JPH109490A - Lubrication device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To stably lubricate an ultra-high-speed rotating bearing, suppress a rise in the temperature of the bearing, and stably lubricate the bearing even in a low-speed rotation range. When a temperature detected by a temperature sensor exceeds a set temperature when a rolling bearing incorporated in a spindle device enters an ultrahigh-speed rotation range, a control device controls an ON of a direction control valve. , The compressed air intensified by the intensifier 14 passes through the shuttle valve 9 and the like,
And then mixed with the lubricating oil discharged from the distributor 6 to form an oil-air mixed flow, which is supplied to the bearing from the nozzle in the device 12. On the other hand, when the bearing enters the low-speed rotation range and the temperature detected by the temperature sensor 17 falls below the set temperature, the control device 15 controls the directional control valve 13 to be OFF, whereby the pressure of the compressed air flowing through the circuit 2b is increased. Instead, it is guided to the junction 8 and then supplied as a mixed oil-air flow from the nozzle in the device 12 to the bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a lubricating device for lubricating a bearing of a high-speed spindle used in a machine tool such as a machining center or a grinding machine.

[0002]

2. Description of the Related Art FIG.
The following are known. This device is provided with first and second circuits b and f which are branched into two and then merge with each other. The compressed air supplied to the first circuit (lubricating oil supply circuit) b b is used as a driving force of an oil pump c interposed between the oil pump c and the oil, and is driven toward the oil metering piston type distributor d by the driving. Further, the oil metering piston type distributor d is driven by oil sent from the oil pump c, and a small amount of fixed amount of lubricating oil is intermittently discharged toward the junction e by such driving. . Then, the trace amount of lubricating oil discharged to the junction e is mixed with the compressed air flowing through the second circuit (pneumatic circuit) f to form an oil-air mixed flow, and thereafter, is guided downstream.

[0003] The oil-air mixture flow guided to the downstream side is
For example, the bearing g is injected from an air nozzle h disposed adjacent to a rolling bearing g incorporated in a spindle device.
And thereby lubricates the bearing g.

[0004]

However, in recent years, in response to demands for improving the quality of processed products by machine tools and reducing manufacturing costs, the number of rotations of a spindle, in other words, the cutting speed of a tool, has been increased to process a workpiece. Are often applied. For this reason, the rolling bearing used for the spindle is also rotated at a high speed in accordance with an increase in the rotation speed of the spindle. Rolling bearings used for spindles generally rotate the inner ring, but when the bearing rotates, the inner ring, rolling elements and cage each rotate with an air layer based on the viscous resistance of air. It functions as a curtain, blocking the airflow from outside. The function of blocking the air flow of the air curtain becomes remarkable as the rotational speed of the bearing (spindle rotational speed) increases.

Therefore, in order to supply the above-described oil / air mixed flow into the inside of the rolling bearing rotating at an ultra-high speed, the injection speed of the oil / air mixed flow injected from the air nozzle h needs to overcome the pressure of the air curtain. is there.

However, in the conventional lubricating apparatus, the compressed air pressure supplied to the first and second circuits b and f is 0.35 to 0.45M which is generally used in a production factory.
Since the air pressure is in the range of Pa and an air pressure of 0.5 MPa or less must be used, for example, a shaft diameter of 65 mm
000 rpm (Dpw · n = 2.4 million: Dp referred to here)
The w · n value is obtained by multiplying the pitch circle diameter (mm) Dpw of the bearing by the number of revolutions per minute n, and this value is used as one measure of high-speed rotation. In the above-mentioned super-high-speed spindle, the injection speed of the oil-air mixed flow injected from the air nozzle h becomes insufficient, and the bearing is affected by the air curtain generated in the bearing g rotating at an ultra-high speed. g will not reach the orbital surface sufficiently. As a result, there is a disadvantage that the lubrication of the bearing g becomes insufficient and the temperature of the bearing rises.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described disadvantages, and can stably lubricate a bearing or the like that rotates at a very high speed, and also suppresses a temperature rise by a cooling effect of increased pressure air. It is another object of the present invention to provide a lubricating device that can perform stable lubrication even in a low-speed rotation range.

