JPH0866842A - Coolant flow passage switching mechanism for oil-hole-equipped tool - Google Patents

Abstract

PURPOSE: To provide a simply constructed coolant switching mechanism which can appropriately switch passages where a coolant flows, according to whether a tool holder is of an axis through type or an end-face through type. CONSTITUTION: Sealing members 8 appropriate for the kinds of tool holders used are fitted into the opening 5a of a coolant circulation hole 5 and into the end of a coolant supply nozzle 10 adapted for an axis through type tool holder Ta, the coolant circulation hole 5 being formed in a main spindle 2 and adapted for an end-face through type tool holder. To install the end-face through type tool holder, a connecting member which communicates the coolant feeding part of the tool holder with the coolant circulation hole 5 is fitted into the opening 5a of the coolant circulation hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coolant flow passage switching mechanism for switching the flow of coolant for a tool having an oil hole in a machine tool, particularly a machining center, and the flow passage of the coolant according to the type of the tool holder. The present invention relates to a coolant distribution path switching mechanism that can be switched appropriately.

[0002]

2. Description of the Related Art A tool with an oil hole, which sprays a high-pressure coolant from the cutting edge to cool the work area between the work and the tool and removes cutting chips, has a long tool life and is suitable for high-speed cutting. In recent years, it has been widely adopted in machine tools that tend to rotate the spindle at high speed to improve the cutting speed. Then, the coolant supplied from the coolant supply device provided outside the machine tool passes through the coolant flow passage of the draw bar provided in the spindle through-hole, and then the tool with the oil hole inserted at the tip of the spindle. It is being supplied.

By the way, the tool holder to which the tool with an oil hole is attached can be classified into two types according to the flow path of the coolant supplied to the tool with an oil hole. That is, one is a so-called axial through type in which a through hole that communicates with the oil hole of the tool with an oil hole attached to one side of the tool holder is formed along the rotation axis of the tool holder. Is provided with a coolant supply portion communicating with the oil hole of the tool with an oil hole by opening it on the end surface of the V-shaped flange of the tool holder on the spindle side.
It is a so-called end face through type in which a tool holder equipped with a tool with an oil hole can be communicated with a coolant circulation hole on the spindle side when the tool holder is attached to the tip of the spindle. These two
The two types of tool holders have the advantage that the former does not need to have a coolant through hole in the main shaft, and the latter does not need to form a through hole in the end face of the pull stud, and the ID element is embedded in the pull stud. Since it has an advantage that it is suitable for managing the life of a tool, it is appropriately used.

However, since the coolant flow path is different between the end face through type and the shaft center through type, depending on whether the end face through type tool holder or the shaft center through type tool holder is attached to the main shaft, the main shaft and the draw bar are inserted. Therefore, there has been a problem that only one type of tool holder, either the axial center through type or the end face through type, can be used for one main shaft.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is appropriately selected depending on whether the tool holder to which the tool with an oil hole is attached is of the axial center through type or the end face through type. It is an object of the present invention to provide a coolant switching mechanism having a simple structure capable of switching the coolant flow path.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, a coolant flow path switching mechanism of the present invention comprises a spindle rotatably supported by a spindle head and a spindle penetrating hole formed at the center of rotation of the spindle. It is installed in the hole so that it can move back and forth,
The tool holder is inserted into the tool insertion portion formed at one end of the main shaft to move forward and backward with the engaging means engaged with the end portion of the tool holder engaged with the tool holder. A coolant flow path switching mechanism for a tool with an oil hole in a machine tool having a draw bar that clamps a tool holder to the tool insertion part by drawing it into the attachment part, and is supplied from a coolant supply device formed in the draw bar. A coolant flow passage through which the coolant flows, a coolant flow hole provided in the main shaft, having an opening at one end face of the main shaft, and communicating with the coolant flow passage, and the coolant flow passage in a state of communicating with the coolant flow passage. It is provided at one end of the draw bar so that it can move back and forth with respect to the draw bar, and it can be used as a tool with an oil hole in the shaft center Coolant supply nozzle that engages so that one end communicates with the through hole when a through shaft type tool holder having a through hole for supplying coolant is inserted into the tool insertion portion of the spindle. And a biasing means for constantly biasing the coolant supply nozzle in a direction in which it projects from the drawbar, and when inserting a through shaft type tool holder into the tool mounting portion, liquid is introduced into the opening of the coolant flow hole. When the end face through type tool holder is tightly fitted and is inserted into the tool insertion part, the coolant supply nozzle is maintained in a state of being pushed into the drawbar side, and the tip side of the coolant supply nozzle is liquid-tight. When the sealing member to be fitted and the end face through type tool holder are inserted into the tool insertion part, the coolant supply part and the front part of the tool holder are inserted. Characterized in that it comprises a connecting member for connecting the coolant flow holes in the communication form.

