JPH09166283A - Method and device for ultrasonic type fog lubrication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lubricate those parts to be lubricated by a low cost and low space device by applying a high frequency voltage to a ultrasonic transducer element immersed in lubricating oil and exciting it at a transmitting frequency near resonance point so as to atomize oil from an oil surface and filling the atomized oil into a case in which those parts be lubricated are stored. SOLUTION: A ultrasonic type fog lubricator 30 assembled into the inside of a gear box 10 is provided in a space under the gear box 10, and provided with a ultrasonic transducer 34 which is immersed in the oil contained in an oil reservoir 31 to feed oil properly from a lubricating oil feed means 32. Also the ultrasonic transducer 34 of, for example, 20mm in diameter and 1.2mm in thickness is excited at a transmitting frequency of 2.4MHz, and a distance H between the oil level and the transducer 34 is held at 30 to 70mm. Then a float switch 38 is set according to the upper and lower limits of the oil level, and atomization is performed within this range. When atomized oil is released in this condition, the gear box 10 is filled with atomized oil, effectively lubricating gears and bearings.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic lubrication method for lubricating a bearing and a gear of a spindle system of a machine tool and an apparatus for carrying out this lubrication method, and more particularly,
The present invention relates to an ultrasonic lubrication method and apparatus in which an ultrasonic vibrator is applied to atomize lubricating oil, and the atomized lubricating oil is suspended in a gear box to lubricate gears, bearings and the like.

[0002]

2. Description of the Related Art Conventionally, there are various lubrication methods adopted in machine tools such as grease lubrication, oil bath lubrication method, continuous lubrication method, cooling oil supply method, oil mist lubrication and oil / air lubrication. .

Among them, in oil bath lubrication, since oil is agitated, the heat of oil agitation generated as the number of rotations of the machine increases, and the oil temperature rises. Recently, as the speed of machines has increased, lubrication methods for cooling and supplying oil have become mainstream.

On the other hand, oil mist lubrication is a lubrication system suitable for lubrication of main shaft bearings for high speeds. In this oil mist lubrication, atomized oil is pumped by air, so atomized oil is sent to the lubricated part for lubrication, and at the same time, a large amount of air cools the bearing, which has a large amount of heat generation, by high-speed rotation. You can

Oil-air lubrication is a lubricating method with a high cooling effect because oil is carried along with the flow of air in the same manner as oil mist lubrication.

[0006]

In the case of the conventional lubrication system of supplying the cooling oil, the oil cooling and circulation system including the oil cooler, the tank, the pump, etc. becomes large, and the circulation device itself is properly installed. There is a problem of taking up space.

On the other hand, in the case of mist lubrication or oil / air lubrication, while having a cooling effect, a large amount of air is consumed and a treatment for improving the quality of supply air is indispensable.
There is a problem in that a large amount of oil-containing exhaust gas is treated so as not to adversely affect the environment, which is expensive.

Therefore, an object of the present invention is to solve the problems of the prior art and to provide a new method of ultrasonic spray lubrication of low cost and space saving, and an apparatus for carrying out this lubrication method. Especially.

[0009]

When a piezoelectric vibrator is vibrated in a liquid, ultrasonic waves are radiated toward the liquid surface. When the liquid cannot follow the repeated pressurization and depressurization by the ultrasonic waves, cavitation occurs. Therefore, it is known that when vibrating the vibrator at a position close to the liquid surface and causing cavitation, the liquid rises like a water column from the liquid surface and the liquid is discharged as fine mist droplets from the surface. There is.

The present invention is based on this principle. A high-frequency electric power is applied to an ultrasonic wave oscillating element immersed in lubricating oil to oscillate at an oscillation frequency near the resonance point to atomize the oil from the oil surface. The lubricated portion is lubricated by filling the case in which the lubricated portion is housed with atomized oil.

In general, the viscosity of the liquid has a great influence on the easiness of atomization of the liquid. The lower the viscosity, the easier the atomization. Since oil is viscous, in order to atomize it, it is necessary to appropriately find the oscillation frequency near the resonance point and keep the distance from the ultrasonic oscillation element to the oil surface within an appropriate range. The oscillation frequency varies depending on the thickness and outer diameter of the oscillation element,
The atomization capacity of oil can be controlled by changing the frequency. If the distance from the oscillating element to the oil surface is changed, the atomization efficiency changes significantly, and if it exceeds a certain range, atomization is stopped.