[0008]

In order to achieve the above object, a lubricating apparatus according to the present invention comprises a lubricating oil supplied from a lubricating oil supply circuit to a pneumatic circuit together with an air flow flowing through the pneumatic circuit on a downstream side. A lubricating device for lubricating an object to be lubricated, such as a bearing, by injecting the lubricating object from a nozzle provided at the downstream end thereof, the pressure increasing means for increasing the air pressure of the pneumatic circuit; Operating state detecting means for detecting the operating state of the symmetric object; and air pressure adjusting means for increasing and decreasing the air pressure of the pneumatic circuit in accordance with the operating state of the lubricating symmetric object detected by the operating state detecting means. It is characterized by.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram for explaining a lubricating device according to a first embodiment of the present invention. In this embodiment, a fine constant oil amount lubrication device is taken as an example of the lubrication device.

In FIG. 1, reference numeral 1 denotes a finely-determined oil amount lubricating device.
The circuit includes first and second circuits 2a and 2b that merge with each other. Compressed air of 0.5 MPa or less (0.35 to 0.45 MPa) is supplied to the first and second circuits 2 a and 2 b from a compressed air supply source P such as a factory pipe of a production factory via the pressure control valve 3. The pressure is regulated and supplied to the specified pressure. here,
The first circuit 2a constitutes the lubricating oil supply circuit of the present invention, and the second circuit 2b constitutes the pneumatic circuit of the present invention.

The first circuit 2a is supplied with compressed air by a switching operation of the directional control valve 4, and the compressed air is supplied to the circuit 2a.
Is used as the driving force of the pneumatic drive pump 5 interposed in the air. By driving the pneumatic drive pump 5, lubricating oil is taken out of the oil tank 7 and the oil metering piston type distributor 6
Sent to The oil metering piston type distributor 6 is driven by the lubricating oil sent from the pneumatic drive pump 5, and a small amount of the lubricating oil is directed toward the junction 8 of the first and second circuits 2 a and 2 b by the driving. Discharged intermittently. In addition, the oil metering piston type distributor 6 is provided corresponding to the number of bearings incorporated in the spindle device 12 described later, but in this embodiment, only three are illustrated.

The second circuit 2b reaches the junction 8 via a shuttle valve 9 and a flow control valve 10 arranged in correspondence with the oil metering piston type distributor 6, and therefore the second circuit 2b
The compressed air flowing through the circuit 2b flows from one inlet 9a of the shuttle valve 9, flows out from the common outlet 9c, is adjusted to a specified flow rate by the flow control valve 10, and then is guided to the junction 8. . The compressed air flow guided to the junction 8 is mixed with the lubricating oil discharged from the oil metering piston type distributor 6 to form an oil-air mixed flow, and then guided downstream through the pipe 11. The downstream end of the pipe 11 is connected to an oil supply hole (not shown) formed in the housing of the spindle device 12. The oil supply hole extends toward a rolling bearing (not shown) which is incorporated in the spindle device 12 and rotatably supports a spindle (not shown), and a tip of which is arranged close to the bearing. ing. Further, an air nozzle (not shown) for jetting an oil-air mixed flow toward the rolling bearing is provided at the tip of the oil supply hole so as to face the bearing.

The second circuit 2b has a branch pneumatic circuit 2c which branches off before one inlet 9a of the shuttle valve 9 and is connected to the other inlet 9b of the shuttle valve 9 and has a branch air pressure. A directional control valve 13 and a pressure intensifier 14 for increasing the pressure of compressed air flowing through the circuit 2c are interposed in the circuit 2c. The directional control valve 13 and the directional control valve 4 interposed in the above-described first circuit 2a are turned ON by the control device 15. OFF control is performed. Here, in this embodiment, the pressure intensifier 14 constitutes the pressure increasing means of the present invention, and the direction control valve 13 and the control device 15 constitute the air pressure adjusting means of the present invention.

The control device 15 turns on and off the direction control valve 4 in response to an operation signal from, for example, a timer or a machine.
A temperature sensor 17 which controls and detects the temperature of the rolling bearing in the spindle device 12 in the vicinity of the rolling bearing.
ON / OFF control of the direction control valve 13 in accordance with the output signal of. Here, the temperature sensor 17 constitutes the operating state detecting means of the present invention, and the control device 15 determines that the rolling bearing (spindle) becomes excessive when the temperature detected by the temperature sensor 17 is higher than a predetermined set temperature. When it is determined that the rolling bearing is in the high-speed rotation region, the directional control valve 13 is turned on. When the temperature is lower than the set temperature, it is determined that the rolling bearing is in the low-speed rotation region, and the directional control valve 13 is turned off.

