JPH0970738A - For lubricating oil feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately supply lubricating oil to a lubricated part by starting to count the number of times of supply by a supply means after the operation of the lubricated part is stopped and stopping the intermittent supply when the number of times of supply reaches a set value. SOLUTION: When the rotation of a spindle 2 is stopped and a rotation stopping signal is outputted from an NC device, the number of times of the output signals of the signal generator 31 after the rotation stopping signal is outputted (i.e., the number of times N of discharge of a pump 13) starts to be counted by a counter 32 of the number of times. When the number of times N of the discharge reaches a set value Nd, the signal output from the signal generator 31 at every set time t is stopped. Thus, the change-over control for a second electromagnetic valve 27 is not carried out and the lubricating oil discharging operation by the pump 13 is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for supplying lubricating oil to a lubricated portion such as a bearing portion of a main shaft of a machining center.

[0002]

2. Description of the Related Art Conventionally, as a lubricating oil supply device of this type, there is a technique described in Japanese Patent Publication No. 7-22871. The technology supplies lubricating oil intermittently to the bearing part based on the rotation of the spindle of the machining center, but when the spindle stops rotating for longer than the delay time set by the off-delay timer. It is configured to stop the intermittent supply of the lubricating oil.

[0003]

The above-mentioned prior art can prevent the lubricating oil from being continuously supplied to the bearing portion of the main shaft in the stopped state, so that the excessive lubricating oil is prevented from accumulating in the bearing portion. It is excellent in suppressing heat generation when the spindle is restarted, but there is still room for improvement in the following points. That is, in the above-described conventional configuration, the total supply amount of lubricating oil after the rotation of the spindle is stopped is indirectly grasped by the set time of the timer, and therefore the number of intermittent supply within the set time of the timer may be some cause. When it changes, the total supply amount of the lubricating oil changes. For this reason, it is not possible to accurately grasp the actual total supply amount of the lubricating oil after the rotation of the main shaft is stopped.

Therefore, according to the above-mentioned prior art, in reality, the lubricating oil is excessively supplied to the bearing portion of the main shaft in the stopped state, and conversely, the amount of the lubricating oil supplied is large. There may be a shortage. Due to the excessive supply of lubricating oil, the spindle is likely to generate heat when restarted. Further, due to insufficient supply of lubricating oil, cooling during stoppage is insufficient, and thermal displacement of the bearing cannot be suppressed sufficiently.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to accurately supply lubricating oil to a lubricated portion such as a bearing portion without excess or deficiency.

[0006]

The present invention is characterized in that a lubricating oil supply device is constructed as follows. For example, as shown in FIGS. 1 and 2, a supply unit 11 that intermittently supplies the lubrication oil L of a set amount ΔQ to the lubricated portion 3,
The control means 25 includes a number counter 32 for measuring the number N of times of supply of the supply means 11, and the control means 25 is lubricated by the supply means 11 based on the operation of the lubricated portion 3. Whereas oil is intermittently supplied,
Based on the operation of the lubricated part 3 being stopped, the number counter 32 starts counting the supply number N of the supply means 11 and the supply number N is set to the set value N.
The intermittent supply of the above-mentioned supply means 11 is stopped based on the arrival at d.

As a concrete example of the intermittent supply of the supply means 11, there are a case where the supply is intermittent every set time and a case where the supply is changed every arbitrary time.

[0008]

The present invention operates as follows, for example, as shown in FIGS. First, as a pre-preparation, even if the standard specification lubricating oil is continuously supplied to the lubricated portion 3 which is not operating, a predetermined amount or more of lubricating oil is accumulated in the lubricated portion 3. The amount of total supply that does not exist is determined by experiments, etc., and the same amount of total supply after operation is stopped is calculated in advance for each lubricating oil used by performing similar experiments for each lubricating oil with different physical properties such as viscosity. Then, based on the calculated total supply amount, the set value Nd of the number of times of supply of the supply means 11 after the operation of the lubricated portion 3 is stopped, and the set amount ΔQ which is the supply amount per time of the supply means 11.
And decide.

When the lubricated portion 3 is in operation, the set amount ΔQ of lubricating oil is intermittently supplied from the supply means 11 to the lubricated portion 3. When the operation of the lubricated part 3 is stopped, the intermittent supply of the supply means 11 is continued, but the supply count N of the supply means 11 starts to be counted by the number counter 32. Then, when the number of times N of supply reaches the set value Nd while the operation of the lubricated part 3 is stopped, the intermittent supply of the supply means 11 is stopped. If the lubricated part 3 is restarted before the supply number N reaches the set value Nd,
The intermittent supply of the supply means 11 is continued.