The particle size of atomized oil can be made finer by increasing the frequency and amplitude. In order to use it as lubrication, effective lubrication can be performed by atomizing so that the particle diameter becomes about 5 to 10 μm.

Further, the lubrication apparatus of the present invention for carrying out such a lubrication method has an oil sump tank in which lubricating oil is stored, and an ultrasonic oscillation element arranged so as to be immersed in the lubricating oil in the oil sump tank. A vibrator oscillating circuit that applies high-frequency power of an oscillating frequency to the ultrasonic oscillating element to excite it, and lubrication that replenishes the oil sump tank with lubricating oil so that the oil level of the oil sump tank is maintained. The oil supply means and the oil level are detected,
The oil level is constituted by oil level control means for controlling the oil level within a proper range in which the oil can be atomized.

According to a preferred embodiment of the present invention, the oil sump tank is installed in a gear box of a machine tool.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An ultrasonic spray lubrication device according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a structural diagram showing an embodiment in which the present invention is applied to lubrication inside a gear box of a machine tool. 1
0 indicates a gear box. Inside the gear box 10, there is a first transmission shaft 1 connected to a motor (not shown).
1 and a second transmission shaft 12 parallel thereto are rotatably supported by bearings 13a, 13b, 14a, 14b at both ends. As a reduction gear, a small gear 15 and a large gear 16 are attached to the first transmission shaft 11, and a small gear 17 and a large gear 18 are similarly attached to the second transmission shaft 12. Therefore, the combination of these gears causes the large gear 16 of the first transmission shaft 11 and the small gear 17 of the second transmission shaft 12 to mesh with each other, and the small gear 15 of the first transmission shaft 11 and the second transmission shaft 12 of the same. Big gear 1
The gear can be shifted in two steps when the gear 8 is engaged.

A gear 22 meshing with a gear 21 rotatably mounted on the main shaft 20 is fixed to the second transmission shaft. The main shaft 20 is supported by bearings 23 and 24 at both ends thereof.

Ultrasonic spray lubrication apparatus 30 of this embodiment
Is to be incorporated in the gear box 10 and to fill the atomized oil directly into the gear box 10 to lubricate the gears and bearings.

Utilizing the space below the gear box 10, an oil sump tank 31 filled with a certain level of oil is installed. The oil sump tank 31 is appropriately replenished with oil from a lubricating oil replenishing means 32 such as a pump through an oil supply pipe 33.

An ultrasonic vibrator 34 immersed in the oil in the oil sump 31 is attached to the bottom of the oil sump 31, and the ultrasonic vibrator 34 has a predetermined frequency from the control circuit shown in FIG. Is applied.

In this embodiment, the piezoelectric vibration used as the ultrasonic vibrator 34 has a diameter of 20 mm and a thickness of 1.2 mm and is excited at an oscillation frequency of 2.4 MHz. Also,
The distance H between the oil surface and the vibrator 34 is kept in the range of 30 to 70 mm. Set the float switch 38 corresponding to the upper and lower limits of the oil level,
It is atomized within this range.

Under this condition, when the ultrasonic vibrator 34 vibrates and emits ultrasonic waves toward the oil surface, the oil column 35 is released from the oil surface.
As a result, finely atomized oil is released from the surface thereof, and as a result, the inside of the gear box 10 is filled with atomized oil, so that each gear and bearing can be lubricated.

The oil sump tank 31 is arranged inside the oil recovery tank 36, and the condensed oil is accumulated in the oil recovery tank 36 and discharged from the drain port 37. From this drain port 37, the oil is returned to the lubricating oil supply means 32,
You may make it circulate.

The level of the oil level in the oil sump 31 is detected by the float switch 38, and when the oil level drops, the oil is replenished from the lubricating oil replenishing means 32 to keep the oil level constant within the proper range. The level is being secured. In addition, 39 is an oil temperature detector which constitutes a part of oil temperature abnormality detection means for detecting an abnormal temperature rise of the oil temperature.

FIG. 2 is a block diagram showing the configuration of the control system. Reference numeral 40 is a power supply circuit, and reference numeral 41 is a vibrator oscillating circuit that applies a high frequency voltage at an oscillating frequency to the ultrasonic vibrator 34 to excite it. In this case, the oscillator oscillating circuit 41 excites the ultrasonic oscillator 34 at a frequency of 2.4 MHz. 42 oscillation stop circuit 42 and abnormal current detection circuit 43
Is a circuit that protects the oscillator circuit 41. Of these, the oscillation stop circuit 42 sends an oscillation stop signal to the oscillator oscillation circuit 41 when the low level signal of the oil level is given from the level switch 38, and the oscillation of the ultrasonic oscillator 34 to which the high level signal is input. Output a signal to restart. The abnormal current detection circuit 43 is a circuit that detects the occurrence of an abnormal current in the ultrasonic transducer 34 and gives an abnormal detection signal to the oscillation stop circuit 42. Upon receiving this abnormality detection signal, the oscillation stop circuit 42 sends an oscillation stop signal to the oscillator oscillation circuit 41.