[0007]

When a through shaft type tool holder with a tool with an oil hole is inserted into one end of the main shaft, a sealing member is fitted in the opening of the coolant flow hole that is opened in the end face of the main shaft. Make sure that the coolant does not flow out of the opening. In this state, when the through shaft type tool holder is inserted into the tool insertion part of the main shaft, one end of the coolant supply nozzle engages with the through hole of the tool holder to establish a communication state, and the coolant is attached to the tool holder. Can be supplied. On the other hand, when inserting the end face through type tool holder with the tool with oil hole attached to one end of the spindle,
A sealing member is fitted in the coolant supply nozzle so that the coolant does not flow out from the tip of the coolant supply nozzle. Further, instead of the sealing member, a connection member that connects the coolant supply portion of the tool holder and the coolant circulation hole is attached to the opening of the coolant circulation hole. In this state, when the end face through type tool holder is inserted into the tool insertion portion of the spindle, the coolant flow hole and the coolant supply portion of the tool holder communicate with each other, so that the coolant can be supplied to the tool holder.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. 1 and 2 relate to an embodiment of a coolant flow passage switching mechanism of the present invention. FIG. 1 shows a coolant flow passage switching mechanism when a through shaft type tool holder is inserted into a tool insertion portion of a main shaft. FIG. 2 is a partial sectional view of the spindle for explaining the operation of the coolant flow path switching mechanism when the end face through type tool holder is inserted into the tool insertion portion of the spindle. In the following embodiments, a horizontal machine tool that supports the spindle in a horizontal state will be described, but it goes without saying that the present invention can also be applied to a vertical machine tool that supports the spindle in a vertical state.

A spindle 2 rotatably supported by a spindle head (not shown) is formed with a spindle through hole 2a at the center of rotation from the front end (left side in the drawing) to the rear end (right side in the drawing) and the front end side. A coolant passage hole 5 is formed from the tip end surface of the main shaft 2 in the thick portion of. In addition, the spindle through hole 2a is passed from the outer peripheral surface of the spindle 2 across the coolant circulation hole 5.
A through hole 6 is formed toward the through hole 6, and the coolant circulation hole 5 communicates with the main shaft through hole 2a through this through hole 6. Reference numeral 6a is a plug screwed to close the opening of the through hole 6. Although one end of the coolant circulation hole 5 is open to the end surface of the spindle 2 (opening 5a), when the tool center Ta of the through shaft type is inserted into the tool insertion portion 2b of the spindle 2, the coolant is A sealing member 8 (see FIG. 1) for liquid-tightly sealing so as not to flow out, is fitted into the opening 5a, and the end face through type tool holder Tb is fitted into the tool insertion portion 2b.
At the time of insertion, the connecting member 9 (see FIG. 2) for connecting the coolant supply portion 20 opening to the end face on the main shaft side of the V-shaped flange and the coolant circulation hole 5 to each other in communication is provided in the opening portion 5a. It is fitted and fixed with set screws 8a and 9b, respectively.

