TWI395884B - Device and method for detecting lubricating condition and motion guiding device or ballscrew device using them - Google Patents

Description

Lubrication state detecting device and lubrication state detecting method and motion guiding device or screw device using same

The present invention relates to a motion guiding device that is slidably assembled to a rail member by a rolling element, or a device in which a nut is rotatably assembled to a screw through a rolling element, and detects a lubrication state of the lubrication state. method.

As a mechanical element for guiding a linear motion or a curved motion of a moving body such as a table, a motion guiding device in which a rolling body such as a ball or a roller is placed in a guiding portion is widely known. The motion guiding device includes a rail member attached to the base or the like and a moving block slidably assembled to the rail member. The moving block is mounted on a moving body such as a workbench. A rolling body is interposed between the rolling element rolling surface of the rail member and the rolling body rolling surface of the moving block. When the moving block moves relative to the track member, the rolling body performs a rolling motion. Since the rolling motion of the rolling elements can be used for light movement, the motion guiding device is widely used in various fields such as robots, work machines, semiconductors, liquid crystal manufacturing devices, and medical devices.

However, when a motion guiding device is used, a film must be created between the rolling elements and the rolling body rolling faces to prevent direct contact of the metal with the metal. The reason is that when used in a state where there is no oil supply, the wear of the rolling elements and the rolling contact surface increases, which is a cause of shortening the life. As the lubricant, there are a liquid lubricant and a solid lubricant. The liquid lubricant can be further divided into high-viscosity grease (lithium-based grease, urea-based grease, etc.) and low-viscosity lubricant (sliding surface oil or turbine oil, ISOVG32~68, etc.). For example, at work In the environment where the coolant such as machinery is scattered, the sliding surface oil is used, and the grease is used in other high-speed moving parts and clean room specifications. As the solid lubricant, there is a solid lubricant typified by molybdenum disulfide or PTFE. Since solid lubricants do not evaporate, they are mostly used in a vacuum environment.

The applicant proposes a lubrication state detecting device that detects the lubrication state of the motion guiding device (see Patent Document 1). In the lubrication state detecting device, when the lubrication state is good, an oil film is formed between the rolling elements and the rolling element rolling contact surface, and the resistance value between the rolling elements and the rolling element rolling contact surface is increased. If the lubrication state is poor, the rolling element forms a metal contact with the rolling contact rolling surface and the resistance value will approach zero.

(Patent Document 1): Japanese Patent Laid-Open Publication No. 2005-54828

However, in the conventional lubrication state detecting device, an oscilloscope is required to display the detected resistance value (actually a voltage signal). This oscilloscope complicates the configuration of the lubrication state detecting device. Even if you look at the waveform displayed on the oscilloscope, it is difficult to judge whether the lubrication state is good.

A workbench is often equipped with a plurality of motion guiding devices, and a plurality of moving blocks are also assembled in a track member. The screw device used as the feed screw is also assembled to the table. Since the lubrication states of the moving blocks or nuts are different, it is desirable to detect the lubrication state for each moving block or nut.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a lubrication state detecting apparatus and method which can visually and easily detect the lubrication state of each moving block or nut.

Further, the factor determining the life of the motion guiding device depends not only on the metal contact between the rolling element and the rolling contact surface, but also on the time during which the rolling element and the rolling element rolling contact surface are in metal contact. The time accumulated by the metal contact has elements that determine the life of the motion guide.

Accordingly, it is another object of the present invention to provide a lubrication state detecting apparatus and method that can detect an accumulation time of a rolling contact between a rolling element and a rolling contact rolling surface.

Further, when a liquid lubricant is used, the film becomes thick when the speed of moving the block is large, and the film becomes thin when the speed is small. The thickness of the oil film formed between the rolling elements and the rolling contact surface of the rolling elements depends on the speed of the moving block. Moreover, the resistance value between the rolling elements and the rolling contact surface of the rolling elements also varies depending on the type of the liquid lubricant. When a solid lubricant is used as the lubricant, if the type and thickness of the solid lubricant are changed, the resistance value between the rolling element and the rolling contact rolling surface also differs. Even with good lubrication, the resistance values will vary depending on the condition of the motion guide or screw unit.

Therefore, a still further object of the present invention is to provide a lubrication state detecting device and method which can set an optimum resistance limit value depending on the use speed of the motion guiding device and the screw device, the type of the lubricant, and the like.

Hereinafter, the present invention will be described.

