21 is made more uniform, and liquid leakage is more reliably prevented.

The sealing member 21 shown in FIG. 21A also has a width of a plurality of pitches (two pitches in this example) in the axial direction of the screw, and has a screw shape corresponding to the shape of the prismatic base 21a and the female screw 14a. (Or a rack-shaped) seal portion 21b. In this example, the upper end surface of the columnar elastic member is formed in a rack shape. FIG. 21 shows the external thread 13a.
As shown in (b), a columnar groove 13b corresponding to the shape of the base 21a is formed, and the seal member 21 is accommodated in the groove 13b. When the nut portion 14 is screwed into the male screw 13a, the sealing member 21 is formed into a male screw 13a and a female screw 14a.
It is sandwiched between and elastically contracts. Thereby, the male screw 13a
The plurality of gaps between the screw and the female screw 14a are shielded. Therefore,
Liquid leakage is more reliably prevented than in the case shown in FIG.

FIG. 22 shows that the helical end of the external thread 13a
An example in which the seal member 21 is arranged is shown. In the figure, parts corresponding to those in FIG. 5 are denoted by the same reference numerals, and description of such parts is omitted. With a configuration in which the seal member is disposed at the end of the male screw portion 13a, formation of a groove for accommodating the seal member or maintenance of the seal member is easy.

In this example, the seal member 21 is disposed in a groove 13b formed in the end portion of the male screw 13a in the axial direction and longitudinally. Examples of the sealing material in this case are shown in FIGS.

For example, the sealing member 2 shown in FIG.
Reference numeral 1 is a horizontal columnar elastic body having the same configuration as the seal member shown in FIG. 18A and having a width of a plurality of pitches (two pitches in this example) in the axial direction of the screw. As shown in FIG. 23 (b), the male screw 13a
A semi-cylindrical groove 13b extending in the screw axis direction in a part of 3a
Is formed, and the columnar seal member 21 is housed in the groove 13b. When the nut portion 14 is screwed into the male screw 13a, the seal member 21 is sandwiched between the male screw 13a and the female screw 14a and elastically contracts. Thereby, a plurality of gaps (two places in this example) existing in the axial direction between the male screw 13a and the female screw 14a are shielded.

The seal member 21 shown in FIG. 24A has the same configuration as the seal member shown in FIG.
It has a width of a plurality of pitches (two pitches in this example) in the axial direction of the screw, but the upper half of the horizontal columnar elastic body is formed in a thread shape (or a rack shape) corresponding to the female screw. ing. As shown in FIG. 24B, the male screw 13a has a semi-cylindrical groove 13b formed in a part of the male screw 13a and extending in the screw axis direction.
Is stored. When the nut portion 14 is screwed into the male screw 13a, the seal member 21 is sandwiched between the male screw 13a and the female screw 14a and elastically contracts. Thereby, a plurality of gaps (two places in this example) existing in the axial direction between the male screw 13a and the female screw 14a are shielded. In this case, the sealing member 2
Since the upper shape of 1 is in accordance with the shape of the female screw 14a, the seal is easily adhered.

In the examples shown in FIGS. 22 to 24, the seal member 21 is arranged at the spiral end of the male screw, but may be arranged at the spiral end of the female screw.

As described above, according to the embodiment of the present invention, it is possible to prevent liquid leakage from the attachment portion of the device for attaching members to each other by the screw structure.

[0048]

As described above, according to the sealing structure of the threaded structure of the present invention, the spiral gap generated in the threaded structure is shielded by the elastic member to prevent the liquid from leaking. There is no need to wrap tape all over or apply sealing material to the screws. Even if screws are repeatedly attached and detached for tool change, etc., the sealing performance against liquid leakage is not lost. In addition, since sealing is performed by the threaded portion, there is no need for a structural part or space for sealing other than the threaded portion, unlike the shielding by the O-ring, so that the condition is good.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a collet chuck as an example of a tool device.

FIG. 2 is a front view of the collet chuck shown in FIG. 1;

FIG. 3 is a sectional view of a chuck unit.

