JPH10235536A - Main spindle cooling system of machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle cooling system of a machine tool that is capable of cooling a spindle around in a simple structure, thereby making an adverse effect on the accuracy of machining abatable in reducing any thermal displacement in a tool position. SOLUTION: This main spindle cooling system is so constituted that it cools a spindle 11 and its circumferential part of a machine tool that is designed so as to make a tool T installed in one end of this spindle 11 set up in a spindle head 5 and also the other end driven by a spindle motor 15, from the outside. In this case, three cooling jackets 19a to 19c covering at least both symmetrical sides and the front part of the spindle 11 are formed on an outer surface of the spindle head 5, and cooling air is fed into these cooling jackets 19a to 19c from the tool installation, side, and then this cooling air is discharge from the side of the spindle motor 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle cooling device for cooling a spindle of a spindle head and its periphery in a machine tool such as a machining center.

[0002]

2. Description of the Related Art Conventionally, as a cooling device for a machine tool in which a spindle is disposed within a spindle head, a tool is mounted on a lower end of the spindle, and a spindle motor for rotating and driving the spindle is disposed on an upper end, there is a conventional cooling device of the above-mentioned spindle motor. Generally, a ventilation fan is used.

[0003]

In the case of the above conventional apparatus,
Although the periphery of the spindle motor is cooled, the periphery of the spindle is not sufficiently cooled. Therefore, there is a problem that thermal displacement of a tool position of the spindle is large, which adversely affects machining accuracy.

In the type in which the spindle drive motor is built in the spindle head, an oil jacket is provided on the outer periphery of the spindle,
In some cases, cooled oil is circulated to cool the oil. However, in this cooling device, the oil cooling device is expensive, the processing and assembly of the oil jacket is troublesome, the number of parts increases, and the rotational inertia of the main shaft increases, so that a relatively high-output motor is required. However, there is a problem that the heat generation increases by that amount and the cooling cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and provides a machine tool capable of cooling around a main spindle with a simple structure, reducing thermal displacement of a tool position and reducing adverse effects on machining accuracy. It is an object to provide a spindle cooling device.

[0006]

According to a first aspect of the present invention, there is provided a machine tool in which a tool is mounted on one end of a spindle disposed in a spindle head and the other end is driven by a spindle motor, and the spindle of the machine tool. In a spindle cooling device for cooling the periphery from the outside, at least the left side of the spindle is provided on an outer surface of the spindle head.
Forming a cooling jacket covering the right side and the front, supplying cooling air from the tool mounting side into the cooling jacket,
The cooling air is discharged from the spindle motor side.

According to a second aspect of the present invention, in the first aspect, a cooling fin extending in a main axis direction is formed in the cooling jacket.

According to a third aspect of the present invention, in the first or second aspect, a compressed air source is connected to the cooling jacket through a cooling air supply passage, and outside air is sucked by compressed air in the middle of the cooling air supply passage. And an increase valve for increasing the air flow rate.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 7 are views for explaining a spindle cooling device of a vertical machining center according to an embodiment of the present invention. FIGS. 1 and 2 are a left side view and a front view of the vertical machining center, and FIG. FIG. 4 is a left side view of the spindle holding portion of the spindle head, FIG. 4 is a left side view of the spindle head with the cooling plate removed, FIGS. 5 and 6 are front and bottom views of the spindle head, and FIG. FIG. 7 is a sectional view taken along line -VII.

In the figure, 1 is a vertical machining center,
Reference numeral 2 denotes a base of the machining center 1, 3 denotes a column base slidably disposed on the base 2 in the X-axis (left-right axis as viewed from the front) direction, and 4 denotes a Y-axis (from the front) on the column base 3. The column 5 slidably disposed in the direction of the front-back axis) has a Z on the front of the column 4 (the front of the hand when viewed from the front).
It is a spindle head slidably disposed in the axial (vertical axis) direction. Reference numeral 6 denotes a pallet exchange device for exchanging a processed work and an unprocessed work.

The vertical machining center 1 has an automatic tool changer (ATC) 7. The tool changing device 7 is arranged at the upper part of the column 4 and has a large number of tools T.
And a tool magazine 8 for holding and holding the required tool in a tool pot, indexing and positioning a required tool at a tool transfer position set on the left and right sides of the column 4, a left and right tool transfer position and a spindle of the spindle head 5. Left and right tool transfer devices 9, 9 for transferring a tool between left and right standby positions set on the left and right sides of the main shaft, and mounting the tool at the standby position on the lower end of the main spindle and the main spindle. And a tool attaching / detaching device 10 for returning the tool mounted on the device to the standby position.

