JPH11320319A - Machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machine tool to reliably remove chips by reliably preventing leakage of compressed air in a feed route. SOLUTION: A machine tool comprises a discharge port 7 formed in the reception part 36 of a main spindle 34; a receipt part 8 formed on the outer peripheral surface of the main spindle 34; a first supply passage 2 to intercommunicate the discharge port 7 and the receipt part 8; a feed part 9 formed on the inner peripheral surface of an annular member 33 in a manner to be positioned opposite to the receipt part 8 when the main spindle 34 is indexed in a specified rotation position; and a second feed passage 3 communicated with the feed part 9. An annular groove 5 is formed along a peripheral direction in the inner peripheral surface of the annular member 33 on both sides in an axial direction with the feed part 9 nipped therebetween. A seal body 6 having a tubular elastic body formed in an annular state is inserted in an annular groove 5. Compressed air is fed in the second feed passage 3 and the internal space of the seal body 6. The seal body 6 is expanded and deformed by compressed air and adhered on the bottom and the side of the annular groove 5 and the outer peripheral surface of the main spindle 34 and a gap between the main spindle 34 and the annular member 33 is sealed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a main shaft having a receiving portion for mounting a tool and rotatably supported about a shaft, an annular member into which the main shaft is inserted to cover an outer peripheral surface of the main shaft. And a machine tool capable of indexing a main spindle to a specific rotational position.

[0002]

2. Description of the Related Art A main shaft has a receiving portion for mounting a tool and is rotatably supported about a shaft, and an annular member into which the main shaft is inserted to cover an outer peripheral surface of the main shaft. Conventionally, a machine tool such as a machining center has been known as a machine tool capable of indexing a spindle to a specific rotational position. In such a machine tool, generally, a plurality of tools to be used for machining are prepared in a tool magazine in advance, and a tool mounted on a spindle and a tool prepared in the tool magazine are sequentially exchanged as needed.

[0003] By the way, in the processing environment, chips and the like may adhere to the receiving portion of the replacement tool, and the tool with the chips and the like adhered to the receiving portion is mounted on the main spindle to perform machining. In this case, the run-out accuracy of the tool is out of the allowable range, and the machining accuracy is deteriorated, and the receiving portion of the spindle and the receiving portion of the tool are damaged.

Therefore, conventionally, when a tool is replaced, compressed air is discharged into a spindle receiving portion, and the compressed air removes chips or the like attached to a receiving portion of the tool. Conventionally, as a machine tool that discharges compressed air into the spindle receiving portion, one disclosed in Japanese Patent Application Laid-Open No. 3-104533 is known. This machine tool is shown in FIG.

[0005] As shown in FIG.
A main shaft 53 having a tapered receiving portion 54 to which a tool holder 90 is mounted, a bearing ring 52 into which a bearing 55 is fitted and rotatably supporting the main shaft 53 via the bearing 55 are provided. A first annular groove 61 formed in the inner peripheral surface of the bearing ring 52 along the circumferential direction;
, One end is open to the receiving portion 54,
The main shaft 53 has its other end facing the first annular groove 61.
A first supply passage 62 opened in the outer peripheral surface of the bearing ring 52;
The second annular groove 63 and the third annular groove 64 provided on the inner peripheral surface of the first annular groove 61 on both sides in the axial direction with the first annular groove 61 interposed therebetween, and the second annular groove 63 and the third annular groove 64 are respectively inserted. An annular seal 65, a first supply unit 70 for supplying compressed air to the first annular groove 61, and a second supply unit 80 for supplying compressed air to the second annular groove 63 and the third annular groove 64. Have.

FIG. 7 is an enlarged view showing a portion D of FIG. 6 in an enlarged manner. As shown in FIG.
Is a ring-shaped elastic body having a substantially X-shaped cross section, and its four free ends 65a are formed in a round shape, and each free end 65a is formed in a no-load state where no compressed air acts. Bottom surface 63a and both side surfaces 63 of second annular groove 63
b, 63b. Note that FIG. 7 shows only the second annular groove 63 and the third annular groove 64 is not specifically shown.
Has the same configuration as that of the second annular groove 63.

[0007] Further, the first supply means 70 is provided with the first supply means 70.
It comprises a second supply path 71 provided in the bearing ring 52 so as to communicate with the annular groove 61, and a first compressed air supply source 73 for supplying compressed air to the second supply path 71 via a valve 72. The second supply means 80 includes a third supply path 81 provided in the bearing ring 52 so as to communicate with the second annular groove 63 and the third annular groove 64, and a third supply path 81 through a valve 82. Compressed air supply source 83 for supplying compressed air to the
Consists of

According to the machine tool 50, after the rotation of the main shaft 53 is stopped, the second annular groove 63 is supplied from the second compressed air supply source 83 via the valve 82 and the third supply path 81.
When the compressed air is supplied to the third annular groove 64 and the outer peripheral surface of the annular seal 65 inserted into each of the second annular groove 63 and the third annular groove 64 (that is, the rear surface opposite to the main shaft 53). Compressed air acts on the surface (surface), and the pressure of the compressed air compresses and deforms the annular seal 65 (the diameter and the circumferential length are reduced) so that the inner peripheral surface thereof comes into contact with the outer peripheral surface of the main shaft 53.