FIG. 4A is an explanatory diagram illustrating play with a male screw and a screw. FIG. 2B is an explanatory diagram for explaining the existence of a spiral gap in a screwed state with a male screw and a female screw.

FIG. 5 is a sectional view of a chuck unit for explaining an embodiment of the present invention.

FIG. 6 is a sectional view taken along the line VI-VI ′ of FIG. 5;

FIG. 7 shows a seal member 2 provided on the female screw side.
FIG. 3 is an explanatory diagram showing an example of No. 1.

FIG. 8 is an explanatory diagram showing an example of a prismatic seal member 21 provided on the female screw side.

FIG. 9 is an explanatory view showing an example of a cylindrical seal member 21 provided on the female screw side.

FIG. 10 is an explanatory view showing an example of a sealing member 21 provided on the female screw side and having a tapered tip portion.

FIG. 11 is an explanatory view showing an example of a sealing member 21 provided at the female screw side and having a rack-like end.

FIG. 12 is an explanatory diagram illustrating an example of a chuck in which a seal member 21 is provided on a male screw side.

FIG. 13 is an explanatory diagram showing an example of a prismatic seal member 21 provided on the male screw side.

FIG. 14 is an explanatory view showing a modified example of the prismatic sealing member 21 provided on the male screw side.

FIG. 15 is an explanatory view showing an example of a vertical cylindrical seal member 21 provided on the male screw side.

FIG. 16 is an explanatory view showing a modification of the cylindrical seal member 21 provided on the male screw side.

FIG. 17 is an explanatory diagram showing an example of a rack-shaped seal member 21 provided on the male screw side.

FIG. 18 is an explanatory view showing an example of a horizontal columnar seal member 21 provided on the male screw side.

FIG. 19 is an explanatory view showing a modification of the cylindrical seal member 21 provided on the male screw side.

FIG. 20 is an explanatory view showing an example of a rack-shaped seal member 21 provided on the male screw side.

FIG. 21 is an explanatory view showing a modification of the cylindrical seal member provided on the male screw side.

FIG. 22 is an explanatory diagram illustrating an example of a chuck in which a seal member 21 is provided at an end of a male screw.

FIG. 23 is an explanatory view showing an example of a horizontal columnar seal member 21 provided at the end on the male screw side.

FIG. 24 is an explanatory diagram showing an example of a horizontal rack-shaped seal member 21 provided at the end on the male screw side.

[Explanation of symbols]

 13 Chuck body 13a Male screw part 13b Groove provided in male screw part 14 Nut part 14a Female screw part 20 Hole 21 Seal member 22 Mounting screw

Claims (9)

[Claims] A first member having a male screw portion; a second member having a female screw portion and screwing with the first member; and an inner surface of the female screw portion projecting from an outer surface of the male screw portion. And a seal member that projects from and seals a helical gap formed at a threaded portion between the male screw portion and the female screw portion at at least one location, and prevents liquid leakage from the threaded portion. Sealing device for screw structure. 2. The sealing device according to claim 1, wherein the seal member is an elastic member having a width longer than a half pitch of the male screw or the female screw in the axial direction of the screw. 3. The sealing device according to claim 1, wherein at least the base of the sealing member is a cylindrical elastic body. 4. The threaded structure according to claim 1, wherein at least the tip of the seal member is formed so as to correspond to a substantially inclined angle of a screw thread or a screw groove of the screw. Sealing device. 5. The seal member and the second member projecting from the inner surface of the female screw portion have a step or a taper structure for preventing the seal member from falling from the female screw portion.
The sealing device for a screwed structure according to any one of claims 1 to 4. 6. The threaded structure according to claim 1, wherein said seal member includes a shape portion having a crest and a valley alternately corresponding to the thread of said thread and said thread groove. Sealing device. 7. The sealing device for a threaded structure according to claim 1, wherein the sealing member includes urethane foam. 8. The device according to claim 1, wherein said seal member is disposed at a spiral end of said male screw portion or said female screw portion.
The sealing device according to any one of claims 6 and 7. 9. A tool holder comprising the screwing structure sealing device according to claim 1.