JP2003083351A - Grease supply confirmation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grease supply confirming device, capable of almost always supervising grease surely supplied to a bearing, early detecting abnormality of grease supply to prevent seizure of a spindle main shaft, and prevent a trouble in a spindle, which can attain long extension of a life in rotation at a high speed by lubrication of grease. SOLUTION: This grease supply confirming device, having a measurement means measuring an amount of grease discharged from a bearing with the grease of prescribed amount supplied to an internal space, detects whether the grease is supplied or not based on the amount of the grease.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grease replenishment confirmation device applied to a bearing, which is used in, for example, a machine tool spindle and is required to have a high speed and a long life.

[0002]

2. Description of the Related Art Grease lubrication is often used for bearings of machine tool spindles and spindle devices because of cost reduction and maintenance-free. From the demand for improved productivity,
The spindle of machine tools has become high-speed and there is an increasing demand for faster bearings. In a grease-lubricated rolling bearing device, the high speed limit is at most about dmN 1.5 million (dm: pitch circle diameter mm, N: shaft rotation speed rpm).

It has been considered to use a grease replenishing device in order to prevent seizure of the bearing. When using the grease replenishing device, it is important to confirm whether the semi-solid grease is normally replenished to the bearing. This is because the semi-solid grease may be clogged in the pipe, and the grease may not be supplied to the bearing. When replenishment is stopped, the grease naturally deteriorates and the bearing seizes, which shortens the service life. In particular, d
At high speeds exceeding 1.5 million mN, the grease scatters and the grease that contributes to lubrication becomes extremely small. Therefore, if the high speed rotation is continued without replenishing the grease, the grease will deteriorate and the bearing will seize immediately. I will end up.

In order to detect an abnormality such as a stoppage of grease replenishment, for example, in Japanese Patent Laid-Open No. 11-93957, a state of the flow of grease replenished to a bearing is visually monitored by making a part of a pipe transparent. Techniques for doing so are disclosed.

[0005]

In the bearing of a machine tool spindle (spindle) which is continuously operated for a long period of time, it is necessary to monitor the state of grease replenishment for a long period of time. For this reason, it is difficult from a practical point of view to visually monitor because the cost such as labor cost is high. Further, in reality, since the visual confirmation can be performed only about several times a day, an abnormality such as the stop of the grease replenishment of the replenishing device could not be found early. Therefore, under high speed rotation exceeding dmN 1.5 million, seizure of the bearing and failure of the spindle have been still a problem. The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a grease replenishment confirmation device capable of almost constantly monitoring that the grease replenishment of the bearing is reliably performed, and capable of quickly detecting an abnormality in grease replenishment.

[0006]

SUMMARY OF THE INVENTION The above object of the present invention is a grease replenishment confirmation device for confirming the replenishment of grease to a bearing, and the amount of grease discharged from the bearing whose interior space has been replenished with a predetermined amount of grease. Has a measuring means for measuring
This is achieved by a grease replenishment confirmation device characterized by detecting whether or not the grease has been replenished based on the amount of grease discharged. According to such a configuration,
It is possible to constantly monitor that the bearing is reliably replenished with grease, and it is possible to detect abnormal grease replenishment and prevent seizure of the bearing remarkably. Therefore, it is possible to achieve a long life of the bearing that rotates at high speed and is lubricated with grease. In addition, since it is not necessary to perform visual monitoring, the burden on the user can be reduced and labor costs can be suppressed. The measuring means preferably measures the weight of the grease discharged from the bearing, which makes it possible to detect whether or not the grease has been replenished with a simple configuration.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a grease replenishment mechanism 100 using a grease replenishment confirmation device 10 according to an embodiment. The grease supply mechanism 100 includes a bearing unit 1 that supports a spindle (not shown), a grease tank 2 that stores grease, a pump P that sends grease from the grease tank 2 to the bearing unit 1 through a supply pipe 3, and a pump P. And a grease supply confirmation device 10 for confirming the supply of grease to the bearing unit 1 based on the amount of grease discharged from the bearing unit 1 via the discharge pipe 4. An abnormality determination circuit 5 is connected to the grease supply confirmation device 10, and an output unit 6 is connected to the abnormality determination circuit 5. The abnormality determination circuit 5 and the output unit 6 can also be regarded as a part of the grease supply confirmation device 10.

An appropriate amount of grease is stored in advance in the grease tank 2. The grease stored in the grease tank 2 is guided to the supply pipe 3 by driving the pump P. One of the supply pipes 3 is connected to the grease tank 2, and the other is connected to the bearing unit 1 via the pump P.
It is connected to the. In this embodiment, the pump P
Are configured to be driven by the rotation of the motor M.

The bearing portion 1 is constructed such that the internal space thereof is supplied with grease from the supply pipe 3. For example,
The grease is supplied from the supply pipe 3 to the internal space through a grease supply hole or the like provided so as to communicate with the outer ring in the radial direction of the bearing. In addition, the bearing unit 1 is
The grease is discharged from the internal space to the discharge pipe 4. Therefore, when grease is replenished from the supply pipe 3 to the inner space of the bearing unit 1, a certain amount of grease is already stored in the inner space of the bearing unit 1. Therefore, depending on the newly replenished grease, A large amount of grease is discharged from the internal space of the bearing portion 1 via the discharge pipe 4.