That is, the free end 65a of the annular seal 65 abuts against the side surfaces 63b, 64b of the second annular groove 63 and the third annular groove 64, respectively, from the upper half position shown in FIG. And slide as shown in the lower half of the figure.
The free end portion 65 a on the inner peripheral side contacts the outer peripheral surface of the main shaft 53.
Thus, both sides of the first annular groove 61 in the axial direction are sealed by the annular seal 65.

Thereafter, when compressed air is supplied from the first compressed air supply source 73 to the second supply path 71 via the valve 72, the second supply path 71 is supplied from the second supply path 71 to the first supply path 62 via the first annular groove 61. The compressed air is supplied to the receiving portion 54, and then the compressed air is discharged into the receiving portion 54 from the opening portion opened to the receiving portion 54, and the inside of the receiving portion 54 is purified by the air flow of the discharged compressed air. At this time, since the both sides in the axial direction of the first annular groove 61 are sealed by the annular seal 65, the compressed air supplied to the first annular groove 61 is prevented from leaking from the gap between the main shaft 53 and the bearing ring 52. As a result, the efficiency of supplying compressed air to the first supply path 62 can be increased,
The purifying effect in the receiving portion 54 can be enhanced.

On the other hand, when the supply from the second compressed air supply source 83 to the third supply path 81 is stopped by switching the valve 82 and the third supply path 81 is communicated with the atmosphere, the third supply path 81 The compressed air is released to the atmosphere, and each of the annular seals 65 recovers to its original shape by its own elasticity.
The contact with is released. Thereby, the main shaft 53 becomes rotatable without receiving a braking torque from the annular seal 65.

By the way, as described above, when the tool holder 90 in a state where the chip is attached to the receiving portion is mounted on the main shaft 53 and machining is performed, the runout accuracy of the tool holder 90 becomes out of an allowable range. Inconveniences such as deterioration of machining accuracy and damage of the receiving portion 54 of the spindle 53 and the received portion of the tool holder 90 occur. Therefore, by any chance the main shaft 5
When chips are caught between the receiving portion 54 of No. 3 and the receiving portion of the tool holder 90, it is desirable to detect this and take measures to prevent the above-mentioned inconvenience from occurring.

As a method of performing such detection, it is conceivable to detect the pressure in the second supply passage 71 by pressure detecting means such as a pressure switch. According to the machine tool 50 described above, when the tool holder 90 is mounted on the receiving part 54 while supplying the compressed air from the first supply means 70 to the first supply path 62 to purify the receiving part 54, The receiving portion and the receiving portion 54 are in close contact with each other, and the opening of the receiving portion 54 is sealed, so that the discharge of compressed air from the opening is suppressed. Further, as described above, since the both sides in the axial direction of the first annular groove 61 are sealed by the annular seal 65, the compressed air does not leak from the gap between the main shaft 53 and the bearing ring 52. On the other hand, when the tool holder 90 with the chips attached to the receiving portion is mounted on the main shaft 53, a gap is generated between the receiving portion of the tool holder 90 and the receiving portion 54 of the main shaft 53 due to the chips. The compressed air is discharged from the opening of the receiving portion 54 to the outside through the gap.

Therefore, when no chips exist between the receiving portion 54 of the main shaft 53 and the receiving portion of the tool holder 90, the internal pressure in the second supply passage 71 increases to a predetermined pressure, while the main shaft 53 When cutting chips are caught between the receiving portion 54 of the tool holder 90 and the receiving portion of the tool holder 90, the internal pressure in the second supply path 71 does not increase to a predetermined pressure, and the pressure detecting means By detecting this pressure difference, it is possible to detect whether or not chips have been caught between the receiving portion 54 of the main shaft 53 and the receiving portion of the tool holder 90.

[0015]

However, according to the above-described annular seal 65 of the conventional machine tool 50, there is a problem that the gap between the main shaft 53 and the bearing ring 52 cannot be sufficiently sealed.

That is, the above-described annular seal 65 is compressed and deformed by the compressed air supplied to the rear surface, and the outer peripheral surface of the main shaft 53 and the side surfaces 6 of the second annular groove 63 and the third annular groove 64 are formed.
3b, 64b, and is provided so as to seal the gap between the main shaft 53 and the bearing ring 52. First, the free end portion 65a of the annular seal 65 is set in a no-load state where no compressed air acts. Side surface 6 of second annular groove 63 and third annular groove 64
3b and 64b must be sufficiently close.

