JPH05111850A - Lubricating device for vertical main spindle of machine tool - Google Patents

Abstract

PURPOSE:To eliminate leakage of lubricating oil after stop of operation in a vertical main spindle type machine tool and to secure lubrication and oil sealing function during operation. CONSTITUTION:A main spindle 16 provided in the vertical direction is mounted on a housing 10 through a bearing 12. An air sealing device is provided which feeds pressurized air to between the upper and lower ends of the housing 10 and the main spindle 16 so that lubricating oil in the housing 10 does not flow outside. A circulation pipe 54 and an oil circulating device 52 are provided so as to supply the lubricating oil to the bearing 12 and to collect the lubricating oil having lubricated the bearing 12 into an oil tank 70. An air supplying device 74 is provided so as to send pressurized air into the housing after operation of the main spindle 16 and the oil circulating device 52 is stopped and to discharge the lubricating oil in the housing 10 to the oil tank 70 through an oil collection side piping 68 of the circulating pipe 54.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device for a spindle of a machine tool having a vertical spindle, and more particularly to a lubricating device for a vertical spindle which prevents its lubricating oil from leaking to the outside of the device even after operation is stopped. ..

[0002]

2. Description of the Related Art Conventionally, a lubricating device for a machine tool having a vertical spindle has been disclosed in JP-A-63-23026 or JP-A-63.
As disclosed in Japanese Patent Laid-Open No. 62638/1994, during rotation of a spindle that rotates at high speed, high-pressure air is sent into a gap between the lower end of the housing and the spindle to serve as a cooling and oil seal. .. Then, when the main shaft stops and the supply of the pressurized air stops, the oil seal function is lost. Therefore, in order to eliminate the gap in the bearing portion, the member having the gap is elastically biased to seal the gap. A biasing member is provided. This urging member has a urging force such that a gap is formed in the bearing portion by the pressure of the pressurized air and the gap can be sealed when the supply of the pressurized air is stopped. As a result, lubrication and cooling are effectively performed while the vertical spindle of the machine tool is rotating at high speed.
Even when stopped, lubricating oil was prevented from leaking through the gap between the spindle and the housing.

[0003]

In the case of the above-mentioned conventional technique, the lubricating oil of the vertical type main shaft rotating at a high speed has a relatively low viscosity,
Moreover, since a large amount of water is circulated, when the lubricating oil overflows from the oil receiving portion at the lower end of the device to the bearing portion after the operation of the main shaft is stopped, even if the bearing portion is in close contact with the urging member, the vertical type Therefore, there is a problem that the lubricating oil easily flows downward through the bearing portion, and the lubricating oil leaks out from the lower end portion of the main shaft. Further, in order to prevent the lubricating oil from completely leaking, it is sufficient to continue supplying the pressurized air even after the main shaft is stopped, but this is wasteful and not realistic.

The present invention has been made in view of the above-mentioned problems of the prior art. Even in the vertical spindle, there is no leakage of lubricating oil after the operation is stopped, and the lubricating and oil sealing functions are ensured even during operation. An object is to provide a lubricating device for a vertical spindle of a working machine tool.

[0005]

The present invention has a main shaft provided in the vertical direction, and the main shaft is attached to a housing via a bearing, and a pressure is applied between the upper and lower end portions of the housing and the main shaft. It has an air seal device that feeds air so that the lubricating oil in the housing does not come out to the outside, and the lubricating oil circulation line formed between the bearing and the oil tank and the circulation line An oil circulating device is provided to supply the lubricating oil to the bearing and to collect the lubricating oil that lubricates the bearing to the oil tank.After the operation of the main shaft and the oil circulating device is stopped, pressurized air is sent into the housing. A lubricating device for a vertical spindle of a machine tool provided with an air supply device for discharging lubricating oil in a housing to an oil tank via an oil recovery side pipe of a circulation pipe.

Further, according to the present invention, pressurized air is introduced into the oil supply side conduit of the circulation conduit, and lubricating oil is discharged to the bottom of the housing and connected to the oil recovery side conduit. A lubricating device for a vertical spindle of a machine tool provided with a small diameter portion.

[0007]

The lubricating device for the vertical spindle of the machine tool of the present invention is
After the operation is stopped, the lubricating oil in the housing is forcibly discharged by the pressurized air using the oil circulation line.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The machine tool of this embodiment has a housing 1
A main shaft 16 is vertically provided in the shaft 0 through bearing bearings 12, 13, 14, and 15. An oil sump 18 for accumulating lubricating oil that lubricates and cools the bearing bearings 12 to 15 is attached to a side of the housing 10, and an oil discharge pipe 22 is vertically arranged between the bottom 20 of the housing 10 and the oil sump 18. A suction pipe 24 and a discharge hole 26 are formed in the oil sump 18, which is attached in a direction. A rotor 28 of an electric motor that rotationally drives the main shaft 16 is fixed to the main shaft 16, and a stator 30 fixed to the housing 10 is provided facing the outer peripheral portion of the rotor 28. Then, the rotor 28 and the stator 30
A cable 32 for supplying electric power to the housing 10 is attached to the side of the housing 10 with one end fixed.

