JPH0722871B2 - Spindle lubrication oil supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a spindle lubricating oil supply device used for a machine tool such as a machining center, and more specifically, a lubricating oil for a bearing supporting the spindle at regular intervals. The present invention relates to a spindle lubricating oil supply device adapted to supply the oil.

<Prior Art> In a spindle head of a machining center in which the spindle is rotated at a high speed, an oil-air mixture of oil and air is supplied to a bearing portion at regular time intervals to lubricate the bearing.

<Problems to be Solved by the Invention> However, in such a conventional one, since the oil air is supplied to the bearing portion at regular intervals even when the spindle is stopped, the spindle is stopped for a long time. If excessive amount of lubricating oil is accumulated in the bearing and high-speed rotation of the main spindle is restarted in this state, heat generation in the bearing portion may increase, which may cause a problem such as thermal displacement of the main spindle.

<Means for Solving Problems> The present invention has a timer function of starting clocking in response to the rotation of the spindle being stopped and resetting clocking in response to the rotation of the spindle being started. With this timer function, spindle stop detection means for detecting that the spindle has been stopped for a certain period of time or more, and in response to the start of rotation of the spindle, supply of lubricating oil to the bearings every certain period of time. And a control means for stopping the lubricating operation when the main spindle stop detecting means detects the stop of the spindle for a predetermined time or more.

<Operation> When the rotation of the main shaft is started, the control means starts the lubricating operation in response to this, and repeats the operation of supplying the lubricating oil to the bearing portion at regular intervals. Then, this operation is continued while the main shaft continues to rotate or while the rotation is repeatedly stopped at short intervals, and an appropriate amount of lubricating oil is supplied to the bearing portion. On the other hand, when the spindle is stopped for a predetermined time or more, this is detected by the spindle stop detecting means, and in response thereto, the control means stops the supply of the lubricating oil until the rotation of the spindle is restarted. As a result, it is possible to prevent the lubricating oil from being accumulated in the bearing portion more than necessary.

<Examples> Examples of the present invention will be described below with reference to the drawings. In Fig. 1, SH is the spindle head of the machining center,
The OAFU is an oil air supply device that supplies oil air to the spindle head SH at regular intervals.

FIG. 2 shows the structure of the spindle head SH. Reference numeral 1 is a spindle head main body, and 2 is a bearing sleeve fitted and integrated with the inner diameter of the spindle head main body 1. A main shaft 6 is rotatably held in the inner diameter of the bearing sleeve 2 via a ball bearing 7. A plurality of ball bearings 7 are arranged at required intervals in the axial direction of the main shaft 6.

The bearing sleeve 2 is provided with an oil-air supply passage 10 and an exhaust passage 12 which are parallel to the axis of the main shaft 6. The supply passage 10 is a supply port 11 provided in the main spindle head body 1.
The exhaust passage 12 communicates with the atmosphere outside the main spindle head body 1. The supply passage 10 has a ball bearing 7
An exhaust port 14 is provided which communicates with a supply nozzle 13 which is located on one side of the exhaust passage 12 and which communicates with the exhaust passage 12 on the other side.

Therefore, when oil air is supplied to the supply passage 10 through the supply port 11, the oil air is supplied from one side of the ball bearing 7 from the supply nozzle 13 arranged in each bearing, and the oil air is supplied. Lubricate.

On the other hand, the lubricating oil supply device OAFU includes an air-driven pump unit 20, a mixing valve 21, an electromagnetic opening / closing valve 22, and a sequence control device 23. The air A, which has been depressurized to a constant pressure, is supplied to the mixing valve 21 and the electromagnetic opening / closing valve 22 via the electromagnetic opening / closing valve 26, and the air supplied to the electromagnetic opening / closing valve 22 is passed through the electromagnetic opening / closing valve 22. Is supplied to the pump unit 20,
The discharge port of this pump unit 20 is a mixing valve.
21, and the leaf outlet of this mixing valve 21 is connected to the supply port 11 of the spindle head SH. Therefore, when the electromagnetic on-off valve 22 is opened by a signal from the sequence control device 23, the pump unit 20 operates, and the lubricating oil stored in the tank 24 is pumped out by the pump unit 20 and supplied to the mixing valve 21. . Then, the supplied air and oil are mixed in the mixing valve 21 to become oil air, and the supply port 11 of the spindle head SH is
Is supplied to.

Further, the sequence control device 23 is programmed to repeatedly perform the lubricating oil supply control process shown in the flowchart of FIG. First, the solenoid valve 26
The solenoid is energized to supply air to the electromagnetic on-off valve 22 and the mixing valve 21. Thereafter, in step (50), whether or not the spindle 6 is in the rotating state is detected by the state of the internal dummy whose state is changed according to the spindle rotation stop command from the NC device (not shown), and the rotating state is detected. If it is, the spindle stop detection timer T1 is reset in step (51), and if it is in the stopped state, the spindle stop detection timer T1 is stepped up in step (52) and the process proceeds to step (53). .

In step (53), it is determined whether or not the count value of the spindle stop detection timer T1 has reached the set value and the time has expired. Start supply control. That is, in step (55), after incrementing the count value of the lubrication interval timer T2 that determines the time interval for supplying lubricating oil, it is determined in step (56) whether this lubrication interval timer T2 has timed up. If the time is up, step (5
At 7), the solenoid 22a of the solenoid valve 22 is energized to open the solenoid valve 22. As a result, a constant pressure of air A is supplied to the pump unit 20, the pump unit 20 is operated, and oil air is supplied to the ball bearing 7 of the spindle head SH.

