JPH0658160B2 - Oil air lubricator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil / air lubrication device for a rotary shaft, and more particularly to an oil / air lubrication device for lubricating a high speed rotary shaft of a machine tool or the like.

[0002]

2. Description of the Related Art Conventionally, lubrication has been performed on a shaft that is continuously driven to rotate. At that time, it is known to enhance the lubrication effect on a shaft rotating at a high speed by mixing air with oil and blowing it.

Recently, the speed of a spindle such as a machining center of a machine tool has been increased, and the spindle that rotates at a high speed is lubricated. However, the spindle of a machining center often starts and stops repeatedly in a short time of several tens of seconds to several minutes, and sometimes stops for a long time. As described above, in the lubrication of a shaft that does not continue continuous rotation for a long time, if the lubrication device is operated even when the shaft is stopped, the problem that the oil and air consumption is large is a problem. It was

When the lubricating device is driven in conjunction with the rotation of the spindle, the supply interval is controlled by an internal or external timer. However, the timer is reset when the spindle stops, so it is short. Start in time
Oil is sent out every time the spindle is repeatedly stopped, and the oil supply becomes excessive. There is a problem that the temperature of the bearing portion rises not only when the supply is insufficient, but also when the supply is excessive, which causes heat generation of the spindle.

[0005]

Therefore, the present invention provides an air supply device, an oil supply device, and a mixing valve for mixing air supplied from the air supply device and oil supplied from the oil supply device. And an oil-air lubrication device that sprays oil mixed with air at _a time interval T _a determined by a timer onto a shaft to be lubricated, the timer being a first timer, and separately from the first timer, when the lubrication device is activated. A second timer that starts counting and continues to operate for a time T _b selected to satisfy T _b ≦ T _a regardless of whether the lubricated shaft is turned on or off is provided. If the first timer is stopped, the first timer is not reset while the second timer is operating. Resolved.

[0006]

According to the present invention, the oil supply device of the lubricating device is continuously driven, or is linked to the rotation of the main shaft which is repeatedly started and stopped in a short time, and is reset when the main shaft is stopped. A second timer that continues to operate regardless of whether the main shaft is on or off is provided instead of being controlled by, and resetting of the conventional timer is restricted by this timer, so excessive supply of oil is suppressed and heat generation of the shaft is prevented. It has become possible. The second timer, which continues to operate regardless of whether the main shaft is on or off, keeps that state until the lubricating device stops according to the stop of the lubricated shaft once it counts up, so it is possible to prevent the first timer from operating. Therefore, there is no shortage of oil supply.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a lubricating unit 1 as a lubricating device.
A pump 4 is connected to the oil tank 2 of FIG.
The outlet of the pump 4 is connected to the mixing valve 5 via a pipe line 6. A pressure switch 7 is connected to the pipeline 6.

The mixing valve 5 connected to the lubrication unit 1 is a metering piston type distributor 8 connected to a pipe line 6.
And a mixing section 10 connected to the distributor 8 via a check valve 9. The mixing section 10 is connected to an air source 13 via a conduit 12 having a throttle 11, and air is mixed with the oil supplied from the distributor 8. The mixed oil mixed with air is blown out from a nozzle (not shown) attached to the mixing valve 5.

A pressure switch 14 is connected to the conduit 12. The air pipeline 15 that drives the pump 4 of the lubrication unit 1 is connected to the pipeline 12 via an electromagnetic valve 16. An external control timer 19, which is a second timer, is connected to the solenoid valve 16. The control timer 19
Is a time interval T _a at which oil mixed with air is sprayed on the main shaft.
It is separate from a timer (not shown) (internal timer of the lubrication unit) that controls the time, starts counting when the lubrication unit is activated, and the time T _b selected to be T _b ≦ T _a regardless of whether the spindle is on or off. Operation continues for
When the preset time _Tb is counted (counted up), a control signal is sent to the solenoid valve 16. A pressure gauge 17 is connected to the conduit 12. Pipeline 12
A solenoid valve 18 is connected between the air source 13 and the air source 13. T
_The timer for controlling a does not enter the reset state even if the spindle is turned off unless the control timer 19 counts up.

The oil tank 2 is provided with a level switch 20.