The housing 10 has a lubricating oil supply hole 34,
35 and 36 are provided, and a discharge hole 38 that is connected to the suction pipe 24 side and discharges the lubricating oil is also formed in the side portion of the housing 10. Further, a gap 4 is formed in the oil seal portion between the tool holder 50 of the main shaft 16 and the bottom portion 20 of the housing 10 and between the upper end portion of the housing 10 and the main shaft 16.
0, 42 are formed, and pressurized air introduction holes 44, 45 for supplying pressurized air to the gaps 40, 42 to seal the oil are provided in the housing 10. Introducing paths 46 and 47 for guiding the lubricating oil to the bearings 12 to 15 are formed inside the housing 10, and discharging paths 48 and 49 for guiding the lubricating oil in the housing 10 to the oil sump 18 are also formed.

An oil circulation device 52 for circulating lubricating oil is connected to this machine tool via a circulation pipe 54. The oil circulation device 52 has an oil supply pump 56 and an oil suction pump 58, and an oil filter 60 is provided between the oil supply pump 56 and the oil suction pump 58. Each pump 5
6, 58 are connected to the motor 62 and driven. The oil circulation device 52 is also provided with an oil cooling device 64 to prevent the lubricating oil from overheating and to supply the cooled lubricating oil. The circulation line 54 includes an oil supply side line 66 connected to the oil supply pump 56 and an oil recovery side line 68 connected to the oil suction pump 62. The lubricating oil circulating here is stored in the oil tank 70,
Circulates while being cooled. Further, between the discharge hole 26 of the oil reservoir 18 and the oil tank 70, an exhaust pipe line 72 opened to the atmospheric pressure in the oil tank 70 is provided. Orifices 73 each having a predetermined inner diameter are attached to a connecting portion between the oil supply side pipeline 66 and the housing 10 so that the lubricating oil is supplied to each portion at a predetermined flow rate. In addition, between the discharge passage 48 of the bottom portion 20 of the housing 10 and the oil recovery side pipeline 68, the small diameter pipe 9 is provided.
Two are provided.

A pressurized air introducing pipe 74 drawn from a pressurized air pipe in the factory is connected to the oil supply side pipe 66, and a solenoid valve 76 and a pressure reducing valve are connected to the pressurized air introducing pipe 74. 7
8 and a variable throttle valve 80 are attached. Further, a check valve 82 capable of passing only to the machine tool side is provided in the pressurized air introduction pipe line 74, and pressurized air is supplied to the oil supply pump 56 side of the oil supply side pipe line 66 by the oil supply pump. A check valve 84 is attached to prevent 56 from going. Further, a check valve 87 that allows lubricating oil to pass in the discharge direction is attached to the outlet of the suction pipe 24 to open and close the exhaust pipe 72, and when the exhaust pipe 72 is closed, the oil recovery side pipe A pilot valve 86 that guides 68 to the atmospheric pressure in the oil tank 70 is provided in the exhaust pipe line 72. The pilot valve 86 is connected to the pressurized air introduction conduit 74 via a pressure reducing valve 88. A switch 90 is attached to the oil supply line 66 near the oil supply pump 56 to detect the oil supply pressure and close the oil supply pump 66 so that the machine tool can be operated.

In the operation of this embodiment, the motors 62 actuate the pumps 56 and 58 to supply the lubricating oil into the machine tool, and the switch 90 is turned on to rotate the main shaft 16 and pressurize it (not shown). Pressurized air is introduced into the pressurized air introduction holes 44 and 45 from the air supply pipeline. Then, the lubricating oil cools the bearings 12 to 15 by lubrication and is accumulated in the oil sump 18 in the form of mist from the discharge paths 48 and 49. At this time, the pressurized air for oil seal is supplied into the housing 10 through the pressurized air introducing holes 44 and 45, so that the pressurized air is provided in the gaps 40 and 42 between the main shaft 16 and the housing 10. The oil seal is formed by and the lubricating oil does not leak to the outside. Further, the pressurized air for the oil seal causes the interior of the housing 10 to be in a pressurized state, and the pumping action thereof causes the housing 1
The lubricating oil accumulated in the lower part of 0 immediately
It passes through 2 and is discharged to the oil sump 18. Oil sump 1
In 8, the lubricating oil accumulated below is collected in the oil tank 70 by the oil suction pump 58 via the suction pipe 24 and the oil recovery side conduit 68. Also, the pressurized air is
The oil is sent into the oil tank 70 through the discharge hole 26 and the exhaust pipe line 72. At this time, a large amount of mist-like lubricating oil is also sent together with air, but this lubricating oil sinks in the oil tank 70. Then, the lubricating oil is cooled in the oil tank 70, is again sent to the main shaft 16 and the like by the oil supply pump 56, and is constantly circulated.