However, the free end 65a of the annular seal 65
To the side surfaces 63b, 6 of the second annular groove 63 and the third annular groove 64.
4b, the compressed air may be supplied to the rear surface of the annular seal 65, and the compressed air may become a resistance to prevent uniform compression deformation of the annular seal 65. In some cases, the annular seal 65 may not be sufficiently adhered to the main shaft 53. In this case, the gap between the main shaft 53 and the bearing ring 52 cannot be reliably sealed. In addition, when the seals are strongly contacted in this manner, the annular seal 65 does not recover its original shape after the supply of the compressed air is stopped, and the inner peripheral surface remains in contact with the outer peripheral surface of the main shaft 53. There is also a problem that a braking torque acts when the main shaft 53 rotates.

Further, the pressure distribution of the compressed air acting on the back surface of the annular seal 65 may become uneven, and the annular seal 65 may be twisted without being uniformly compressed and deformed. If the state of close contact of the annular seal 65 with the side surfaces 63b, 64b of the second annular groove 63 and the third annular groove 64 is various, the annular seal 65 is more likely to be twisted.
When the annular seal 65 is twisted in this manner, the main shaft 53 of the annular seal 65 has an X-shaped cross-sectional shape.
Outer peripheral surface, and the second annular groove 63 and the third annular groove 64
The contact of the main shaft 5 with the side surfaces 63b and 64b is lost.
The gap between the bearing ring 3 and the bearing ring 52 cannot be sufficiently sealed.

As described above, according to the conventional annular seal 65, the gap between the main shaft 53 and the bearing ring 52 cannot always be sufficiently sealed, and leakage of the compressed air from the annular seal 65 is completely prevented. Could not be prevented. Therefore, in the machine tool 50 described above, the airflow necessary and sufficient for purification cannot be generated in the receiving portion 54, and the purification effect is reduced, and the chips can be sufficiently removed. In addition, there has been a problem that it is impossible to reliably detect whether or not cutting chips are caught between the receiving portion 54 of the main shaft 53 and the receiving portion of the tool holder 90.

The present invention has been made in order to solve the above-described problems, and it is possible to reliably prevent leakage of compressed air in a supply path and to reliably remove chips.
It is another object of the present invention to provide a machine tool capable of reliably detecting whether a tool (holder) is in close contact with a spindle receiving portion.

[0021]

According to the first aspect of the present invention, there is provided a spindle having a receiving portion for mounting a tool and rotatably supported about an axis. And a ring member into which the main shaft is inserted to cover the outer peripheral surface of the main shaft, and a discharge port formed in a receiving portion of the main shaft in a machine tool capable of indexing the main shaft to a specific rotation position. A receiving section formed on the outer peripheral surface of the main spindle, a supply path provided on the main spindle, a first supply path communicating the discharge port with the receiving section, and indexing the main spindle to the specific rotation position. A supply section formed on the inner peripheral surface of the annular member so as to face the receiving section, a supply path provided in the annular member, a second supply path communicating with the supply section, Formed along the circumferential direction on the inner peripheral surface of the annular member, and At least two annular grooves formed on both sides in the axial direction with the supply portion interposed therebetween, and a tubular elastic body formed in an annular shape, and an inner diameter formed to be larger than an outer diameter of the main shaft. A seal body inserted into the
A compressed air supply source for supplying compressed air to the second supply path and the internal space of each of the seals is provided.

According to the present invention, first, after the main shaft is indexed to a specific rotational position and the receiving section and the supply section are opposed to each other, the compressed air supply source supplies the second supply path and the internal space of each seal body. Supply compressed air. Before the compressed air is supplied to the internal space, each seal body has an inner diameter formed to be larger than the outer diameter of the main shaft, and thus does not contact the outer peripheral surface of the main shaft.

Each of the seals is expanded and deformed by the supplied compressed air, and its outer peripheral surface is in close contact with the bottom surface of the annular groove, while its inner diameter is reduced and its inner peripheral surface is in close contact with the outer peripheral surface of the main shaft. Closely adheres to the side surface of the annular groove to completely seal the gap between the main shaft and the annular member, thereby sealing both sides in the axial direction with the supply portion interposed therebetween.

According to the present invention, since the annular seal body is brought into close contact with the main shaft and the annular groove by expansion deformation, the seal body is uniformly deformed, and the entire seal body is fitted to the main shaft and the annular groove. The uniform and reliable close contact can be achieved, and the gap between the main shaft and the annular member can be reliably sealed. Further, since the seal body is in pressure contact with the main shaft and the annular groove with a predetermined pressing force, the indexed main shaft can be held at the indexing position.

