JP2019168414A - Liquid surface level sensor and lubricating oil supply device - Google Patents

Abstract

To make it possible to detect at least an upper level and a lower level of a liquid surface substantially with one float switch.SOLUTION: In a liquid surface level sensor 30 comprising: a float 320 that has a permanent magnet and moves up and down along a vertical float guide shaft 310 according to variations in the level of a liquid surface to be detected; and a lead switch 311 that is arranged within a movable range of the float and is turned on or off by approach or separation of the permanent magnet, the number of both the float 320 and lead switch 311 is one, and the float 320 is provided with more than one, such as two permanent magnets 321, 322 along the axial direction of the float guide shaft 310.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid level sensor and a lubricating oil supply device, and more particularly to a liquid level sensor comprising a float switch composed of a reed switch and a permanent magnet, and a lubricating oil supply device having the same liquid level sensor. is there.

  In a lubricating oil supply system that supplies lubricating oil from an oil supply pump to an oil supply location via a metering distributor, the oil pump is repeatedly discharged and depressurized at predetermined time intervals and measured by the metering distributor. Lubricating oil is intermittently supplied to the oil supply location.

  If oil leakage or clogging occurs in the piping during this operation, or if the dispensing device malfunctions, lubrication will not be performed sufficiently and the lubricated parts such as machine tools may be damaged. Is required.

  Therefore, in the invention described in Patent Document 1 (inspection prediction method for the lubricating oil supply device), the first float switch A for detecting the upper limit level and the second float switch B for detecting the lower limit level in the oil tank of the oil supply pump. And counting the number of discharges of the total amount of the effective oil amount between the float switches A and B, with the first number of discharges as the initial value, and the number of discharges after each second as the initial value In comparison, when an increase or decrease in the number of discharges occurs, the inspection timing for oil leakage or piping clogging is predicted as being abnormal.

Japanese Patent Laid-Open No. 06-74392

  According to the above prior art, it is possible to grasp the amount of lubricating oil discharged from the oil supply pump toward the oil supply location (the total amount of effective oil), but this requires two float switches A and B. For this reason, there is a problem that it is not preferable in terms of cost, and that it takes time and effort to attach it.

  Accordingly, an object of the present invention is to provide a lubricating oil supply apparatus to which the liquid level sensor and the liquid level sensor that are capable of detecting at least the upper level and the lower level of the liquid level with a single float switch are applied. It is to provide.

  In order to solve the above-described problem, the invention according to claim 1 of the present application includes a float that has a permanent magnet and moves up and down along a vertical float guide shaft in accordance with fluctuations in the level of the liquid surface to be detected, and the movable of the float In the liquid level sensor including a reed switch that is disposed within a range and that is turned on and off by the approach and separation of the permanent magnet, the float and the reed switch are both one, and the float has an axial direction of the float guide shaft. A plurality of the permanent magnets are provided along the same.

  The invention according to claim 2 of the present application includes an oil tank having an open upper surface for storing lubricating oil, and a base that is detachably placed on the upper surface of the oil tank. 2. The liquid according to claim 1, wherein the liquid level sensor includes a pump that pumps up the lubricating oil in the tank and a liquid level sensor that detects a liquid level of the lubricating oil. A surface level sensor is used.

  The invention according to claim 3 of the present application is the lubricating oil supply apparatus according to claim 2, further comprising a control unit that controls the operation of the pump and that receives a detection signal from a liquid level sensor. The presence / absence of an abnormality is determined based on the elapsed time between the first on signal and the second on signal output from the reed switch by the two upper and lower permanent magnets adjacent to each other or the number of pump discharges. It is characterized by doing.

  According to the present invention, a plurality of permanent magnets are provided on the float side along the axial direction of the float's float guide shaft. The upper liquid level is detected when the reed switch is turned on, and then the lower liquid level is detected when the liquid level is lowered and the reed switch is turned on by the upper permanent magnet. Therefore, by counting the number of pump discharges from the time when the upper liquid level is detected to the time when the lower liquid level is detected with one float switch (liquid level sensor), oil leakage or It is possible to determine whether there is a pipe clogging or the like.

