JP4607563B2 - Lubricating oil supply detection device - Google Patents

Description

  The present invention relates to a lubricating oil supply detection device that can reliably detect that a certain amount of lubricating oil is intermittently supplied to a fluid device.

  For example, as a fluid device in which lubricating oil is intermittently required, a ball screw shaft, a nut formed with a screw portion that is screwed to the ball screw shaft, and a ball screw shaft and the nut are interposed. 2. Description of the Related Art Conventionally, a ball screw mechanism including a plurality of balls that are mounted and roll along an endless circulation track is known.

  In this case, in order to reduce sliding friction and to ensure smooth rolling of the plurality of balls, a fixed amount of lubricating oil is supplied to a lubricating portion such as an endless circulation track on which the balls roll, and the lubricating oil In response to this decrease, it is required that a predetermined amount of lubricating oil be appropriately replenished.

  The lubricating oil needs to be intermittently supplied to the lubrication part by a predetermined amount. However, if the supply of the lubricating oil is not reliably supplied to the end of the lubrication part (infinite circulation track), In addition, since the wear of the rolling ball and the ball screw shaft occurs and the smooth rotational movement of the ball screw shaft is hindered, it is detected whether or not the lubricating oil has been reliably supplied to the end of the lubrication site. It will be necessary.

  Therefore, in the lubricating oil supply detection device described in Patent Document 1, the discharge pipe and the movable body are formed of a conductive material, and when the lubricating oil is intermittently discharged from the discharge pipe, it is movable by the discharge pressure. It is disclosed that a detecting means is provided for detecting a non-conducting state as a pulse-like signal when a body moves backward against an urging force and the movable body moves away from the discharge pipe and becomes non-conducting.

  According to this Patent Document 1, it can be determined that the lubricant is discharged and reliably conveyed to the lubrication site via the downstream air supply pipe by detecting the non-conduction state, Since the quantity is known in advance, the amount of lubricant supplied per unit time can be calculated by counting the number of pulses per unit time of the pulse signal.

JP 2001-248787 A

  However, according to the technical idea disclosed in Patent Document 1, the opening of the discharge pipe that discharges intermittently pressurized lubricating oil for each fixed amount communicates with the air supply pipe that supplies air to the lubrication site. It can be suitably applied to a device that is disposed at a position and conveys and supplies discharged lubricating oil to the lubrication site by an air flow in the air supply pipe. The lubricating oil is introduced into the chamber of the main body portion provided with, and the piston is slid along the chamber to press the lubricating oil, thereby applying the lubricating oil from the output port. Have difficulty.

  This is because even if lubricating oil is introduced into the chamber of the main body, the piston is slidably displaced in a state of being in constant contact with the chamber of the main body, so that the main body formed of a conductive material and the piston are in a non-conductive state. Because you can't.

  The present invention has been made in consideration of the above points, and based on the displacement amount of the piston, the supply start position of intermittently discharged lubricating oil into the main body and the completion of discharging of the lubricating oil from the output port are completed. It is an object of the present invention to provide a lubricating oil supply detection device capable of reliably detecting the lubricating oil discharged from the output port by detecting each position.

To achieve the above object, the present invention provides an input port to which lubricating oil is supplied, an output port for discharging the lubricating oil supplied from the input port to an external fluid device, and the input port and the output port. A main body having a chamber that is in communication with the chamber and into which the lubricating oil supplied through the input port is introduced.
Corresponding to the ratio of the inner diameter of the input port to the inner diameter of the output port by being slidably provided in the chamber along the axial direction of the main body and being pressed by the lubricating oil introduced into the chamber. A piston that displaces
A detection unit for detecting a displacement amount of the piston along the axial direction of the main body unit;
With
In the detection unit, the supply of lubricating oil to the piston when the supply of lubricating oil to the room is started via the input port, and the lubricating oil of the piston when the supply of a fixed amount of lubricating oil to the room is completed A supply completion position and a lubricating oil discharge completion position of the piston when all the fixed amount of lubricating oil supplied into the room is discharged to an external fluid device through an output port are detected. To do.