In the spindle through hole 2a, a drawbar 7 is provided for pulling a tool holder to which a tool such as a drill or a milling cutter is attached and inserting the tool holder into the tool insertion portion 2b at the tip of the spindle 2. The drawbar 7 is movable back and forth in a direction parallel to the axis of the main shaft 2, and a screw portion 7e at its tip is screwed into a rear end of the collet opening / closing member 7d, and the collet opening / closing member 7d is integrated with the drawbar 7. At the same time, it is slidably supported by the drawbar guide member 4 fitted in the spindle through hole 2a. At the center of rotation of the draw bar 7 and the collet opening / closing member 7d, a coolant flow passage 7a through which the coolant supplied by an external coolant supply device (not shown) flows is formed. Note that the collet opening / closing member 7d and the draw bar 7 are generally configured as separate bodies in order to facilitate processing, but they may be integrally formed. Further, a collet 3 as an engaging member that is engageable with the pull stud P protruding from the end of the tool holder Ta (Tb) is provided at the tip of the collet opening / closing member 7d. When the tool holder Ta (Tb) is inserted into the tool insertion portion 2b at the tip of the spindle 2 and the draw bar 7 is retracted, the collet 3 is formed into the collet opening / closing member 7d and the tapered portion 2c formed on the inner wall surface of the spindle through hole 2a. And is engaged with the tip of the pull stud P. When the drawbar 7 is further retracted in this state, the tool holder Ta (Tb) is pulled rearward (to the right in the drawing) via the collet 3 and the pull stud P, so that the tool holder Ta (T
b) is inserted and attached to the tool insertion portion 2b. Such a tool clamp mechanism is known in Japanese Utility Model Publication No. 63-12886. Further, as the tool clamp mechanism, a pulling stud is pulled by a collet type pulling mechanism or a ball type pulling mechanism in the direction of the spindle axis to insert the tool insertion portion 2
A method of clamping to b may be used.

An annular groove 14 is formed at the tip of the draw bar guide member 4 for supporting the collet opening / closing member 7d over the entire outer peripheral surface thereof, and the through hole 6 is opened in the annular groove 14. There is. At the bottom of this annular groove 14,
The through hole 4a penetrating toward the collet opening / closing member 7d is
In addition to being formed in the circumferential direction at equal intervals,
An annular groove 7b having a predetermined width is formed in the portion of the collet opening / closing member 7d corresponding to the through hole 4a over the entire circumference of the collet opening / closing member 7d. That is, the through hole 4a is always open to the annular groove 7b side even if the draw bar 7 moves back and forth. Therefore, the width of the annular groove 7b must be at least larger than the amount of forward / backward movement of the draw bar 7 (collet opening / closing member 7d). Also, the annular groove 7b
A plurality of through holes 7c penetrating to the coolant flow passage 7a of the collet opening / closing member 7d are formed at equal intervals in the circumferential direction at the bottom of the. Then, the above-described annular groove 14, through hole 4a, annular groove 7b, and through hole 7c bring the coolant flow hole 5 and the coolant flow passage 7a into communication with each other.
In the figure, reference numerals 18 and 19 denote O-rings and packings for preventing coolant from leaking from the boundary surface between the drawbar guide member 4 and the main shaft 2 and the boundary surface between the collet opening / closing member 7d and the drawbar guide member 4. It is a prevention member. Further, it is preferable to provide a plurality of the communication holes 7c and the through holes 4a in the circumferential direction in order to smooth the flow of the coolant, but one may be provided.

Further, in this embodiment, in the main shaft 2,
When exchanging tools, the tool insertion portion 2b and the tool holder Ta
A cleaning air flow passage for removing dust adhering to (Tb) is formed. That is, the high-pressure air supplied from the rear end of the main shaft 2 is formed on the air flow passage 21 formed between the drawbar guide member 4 and the inner peripheral surface of the main shaft 2, and on the tip side of the air flow passage 21. Communication passage 4b, this communication passage 4
It is jetted toward the tool insertion portion 2b and the tool holder Ta (Tb) through the air flow passage 15 penetratingly formed from b toward the tip of the draw bar guide member 4. Reference numeral 12 is a coolant backflow prevention mechanism provided at an intermediate portion of the air flow passage 15 so that the coolant does not flow back.
A sphere 17 that moves back and forth inside to open and close the air flow passage 15
And a spring 13 that constantly urges the sphere 17 in a direction to press it against the inner diameter changing portion of the air flow passage 15.
Then, the sphere 17 closes the air flow passage 15 to prevent the reverse flow of the coolant during the processing of the workpiece, and the high pressure air supplied from the rear end side of the spindle is urged by the spring 13 when the tool is replaced. Against this, the spherical body 17 is pushed back to the tip side of the main shaft 2 to open the air flow passage 15 and allow air to flow.