In FIG. 1, reference numeral 18 denotes a pressure switch for monitoring the supply state of the compressed air supplied through the pressure control valve 3, and 19 denotes a pressure switch for detecting the operation of the pneumatic drive pump 5. Pressure switches 18, 19
The power supply is operated in the event of an abnormality to turn off the power of the spindle motor to prevent the rolling bearing from being damaged. Reference numeral 16 denotes a flow sensor which is interposed in the pipe 11 and monitors whether or not pressure increase control described later is being executed. The flow sensor 16 operates when the pressure increase control is not being executed and is shown in the figure. Activate alarms that do not work.

Next, the operation of the fine constant oil amount lubrication apparatus will be described. A specified pressure (in this embodiment, from a compressed air supply source P such as factory piping of a production factory via a pressure control valve 3)
For example, assuming that the outlet pressure of the air nozzle is 0.3 MPa, the pressure is set to 0.4 MPa. By the way, at 0.4 MPa, the flow rate of the oil / air is 260 m / sec and the flow rate is 25 NL / min. ) Is supplied to the first and second circuits 2a and 2b, the compressed air flowing into the second circuit 2b flows from one inlet 9a of the shuttle valve 9, and After flowing out from the common outlet 9c, the flow rate is adjusted to a specified flow rate by the flow rate control valve 10, and then flows into the spindle device 12 via the junction 8 and the pipe 11.

When an operation signal is output from the timer or the machine side, the direction control valve 4 on the first circuit 2a side is turned on in accordance with the signal. As a result, compressed air is supplied to the pneumatic drive pump 5 to drive the pneumatic drive pump 5, and the lubricating oil is taken out from the oil tank 7 and sent to the oil metering piston type distributor 6, and The oil metering piston type distributor 6 is driven by the lubricating oil sent from the pressure drive pump 5, and a small amount of lubricating oil is intermittently discharged toward the junction 8.

The lubricating oil discharged to the junction 8 flows through the second circuit 2b and is mixed with the compressed air guided to the junction 8 to form an oil-air mixed flow. The oil flows into the oil supply hole of the device 12 and is supplied to the raceway surface of the rotating rolling bearing from an air nozzle provided at the tip of the oil supply hole, whereby the bearing is lubricated.

When the spindle device 12 is used,
When the temperature detected by the temperature sensor 17 exceeds the predetermined set temperature when the rolling bearing enters the ultra-high speed rotation range, the control device 15 controls the directional control valve 13 to be ON,
This allows the compressed air to flow through the branch air pressure circuit 2c to the intensifier 1
4 and is increased by the pressure intensifier 14 (in this embodiment, it is 0.8 MPa. Incidentally, 0.8 MPa
And the flow rate of oil and air is 340m / sec and the flow rate is 65NL
/ Min. ), The high-pressure air flow of which pressure has been increased flows into the other inlet 9b of the shuttle valve 9 and then flows into the common outlet 9c.
And then flows downstream through the second circuit 2b,
After being adjusted to a specified flow rate by the flow control valve 10, it flows into the oil supply hole in the spindle device 12 via the junction 8 and the pipe 11. As a result, an oil / air mixed flow containing high-pressure fine-grained lubricating oil becomes a high-speed air flow from the air nozzle, easily breaks through an air curtain generated inside or near the rolling bearing that rotates at an ultra-high speed, and is supplied to the raceway surface. ,
The bearing can be stably lubricated, and the temperature rise of the bearing can be satisfactorily suppressed by the cooling effect of the air whose pressure has been increased and the flow rate has increased.

In the case of using the spindle in the low-speed rotation range in the ultra-high-speed spindle device 12, if the flow rate of the oil-air mixed flow is kept at the above-mentioned set value in the ultra-high-speed rotation range, the air flow rate is high. As a result, although the cooling effect is promoted, lubricating oil supplied from the air nozzle to the rolling bearing is blown from the inside of the bearing to the outside, resulting in insufficient lubrication, possibly leading to damage to the bearing. It is uneconomical to consume air unnecessarily during low-speed rotation.

Therefore, in this embodiment, when the temperature detected by the temperature sensor 17 falls below a predetermined set temperature when the rolling bearing enters the low-speed rotation range, the control device 15 turns off the direction control valve 13. The control circuit shuts off the branch air pressure circuit 2c, so that the compressed air flowing through the second circuit 2b flows from one inlet 9a of the shuttle valve 9 without being boosted by the pressure booster 14, and then to the common outlet 9c.
After being adjusted to a specified flow rate by the flow control valve 10, the air is supplied from the air nozzle to the raceway surface of the rolling bearing through the junction 8, the pipe 11 and the oil supply hole in the spindle device 12. Therefore, in the low-speed rotation region of the bearing, the air flow velocity of the oil-air mixed flow returns to the flow velocity before the pressure was increased, and the flow rate also decreases. In this state, the oil flow is supplied to the raceway surface of the rolling bearing. The bearing can be stably lubricated without being blown from the inside to the outside.