The compressed air supplied to the second supply path passes through the supply section, the supply section, and the first supply path, and is discharged from the discharge port into the spindle receiving section to purify the inside of the spindle receiving section.
At this time, at least two axial sides sandwiching the supply unit
Since the two sealing members are securely sealed, when compressed air is supplied from the supply unit to the reception unit, the compressed air does not leak from the gap between the main shaft and the annular member, and is necessary for purification and has sufficient compression. Air can be supplied to the spindle receiver.

On the other hand, when the supply of the compressed air to the seal body is stopped and the internal space of the seal body is communicated with the atmosphere, the compressed air in the internal space is released to the atmosphere, and the seal body contracts due to its own elasticity. Then, it recovers its original shape and comes into a state of non-contact with the main shaft. As a result, the main shaft can freely rotate without receiving the braking torque by the seal body. As described above, according to the present invention, since the seal body is made to recover to the original shape by shrinkage, the recovery to the original shape is not hindered by the external force as in the related art, and the main shaft is surely prevented. And non-contact state.

In the present invention, the side faces of the seal body are provided so as to abut against the side faces of the annular groove when no load is supplied to the internal space of each seal body in a normal state with no load. However, conversely, any one provided so as not to contact the side surface of the annular groove may be used.

According to a second aspect of the present invention, there is provided a main shaft having a receiving portion for mounting a tool, rotatably supported on the center of the shaft, and having the main shaft inserted therein. An annular member that covers an outer peripheral surface of the main spindle, and a discharge port formed in a receiving portion of the main spindle and an outer peripheral surface of the main spindle in a machine tool capable of indexing the main spindle to a specific rotation position. Receiving part, a supply path provided in the main shaft, a first supply path communicating the discharge port and the receiving part, and when the main shaft is indexed to the specific rotation position,
A supply section formed on the inner peripheral surface of the annular member so as to face the receiving section, a supply path provided in the annular member, a second supply path communicating with the supply section, and the supply section An annular groove provided on the inner peripheral surface of the annular member so as to surround it; and a tubular elastic body formed in an annular shape, and a seal body inserted into the annular groove so as to be separated from the outer peripheral surface of the main shaft. And a compressed air supply source for supplying compressed air to the second supply path and the internal space of the seal body.

According to the present invention, first, after the main spindle is indexed to a specific rotation position, the receiving section and the supply section are opposed to each other, and then compressed from the compressed air supply source to the second supply path and the internal space of the seal body. Supply air. Note that the seal body before supplying the compressed air to the internal space is provided so as to be separated from the outer peripheral surface of the main shaft, and therefore does not naturally contact the outer peripheral surface of the main shaft.

The seal body is expanded and deformed by the supplied compressed air, and closely adheres to the bottom surface and side surfaces of the annular groove and to the outer peripheral surface of the main shaft to completely seal the gap between the main shaft and the annular member. Thereby, the periphery of the supply unit and the reception unit is sealed.

According to the present invention, since the annular seal body is brought into close contact with the main shaft and the annular groove by expansion deformation, the seal body is uniformly deformed, and the entire seal body is fitted to the main shaft and the annular groove. The uniform and reliable close contact can be achieved, and the gap between the main shaft and the annular member can be reliably sealed. Also in this case, since the seal body is pressed against the main shaft and the annular groove with a predetermined pressing force, the indexed main shaft can be held at the indexing position.

[0032] The compressed air supplied to the second supply path passes through the supply section, the supply section, and the first supply path, and is discharged from the discharge port into the spindle receiving section to purify the inside of the spindle receiving section.
At this time, since the periphery of the supply unit and the receiving unit is securely sealed by the seal body, when compressed air is supplied from the supply unit to the receiving unit, the compressed air may leak from the gap between the main shaft and the annular member. In addition, it is possible to supply the compressed air necessary for purification and sufficient to the spindle receiving portion.

On the other hand, when the supply of the compressed air to the seal body is stopped and the internal space of the seal body is communicated with the atmosphere, the compressed air in the internal space is released to the atmosphere, and the seal body contracts due to its own elasticity. Then, it recovers its original shape and comes into a state of non-contact with the main shaft. As a result, the main shaft can freely rotate without receiving the braking torque by the seal body. As described above, according to the present invention, since the seal body is made to recover to the original shape by shrinkage, the recovery to the original shape is not hindered by the external force as in the related art, and the main shaft is surely prevented. And non-contact state.

In the present invention, the side surfaces of the seal members are provided so as to abut against the side surfaces of the annular groove when no load is supplied to the internal space of each seal member and the load is in a normal state. However, conversely, any one provided so as not to contact the side surface of the annular groove may be used.