Next, when the operation of the machine tool is stopped, the motor 62 is stopped after a fixed time and the circulation of the lubricating oil is stopped. Then, the solenoid valve 76 is activated to send the pressurized air from the pressurized air introduction conduit 74 to the oil supply side conduit 66. Along with this, the pilot valve 86 is switched, the exhaust pipe line 72 is closed, and the oil recovery side pipe line 68 is connected to the oil tank 70.
Open to atmospheric pressure inside. As a result, the pressurized air forces the lubricating oil in the housing 10 to force the oil recovery side conduit 6
The small amount of lubricating oil that has been discharged to 8 and remains on the bottom 20 is also reliably collected in the oil tank 70 by the small-diameter pipe 92. At this time, since the pressurized air for the oil seal is continuously supplied, the lubricating oil does not leak from the gaps 40 and 42. Here, the small-diameter pipe 92 is for surely discharging the small amount of lubricating oil remaining at the end, and for a large-sized pipe, only air flows out and the lubricating oil is not discharged. Moreover, since the suction pipe 24 is formed to have an inner diameter necessary for reducing the pipeline resistance and allowing the lubricating oil to circulate efficiently during the rotation of the main shaft, the suction pipe 24 cannot be made too thin. Is provided. This thin pipe 9
The pressure at which the lubricating oil is sent to 2 is equal to the opening pressure of the check valve 87. Then, when the discharge of the lubricating oil is completed, the introduction of the pressurized air to the pressurized air introduction conduit 74 is stopped, the supply of the pressurized air for the oil seal of the main shaft 16 is also stopped, and the system of the apparatus is stopped. . The above operation is programmed in sequence and automatically executed.

According to the vertical spindle lubricating device of this embodiment, the lubricating oil in the housing 10 is automatically and forcibly discharged after the operation of the spindle 16 is stopped, and the lubricating oil leaks from the lower portion of the spindle 16. Never come. In particular, since the last small amount of lubricating oil is completely discharged by the small-diameter pipe 92, even if a large amount of low-viscosity lubricating oil is used, there is no oil leakage and the surroundings of the machine can be kept clean. ..

The vertical spindle lubricating device of the present invention is
The lubricating oil may be circulated and discharged after the operation is stopped only by the suction pipe without providing the small diameter pipe. Further, the pressure of the pressurized air for the oil seal of the main shaft may be used to discharge the oil in the housing after the operation of the main shaft is stopped. In this case, the oil supply side conduit is closed by a solenoid valve or the like, and the pressurized oil is sent to the oil recovery side conduit or the like as in the above embodiment to forcibly push out the lubricating oil in the housing.

[0016]

The vertical spindle lubricator of the present invention introduces pressurized air into the housing after the spindle is stopped, and discharges all the lubricating oil from the inside by utilizing the oil recovery side pipe line or the like. Therefore, the lubricating oil does not leak from the bottom of the machine during the operation stop. Moreover, lubrication of bearings during operation is reliably performed, and there is no risk of oil leakage, so a large amount of lubricating oil of the desired viscosity can be used, the configuration is simple, and there is no major change in machine tools with vertical spindles. This lubrication device can be provided in.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a lubricating device for a vertical spindle of a machine tool according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the machine tool of this embodiment.

[Explanation of symbols]

 10 Housing 12, 13, 14, 15 Bearing Bearing 16 Main Spindle 52 Oil Circulation Device 54 Circulation Pipeline 66 Oil Supply Side Pipeline 68 Oil Recovery Side Pipeline 70 Oil Tank 74 Pressurized Air Introduction Pipeline

Claims (3)

[Claims] 1. Lubricating the inside of a housing by having a main shaft provided in a vertical direction, the main shaft being attached to a housing via a bearing, and sending pressurized air between the upper and lower ends of the housing and the main shaft. It has an air seal device to prevent oil from leaking to the outside, and a lubricating oil circulation pipe formed between the bearing and the oil tank, and lubricating oil to the bearing provided in the circulation pipe. In a lubrication device for a vertical spindle of a machine tool, which is provided with an oil circulating device that supplies the lubricating oil that lubricates the bearings to an oil tank, pressurizes the housing after stopping the operation of the spindle and the oil circulating device. A lubricator for vertical spindles of machine tools, which is equipped with an air supply device that feeds air and discharges the lubricating oil in the housing to the oil tank through the oil recovery side conduit of the circulation conduit. 2. The vertical spindle of a machine tool according to claim 1, wherein the air supply device is connected to an oil supply side pipeline of the circulation pipeline and sends pressurized air into the housing. Lubricator. 3. The vertical spindle of a machine tool according to claim 1, wherein the housing has a bottom portion provided with a small-diameter portion which is connected to the oil recovery side conduit for discharging lubricating oil. Lubricator.