  In this case, a change in the inductance of the coil generated by the relative displacement between the piston and the coil is configured by including a piston formed of a magnetic material and a coil disposed inside or outside the piston. Is detected as a frequency change, and the displacement amount of the piston may be calculated based on the detected frequency.

  The piston may be constituted by a columnar portion to which a seal member is attached and a hollow cylindrical portion through which a coil can be inserted.

  The piston may be provided with a protrusion having a diameter substantially the same as the inner diameter of the input port and projecting a predetermined length toward the input port. By providing this protrusion, the area received by the lubricating oil introduced from the input port is reduced, and the response speed can be improved.

  Furthermore, a spring member that discharges the lubricating oil from the output port by pressing the piston toward the input port side after a certain amount of lubricating oil is supplied into the chamber may be provided in the main body. . This is because the structure in the main body can be simplified.

  According to the present invention, the piston lubricant supply start position when the supply of the lubricant to the room via the input port is started, and the piston lubricant supply when the supply of the fixed amount of lubricant to the room is completed. Based on the displacement amount of the piston, the completion position and the piston lubricating oil discharge completion position when all of the fixed amount of lubricating oil supplied into the chamber is discharged to an external fluid device via the output port are detected. By detecting each part, it is confirmed that a certain amount of lubricating oil discharged intermittently is reliably supplied to the fluid equipment, and the lubricating oil reaches the end of the lubrication passage of the fluid equipment. It is confirmed that

  According to the present invention, the following effects can be obtained.

  In other words, based on the displacement amount of the piston, the lubricant is discharged from the output port by detecting the lubricant supply start position into the main body of the intermittently discharged lubricant and the lubricant discharge completion position from the output port. It is possible to reliably detect the lubricating oil.

  Therefore, even when the lubricating oil of the fluid device is reduced, a constant amount of lubricating oil can be intermittently and simply supplied to perform the maintenance work efficiently.

  A preferred embodiment of the lubricant supply detection device according to the present invention will be described below and described in detail with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates a lubricant supply detection device according to an embodiment of the present invention.

  The lubricating oil supply detection device 10 is formed in a cylindrical body extending in a predetermined length along the axial direction and having a main body portion 16 in which an input port 12 and an output port 14 are formed, and is formed inside the main body portion 16. A piston 20 slidably provided within a predetermined range of the chamber 18, an end block 22 attached to the end of the main body 16, and a screw portion formed in the center hole of the end block 22. A holding member 24 and a detection unit 26 that is held by the holding member 24 and is arranged so as to face the axis of the main body 16 toward the inside of the chamber 18.

  Further, the lubricating oil supply detection device 10 is arranged at a substantially central part of the main body part 16 via an annular step part formed on the inner wall, and the cylinder of the piston 20 via a hole part 28 formed at the central part. The locking member 32 that supports the displacement of the piston 20 by inserting the portion 30 and the annular groove formed in the inner wall are attached to the locking member 32 along the axial direction in the chamber 18. It has a ring member 34 that is locked at an intermediate position, and a coil spring (spring member) 36 that has one end engaged with the piston 20 and the other end engaged with the locking member 32.

  The input port 12 is formed at an end opposite to the end block 22, and the output port 14 is formed along a direction close to the input port 12 and perpendicular to the axis of the input port 12. .

  In this case, the inner diameter A of the input port 12 is set larger than the inner diameter B of the output port 14 (A> B), and the inner diameter sectional area of the input port 12 and the inner diameter sectional area of the output port 14 are a predetermined ratio. Thus, the piston 20 is provided so as to operate according to the ratio of the inner diameter sectional area of the input port 12 and the inner diameter sectional area of the output port 14.

  Therefore, the lubricating oil introduced into the chamber 18 through the input port 12 is not immediately discharged from the output port 14 because the inner diameter B of the output port 14 is reduced, and the piston 20 is moved to the right in FIG. It acts so as to press it toward (see FIG. 6).

