JPH0832393B2 - Air blow structure of the spindle - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air blow structure of a spindle of a machine such as a machining center, a boring machine, and a combined machining lathe, which has an automatic tool changing function.

2. Description of the Related Art For example, a portal machining center as shown in FIG. 3 in which an attachment 9 having a horizontal spindle 7 at the lower end of the spindle ram 5 is provided to prevent chips from adhering to the spindle bearing and cutting fluid during cutting. Further, air blow is performed to prevent lubricant from entering the bearing portion in the swivel head, and the taper portion of the tool mounting surface of the horizontal spindle is cleaned during the tool changing operation.
That is, in FIGS. 3 and 4, the air circuit for air blow in the known gate type machining center includes the column 1, the top beam 2,
It is connected to the upper part of the main spindle ram 5 through the cross rail 3 and the saddle 4, and two circuits are connected to the lower part of the main spindle ram 5 via two electromagnetic switching valves (not shown) provided on the upper part of the main spindle ram 5. There is. An air flow path that is attached to the lower end of the main spindle ram 5 and connects to one of two circuits in the main spindle ram 5 via a rotary joint (not shown) to an attachment 9 that rotatably supports the horizontal main spindle 7 with a bearing 8. 11 are drilled. The horizontal spindle 7 is a well-known collet for pulling the tool T into the central hole following the taper hole.
13 A lifting rod 14 and a disc spring 15 are installed. The pulling rod 14 is provided with an air passage 16 for air blowing on the tapered surface. A hydraulic cylinder 20 for releasing the grip of the collet 13 by pressing the pulling rod 14 concentrically on the rear side of the horizontal main shaft 7 and a piston 21 fitted to the hydraulic cylinder 20 are provided, and an air passage 22 is provided at the center of the piston 21. A perforated contact rod 23 is screwed on. A flow passage 25 connected to the air flow passage 11 is formed in the rear lid 24 of the hydraulic cylinder 20 and opens in the space on the back side of the piston 21.

Further, an air flow path 26, which is connected to another circuit of the main spindle ram from a rotary joint (not shown), is formed in the attachment 9 and opens inside the bearing 8 outer seal portion.

In this case, when one of the two solenoid directional control valves is turned on, air is ejected from the flow path 26 to the inside of the bearing seal portion to increase the pressure in the bearing portion and infiltrate the cutting fluid fine particles and accumulate in the attachment. Part of the lubricating oil is prevented from entering. Another one again
The individual electromagnetic switching valves are turned on by loosening the tool in accordance with the tool change command and supplied from the air flow path 11 to the flow path 25. Further, when pressure oil is sent to the rear chamber of the hydraulic cylinder 20 and the piston 21 is advanced, the contact rod 23 is brought into contact with the pulling rod 14 and the pulling rod 14 is pushed against the force of the disc spring 15 to collet the collet 13. Open up. Abutment rod
The forward abutment of 23 causes the air flow paths 22 and 16 to communicate with each other, and the pressure air from the flow path 25 is ejected to the tool fitting taper surface to clean the taper surface.

Problems to be Solved by the Invention Since two air circuits are formed in the attachment after the main spindle ram, the rotary joint becomes complicated and two electromagnetic switching valves are required, which causes a problem of cost increase.

The present invention has been made in view of the above problems of the conventional technique, and an object of the present invention is to provide an air blow structure for a spindle with a reduced cost by using only one air circuit to the attachment. is there.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention is a tool mounting surface of a spindle having a mechanism for fitting a tool with a pulling rod and loosening the tool by pushing the pulling rod with a fluid pressure cylinder member. In a machine tool configured to blow air to the main bearing portion, a passage for supplying air to the bearing seal portion is opened when the piston of the fluid pressure cylinder retracts, and when the piston moves forward to press the pulling rod, The fluid pressure cylinder member is provided with a switching valve that connects the center to the center passage of the passage pulling rod and opens a passage for air blow to the tool device tapered surface, and one air supply circuit is operated by one fluid pressure cylinder. , Is configured to be switched to another application.

Action When a tool is fitted to the main shaft and the piston of the tool-releasing hydraulic cylinder retracts, pressure air is sent to the bearing seal through the switching valve and when the tool is loosened and the piston moves forward, the center passage of the piston and the center of the lifting rod When the passage is connected and the switching valve is switched, the pressurized air is sent to the center hole of the piston and the lifting rod to blow air on the tapered surface of the tool.