The invention according to claim 3 of the present invention for solving the above-mentioned problems has a main shaft having a receiving portion for mounting a tool, rotatably supported on the center of the shaft, and having the main shaft inserted therein. In a machine tool provided with an annular member that covers an outer peripheral surface of the main shaft, a discharge port formed in a receiving portion of the main shaft, a receiving portion formed in an outer peripheral surface of the main shaft, and a supply passage provided in the main shaft. A first supply path communicating the discharge port with a receiving unit; a supply unit formed on an inner peripheral surface of the annular member so that at least a part thereof faces the receiving unit; and a supply unit provided on the annular member. A second supply path communicating with the supply section, and at least two annular sections formed along the circumferential direction on an inner peripheral surface of the annular member and formed on both sides in the axial direction with the supply section interposed therebetween. The groove and the tubular elastic body are formed in an annular shape, and the inner diameter is A seal member formed to have a diameter larger than the outer diameter of the seal member and inserted into each of the annular grooves; and a compressed air supply source for supplying compressed air to the second supply path and the internal space of each of the seal members. Is provided.

According to the present invention, by the same action as in the first aspect of the present invention, the entire seal body can be uniformly and securely brought into close contact with the main shaft and the annular groove, and the gap between the main shaft and the annular member can be improved. Can be reliably sealed.
Accordingly, when the compressed air is supplied from the supply unit to the receiving unit, the compressed air is not leaked from the gap between the main shaft and the annular member, and the compressed air required for purification and sufficient is supplied to the main shaft receiving unit. be able to. On the other hand, when the supply of compressed air to the seal body is stopped and the internal space of the seal body is communicated with the atmosphere, the seal body contracts due to its own elasticity and recovers its original shape, and is brought into a state of non-contact with the main shaft. As a result, the main shaft can freely rotate without receiving the braking torque by the seal body.

Incidentally, in the present invention, similarly, when no load is supplied to the internal space of each of the seals in a normal state without load, the side surfaces of the seals are provided so as to abut the side surfaces of the annular groove. Alternatively, any of those provided so as not to contact the side surface of the annular groove may be used.

According to the invention, the receiving unit and the supplying unit are provided so as to face each other at least partially.
Since the second supply passage and the first supply passage communicate with each other at any rotational position of the main shaft, compressed air can be supplied to the main shaft receiving portion without indexing the main shaft.

It is sufficient that the receiving section and the supplying section are provided so as to face each other at least in part, and the receiving section and the supplying section may have any shape. For example, the receiving part is a hole, and the supplying part is an annular groove along the circumferential direction of the inner peripheral surface of the annular member. Conversely, the supplying part is a hole, and the receiving part is a peripheral part of the outer peripheral surface of the main shaft. Or the receiving portion is an annular groove along the circumferential direction of the outer peripheral surface of the main shaft, and the supplying portion is an annular groove along the circumferential direction of the inner circumferential surface of the annular member. And so on.

The invention according to claim 4 of the present invention for solving the above-mentioned problem is characterized in that the seal member according to claim 1 or 2 or 3 is bonded to the bottom surface of the annular groove. It is assumed that.

According to the present invention, since the seal is bonded to the bottom surface of the annular groove, the seal can be fixed in the annular groove, and when the seal is contracted and restored to the original shape. In addition, the sealing body can be reliably brought into non-contact with the main shaft. Further, when the spindle is provided so as to be indexed to a specific position, the indexed spindle can be more reliably held at the indexing position by the pressing force of the seal body.

According to a fifth aspect of the present invention for solving the above-mentioned problems, a pressure detecting means for detecting the pressure in the second supply passage according to the first, second, third or fourth aspect of the present invention is provided. It is characterized by the following.

According to this invention, the gap between the main shaft and the annular member can be reliably sealed in the same manner as in the first, second, third, or fourth aspect of the present invention. When compressed air is supplied to the main body, it is possible to reliably prevent the compressed air from leaking from the gap between the main shaft and the annular member, so that a sufficient amount of compressed air can be supplied to the main shaft receiving portion. .

When a clean tool having no chips attached thereto is mounted on the receiving portion, the discharge port is sealed by the receiving portion of the tool, and the discharge of compressed air from the discharge port is suppressed. . At that time, as described above, since the gap between the main shaft and the annular member is completely sealed by the seal body,
Compressed air does not leak from the gap between the main shaft and the annular member, and the pressure in the second supply path surely increases to a predetermined pressure or more.

On the other hand, when the tool having the chip attached to the receiving portion is mounted on the receiving portion, a gap is generated between the receiving portion of the tool and the receiving portion of the main shaft by the chip, and the gap is formed through the gap. Since the compressed air is discharged from the discharge port to the outside, the pressure in the second supply path does not rise to a predetermined pressure.