  The piston 20 is connected to the large-diameter portion 20a integrally with the disc-shaped large-diameter portion 20a, which is set slightly smaller than the diameter of the inner wall constituting the chamber 18 of the main body portion 16, and the large-diameter portion 20a. A small-diameter portion 20b having a smaller diameter, and a cylindrical portion 30 having one end attached to the small-diameter portion 20b and the other end surrounding an outer peripheral surface of a coil 38, which will be described later. The part 20b and the cylindrical part 30 are formed of a magnetic material. In addition, the said large diameter part 20a and the small diameter part 20b function as a cylindrical part.

  The side surface of the large-diameter portion 20a of the piston 20 is pressed by the lubricating oil introduced into the chamber 18 through the input port 12, whereby the large-diameter portion 20a, the small-diameter portion 20b, and the cylindrical portion 30 constituting the piston 20 are pressed. Is integrally displaced in the right direction in FIG. 1 against the spring force of the coil spring 36. The lubricating oil introduced into the chamber 18 is sealed by a piston packing (seal member) 40 mounted through an annular groove formed on the outer peripheral surface of the large diameter portion 20a.

  When the piston 20 is displaced, the cylindrical portion 30 of the piston 20 is supported by the locking member 32 by being inserted along the hole 28, and the outer peripheral surface of the coil 38 is gradually inserted into the hollow portion of the cylindrical portion 30. It is provided so as to be covered (enclosed). A predetermined clearance is formed between the cylindrical portion 30 and the coil 38.

  As shown in FIG. 2, the detection unit 26 includes a coil 38 in which a plurality of conductors are wound on a hollow rod 41 that is a bobbin, and a winding interval is wound along the axial direction of the hollow rod 41. And an inductance change detector 42. The inductance change detector 42 includes a capacitor 44 connected to both terminals 38 a and 38 b of the coil 38, an LC oscillation circuit 46 including the inductance of the coil 38 and the capacitor 44, and an output side of the LC oscillation circuit 46. And a frequency counter 48 to be connected.

  A frequency / position conversion unit 50 by a microcomputer is connected to the output side of the frequency counter 48. A display unit 52 and an output terminal 54 may be connected to the frequency / position conversion unit 50, and the frequency counter 48 and the frequency / position conversion unit 50 may be configured by a one-chip microcomputer. The microcomputer includes a central processing unit (CPU) having control / calculation / determination functions, a ROM (read only memory) in which a program and the like are stored, and an electrically erasable programmable ROM (EEPROM) capable of being electrically written and erased. RAM (random access memory) and an input / output interface such as an A / D converter and a D / A converter.

  In the detection unit 26, when the coil 38 is excited by alternating current and the cylindrical portion 30 of the piston 20 is displaced along the axial direction of the hollow rod 41, the inductance of the coil 38 changes, and this inductance and the capacitance of the capacitor 44. The oscillation frequency fa of the oscillation signal of the LC oscillation circuit 46 determined by the above changes.

  The frequency of the oscillation frequency fa is detected by the frequency counter 48 and supplied to the frequency / position converting unit 50 as the oscillation frequency fa. The frequency / position conversion unit 50 relates to a change characteristic between the oscillation frequency fa (Hz) and the position x (mm) corresponding to the change of the inductance stored in advance, for example, as shown in FIG. The current position of the piston 20 (cylindrical portion 30) is calculated with reference to the table. The calculated current position is displayed on the display unit 52 or supplied to the output terminal 54. The calculated current position may be transmitted by communication to an external receiving means via a transmitting means (not shown).

  In other words, when relative displacement occurs between the cylindrical portion 30 of the outer peripheral piston 20 formed of a magnetic material and the inner peripheral coil 38, the inductance of the coil 38 changes. In this case, since the oscillation frequency fa oscillated from the LC oscillation circuit 46 changes as the inductance of the coil 38 changes, the displacement amount of the piston 20 is calculated based on the frequency that changes depending on the change amount of the inductance. The

  In FIG. 2, the coil 38 is arranged on the inner peripheral side of the cylindrical portion 30 of the piston 20 made of a magnetic material. However, the present invention is not limited to this, and the outer side of the cylindrical portion 30 of the piston 20 is not limited thereto. The coil 38 may be arranged on the front.