The front view which shows 1st Embodiment of the lubricating oil supply apparatus of this invention. The front view similar to FIG. 1 which shows the motion of the float when a liquid level falls to a low level in the said 1st Embodiment. The front view which shows 2nd Embodiment of the lubricating oil supply apparatus of this invention. The front view similar to FIG. 3 which shows the motion of the float when the liquid level falls to the middle level in the second embodiment. The front view similar to FIG. 3 which shows the motion of the float when the liquid level falls to the middle level in the second embodiment.

  Next, embodiments of the present invention (first embodiment and second embodiment) will be described with reference to FIGS. 1 to 5, but the present invention is not limited thereto.

  First, referring to FIG. 1, a lubricating oil supply device (oil supply pump) 1 according to the first embodiment includes, as a basic configuration, an oil tank 10 having an open upper surface for storing lubricating oil, and an oil tank 10. And a base 20 that is detachably covered as a lid member.

  The oil tank 10 is preferably made of a resin whose inside can be seen through, but may be a metal tank. The shape is not particularly limited. The base 20 is preferably made of a cast molded body such as an aluminum alloy, but may be made of other materials.

  A gear pump 21 as a pump means for pumping the lubricating oil in the oil tank 10 is suspended from the lower surface side of the base 20 via a support 25. Although not shown, a drive shaft of the gear pump 21 and a passage of pumped lubricating oil are provided in the column 22.

  In addition to the lower limit detection float switch 23, an abnormality detection liquid level sensor 30 is attached to the bottom surface of the base 20. The lower limit detection float switch 23 detects the level of the lubricating oil at a lower limit level at a position higher than the suction port of the gear pump 21.

  Mounted on the upper surface side of the base 20 is a pump drive unit 24 including a motor for driving the gear pump 21, its electrical components, a control unit, and the like. Further, a pressure gauge 25 and a lubricating oil inlet cap 26 are provided on the upper surface of the base 20.

  The fixed quantity distributor 2 is connected to the discharge port 27 of the lubricating oil supply apparatus 1, and the lubricating oil pumped up by the gear pump 21 is supplied to the oil supply point 3 (3 a, 3 b, 3 c...) Via the fixed quantity distributor 2. Is done. The operation is performed so as to repeat the discharge and depressurization, and the amount of lubricating oil measured by the metering distributor 2 is intermittently supplied to the oil supply point 3. 2 to 5 do not show the metering distributor 2 and the oiled portion 3.

  The liquid level sensor 30 includes a float guide shaft 310 that is attached substantially vertically to the bottom surface of the base 20, and a float 320 that moves up and down along the float guide shaft 310 according to fluctuations in the level of the liquid surface to be detected. Yes. The float 320 has a cylindrical shape, and a float guide shaft 310 is inserted through a hollow portion inside the float 320.

  A reed switch 311 is provided on the float guide shaft 310. There is one reed switch 311 provided on the float guide shaft 310. On the other hand, the float 320 is provided with a plurality of first and second permanent magnets 321 and 322 along the axial direction of the float guide shaft 310 in the first embodiment.

  Assuming that one first permanent magnet 321 is provided on the lower end side of the float 320 and the other second permanent magnet 322 is provided on the upper end side of the float 320, the axial length of the float guide shaft 310 is twice the axial length of the float 320. As described above, it is preferable that the reed switch 311 is disposed at an intermediate portion of the float guide shaft 310.

  Note that a stopper ring 312 for preventing the float 320 from falling off is provided at the lower end of the float guide shaft 310. In addition, the float 320 may be a mode in which two floats each having a permanent magnet are integrally combined with an adhesive or the like to be substantially one.

  According to the liquid level sensor 30, first, as shown in FIG. 1, when the reed switch 311 is turned on by the first permanent magnet 321 on the lower end side (first turn-on), the upper level for abnormality detection is used. The liquid level is detected.

  Next, as shown in FIG. 2, when the reed switch 311 is turned on by the second permanent magnet 322 on the upper end side (the second turn-on), the lower liquid level for detecting an abnormality as shown in FIG. 2. The level is detected.