Thus, after the supply of the lubricating oil is started, the lubricating time timer T3 for determining the lubricating oil supply time is incremented in step (58), and then the lubricating time timer T3 is calculated in step (60). Determines whether or not the time has expired, and if it has not timed out, does nothing and returns to step (50). If the time is up, the solenoid 22a of the solenoid on-off valve 22 is deenergized at step (61). Then, in step (62), the spindle stop detection timer T1 and the lubrication interval timer T2 are reset and the process returns to step (50), whereby the above operation is repeated. t1 is set shorter than the set time t2 of the lubrication interval timer T2.

By repeating the above process, the steps (53) → (5
5), (56) → (57), (60) → (50) The process shifts, and as shown in FIGS. 4 (d) and 4 (e), until the lubrication time timer T3 expires. The solenoid 22a of the solenoid valve 22 is continuously energized for a certain period of time, and the supply of oil air is continued for a set time t3 of the lubrication time timer T3.

Then, when the lubrication time timer T3 expires, this is determined in step (60), the process proceeds to step (61), the solenoid of the electromagnetic opening / closing valve 22 is de-energized, and then the spindle stop detection timer T1 and the lubrication interval timer Reset T2 and return to step (50). As a result, the electromagnetic opening / closing valve 22 is closed and the supply of oil air is stopped.

In this way, after the oil / air supply is stopped,
Only the increment of the lubrication interval timer T2 is performed in step (55), and when the lubrication interval timer T2 times out, the process moves from step (56) to (57) again, and the solenoid 22a of the electromagnetic opening / closing valve 22 is energized. Then supply the oil air again. While the spindle 6 is rotating, the reset state of the spindle stop detection timer T1 is maintained, so that the process shifts from step (53) to (55) and the above operation is repeated.

On the other hand, if the stopped state continues for the set time t1 of the spindle stop detection timer T1 after the spindle 6 stops and the process moves from step (50) to (52), the spindle stop detection timer T1 at that point Has timed out and this is step (5
The determination is made in 3) and the process returns to step (50) through steps (65) and (66), and the electromagnetic on-off valve 22 is closed. As a result, the oil / air supply process after step (55) is not performed, the oil / air supply is stopped until the rotation of the main shaft 6 is restarted and the main shaft stop detection timer T1 is reset. As a result, it is possible to prevent more than necessary lubricant oil from accumulating in the ball bearing 7.

Further, the electromagnetic on-off valve 26 is closed at the same time as the electromagnetic on-off valve 22 is closed, and the air supply is also stopped. Even if the spindle 6 stops, if the stop time is shorter than the set time of the spindle stop detection timer T1, the spindle stop detection timer T1 does not time up, so after step (55) The oil / air supply process is not stopped.

Further, since the set time of the spindle stop detection timer T1 is set shorter than the set time of the lubrication interval timer T2, the number of supply of oil air after the spindle 6 is stopped is 1
This is less than the number of times, and the supply of unnecessary lubricating oil can be minimized.

In the above-described embodiment, the pump unit 20 is an air-driven pump, and the supply of air to the pump unit 20 is controlled by the electromagnetic opening / closing valve 22 to intermittently supply the lubricating oil. As shown, the pump 20 'is driven by an electric motor 25, which
The intermittent supply of the lubricating oil may be performed by controlling the on / off of.

The present invention can be applied not only to the oil-air type main shaft lubricating oil supply device described above, but also to the main shaft lubricating oil supply device that supplies only the lubricating oil to the bearing.

Furthermore, the present invention can be applied not only to the spindle of a machining center but also to the supply of lubricating oil to other high-speed spindles.

<Effects of the Invention> As described above, in the present invention, even when the machine is in the operating state, the supply of the lubricating oil to the bearing portion is stopped when the main shaft stops for a certain time or more. So
It is possible to prevent an excessive amount of lubricating oil from being supplied to the bearing portion in the stopped state, and to effectively prevent heat generation of the spindle when the spindle is restarted.

Moreover, in the present invention, even when the spindle is repeatedly started and stopped, it is considered that the operating state is continuing unless the stop continues for a certain period of time or more, and the lubricating oil is supplied to the bearing every certain period of time. Since it is configured, it is possible to supply the lubricating oil even when the main shaft is stopped, and it is possible to prevent the lubricant from running out.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a block diagram showing the overall configuration of a spindle lubricating oil supply apparatus, and FIG.
FIG. 3 is a sectional view of the spindle head SH in the figure, and FIG. 3 is a flowchart showing the operation of the sequence controller 23 in FIG.
FIG. 4 is a time chart explaining the operation of the main spindle lubricating oil supply device shown in FIG. 1, and FIG. 5 is a block diagram of the main spindle lubricating oil supply device showing a modified example. 1 ... Spindle head body, 6 ... Spindle, 7 ... Ball bearing, 10 ... Supply passage, 13 ... Supply nozzle, 20, 20 '...
Pump unit, 21 …… Mixing valve, 22,26 ……
Electromagnetic on-off valve, 23 …… Sequence control device, OAFU …… Lubricating oil supply device, SH …… Spindle head, T1 …… Spindle stop detection timer, T2 …… Lubrication interval timer, T3 …… Lubrication time timer.

Claims (1)

[Claims] 1. A spindle lubrication oil supply device configured to supply lubrication oil to a bearing that supports the spindle at regular time intervals, and starts timing in response to stoppage of rotation of the spindle. It has a timer function that resets the clock in response to the start of rotation, and this timer function starts spindle rotation detection means that detects that the spindle has been stopped for a certain period of time In response to this, a control for starting a lubricating operation of supplying lubricating oil to the bearing at regular intervals and stopping the lubricating operation when the main spindle stop detection means detects a stop of the main spindle for a predetermined time or more And a spindle lubricating oil supply device.