In order to solve the above problem, the lubrication state detecting device according to the invention of claim 1 is movably assembled to the rail member by the moving block through the rolling elements, and the rolling elements are rolled when the moving block relatively moves in the axial direction of the rail member. The moving motion guiding device or the nut can pass through the rolling body a screw device that is relatively rotatably assembled to the screw detects a lubrication state thereof; the lubrication state detecting device includes: a resistance value detecting means that applies a voltage between the rail member and the moving block or between the screw and the nut And detecting a resistance value between the track member and the moving block or between the screw and the nut; a limit value setting means for setting a limit value of the resistance; and comparing means for comparing the limit value set by the limit value setting means a signal for generating a comparison result with the resistance value detected by the resistance value detecting means; and a light-emitting element provided on the moving block of the motion guiding device or the nut of the screw device, and the signal generated by the comparing means And glow.

The lubrication state detecting device according to the invention of claim 2, wherein the moving block is movably assembled to the rail member by the rolling element, and the rolling guide performs a rolling motion when the moving block moves relative to the axial direction of the rail member. The device or the nut is rotatably assembled to the screw device of the screw through the rolling element to detect the lubrication state thereof; the lubrication state detecting device includes: a resistance value detecting means between the track member and the moving block, or the above Applying a voltage between the screw and the nut to detect a resistance value between the rail member and the moving block or between the screw and the nut; a limit value setting means, setting a limit value of the resistance; comparing means, comparing the above a limit value set by the limit value setting means and a resistance value detected by the resistance value detecting means to generate a signal of a comparison result; and a counting means for accumulating a signal-time-related index generated by the comparison means, when the accumulated value reaches a predetermined value or more Generate a signal.

The lubrication state detecting device of the invention of claim 3, The moving guide is movably assembled to the rail member through the rolling body, and the rolling guide performs a rolling motion when the moving block moves relative to the axial direction of the rail member, or the nut is rotatably assembled to the screw through the rolling body. a screw device for detecting a lubrication state; the lubrication state detecting device comprising: a resistance value detecting means for applying a voltage between the rail member and the moving block or between the screw and the nut to detect the rail member and a resistance value between the moving blocks or between the screw and the nut; a variable resistor capable of setting a limit value of the resistance and changing a limit value; and comparing means for comparing the set of the variable resistor The limit value and the resistance value detected by the resistance value detecting means generate a signal of a comparison result.

According to the invention of claim 4, in the lubrication state detecting device of the second aspect of the patent application, the counting means includes: a pulse wave transmitter that generates a pulse wave signal at a certain time interval; and an AND circuit that accepts the input The signal generated by the comparison means and the pulse signal; and the counter accumulate the signal generated by the AND circuit.

In the invention of claim 5, in the lubrication state detecting device of claim 3, the variable resistor has a limit value and a lower limit value which can be respectively set and can be respectively changed. a first variable resistor and a second variable resistor having an upper limit value and a lower limit value; wherein the comparing means compares the upper limit value of the limit value set by the first variable resistor and the second variable resistor And a lower limit value and a resistance value detected by the resistance value detecting means.

Applying for the invention contained in item 6 of the patent application, in the scope of application for patents In the lubrication state detecting device according to any one of the items 5, wherein the movement guiding device or the screw device is provided with a mounting hole or a mounting thread for mounting the motion guiding device or the screw device to the target component, the mounting The circumference of the hole or mounting thread is made up of an insulator.

A motion guiding device or a screw device according to the invention of claim 7 is the lubricating state detecting device according to any one of claims 1 to 5.

The lubrication state detecting method of the invention of claim 8 is movably assembled to the rail member by the rolling block through the rolling element, and the rolling guide performs the rolling motion of the rolling body when the moving block relatively moves in the axial direction of the rail member The device or the nut is rotatably assembled to the screw device of the screw through the rolling element to detect the lubrication state thereof; the lubrication state detecting method includes: a resistance value detecting step between the track member and the moving block, or the above Applying a voltage between the screw and the nut to detect a resistance value between the rail member and the moving block or between the screw and the nut; a limit value setting step of setting a limit value of the resistance; comparing steps, comparing a signal for generating a comparison result between the limit value set in the limit value setting step and the resistance value detected in the resistance value detecting step; and a light-emitting step of setting the signal according to the signal generated in the comparing step Light-emitting element of the above-mentioned moving block of the motion guiding device or the above-mentioned nut of the screw device .