  The lubricating oil supply detection device 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and action and effects thereof will be described.

  FIG. 4 is a characteristic diagram showing the relationship between the displacement amount of the piston 20 calculated based on the current position of the piston 20 detected by the detection unit 26 and time. The piston 20 is assumed to be at the origin position in the initial state, and at the origin position, the piston 20 adheres to the inner wall surface on the input port 12 side and the amount of lubricating oil introduced into the chamber 18 is zero. is there.

  First, the lubricating oil supply source 60 shown in FIG. 1 is energized to supply a predetermined amount of lubricating oil to the input port 12 of the main body 16 (see FIG. 5). The lubricating oil supplied to the input port 12 is introduced into the chamber 18 of the main body portion 16 to press the piston 20, and the piston 20 overcomes the spring force of the coil spring 36 and the coil 38 side (in FIG. 5). Displace toward right). Since the inner diameter B of the output port 14 is narrowed, the lubricating oil introduced into the chamber 18 of the main body 16 does not discharge from the output port 14 in an ideal state, and acts only on the piston 20. Shall.

  Accordingly, the piston 20 is pressed by the lubricating oil introduced into the chamber 18, and the piston 20 is set to operate according to the ratio of the inner diameter sectional area of the input port 12 and the inner diameter sectional area of the output port 14 (FIG. 6). reference). When the piston 20 is pressed by the lubricating oil, the cylindrical portion 30 is displaced integrally with the piston 20, and a change in the inductance of the coil 38 whose winding interval is set constant is detected as a change in the oscillation frequency fa. A displacement amount of the piston 20 proportional to the change of the oscillation frequency fa is obtained.

  When the piston 20 is displaced from the origin position and time T1 is reached, the detection unit 26 detects that the lubricant supply start position where the supply of the lubricant oil to the inside of the chamber 18 of the main body part 16 is started (see FIG. 4). The lubricating oil supply start position is stored in a memory and preset by experimental data in a state corresponding to the installation state.

  Accordingly, the CPU compares and determines position information (oscillation frequency) based on the detection signal derived from the detection unit 26 and information (first reference frequency) set in advance by experiment, and when both pieces of information match. It is confirmed that the piston 20 has reached the lubricating oil supply start position.

  The reason why the lubricant supply start position is not the origin position is that disturbance, noise, temperature change and the like are taken into consideration, and the piston 20 is set at a position slightly displaced toward the coil 38 side.

  Next, when the piston 20 is displaced from the lubricating oil supply position and time T2 is reached, it is detected that the lubricating oil supply completion position at which a certain amount of lubricating oil has been supplied into the chamber 18 of the main body 16 has been reached. It detects by the part 26 (refer FIG. 4). The lubricant supply completion position is set in advance by experimental data stored in the memory.

  Therefore, the CPU compares and determines position information (oscillation frequency) based on the detection signal derived from the detection unit 26 and information (second reference frequency) set in advance by experiment, and when both pieces of information match. It is confirmed that the piston 20 has reached the lubricating oil supply completion position.

  The lubricating oil supply completion position is set to a position slightly before the displacement end position (peak position) of the piston 20. This is because it may not be said that the supply of lubricating oil is completed when the piston 20 reaches the displacement end position.

  When supply of a certain amount of lubricating oil into the chamber 18 of the main body 16 is completed, the supply of lubricating oil from the lubricating oil supply source 60 is stopped, and the piston 20 is displaced slightly from the lubricating oil supply completion position. The terminal position (peak position) is reached (see FIG. 7).