Thus, by detecting the pressure difference by the pressure detecting means, it is determined whether or not chips are present between the receiving portion of the main shaft and the receiving portion of the tool, in other words, whether or not the tool has the main shaft. Can be detected as to whether or not it is in close contact with the receiving part.

[0047]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view showing a spindle head of a machine tool according to the present embodiment.

As shown in FIG. 1, a spindle head 30 of the machine tool 1 has a housing 32 for supporting a bearing 31.
An annular main shaft cover 33 fixed to the front end of the housing 32; and a main shaft 34 rotatably supported around the shaft by the bearing 31 and having a front end loosely inserted in the main shaft cover 33. ing. A tapered receiving portion 36 for mounting a tool holder 35 is provided at a central portion of the main shaft 34.
Is determined to a specific rotational position.

The main shaft 34 is provided with a first supply path 2. One end of the first supply path 2 opens to the receiving portion to form a discharge port 7, and the other end of the first supply path 2 An opening 8 is formed in the outer peripheral surface to form a receiving port 8.

The spindle cover 33 is provided with a second supply path 3, one end of which is opened on the inner peripheral surface of the spindle cover 33 to form a supply port 9. The supply port 9 and the receiving port 8 are provided so as to face each other when the main shaft 34 is indexed to a specific rotation position.

On the inner peripheral surface of the main shaft cover 33, annular grooves 5 and 5 formed along the circumferential direction are provided on both sides in the axial direction with the supply port 9 interposed therebetween. 5,
The seal bodies 6, 6 are inserted into 5.

As shown in FIG. 2, the seal body 6 includes a seal ring 10 formed by forming a hollow (tubular) elastic body into a ring shape, and a state in which one end is inserted into the hollow portion (internal space) 10a. And a supply pipe 11 fixed to the seal ring 10,
As shown in FIGS. 1 and 3, each seal body 6 is inserted into the annular groove 5 in a state where the supply pipe 11 is inserted into the communication path 4 branched from the second supply path 3. Seal ring 1
0 is adhered and fixed to the bottom surface of the annular groove 5. A plurality of ridges (lip) are formed on the inner peripheral surface of the seal ring 10, and the side surface is provided to be separated from the side surface of the annular groove 5 with a predetermined gap. Also,
The gap between the supply pipe 11 and the communication path 4 is sealed by an O-ring 12. FIG. 3 is an enlarged view of a portion B in FIG. 1 and is also a cross-sectional view in the direction of arrows AA in FIG.

Further, a compressed air supply source (not shown) such as a compressor connected to the second supply path 3 is provided, and a pressure detecting means (such as a pressure switch for detecting the pressure in the second supply path 3) is provided. (Not shown).

Next, of the machine tool 1 having the above configuration,
The operation at the time of tool change will be described.

First, when the rotation of the main shaft 34 is stopped, the main shaft 34 is indexed to a predetermined rotational position. Thereby, the supply port 9 and the receiving port 8 face each other.

Next, when compressed air is supplied from a compressed air supply source (not shown) to the second supply path 3, the compressed air is supplied to the first supply path 2 via the supply port 9 and the receiving port 8, and Ring 10 through the communication passage 4 and the supply pipe 11
Compressed air is supplied into the hollow portion 10a.

The compressed air supplied to the first supply passage 2 is discharged from the discharge port 7 into the receiving portion 34, whereby the receiving portion 35 a of the tool holder 35 mounted in the receiving portion 36 and the receiving portion 36 is received. Is purified.

On the other hand, the compressed air supplied to the hollow portion 10a of the seal ring 10 acts to expand the volume of the hollow portion 10a. As described above, since the outer peripheral surface of the seal ring 10 is bonded to the bottom surface of the annular groove 5 and is regulated by the bottom surface, the hollow portion 10a expands toward the inner diameter side and the side surface side of the seal ring 10. The side surface of the seal ring 10 comes into contact with the side surface of the annular groove 5 to be in close contact therewith, the inner diameter of the seal ring 10 is reduced, and the inner peripheral surface
4 and comes into close contact with the outer peripheral surface thereof. Thereby, the spindle 34
And the gap between the spindle cover 33 and the supply port 9 are completely sealed.
Are completely sealed on both sides in the axial direction.

According to the machine tool 1, since the seal ring 10 is brought into close contact with the main shaft 34 and the annular groove 5 by expansion deformation, the seal ring 10 is uniformly deformed and the entire seal ring 10 is formed. Can be uniformly and reliably adhered to the main shaft 34 and the annular groove 5, and the gap between the main shaft 34 and the main shaft cover 33 can be reliably sealed. Also,
Since the seal ring 10 is pressed against the main shaft 34 and the annular groove 5 with a predetermined pressing force, the indexed main shaft 34 can be reliably held at the indexing position.