A main shaft 11 is inserted and arranged in parallel with the Z-axis in a main shaft holding portion 5a formed in a rectangular cylindrical shape at the tip end of the main shaft head 5. The main shaft 11 has a lower end portion and an intermediate portion. Are rotatably supported by a lower bearing 12 and an upper bearing 13 which are arranged at the same position. A tool T is inserted into a tapered hole 11 a formed at a lower end of the main shaft 11, and the tool T is clamped by a clamp mechanism 14 arranged in the main shaft 11. Reference numeral 5d denotes an opening for a tool unclamping mechanism (not shown) formed on the left and right side surfaces of the spindle holding portion 5a, and reference numeral 5e denotes a shaft support hole of an unclamping lever constituting the spindle unclamping mechanism.

An output shaft 15a of a spindle motor 15 is connected to the upper end of the spindle 11 via a connecting member 11b so as to be able to transmit torque. The spindle motor 15 is mounted on a motor mounting surface 5b formed at the upper end of the spindle holding portion 5a, and a flange portion 15b is fixedly fastened by a bolt 16.

A plurality of cooling fins extending in the axial direction are formed on the outer peripheral surface of the spindle motor 15, and a cooling jacket 15c is formed by surrounding the outside of the cooling fins with an exterior plate 15d. A blower fan (not shown) is provided at an upper portion of the fan 15. By the rotation of the blower fan, the outside air is removed from the flange 15b.
The main shaft motor 15 is configured to be cooled by sucking into the cooling jacket 15c from the vicinity and discharging the suction motor to the outside through the upper end opening.

A large number of cooling fins 17 extending in the spindle direction are provided on the front face, left and right sides of the spindle holding portion 5a of the spindle head 5.
Are integrally formed. Cooling plates 18a, 18b, 18c detachably mounted on the front, left and right sides of the spindle holding portion 5a on the outside of the cooling fins 17.
In this manner, three cooling jackets 19a, 19b, and 19c are formed on the front surface, the left side, and the right side surface of the spindle holding portion 5a.

The lower end of the cooling jacket 19a on the front side is closed by bending the lower end 18d of the cooling plate 18a rearward and fixing it to the lower end surface 5c of the spindle holding portion 5a. Cooling jacket 19
The lower ends of b and 19c are closed by a guide member 20 for regulating the operation of a tool attachment / detachment device (not shown). The upper ends of the cooling jackets 19a to 19c are open so as to surround the front edge, left and right edges of the flange portion 15b of the spindle motor 15. Further, the cooling jackets 19b and 19c on the left and right sides and the cooling jacket 19a on the front side are further provided.
Are connected to each other by a communication hole 19e formed near the lower end.

The left and right cooling jackets 1
Cooling air supply pipes 21 and 21 are connected to 9 b and 19 c via the guide member 20. The cooling air supply pipe 21 is connected to a compressed air source (not shown) via an increase valve 22 and a compressed air hose 23.

The increasing valve 22 suctions the surrounding air with a negative pressure generated by flowing the compressed air at a high speed to increase the air flow rate. The rear end large-diameter portion 22b is connected to the supply pipe 21, and the rear end large-diameter portion 22b is open to the atmosphere.

Next, the function and effect of this embodiment will be described. In the cooling device of the present embodiment, the compressed air is supplied from the compressed air source to the increasing valve 22 while the main shaft 11 is rotating. The cooling air increased by sucking the outside air in the increasing valve 22 is supplied to the cooling jackets 19b and 19c on the left and right sides through the cooling air supply pipe 21, and a part of the cooling jackets passes through the communication holes 19e and is provided on the front side. After flowing into the cooling jacket 19a, these cooling jackets 19
Heat flows around the main shaft 11 along the cooling fins 17 through the insides a to 19c while flowing upward, and is discharged from the upper end opening. A part thereof flows into the cooling jacket 15c of the spindle motor 15 and flows upward while absorbing heat from the spindle motor 15, and the cooling jacket 1c of the motor 15
5c is discharged from the upper end opening. During the period in which the rotation of the main shaft 11 is stopped, the supply of the cooling air is also stopped.