  Subsequently, the piston 20 is pressed away from the coil 38 by the spring force (pressing force) of the coil spring 36 interposed between the large-diameter portion 20a of the piston 20 and the locking member 32, and The piston 20 is displaced in the opposite direction. In this case, since the supply of the lubricating oil from the lubricating oil supply source 60 to the input port 12 is stopped, the lubricating oil pressurized by the piston 20 is discharged from the output port 14 (see FIG. 8). The lubricating oil discharged from the output port 14 is supplied to an external fluid device 62 such as a ball screw mechanism, for example.

  When the piston 20 moves away from the coil 38 (in the direction of the arrow in FIG. 8), that is, toward the origin, and when a predetermined time elapses from the time T3 and reaches the time T4, the chamber 18 of the main body 16 is provided. The detection unit detects that a certain amount of lubricating oil supplied to the inside has been discharged to the external fluid device 62, that is, has reached the lubricating oil discharge completion position at which all of the lubricating oil has been discharged from the output port 14. 26 (see FIG. 4). The lubricant discharge completion position is set in advance by experimental data stored in the memory.

  Therefore, the CPU compares the position information (oscillation frequency) based on the detection signal derived from the detection unit 26 with the information (third reference frequency) set in advance by experiment, and when both information match. It is confirmed that the piston 20 has reached the lubricating oil discharge completion position. The lubricating oil discharge completion position is set to a position slightly before the piston 20 returns to the origin position.

  Furthermore, when the piston 20 is slightly displaced from the lubricant discharge completion position and returns to the origin position, the operation of supplying the lubricant to the fluid device 62 is completed. The lubricating oil supply operation is intermittently performed as the lubricating oil in the fluid device 62 decreases.

  In the present embodiment, a change in inductance generated by setting the coil 38 excited by alternating current as the fixed side and the piston 20 (cylindrical portion 30) made of a magnetic material as the movable side is converted into a change in the oscillation frequency fa. Furthermore, by making the change in the oscillation frequency fa correspond to the displacement amount of the piston 20, the displacement amount of the piston 20 can be detected with high accuracy.

  In this case, based on a plurality of predetermined positions set in advance by experimental data, the lubricant supply start position where the supply of the lubricant to the chamber 18 of the main body 16 is started, and a constant value for the chamber 18 of the main body 16 is constant. The lubricating oil supply completion position where the supply of the amount of lubricating oil has been completed, and a certain amount of lubricating oil supplied into the chamber 18 of the main body portion 16 are all discharged to the external fluid device 62, and the discharging of the lubricating oil is completed. By detecting the lubricating oil discharge completion position by the detection unit 26, a certain amount of intermittently discharged lubricating oil is reliably supplied to the fluid device 62, and the lubricating oil is used to lubricate the fluid device 62. It is confirmed that it has reached the end of the passage.

  As a result, in the present embodiment, based on the amount of displacement of the piston 20, when supply of intermittently discharged lubricating oil into the main body 16 is started and when discharge of lubricating oil from the output port 14 is completed, respectively. By detecting, the lubricating oil discharged from the output port 14 can be detected reliably.

  Next, a lubricating oil supply detection device 100 according to another embodiment of the present invention is shown in FIGS. Note that the same reference numerals are assigned to the same components as those in the above-described embodiment, and detailed description thereof is omitted.

  In the lubricating oil supply detection device 100 according to another embodiment, the piston 20 is provided with a protrusion 102 that is substantially the same diameter as the input port 12 and protrudes by a predetermined length toward the input port 12 side. This is different from the above embodiment.

  By attaching the protruding portion 102 to the piston 20, when lubricating oil is first supplied from the input port 12, the pressure receiving area of the lubricating oil becomes smaller than when the protruding portion 102 is not provided.

  That is, the area that is first received by the lubricant when the protrusion 102 is not provided is the area of the large-diameter portion 20a of the piston 20, and the area that is initially received by the lubricant when the protrusion 102 is provided is the input. It substantially matches the inner diameter area of the port 12. For this reason, the displacement start time of the piston 20 becomes rapid as the pressure receiving area decreases. As a result, there is an advantage that the response sensitivity is improved and the response speed can be improved. Since other functions and effects are the same as those of the above-described embodiment, detailed description thereof is omitted.