The lubricating oil supply device control circuit 44 is a circuit which constitutes an oil level control means together with the level switch 38. In this embodiment, the upper oil level of the range in which oil can be atomized is set to a high level and the lower limit is set to a low level. Lubricating oil supply device control circuit 44
When receiving the low level signal given from the level switch 38, starts the operation of the lubricating oil supply device 32 and continues the operation until it receives the high level signal. In addition, 45 is
In the liquid level drop abnormality detection circuit, this liquid level drop abnormality detection circuit 4
A circuit 5 outputs a warning signal to a warning device (not shown) when a timer (not shown) is activated when replenishment is started and the high level is not reached even after a preset time. In this way, the ultrasonic transducer 34 is exposed to the air so as not to oscillate, and the oil level of the oil reservoir 31 is kept in an appropriate range where oil is easily atomized. When the oil temperature of the oil in the oil sump 31 rises above the set temperature, the oil temperature abnormality detection circuit 46 detects an abnormal oil temperature rise from the detection signal of the oil temperature detector 39 and turns on the thermostat 47. When activated, the vibration of the ultrasonic transducer 34 is stopped.

Next, FIG. 3 shows another embodiment of the present invention. An air source 50 supplies air to the atomizing chambers 51 and 52 provided in parallel. Inside the atomization chambers 51 and 52, respectively, an oil reservoir 31 having an ultrasonic transducer 34 attached to the bottom is housed. Therefore, the oil atomized in the atomization chambers 51 and 52 can be supplied to the pipes 53 and 54,
It can be fed through 55 to various parts of the machine.

[0028]

As is apparent from the above description, according to the present invention, a high-frequency voltage is applied to an ultrasonic oscillator element immersed in lubricating oil to oscillate at an oscillation frequency near the resonance point, so that the oil is removed from the oil surface. Is atomized and lubricated with this atomized oil, so the size and amount of lubricating oil particles can be determined by the amplitude of ultrasonic waves,
It is possible to lubricate the gears and bearings in the gear chamber of the machine by controlling the change in frequency, and to provide a new type of lubrication method that simplifies conventional piping equipment and has a low operating cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an ultrasonic lubricating device according to the present invention.

FIG. 2 is a control block diagram of an ultrasonic lubricating device according to the present invention.

FIG. 3 is a structural explanatory view of an ultrasonic lubricating device according to another embodiment.

[Explanation of symbols]

 10 Gear Box 20 Spindle 30 Ultrasonic Lubrication Device 31 Oil Storage Tank 32 Lubricating Oil Supply Device 34 Ultrasonic Transducer 35 Oil Column 38 Level Switch 39 Oil Temperature Detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masanori Kurobe 2068 Ooka, Numazu City, Shizuoka Prefecture Toshiba Machine Co., Ltd. Numazu Office

Claims (4)

[Claims] 1. A high-frequency voltage is applied to an ultrasonic oscillation element immersed in lubricating oil to oscillate at an oscillation frequency near the resonance point to atomize the oil from the oil surface, and the atomized oil An ultrasonic spray lubrication method, characterized in that a lubricated portion is lubricated by filling a case housed therein. 2. The ultrasonic spray lubrication method according to claim 1, wherein the lubricating oil atomized in the atomizing chamber is supplied to the lubricated portion by air. 3. An oil sump tank storing a lubricating oil, an ultrasonic oscillator element arranged so as to be immersed in the lubricating oil in the oil sump tank, and a high frequency voltage having an oscillation frequency is applied to the ultrasonic oscillator element. And an oscillator circuit for exciting the oil sump, and a lubricating oil replenishing means for supplying lubricating oil to the oil sump so that the oil level in the oil sump is maintained An ultrasonic spray lubrication device, comprising: an oil level control means for controlling the oil level within an appropriate range where oil can be atomized. 4. The ultrasonic spray lubrication device according to claim 3, wherein the oil sump tank is installed in a gear box of a machine.