  Therefore, a large amount of lubricating oil is put in the oil tank 10 so that the first permanent magnet 321 on the lower end side is positioned above the reed switch 311 and the operation of the oil supply pump is started. By counting the number of pump discharges from the time when the upper liquid level is detected until the lower liquid level is detected by the second permanent magnet 322 on the upper end side, there is no oil leakage or piping clogging. You can judge whether or not.

  From another point of view, the time from when the upper liquid level is detected until the lower liquid level is detected (time called total operation time or total operation time) is counted, It can be determined that there is oil leakage if it is shorter than the normal time when there is no oil leakage or piping clogging, and that there is piping clogging if it is longer.

  These determinations are made by a control unit including a microcomputer (not shown) included in the motor driving unit 24. The ON / OFF signal by the reed switch 311 and the detection signal of the lower limit detection float switch 23 are transmitted to the control unit, and the control unit stops the operation of the gear pump 21 when receiving the lower limit detection signal of the float switch 23.

  Next, a second embodiment of FIG. 3 will be described. The second embodiment is different from the first embodiment in that another permanent magnet 323 is added to the float 320 of the liquid level sensor 30 and the number of permanent magnets provided in the float 320 is three. The configuration is the same as in the first embodiment.

  That is, in the second embodiment, in addition to the first permanent magnet 321 on the lower end side of the float 320 and the second permanent magnet 322 on the upper end side, the third permanent magnet 323 is attached at an intermediate position therebetween.

  Therefore, according to the second embodiment, as shown in FIG. 3, the liquid level for abnormality detection is the upper liquid level by the first permanent magnet 321 on the lower end side, and the intermediate position as shown in FIG. As shown in FIG. 5, three liquid level levels are detected, that is, a middle liquid level by the third permanent magnet 323 and a lower liquid level by the second permanent magnet 322 on the upper end side.

  The interval between the first permanent magnet 321 and the third permanent magnet 323 and the interval between the third permanent magnet 323 and the second permanent magnet 322 are equal intervals, and the side wall surface of the oil tank 10 is a vertical surface with no inclination. The time from the upper liquid level to the middle liquid level (or the number of pump discharges) and the time from the middle liquid level to the lower liquid level (or pump discharge) If the difference exceeds a predetermined threshold, it can be estimated that there is an abnormality. That is, abnormality detection can be performed by one movement of the float 320 (movement from the top to the bottom).

  As described above, according to the liquid level sensor of the present invention, it is possible to detect the upper liquid level and the lower liquid level with one float switch without using two float switches. .

DESCRIPTION OF SYMBOLS 1 Lubricating oil supply apparatus 2 Fixed quantity distributor 3 (3a, 3b, 3c ...) Oil supply location 10 Oil tank 20 Base 21 Pump (gear pump)
22 Post 23 Float switch for lower limit detection 24 Pump drive unit 25 Pressure gauge 27 Discharge port 30 Liquid level sensor 310 Float guide shaft 311 Reed switch 312 Stopper ring 320 Float 321, 322, 323 Permanent magnet

Claims (3)

A float that has a permanent magnet and moves up and down along a vertical float guide shaft in response to fluctuations in the level of the liquid surface to be detected; In liquid level sensor including
The float and the reed switch are one, and the float is provided with a plurality of permanent magnets along the axial direction of the float guide shaft. An oil tank having an open upper surface for storing the lubricating oil; and a base that is detachably placed on the upper surface of the oil tank. In the lubricating oil supply apparatus provided with a liquid level sensor for detecting the liquid level of the oil,
The lubricating oil supply apparatus according to claim 1, wherein the liquid level sensor according to claim 1 is used as the liquid level sensor.   A control unit that controls the operation of the pump and receives a detection signal from the liquid level sensor, the control unit is a first time output from the reed switch by the two upper and lower permanent magnets adjacent to each other. The lubricating oil supply device according to claim 2, wherein the presence or absence of abnormality is determined based on an elapsed time between the ON signal and the second ON signal or the number of discharges of the pump.