It is a schematic structure longitudinal cross-sectional view of the lubricating oil supply detection apparatus which concerns on embodiment of this invention. It is a schematic block diagram of the detection part which comprises the lubricating oil supply detection apparatus shown in FIG. It is a characteristic view which shows the relationship between an oscillation frequency and a position. It is a characteristic view which shows the relationship between the displacement amount of a piston, and time. It is operation | movement explanatory drawing which shows the state by which lubricating oil was supplied to the input port of the main-body part. It is operation | movement explanatory drawing which shows the state which the said lubricating oil was introduce | transduced into the chamber | room of the main-body part, the piston was pressed, and the said piston displaced. It is operation | movement explanatory drawing which shows the state which the said piston reached | attained a displacement termination position and supply of lubricating oil from the lubricating oil supply source stopped. It is operation | movement explanatory drawing which shows the state which a piston displaces in the direction away from a coil with the pressing force of a coil spring, and the lubricating oil introduce | transduced indoors is discharged via an output port. It is a schematic structure longitudinal cross-sectional view of the lubricating oil supply detection apparatus which concerns on other embodiment of this invention. FIG. 10 is an operation explanatory diagram showing a state in which the lubricating oil supplied through the input port is introduced into the room and the piston is displaced in the lubricating oil supply detection apparatus shown in FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,100 ... Lubricating oil supply detection apparatus 12 ... Input port 14 ... Output port 16 ... Main-body part 18 ... Chamber 20 ... Piston 22 ... End block 24 ... Holding member 26 ... Detection part 28 ... Hole part 30 ... Cylindrical part 32 ... Engagement Stop member 34 ... Ring member 36 ... Coil spring 38 ... Coil 40 ... Piston packing 41 ... Hollow rod 44 ... Capacitor 46 ... LC oscillation circuit 48 ... Frequency counter 50 ... Frequency / position converter 52 ... Display 102 ... Projection

Claims (5)

An input port to which lubricating oil is supplied, an output port for discharging the lubricating oil supplied from the input port to an external fluid device, and lubrication communicated with the input port and the output port and supplied via the input port A main body having a chamber into which oil is introduced;
Corresponding to the ratio of the inner diameter of the input port to the inner diameter of the output port by being slidably provided in the chamber along the axial direction of the main body and being pressed by the lubricating oil introduced into the chamber. A piston that displaces
A detection unit for detecting a displacement amount of the piston along the axial direction of the main body unit;
With
Wherein with the inner diameter of the input port is set larger than the inner diameter of the output ports, in the detection unit, spaced from the inner wall surface of the input port side, the supply of the lubricating oil is started with respect to the room through the input port The piston is provided with a lubricating oil supply start position, and a piston lubricating oil supply completion position, which is set before the displacement end position of the piston and when the supply of a predetermined amount of lubricating oil to the chamber is completed, and the piston Is displaced in a direction away from the lubricating oil supply completion position, and the lubricating oil discharge completion position of the piston when all the fixed amount of lubricating oil supplied into the chamber is discharged to an external fluid device through the output port And a lubricating oil supply detecting device. The apparatus of claim 1.
The detection unit includes a piston formed of a magnetic material and a coil disposed inside or outside the piston, and changes in the inductance of the coil caused by relative displacement between the piston and the coil are changed in frequency. And a displacement amount of the piston is calculated based on the detected frequency. The apparatus of claim 2.
The piston includes a columnar portion on which a seal member is mounted and a hollow cylindrical portion through which a coil can be inserted. The apparatus of claim 1.
The lubricating oil supply detection device according to claim 1, wherein the piston has a pressure receiving area that substantially coincides with an inner diameter area of the input port, and is provided with a protrusion that protrudes toward the input port by a predetermined length. The apparatus of claim 1.
A spring member that discharges the lubricating oil from the output port by pressing the piston toward the input port side after a certain amount of lubricating oil is supplied into the room is provided in the main body. Lubricating oil supply detection device.

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