In the above embodiment, the temperature sensor 17 determines whether or not the rolling bearing is in the ultra high speed or low speed rotation range.
Although the detection is performed by detecting the temperature of the rolling bearing, it is not necessarily limited to this. For example, by detecting the number of revolutions of the spindle, it is determined whether the rolling bearing is in an ultra-high speed or low-speed rotation range. May be performed. That is, an ultra-high speed and a low speed are set in advance, and if the speed detected by the speed sensor is higher than the set speed, it is determined that the rolling bearing (spindle) is in the ultra-high speed range. Then, the direction control valve 13 is ON-controlled, and when the rotational speed is lower than the set low-speed rotation speed, it is determined that the rolling bearing is in the low-speed rotation range, and the direction control valve 13 is OFF-controlled.

In the above embodiment, the lubricating oil supply circuit is a pneumatic circuit, and the pneumatic drive pump 5 interposed in the first circuit 2a drives the oil metering piston type distributor 6 to supply a trace amount and metering amount. Is intermittently discharged to the merging section 8, but it is not necessarily limited to this. For example, the lubricating oil supply circuit is not an air pressure circuit, and an electric drive pump (not shown) is used. By interposing the lubricating oil, the lubricating oil may be sent out to the oil metering piston type distributor 6 by the electric drive of the pump, and a small amount of the lubricating oil may be intermittently discharged to the junction 8.

Further, in the above embodiment, the pressure control valve 3, the direction control valves 4, 13, the pressure switches 18, 19, the pneumatic drive pump 4, the oil tank 6, the shuttle valve 9, the pressure intensifier 14, and the control device 15 Are unitized to constitute the lubrication unit 20, but this is not always necessary, and for example, the pressure intensifier 14 may be externally provided.

Further, in the above embodiment, the temperature sensor 1 determines whether or not the rolling bearing is in the ultra-high speed or low-speed rotation range.
Although only 7 is used, the present invention is not limited to this, and it is also possible to determine whether the rolling bearing is in a super high speed or low speed rotation range using both the temperature sensor 17 and the above-mentioned rotation speed detection sensor. Good.

Further, in the above embodiment, the direction control valve 4 is turned ON / OFF in response to an operation signal from the timer or the machine side.
The directional control valve 13 is controlled to be ON / OFF in accordance with the output signal of the temperature sensor 17 while performing the OFF control.
When the control unit 7 (and / or the rotation speed detection sensor) operates, both the directional control valve 4 and the directional control valve 13 may be automatically turned on / off via the control device 15.

FIG. 2 is an explanatory diagram for explaining a second embodiment of the present invention. In addition, parts that are the same as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The difference from the first embodiment is that the directional control valve 13 interposed in the branch pneumatic circuit 2c is arranged downstream of the pressure intensifier 14 and the directional control valve 13 and the pressure intensifier 14 The point is that the accumulator 21 is interposed in the circuit 2c between them. By interposing the accumulator 21 in this manner, a large amount of accumulated energy can be released in a short time to increase the pressure responsiveness and compensate for changes in pressure and flow rate. The other operation and effects are the same as those of the first embodiment, and the description thereof is omitted.

FIG. 3 is an explanatory diagram for explaining a third embodiment of the present invention. In addition, parts that are the same as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The difference from the first embodiment is that the pressure intensifier 14 is provided externally and the pressure of the compressed air supplied from the compressed air supply source P is increased beforehand by the pressure intensifier 14 before the lubrication unit 22. The pressure of the compressed air is regulated to a specified pressure (for example, 0.4 MPa) by the pressure control valve 23 and supplied to the first and second circuits 2a and 2b. Pneumatic circuit 2c (intensifier 1
4. Includes directional control valve 13. ), A branch pneumatic circuit 24 branched from between the pressure intensifier 14 and the pressure control valve 23 and connected to the other inlet 9b of the shuttle valve 9 is provided, and the direction control valve 13 is interposed in the circuit 24. It is in the point which made it.

In the super-high speed rotation range of the bearing,
The direction control valve 13 is ON-controlled by the control device 15,
Thereby, the compressed air increased in pressure by the pressure intensifier 14 is guided to the junction 8 through the branch air pressure circuit 24, the shuttle valve 9, the flow control valve 10, and the like.