The grease supply confirmation device 10 has a measuring means for measuring the weight of the grease discharged from the discharge pipe 4 at predetermined time intervals. In this embodiment, the discharge pipe 4
There is used a measuring unit that receives the grease discharged from the measuring plate, measures the total weight of the grease on the measuring plate, and outputs an output value such as a voltage proportional to the increase in the weight. The measuring means is connected to the abnormality determination circuit 5 via the signal line L. The output value (hereinafter referred to as output) calculated by the measuring means is transmitted to the abnormality determination circuit via the signal line L. The measuring means may be a detecting means using other sensor members or the like as long as it can detect the amount of grease discharged.

The abnormality determining circuit 5 acquires an output from the measuring means at predetermined time intervals in an environment in which a constant amount of grease is continuously supplied from the grease tank 2 to the bearing portion 1. If the measured output does not increase compared to the output measured at the previous predetermined time, it is determined that the grease replenishment is abnormal. Then, a command is given to the output unit 6 to sound an alarm or stop the rotation of the spindle.

Next, the procedure for detecting the grease supply state in the abnormality determination circuit 5 will be described with reference to the flow chart shown in FIG. After a lapse of time t from the start of grease replenishment, the output of the measuring means corresponding to the total weight of the discharged grease is A (t). At the start of replenishment (t =
The output of 0) can be represented by A (0), and its value is 0.
Is. When the predetermined elapsed time (predetermined time) from the previously measured time is Δt, the abnormality determination circuit 5 determines that the time Δt
The output A (t) is acquired from the measuring means each time. The abnormality determination circuit 5 compares the acquired output A (t) with the output A (t-Δt) acquired in the previous measurement, and sequentially determines the grease supply state. The predetermined time Δt is fixed in this embodiment. However, it can be set as appropriate according to the conditions of grease replenishment, and does not have to be always constant. Further, since there is a time difference of several seconds to at most several tens of seconds from the start of the replenishment of grease to the bearing portion 1 to the discharge of the grease in the internal space, the predetermined time Δt is taken into consideration in consideration of this time difference. Must be set.

First, as an initial setting, the time t is set to 0, and the output (initial output) A (0) at the time of measurement disclosure (that is, when t = 0) is set to 0 (step S10).
1). After the start of replenishment, the predetermined time Δt is added to the current time t according to the passage of the predetermined time Δt, and the new time t
(Step S102), and step S103
I will proceed. Then, the output A (t) at time t is acquired from the measuring means (step S103). Further, the output at the time of the previous measurement, that is, the output before the predetermined time Δt is stored as a reference output A (t−Δt) in a storage unit or the like not shown. The reference output A (t-Δ
t) is the initial output A (0).

Next, the output A (t) obtained in step S103 is compared with the reference output A (t-Δt) (step S104). At this time, if the output A (t) is larger than the reference output A (t−Δt), the total weight of the grease discharged from the bearing unit 1 increases during the elapse of the predetermined time Δt from the previous measurement. Therefore, it is determined that the grease replenishment is normal, and the process proceeds to step S102. Then, the predetermined time Δt is made to elapse, and similarly, step S10
Proceed to the process of 3. Therefore, the output A (t) at time t
Is a value larger than the reference output A (t−Δt), step S102 → step S103 → step S
The routine of step 104 → step S102 is repeated. That is, the total weight of grease measured at each predetermined time Δt is
If the total weight of grease at the previous measurement is larger, continue the measurement.

On the other hand, the output A (t) is the reference output A (t-Δ
If t) or less, the process proceeds to step S105.
In step S105, since the total weight of the grease discharged during the elapse of the predetermined time Δt has not increased from the total weight of the grease at the previous measurement, the grease is not normally replenished to the bearing portion 1. To determine. If the abnormality determination circuit 5 determines that the grease supply state is abnormal in step S105, it sends a command to the output unit 6, issues an alarm, or sends a signal to the control unit that controls the rotation of the spindle. Stops (or slows down) the rotation of the spindle. Regarding the measurement of the grease discharge amount, a time limit may be set in advance. For example,
The detection period may be set to T, and the detection may be ended when the time t is equal to or longer than the detection period T.

The present invention is not limited to the above-described embodiments, but can be appropriately modified and improved. In the present embodiment, the grease is configured to be forcibly supplied to the internal space of the bearing portion from the pump provided outside the bearing portion, but the present invention is not limited to this. For example, a grease reservoir may be provided on the shaft of the bearing unit and the grease may be replenished by utilizing centrifugal force. The grease supply confirmation device is not limited to bearings that support the spindle, but can be applied to any bearing.

[0017]

As described above, according to the present invention,
It is possible to provide a grease replenishment confirmation device that can almost always monitor that the grease is being replenished to the bearings reliably, and that can quickly detect an abnormality in grease replenishment.

[Brief description of drawings]

FIG. 1 is an overall view showing a grease supply mechanism using a grease supply confirmation device of the present invention.

FIG. 2 is a flowchart illustrating a procedure for detecting an abnormality in grease supply in an abnormality determination circuit.

[Explanation of symbols]

1 bearing 2 Grease tank 3 supply pipes 4 discharge pipe 5 Abnormality judgment circuit 6 Output section 10 Grease supply confirmation device

Claims (2)

[Claims] 1. A grease replenishment confirmation device for confirming the replenishment of grease to a bearing, comprising a measuring means for measuring the amount of grease discharged from the bearing whose inner space has been replenished with a predetermined amount of grease. A grease replenishment confirmation device characterized by detecting whether or not the grease is replenished based on the amount. 2. The grease replenishment confirmation device, wherein the measuring means measures the weight of the grease discharged from the bearing.