[0010]

The present invention has the following effects because it is configured and operates as described above. When the lubricated part continues to stop operating, the total supply amount of lubricating oil after the operation is stopped is accurately determined by “the set amount of supply means (ΔQ)” × “the set value of the number of times of supply (Nd)” Therefore, unlike the above-mentioned conventional technology using the delay time of the timer,
Lubricating oil can now be accurately supplied to the lubricated portion in the above-mentioned operation stopped state. As a result, it is possible to reliably prevent the lubricating oil from being accumulated more than necessary in the lubricated portion that is not operating, and to prevent heat generation when the lubricated portion is restarted. In addition, since the lubricated portion in the inoperative state can be sufficiently cooled by an appropriate amount of lubricating oil, the thermal displacement of the lubricated portion can be suppressed.

[0011]

1 and 2 show an embodiment of the present invention. FIG. 1 is a system diagram of an apparatus in which the present invention is applied to lubricate a spindle of a machining center. FIG. 2 is a time chart explaining the operation of the control means provided in the above device.

First, the overall structure of the apparatus will be described with reference to FIG. Spindle 2 on the spindle head 1 of the machining center
There are multiple bearings 3 (only two are shown here)
It is rotatably supported by. Two oil cooling passages 4 and 5 are formed in the spindle head 1. The tool holder 6 is pressed and fixed to the tapered surface 8 of the cylinder hole 7 by a collet and a draw bar (both not shown) arranged in the cylinder hole 7 of the main shaft 2.

A lubricating oil supply passage 10 formed in the spindle head 1 is provided in each of the bearings 3 which are parts to be lubricated.
The end portions of are faced. The lubricating oil supply unit 11 includes a tank 12 that stores the lubricating oil L, a reciprocating pump 13, and a lubricator 14. The pump 13 has a pneumatic chamber 16
A piston 17 inserted in an airtight manner inside, a plunger 19 inserted in an oiltight manner inside a pump chamber 18, and a return spring 20 are provided. Reference numeral 21 is a check valve for suction, and reference numeral 22 is a check valve for discharge. Although not shown, the pump 1
3 is provided with a mechanism for adjusting the discharge amount per time.

When the first solenoid valve (solenoid valve for air supply) 26 at the closed position B is switched to the open position A by the electronic control means 25, the compressed air from the air pressure source 29 is supplied to the lubricator 14. At the same time, it is supplied to the second electromagnetic valve (electromagnetic valve for supplying lubricating oil) 27. When the second solenoid valve 27 is switched to the discharge position Y shown in the figure by the control means 25, the plunger 19 is retracted leftward by the return spring 20 so that the lubricating oil L in the tank 12 is pumped. Inhaled into chamber 18.

On the other hand, when the second solenoid valve 27 of the above is switched to the supply position X by the control means 25 of the above, the compressed air from the air pressure source 29 is also supplied into the air pressure chamber 16, and the piston The plunger 19 is advanced into the pump chamber 18 by the same as 17, and the set amount ΔQ of the lubricating oil L corresponding to the discharge volume of the pump chamber 18 is supplied to the lubricator 14. The lubricating oil supplied to the lubricator 14 is atomized by the compressed air supplied from the pneumatic pressure source 29 through the first electromagnetic valve 26, and thereafter,
It is pressure-fed to the bearing 3 through the lubricating oil supply passage 10. Then, the second electromagnetic valve 27 is set to the discharge position Y.
The lubricating oil having the above-mentioned set amount ΔQ is intermittently supplied to the bearing 3 every time the switching is made from the supply position X to the supply position X.

The control means 25 controls the number of discharges of the pump 13 and the signal generator 31 that functions to intermittently discharge the pump 13 by switching the second electromagnetic valve 27 at every set time. The number counter 32 for measuring is provided. The control means 25 operates as follows, as shown in the time charts of FIGS. 1 and 2 above.

When the main shaft 2 is rotated,
A signal is output from the signal generator 31 based on a rotation signal of an NC device (not shown) of the machining center at every set time t. The first electromagnetic valve 26 is switched to the open position A by the output signal of the signal generator 31, and air is supplied to the lubricator 14. The supply of the air is continued while the signal is output from the signal generator 31 every set time t. In addition, the second electromagnetic valve 27 is switched to the supply position X by Δt time at each set time t by the output signal of the signal generator 31 of the above, whereby the set time t of the pump 13 from the pump 13 is changed. The set amount ΔQ of lubricating oil is intermittently discharged every time.

The rotation of the main shaft 2 is stopped and the above N
When a rotation stop signal is output from the C device (not shown), air is supplied to the lubricator 14 and the pump 1
Although the discharge operation of No. 3 is continued, the number of times of the output signal of the signal generator 31 (that is, the discharge number N of the pump 13) from the time when the rotation stop signal is output is started to be counted by the number counter 32.