On the other hand, in the low-speed rotation range of the bearing, the direction control valve 13 is turned off by the control device 15, whereby the specified pressure (for example,
0.4 MPa) compressed air is supplied to the shuttle valve 9,
It is led to the junction 8 via the flow control valve 10 and the like. The other operation and effects are the same as those of the first embodiment, and the description thereof is omitted.

FIG. 4 is an explanatory diagram for explaining a fourth embodiment of the present invention. In addition, parts that are the same as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The difference from the first embodiment is that the pressure intensifier 14 is provided externally and the pressure of the compressed air supplied from the compressed air supply source P is increased by the pressure intensifier 14 before the lubrication unit 25. The pressurized compressed air is supplied to the first and second circuits 2a and 2b while the pressure control valve 23 is interposed in the first pneumatic circuit 2a. The specified pressure (for example, 0.4
(MPa) and sends it out to the directional control valve 4, and the second pneumatic circuit 2 b has a shuttle valve 9 and a branch pneumatic circuit 2 c (intensifier 14, directional control valve 13) as shown in FIG. ) Is provided, and a proportional electromagnetic pressure control valve 27 that can continuously control the air pressure in proportion to the electric signal is interposed.

Here, in this embodiment, the proportional electromagnetic pressure control valve 27 and the control device 15 constitute the air pressure adjusting means of the present invention, and the control device 15 responds to a detection signal output from the temperature sensor 17. Proportional solenoid pressure control valve 2
7, the pressure is steplessly increased, that is, proportionally controlled so that the air pressure is increased steplessly in proportion to the rise in the temperature of the bearing, and the direction control valve 4 is operated in response to an operation signal from the timer or the machine side. ON / OFF control.

Therefore, the pressure of the compressed air increased by the pressure intensifier 14 is steplessly adjusted by the proportional electromagnetic pressure control valve 27 from the low speed rotation range to the high speed rotation range of the bearing in accordance with the rotation speed. The lubricating oil is guided to the junction 8 via the valve 10, and as a result, appropriate lubricating oil can always be supplied to the raceway surface of the bearing regardless of the rotation speed of the bearing. The other operation and effects are the same as those of the first embodiment, and the description thereof is omitted.

[0037]

As is apparent from the above description, according to the present invention, even if the function of shutting off the air flow of the air curtain generated in the bearing increases due to the increase in the number of revolutions of the spindle, the mixed flow of the oil and air is reduced. Since the curtain is easily pierced and supplied to the raceway surface of the bearing, the bearing can be stably lubricated, and the temperature rise of the bearing can be satisfactorily increased due to the cooling effect of the increased pressure and the increased flow rate. The effect of being able to suppress is obtained.

Further, in the low-speed rotation range of the bearing, the air flow velocity of the oil-air mixed flow returns to the flow velocity before the pressure is increased, and the flow rate also decreases. In this state, the oil flow is supplied to the bearing raceway surface. The effect is obtained that the bearing can be stably lubricated without the oil being blown from the inside of the bearing to the outside.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram illustrating a lubricating device according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram for explaining a lubricating device according to a third embodiment of the present invention.

FIG. 4 is an explanatory diagram for explaining a lubricating device according to a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram for explaining a conventional lubrication device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fine constant oil amount lubrication apparatus 2a ... 1st circuit (lubricating oil supply circuit) 2b ... 2nd circuit (pneumatic circuit) 5 ... Pneumatic drive pump 6 ... Oil metering piston type distributor 8 ... Confluence part 13 ... Direction control valve (pneumatic pressure adjusting means) 14 ... pressure intensifier (pressure increasing means) 15 ... control device (pneumatic pressure adjusting means) 17 ... temperature sensor (operating state detecting means)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshio Masada 1-5-150 Kugenuma Shinmei, Fujisawa-shi, Kanagawa Nippon Seiko Co., Ltd. Nippon Seiko Co., Ltd. (72) Inventor Nobuhiko Takubo 2-30-5 Makizukadai, Sakai City, Osaka Prefecture

Claims (1)

[Claims] 1. A bearing in which a lubricating oil supplied from a lubricating oil supply circuit to a pneumatic circuit is directed downstream along with an airflow flowing through the pneumatic circuit and is injected from a nozzle provided at the downstream end. In a lubricating device adapted to lubricate an object to be lubricated, pressure increasing means for increasing the air pressure of the pneumatic circuit, operating state detecting means for detecting an operating state of the lubricating object, and operating state detecting means A lubricating device comprising: air pressure adjusting means for increasing or decreasing the air pressure of the pneumatic circuit in accordance with the detected operating state of the lubrication symmetric object.