Thus, when the compressed air supplied to the second supply passage 3 moves from the supply port 9 to the receiving port 8, the main shaft 3
Leakage to the outside from the gap between the shaft 4 and the spindle cover 33 is prevented, and sufficient compressed air required for purification and sufficient for the receiving portion 36 can be supplied.

Next, when the tool holder 35 is mounted on the receiving portion 36, if the receiving portion 35a is a clean tool holder with no chips attached thereto, the receiving portion 35a of the tool holder 35 is moved to the receiving portion 35a. The discharge port 7 is sealed in close contact with the inner peripheral surface of the discharge port 36, and the discharge of compressed air from the discharge port 7 is suppressed. As described above, since the gap between the main shaft 34 and the main shaft cover 33 is completely sealed by the seal ring 10, the compressed air does not leak from the gap between the main shaft 34 and the main shaft cover 33. The pressure in the two supply paths 3 is surely increased to a predetermined pressure or more.

On the other hand, when the tool holder 35 with the chips attached to the receiving portion 35a is mounted on the receiving portion 36, the chips cause a gap between the receiving portion 35a of the tool holder 35 and the receiving portion 36 of the main shaft 34. Since the compressed air is discharged from the discharge port 7 to the outside through the gap, the pressure in the second supply passage 3 does not rise to a predetermined pressure.

Thus, by detecting this pressure difference by the pressure detecting means, it is determined whether or not chips are present between the receiving portion 36 of the main shaft 34 and the received portion 35a of the tool holder 35, in other words. For example, it is possible to detect whether the tool holder 35 is mounted in close contact with the receiving portion 36 of the main shaft 34.

Next, when the supply of compressed air from the compressed air supply source (not shown) to the second supply path 3 is stopped and the second supply path 3 is communicated with the outside air, the hollow portion 10a of the seal ring 10 is opened.
Is released to the outside air through the second supply passage 3, the expanded seal ring 10 contracts and its inner diameter increases, and its inner peripheral surface is separated from the outer peripheral surface of the main shaft 34. I do. Thereby, the main shaft 34 becomes rotatable without receiving the braking torque. On the other hand, also in the seal ring 10,
Since it does not contact the rotating main shaft 34, its wear can be prevented. In addition, since the outer peripheral surface of the seal ring 10 is adhered and fixed to the bottom surface of the annular groove 5, the seal ring 10 can be reliably restored to the original state when contracted, and the inner circumference of the main shaft 34 and the seal ring 10 is formed. The surface can be reliably separated.

In this embodiment, on the inner peripheral surface of the main shaft cover 33, on both sides in the axial direction with the supply port 9 interposed therebetween, annular grooves 5 and 5 are provided along the circumferential direction. Although the seal members 6 and 6 are configured to be inserted, as shown in FIGS. 4 and 5, one annular groove 15 surrounding the supply port 9 is provided on the inner peripheral surface of the spindle cover 33. A configuration in which an annular seal body 16 is inserted into the annular groove 15 and this is adhered and fixed to the bottom surface of the annular groove 15 may be adopted.

Even in this configuration, as in the above example, the compressed air supplied to the hollow portion 16a expands the seal body 16 so that the seal body 16 comes into contact with the side surface of the annular groove 15 to be in close contact therewith. Abuts against the outer peripheral surface of Thereby, the gap between the main shaft 34 and the main shaft cover 33 is completely sealed, the periphery of the supply port 9 is completely sealed, and leakage of compressed air from the same portion can be reliably prevented. FIG.
5 is a diagram showing the inner peripheral surface of the spindle cover 33 as viewed from the direction of arrows CC in FIG.

In the above example, the hollow portion 1 of the seal ring 10 is used.
The supply of the compressed air to the first supply passage 2 and the supply of the compressed air to the first supply passage 2 are performed through the second supply passage 3 which is the same supply passage. The supply of compressed air to the first supply path 2 and the supply of compressed air to the first supply path 2 may be performed through separate supply paths. In this manner, the seal ring 1 is independent of the first supply path 2.
Since the compressed air of a predetermined pressure can be supplied to the hollow portion 10a of 0, the seal ring 10 can be more reliably expanded and brought into close contact with the annular groove 5 and the main shaft 34.

In the above example, the supply port 9 faces the receiving port 8 when the main shaft 34 is indexed to the specific rotation position. However, instead of the supplying port 9, the supply port 9 faces the receiving port 8. In order to do so, an annular groove formed along the circumferential direction may be provided on the inner peripheral surface of the spindle cover 33. In this case, since the second supply path 3 and the first supply path 2 can always be in a state of communication, the main shaft when supplying compressed air from the second supply path 3 to the first supply path 2 can be provided. 34 is no longer necessary. Similarly, instead of the receiving port 8, an annular groove formed along the circumferential direction may be provided on the outer peripheral surface of the main shaft 34 so as to face the supplying port 9. Further, an annular groove formed along the circumferential direction is provided on the inner peripheral surface of the spindle cover 33 instead of the supply port 9, and the spindle 34 is provided instead of the supply port 8.
An annular groove formed along the circumferential direction may be provided on the outer peripheral surface of the, and both annular grooves may be provided so as to face each other.