When the discharge number N reaches the set value Nd, the signal output from the signal generator 31 at every set time t is stopped. Therefore, the switching control of the second electromagnetic valve 27 is not performed, and the discharge operation of the lubricating oil by the pump 13 is also stopped. Further, when the signal from the signal generator 31 is no longer output, the first electromagnetic valve 26 for air supply is switched to the closed position B to stop air supply. When the main shaft 2 is rotated again, the output signal of the signal generator 31 causes the lubricator 1 to rotate.
4 is supplied with air and the discharge operation of the lubricating oil by the pump 13 is started. At the same time, the counter 32 is reset to prepare for the next stop of the spindle 2.

After the main shaft 2 is stopped, if the main shaft 2 is rotated again before the number of discharges N of the pump 13 reaches the set value Nd, the air supply is continued and the pump 13 is the same as above. The lubricating oil discharge operation is continued, and at the same time, the number counter 32 is reset to prepare for the next stop of the spindle 2.

According to the above embodiment, the signal generator 31
Since it is possible to quantitatively discharge the set amount ΔQ of lubricating oil from the reciprocating pump 13 every set time t in accordance with the output signal of, the total supply amount of lubricating oil after the bearing 3 is stopped can be accurately grasped. It became so.

The amount of lubricating oil supplied to the bearing 3 is preferably changed according to the rotation speed of the main shaft 2. For that purpose, it is conceivable to program the control means 25 so as to change the set time t of the signal generator 31 according to the number of revolutions of the spindle 2. As a result, the number of discharges per unit time of the pump 13 is changed, and the supply amount of lubricating oil is changed.

The above embodiment can be modified as follows. The rotation of the spindle 2 and the rotation stop are detected by detecting the actual rotation state of the spindle 2 (or the motor for driving the spindle) and outputting the detection signal instead of the output signal from the NC device. Good. Regarding the number of times of supplying the lubricating oil supply means 11, instead of measuring the output signal of the signal generator 31, the second electromagnetic valve 27 for supplying lubricating oil is used.
It is also possible to measure the number of times of switching of the above, or to directly measure the number of times of discharge of the pump 13 by a pressure switch, a flow rate switch or the like. Further, the above-mentioned supply means 11 may be provided with another type of pump such as a diaphragm type pump or a trochoid type pump instead of the one provided with the reciprocating type pump 13. Also,
The drive means of the pump may be an electric drive type or an electromagnetic drive type instead of the air drive type.

Further, according to the present invention, the amount of lubricating oil supplied after the operation of the lubricated portion such as the bearing is stopped is calculated by the number of times the lubricating oil is supplied. Therefore, the lubricating oil is intermittently supplied at regular intervals. Instead of this, the lubricating oil may be intermittently supplied at every arbitrary changing time. Further, the present invention is suitable for a lubricated portion that is rotated at an ultra-high speed such as a bearing portion of a spindle of a machining center, but a bearing portion of a spindle of a lathe, a rolling guide portion or a sliding guide portion of a table of a machining center, etc. It is also applicable to lubrication of gear mechanism of index table. Further, the lubricating oil supply means of the present invention is not limited to the spray lubrication system, and may be oil-air lubrication or a system that supplies only the lubricating oil to the lubricated portion. .

[Brief description of drawings]

FIG. 1 is a system diagram of an apparatus to which the present invention is applied for lubricating a spindle of a machining center, showing an embodiment of the present invention.

FIG. 2 is a time chart explaining the operation of the control means provided in the above device.

[Explanation of symbols]

3 ... Lubricated part (bearing), 11 ... Supply means, 13 ... Pump, 25 ... Control means, 31 ... Signal generator, 32 ... Count counter, L ... Lubricating oil, N ... Supply count (discharge count of pump 13) , Nd ... Set value, ΔQ ... Set amount, t ... Set time.

Claims (1)

[Claims] 1. A portion to be lubricated with a set amount (ΔQ) of lubricating oil (L)
A supply means (11) for intermittently supplying to (3) and a number counter (3) for measuring the supply frequency (N) of the supply means (11).
Control means (25) provided with 2), and the control means (25) intermittently supplies the lubricating oil by the supply means (11) based on the operation of the lubricated portion (3). On the other hand, based on the operation stop of the lubricated part (3) of the above, the number of times (N) of supply of the above-mentioned supply means (11) is started to be counted by the above-mentioned number counter (32), and the supply is started. A lubricating oil supply apparatus, characterized in that the intermittent supply of the supply means (11) is stopped based on the number of times (N) reaching a set value (Nd).