At the tip of the collet opening / closing member 7d, a coolant supply nozzle 10 (hereinafter referred to as a nozzle 10) for supplying a coolant to the axial center through type tool holder Ta is provided. The tip of the nozzle 10 projects from the tip of the collet opening / closing member 7d and is movable back and forth in a direction parallel to the axis of the main shaft 2. Further, the rear end portion of the nozzle 19 is formed as a large diameter portion 10b having a diameter slightly smaller than the inner diameter of the coolant flow passage 7a, and a through hole 10c is formed across the through hole 10a of the nozzle 10 from the side surface of the large diameter portion 10b. Are formed. The coolant flows from the coolant flow passage 7a through the end of the through hole 10a and the through hole 10c, and then flows through the through hole 10a to the tip side of the main shaft 2.

The coolant flow passage 7a of the drawbar 7
One end of the spring S, which is a biasing means fitted in the inside, has a large diameter portion 1
0b and always urges the nozzle 10 in a direction projecting from the collet opening / closing member 7d. Reference numeral 10d is a sealing member such as an O-ring and packing. Nozzle 1
The tip of 0 can be engaged with and disengaged from the engagement hole Pa of the pull stud P which is a part of the through hole 16 of the through hole type tool holder Ta. The engagement hole Pa is formed slightly larger than the tip diameter of the nozzle 10 so that the tip of the nozzle 10 can be pulled out. Then, when the tool holder Ta is inserted into the tool insertion portion 2b of the main shaft 2, the tip of the nozzle 10 is inserted into and engaged with the engagement hole Pa, and the through hole 10a of the nozzle 10 and the through hole 16 of the tool holder Ta. And are in communication. In addition,
As long as the through hole 16 of the through hole type tool holder Ta and the through hole 10a of the nozzle 10 can be engaged so as to communicate with each other, the engagement mode between the tool holder Ta and the nozzle 10 is limited to the above. I can't. FIG. 3 shows the tool holder Ta
Another example of the engagement between the nozzle 10 and the nozzle 10 is shown. The tip of the nozzle 10 is the pull stud P ′ of the tool holder Ta.
The through hole 10a of the nozzle 10 and the through hole 16 of the tool holder Ta communicate with each other by contacting the end surface of the tool holder. Reference numeral 22 denotes the end surface of the pull stud P'or the nozzle 1
No. 0 is provided on the tip surface of the nozzle 10 when the tip of the nozzle 10 comes into contact with the end surface of the pull stud P ′.
Is a sealing member such as an O-ring or packing for preventing the coolant from leaking from the boundary surface between the front end surface of P and the end surface of the pull stud P '.

Next, the operation of the present invention having the above construction will be described.
When inserting the through shaft type tool holder Ta into the tool insertion portion 2b of the main shaft 2, the sealing member 8 is fitted into the opening 5a of the coolant circulation hole 5 and fixed with the set screw 8a. . The tool holder Ta is attached to the tool insertion portion 2b by ATC or the like.
When is inserted, the engagement hole Pa of the tool holder Ta and the nozzle 10 engage with each other, so that the coolant flowing through the coolant flow passage 7a passes through the coolant circulation hole 5 and the opening 5
It is supplied to the tool holder Ta through the nozzle 10 without ejecting from a. When the end face through type tool holder Tb is inserted into the tool insertion portion 2b of the main shaft 2, instead of the sealing member 8, a connection member having a communication hole 9a through which coolant can flow is inserted into the opening 5a. Secure with set screw 9b. Further, the collet opening / closing member 7d is pushed in against the urging force of the spring S, and the sealing member 11 is liquid-tightly fitted so that the coolant does not leak from the tip of the collet opening / closing member 7d. As the sealing member 11, a hexagon socket plug having a taper screw hole (JISB0203) for pipe formed in the tip of the collet opening / closing member 7d and screwed into this screw hole is suitable. When the tool holder Tb is inserted into the tool insertion portion 2b by ATC or the like, the coolant flow hole 5 and the coolant supply portion 20 are brought into communication with each other through the connecting member 9, so that the coolant flows from the coolant flow passage 7a into the through hole. 7c, annular groove 7b, through hole 4a,
It is supplied to the end face through type tool holder Tb through the annular groove 14 and the coolant circulation hole 5.