Embodiment An explanation will be given below based on FIG. 1 and FIG.

The same parts as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted.

The solenoid directional control valve provided on the upper portion of the main spindle ram 5 is one, and one air circuit is connected to the air flow path 11 via the rotary joint.
An inner cylinder 21a and an outer cylinder 21b that are concentric double cylinders that form an annular recess 21c on the boss at the rear of the piston 21 are formed.
The base of the inner cylinder 21a is provided with a wide hollow. On the rear lid 24A of the cylinder, there is formed an annular convex portion 24a which is inserted into the annular recess 21c and rubs against the inner cylinder 21a via the O-ring so as to keep airtightness. And the air flow path 2 communicating with the flow path 11
5A is switched to open in the recess 21c when the piston 21 is in the retracted inactive position in the middle of the annular convex portion 24a, and to open in the central space 24b of the outer annular convex portion 24a when the piston 21 advances. .

An air passage 26A for supplying air to the seal portion of the bearing 8 extends to the rear lid 24A of the cylinder and is opened outside the annular convex portion 24a so as to communicate with the recess 21c.

 The operation of the present invention thus configured will be described.

When the power of the machine is turned on and the operation is started, the electromagnetic switching valve above the main spindle ram 5 is turned on and the pressurized air is supplied to the air passage 11. Since the piston 21 is in the retracted position, the compressed air is sent into the opening 25a of the flow passage 25A and the annular recess 21c, passes through the recessed portion, and is jetted from the flow passage 26A into the seal of the bearing 8 to generate cutting fluid.
Prevents the ingress of fine chips and a part of the lubricating oil in the attachment. When machining is completed and a tool replacement command is issued, the horizontal spindle 7 is positioned at the tool replacement position, and pressure oil is supplied to the rear chamber of the cylinder 20 by a tool loosening command, the piston 21 moves forward and the contact rod 23 pulls up. Press 14 (second
Figure).

As the piston advances, the inner cylinder 21a switches the opening 25a to the outside of the recess 21c and stops the supply to the flow path 26A. The pressurized air is supplied to the central space 24b of the annular convex portion 24a, and the abutment rod 23 of the piston 21.
It is sent from the channel 22 to the channel 16 of the pulling rod 14 and ejected to the rear side of the tool. When the pulling rod 14 is pressed, the collet 13 releases the grip of the pull stud, the tip of the pulling rod 14 collides with the pull stud TA, and the fitting of the tapered portion is loosened.
The compressed air is ejected from the gap between the tapered surfaces to clean the tapered surfaces. When the mounting of the tool is completed, the pressure oil to the cylinder 20 is switched to the front chamber, the piston 21 is retracted and the opening 25a is switched to become the annular recess 21c, and the pressure air to the flow path 22 is blocked, and instead the annular recess is formed. Air is blown to the seal portion of the bearing 8 again by communicating with the flow path 26A from the location 21c.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, the present invention has the following effects.

Since there is only one air circuit, the number of solenoid operated directional control valves can be reduced to one, and the number of circuits in the rotary joint can be reduced, contributing to cost reduction.

[Brief description of drawings]

FIG. 1 is a diagram showing a circuit structure for air blow of the present invention, FIG. 2 is a diagram showing a flow path switching state when a piston of a fluid pressure cylinder member is moving forward, and FIG. 3 is a diagram showing an example of a machining center. FIG. 4 is a diagram showing a conventional air blow circuit configuration. 7 …… Transverse spindle, 8 …… Bearing 9 …… Attachment, 14 …… Pulling rod 20 …… Cylinder, 21 …… Piston 11,16,22,25A, 26A …… Flow passage 21a …… Inner cylinder, 21c… … Annular recess 23 …… Abutment rod, 24A …… Rear lid 25a …… Opening

Claims (1)

[Claims] 1. A machine tool in which a tool is fitted with a pulling rod, and a fluid pressure cylinder member has a mechanism for loosening the tool by pushing the pulling rod to blow air on a tool mounting surface of a spindle and a main bearing portion. When the piston of the fluid pressure cylinder retreats, the passage for supplying air to the bearing seal portion is opened, and when the piston moves forward and presses the pulling rod, the central passage of the piston and the central passage of the pulling rod are connected and a tool A switching valve that opens a passage for blowing air to the taper surface of the device is provided in the member of the fluid pressure cylinder, and one air supply circuit is configured to be switched to another application by the operation of one fluid pressure cylinder. Air blow structure of the main shaft.