In the flow chart of FIG. 2, the control device first determines whether or not there is a spindle start command (step 1), and if YES, determines whether the lubricating unit is in operation by the spindle start subroutine (FIG. 3). It is determined whether or not (step 10). When step 10 is NO, the lubrication unit is started (step 11), the external control timer is started (step 12), and the spindle is started (step 1).
3). When step 10 is YES, the spindle is immediately activated (step 13).

When the step 1 is NO, it is determined whether or not the spindle stop command is issued (step 2), and when the spindle stop command is not issued, it is determined whether or not the external control timer is ON (step 3). ). If the external control timer is not ON, repeat from step 1. If the timer is ON, it is determined whether or not the external control timer has counted up a fixed time (T _b ) (step 4). If the count is not up, the process is repeated from step 1, and if the count is up, it is determined whether or not the spindle is in operation (step 5). If step 5 is YES, the process is repeated from step 1, and if NO, the lubrication unit is stopped (step 6), the external control timer is stopped (step 7), and the process is repeated from step 1.

When the spindle stop command is issued in step 2, the spindle is stopped (step 8), it is judged whether or not the external control timer has counted up a fixed time (step 9), and the count is up. In this case, the lubrication unit and the external control timer are stopped by steps 6 and 7, and the process is repeated from step 1.

If the external control timer has not counted up, step 1 is repeated.

The above operation timing is as shown in the time chart of FIG. A shows the progress of the start / stop of the spindle, B shows the progress of the external control timer, and C
Indicates the progress of starting and stopping the lubrication unit. Lubrication unit is originally but is adapted to start and stop in synchronism with the start and stop of the main shaft, after starting of the lubrication unit, the lubrication unit is also stopped spindle is a within a predetermined time T _b You are blocked from stopping. The lubrication unit beginning to the spindle is stopped after a time T _b lapse can be stopped. Since this is a lubrication unit that is started and stopped originally in synchronization with the start and stop of the main spindle, the lubrication unit does not stop while the main spindle is rotating, that is, the lubrication unit operates until the main spindle stops. Since the oil can be discharged, a shortage of the oil supply does not occur. D shows the progress of discharge of the mixed oil by the lubrication unit. Lubrication unit shows the oil mixture, and startup lubrication unit, to discharge prescribed by time per interval T _a by an internal timer of the lubrication unit. Stop the lubrication unit after the external control timer counts up.
Since the operation is performed only after the main shaft stops, when the time interval from the start of the lubrication unit to the stop is T _b (B region), only the discharge is performed at the start and the oil is not discharged until the next start. . When the lubrication unit is started and stopped in a time longer than the time interval T _a where T _a ≧ T _b and shorter than 2T _a (A region and C region),
The oil is discharged twice at startup and after T _{a has} elapsed,
The count-up state of the external control timer is maintained from the time point _{Tb has} elapsed until the lubrication unit is stopped. Therefore, when the lubrication unit is activated again at a relatively short time interval _Tc after the last ejection after the external control timer has counted up, oil is ejected at the time of activation, but once the lubrication unit is activated. Is activated,
Since the lubrication unit does not stop until T _b elapses, and therefore the external timer does not stop, the internal timer is not reset, and the oil discharge is avoided from being repeated three times or more at short intervals.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a lubricating device according to the present invention.

FIG. 2 is a flow chart showing the operation of the device according to the present invention.

FIG. 3 is a flowchart of the subroutine of FIG.

FIG. 4 is a time chart.

[Explanation of symbols]

 1 Lubrication unit 4 Pump (oil supply device) 5 Mixing valve 12 Pipe line 13 Air source (air supply device) 19 Control timer (second timer)

Claims (1)

[Claims] An air supply device, and an oil supply device, and a mixing valve for mixing the oil supplied from the oil supply device and air supplied from the air supply device, the air in the time interval T _a specified by the timer In an oil-air lubrication device that sprays mixed oil onto a lubricated shaft, the timer is a first timer, and apart from the first timer, counting is started when the lubrication device is activated, regardless of whether the lubricated shaft is on or off. _A second timer is provided which continues to operate for a time T _b selected so that _b ≦ T _a , and the lubricating device once activated can be stopped only when the second timer counts up. Is configured so that it is not reset while the second timer is operating.