As described above, the coolant flow path switching mechanism 1 of the present invention is appropriately selected depending on whether the shaft center through type tool holder Ta or the end face through type tool holder Tb is inserted at the tip of the main shaft 2. By inserting the sealing members 8 and 11 into the tip of the collet opening / closing member 7d or the tip of one of the coolant flow holes 5, the flow path of the coolant is switched. Therefore,
It is characterized in that its structure is extremely simple and can be implemented inexpensively and easily without making a great improvement to the existing spindle.

In the above embodiment, the tool holder Ta,
Although Tb has been described as having the pull stud P protruding from the end, it is disclosed in the tool holder without the pull stud P (for example, hollow tool shank specified in DIN69893, JP-A-59-142177). Needless to say, the coolant flow path switching mechanism 1 of the present invention can also be applied to the tool holder) having the same structure.

[0018]

Since the present invention is constructed as described above, depending on whether the tool holder is the axial center through type or the end face through type, either the coolant supply nozzle or the coolant circulation hole can be appropriately used. By inserting the sealing member, the flow path of the coolant in the spindle can be switched, so it is possible to use two types of tool holders with different coolant supply methods in one machine tool. Can be effectively used. Further, since the configuration of the switching mechanism is extremely simple, it can be implemented easily and inexpensively without making a major improvement on the spindle of the existing machine tool. Further, even when manufacturing a machine tool, it is not necessary to prepare two types of spindle structures, which reduces variations in models and enables efficient manufacturing.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating the operation of a coolant distribution path switching mechanism according to an embodiment of the coolant distribution path switching mechanism of the present invention, in the case where a through shaft type tool holder is attached to the tip of a spindle.

FIG. 2 is a cross-sectional view illustrating the operation of the coolant flow path switching mechanism according to the embodiment of the coolant flow path switching mechanism of the present invention when the end face through type tool holder is inserted and attached to the tip of the main shaft.

FIG. 3 is a cross-sectional view of a main part showing another example of the manner of engagement between the through shaft type tool holder and the coolant supply nozzle.

[Explanation of symbols]

 Ta tool holder (through shaft type) Tb tool holder (through end type) P Pull stud Pa Engagement hole 1 Coolant flow path switching mechanism 2 Spindle 2a Spindle through hole 2b Tool insertion part 3 Collet (engaging means) 4 Drawbar guide member 4a Through hole 5 Coolant flow hole 6 Through hole 7 Drawbar 7a Coolant flow passage 7c Through hole 8,11 Sealing member 9 Connecting member 9a Communication hole 10 Coolant supply nozzle 12 Coolant non-return prevention mechanism 14 Annular groove 16 Through hole 20 Coolant supply section

Claims (1)

[Claims] 1. A main shaft rotatably supported by a main shaft head, and a main shaft through hole formed at the center of rotation of the main shaft so as to be movable back and forth and inserted into a tool insertion portion formed at one end of the main shaft. A tool is attached to the tool insertion portion by retracting the tool holder into the tool insertion portion by moving the engaging means that engages the end portion of the tool holder attached to the tool holder forward and backward. A coolant flow path switching mechanism for a tool with an oil hole in a machine tool having a draw bar for clamping a holder, wherein a coolant flow path, through which coolant supplied from a coolant supply device flows, flows through the spindle. And a coolant flow hole that has an opening at one end surface of the main shaft and that communicates with the coolant flow passage, and that communicates with the coolant flow passage. A through-axis tool that is provided so as to project from one end of the drawbar in a passed state, is movable back and forth with respect to the drawbar, and has a through hole for supplying coolant to the tool with an oil hole in the shaft center. A coolant supply nozzle that engages so that one end thereof communicates with the through hole when the holder is inserted into the tool insertion portion of the spindle, and a coolant supply nozzle that is attached in a direction in which the coolant supply nozzle always projects from the drawbar. When the biasing means for biasing and the axial center through type tool holder are inserted into the tool mounting portion, they are liquid-tightly fitted into the opening of the coolant flow hole, and the end face through type tool holder is inserted into the tool inserting section. When inserting into the attachment part, while maintaining the coolant supply nozzle pushed into the drawbar side, it is fitted in a liquid tight manner on the tip side of the coolant supply nozzle. A sealing member, and a connecting member for connecting the coolant supply portion of the tool holder and the coolant circulation hole in a communicating state when the end surface through type tool holder is inserted into the tool insertion portion. And a coolant flow path switching mechanism for an oil hole tool.