The shape of the inner peripheral surface of the seal ring 10 is not limited to the above example, but may be any shape as long as it can be securely adhered to the outer peripheral surface of the main shaft 34 and the same portion can be sealed. Is also good.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a spindle head of a machine tool according to an embodiment of the present invention.

FIG. 2 is a plan view showing a seal body according to the embodiment.

FIG. 3 is a sectional view in the direction of arrows AA in FIG. 2;

FIG. 4 is an enlarged sectional view showing a part of a machine tool according to another embodiment of the present invention.

FIG. 5 is a diagram viewed from the direction of arrows CC in FIG. 4;

FIG. 6 is a sectional view showing a spindle head of a conventional machine tool.

FIG. 7 is an enlarged view showing a portion D in FIG. 6 in an enlarged manner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Machine tool 2 1st supply path 3 2nd supply path 5 Annular groove 6 Seal body 7 Discharge port 8 Receiving port 9 Supply port 30 Main shaft head 33 Main shaft cover 34 Main shaft 35 Tool holder 36 Receiving part

Claims (5)

[Claims] A main shaft having a receiving portion for mounting a tool and rotatably supported about a shaft; an annular member into which the main shaft is inserted to cover an outer peripheral surface of the main shaft; In a machine tool capable of indexing to a specific rotation position, a discharge port formed in a receiving portion of the main shaft, a receiving portion formed on an outer peripheral surface of the main shaft, and a supply path provided in the main shaft, A first supply path communicating the discharge port with a receiving unit, and a supply unit formed on an inner peripheral surface of the annular member so as to face the receiving unit when the main shaft is indexed to the specific rotation position. A supply path provided in the annular member, a second supply path communicating with the supply unit, and a circumferentially formed inner circumferential surface of the annular member, and an axial direction sandwiching the supply unit. At least two annular grooves formed on both sides and a tubular elastic body And a seal body having an inner diameter formed to be larger than the outer diameter of the main shaft and inserted into each of the annular grooves, and compressed into the second supply passage and the internal space of each of the seal bodies. A machine tool comprising a compressed air supply source for supplying air. A main shaft having a receiving portion for mounting a tool and rotatably supported about a shaft; an annular member into which the main shaft is inserted to cover an outer peripheral surface of the main shaft; In a machine tool capable of indexing to a specific rotation position, a discharge port formed in a receiving portion of the main shaft, a receiving portion formed on an outer peripheral surface of the main shaft, and a supply path provided in the main shaft, A first supply path communicating the discharge port with a receiving unit, and a supply unit formed on an inner peripheral surface of the annular member so as to face the receiving unit when the main shaft is indexed to the specific rotation position. A supply path provided in the annular member, a second supply path communicating with the supply section, an annular groove provided on an inner peripheral surface of the annular member so as to surround the supply section, and a tubular elastic member. The body is formed in a ring shape so as to be separated from the outer peripheral surface of the spindle. Machine tool, characterized in that said a sealing member was allowed inserted into the annular groove, which is configured by providing the compressed air supply source for supplying compressed air to the internal space of the second supply path and the seal body. 3. A machine tool comprising: a main shaft having a receiving portion for mounting a tool, rotatably supported on a shaft center, and an annular member into which the main shaft is inserted to cover an outer peripheral surface of the main shaft. A discharge port formed in a receiving portion of the main shaft, a receiving portion formed on an outer peripheral surface of the main shaft, and a supply path provided in the main shaft, the first supply path communicating the discharge port and the receiving portion. A supply section formed on the inner peripheral surface of the annular member so that at least a part thereof faces the receiving section; and a supply path provided in the annular member, the second supply path communicating with the supply section. At least two annular grooves formed on the inner circumferential surface of the annular member along the circumferential direction and formed on both sides in the axial direction with the supply portion interposed therebetween; It is formed to have a diameter larger than the outer diameter of the main shaft, and is formed in each of the annular grooves. Machine tool, wherein the insertion and sealing member was allowed, that which is configured by providing the compressed air supply source for supplying compressed air to the inner space of the second supply path and the respective seal member. 4. The machine tool according to claim 1, wherein the seal body is adhered to a bottom surface of the annular groove. 5. The machine tool according to claim 1, further comprising pressure detection means for detecting a pressure in the second supply path.