Here, the increasing valve 22 of the present embodiment includes:
For example, a commercially available product such as "Wonder Gun W501" of "OSAWA &COMPANY" can be adopted, and when this is adopted, for example, 4 kg / cm ² of compressed air is used at 0.1 kg / cm ² .
1 to 0.2 Nm ³ / min.
Cooling air of 7 Nm ³ / min can be secured.

As described above, in this embodiment, the cooling jackets 19a to 19c are formed by attaching the cooling plates 18a to 18c to the outer surface of the spindle holding portion 5a of the spindle head 5, and the cooling air is supplied into the cooling jackets. Therefore, heat around the main shaft 11 can be discharged with a very simple structure, and a rise in the temperature of the main shaft 11 can be suppressed. In this case, since the cooling air is supplied from the tool mounting side of the main shaft 11, the tool mounting side can be cooled more reliably, the thermal displacement of the tool position can be reduced, and the adverse effect on the machining accuracy can be reduced.

Further, in supplying the cooling air, the increase valve 22 for increasing the air flow rate by supplying the compressed air is employed, so that a large amount of the cooling air can be easily secured by the compressed air from the ordinary air compressor.

Further, when the rotation of the main shaft 11 is stopped, the supply of the cooling air is also stopped.
It is possible to prevent one part from being excessively cooled, and to prevent the tool position from fluctuating due to excessive cooling.

In the above embodiment, the cooling fins 17
Although the case where the cooling fin is provided has been described, the cooling fin is not always necessary. Further, in the above embodiment, the case of the vertical machining center having the main shaft arranged vertically has been described.
The present invention can of course be applied to a horizontal machining center having a main shaft arranged in a horizontal direction.

[0025]

According to the spindle cooling device for a machine tool according to the first aspect of the present invention, a cooling jacket is formed on the outer surface of the spindle head, and cooling air is supplied into the cooling jacket from a tool mounting side to provide a spindle motor. Since the heat is discharged from the side, heat around the spindle can be discharged with a simple structure and at low cost, which has the effect of suppressing the thermal displacement of the tool position and reducing the adverse effect on machining accuracy. There is also an effect that the influence on the mounting side can be prevented.

According to the second aspect of the present invention, since the cooling fins extending in the main shaft direction are provided in the cooling jacket, the heat around the main shaft can be more reliably discharged.

According to the third aspect of the present invention, since the increasing valve for increasing the air flow rate by sucking the outside air by the compressed air is provided in the middle of the cooling air supply passage, a simple structure, a low cost and a large amount are provided. Cooling air can be secured.

[0028]

[Brief description of the drawings]

FIG. 1 is a left side view of a machining center provided with a spindle cooling device according to an embodiment of the present invention.

FIG. 2 is a front view of the machining center.

FIG. 3 is a left side view of a spindle holding portion of a spindle head of the machining center.

FIG. 4 is a left side view showing a state where a cooling plate of the spindle head is removed.

FIG. 5 is a front view of the spindle head.

FIG. 6 is a bottom view of the spindle head.

FIG. 7 is a sectional view taken along line VII-VII of FIG. 4;

[Explanation of symbols]

Reference Signs List 1 machining center (machine tool) 5 spindle head 11 spindle 15 spindle motor 17 cooling fins 19a to 19c cooling jacket 21, 23 cooling air supply pipe, compressed air hose (cooling air supply passage) 22 increase valve T tool

Claims (3)

[Claims] 1. A spindle cooling device for cooling a spindle and its periphery of a machine tool in which a tool is mounted on one end of a spindle disposed in a spindle head and the other end is driven by a spindle motor, from the outside, A cooling jacket is formed on the outer surface of the spindle head to cover at least the left, right and front sides of the spindle. Cooling air is supplied from the tool mounting side into the cooling jacket, and the cooling air is supplied from the spindle motor side. A spindle cooling device for a machine tool, which is discharged. 2. The spindle cooling device for a machine tool according to claim 1, wherein cooling fins extending in a spindle direction are formed in the cooling jacket. 3. A cooling air supply according to claim 1, wherein a compressed air source is connected to said cooling jacket via a cooling air supply passage, and outside air is sucked by compressed air in the cooling air supply passage to reduce an air flow rate. A spindle cooling device for a machine tool, comprising an increasing valve for increasing the amount.