The method for detecting a lubrication state according to the invention of claim 9 is that the moving block is movably assembled to the rail member through the rolling element, and the rolling element is rolled when the moving block relatively moves in the axial direction of the rail member. The moving motion guiding device or the nut is rotatably assembled to the screw device of the screw through the rolling element to detect the lubrication state thereof; the lubrication state detecting method includes: a resistance value detecting step, the track member and the moving block Applying a voltage between the screw and the nut to detect a resistance value between the rail member and the moving block or between the screw and the nut; a limit value setting step of setting a limit value of the resistor; a comparison step of comparing a limit value set in the limit value setting step with a resistance value detected in the resistance value detecting step to generate a signal of a comparison result; and a counting step of accumulating the signal generated in the comparing step A time-related indicator that produces a signal when the cumulative value reaches a predetermined value or more.

The lubrication state detecting method of the invention of claim 10, wherein the moving block is movably assembled to the rail member through the rolling elements, and the rolling guide performs the rolling motion when the moving block moves relative to the axis direction of the rail member. The device or the nut can be assembled to the screw device of the screw through the rolling element to detect the lubrication state thereof; the lubrication state detecting method includes: a resistance value detecting step between the track member and the moving block, or Applying a voltage between the screw and the nut to detect a resistance value between the rail member and the moving block or between the screw and the nut; a limit value setting step by changing a limit value of the resistor The variable resistor sets a limit value of the resistance; and a comparing step of comparing the limit value set in the limit value setting step with the resistance value detected in the resistance value detecting step to generate a signal of the comparison result.

According to the invention of claim 1, the resistance value between the track member and the moving block or between the screw and the nut is detected, and the detected resistance value is compared with the limit value, and the light-emitting element is made according to the comparison result. Glowing. Since the illuminating element is provided on the moving block of the motion guiding device or the nut of the screw device, the moving block or the nut can display the lubrication state while traveling. Therefore, the lubrication state of the moving block or the nut can be easily judged by visual observation.

According to the invention of claim 2, since the accumulation time of the metal contact between the rolling elements and the rolling contact rolling surface can be detected, the life of the motion guiding device or the screw device can be accurately grasped.

According to the invention of claim 3, since the limit value of the resistance is changed by the variable resistor, the optimum resistance value can be set in the case where the motion guiding device or the screw device is actually used.

According to the invention of claim 4 of the patent application, the time at which the comparison means generates a signal can be accumulated.

According to the invention of claim 5, it is possible to distinguish whether the detected resistance value is within the upper limit value and the lower limit value of the limit value. Therefore, it can be judged whether or not the lubricant film thickness formed between the rolling elements and the rolling contact rolling surface is within an appropriate range.

According to the invention of claim 6, in the case where the motion guiding device or the screw device is attached to the target member, the bolt is insulated by the insulator even if the bolt is fitted in the mounting hole or the mounting screw of the motion guiding device or the screw device. Therefore, the correct resistance value of the motion guiding device or the screw device can be detected.

According to the invention of claim 7, the lubrication state of the motion guiding device or the screw device can be detected.

According to the invention of claim 8 of the patent application, the resistance value between the rail member and the moving block or between the screw and the nut is detected, and the detected resistance value is compared with the limit value, and the light emitting element is caused to emit light according to the comparison result. . Since the illuminating element is provided on the moving block of the motion guiding device or the nut of the screw device, the moving block or the nut can display the lubrication state while traveling. Therefore, the lubrication state of the moving block or the nut can be easily judged by visual observation.

According to the invention of claim 9 of the invention, since the cumulative time of the metal contact between the rolling elements and the rolling contact rolling surface can be detected, the life of the motion guiding device or the screw device can be correctly grasped.

According to the invention of claim 10, since the limit value of the resistance is changed by the variable resistor, the optimum resistance value can be set in the case where the motion guiding device or the screw device is actually used.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Fig. 1 shows a resistance value detecting circuit for detecting a resistance value of a motion guiding device. In the resistance value detecting circuit, a voltage is applied between the moving block 1 of the motion guiding device 3 and the rail member 2, and the resistance value between the moving block 1 and the rail member 2 is detected. A rolling body is interposed between the rail member 2 and the moving block 1. When the lubricant film is formed around the rolling elements, the moving block 1 and the rail member 2 are insulated. On the other hand, when the lubricant film is not formed around the rolling elements, the rolling elements form a metal contact with the moving block 1 and the rail member 2, so the resistance value is zero.

A resistor R1 and a DC power source E1 are connected in series to the motion guiding device 3. Further, a resistor R2 is connected in parallel to the motion guiding device 3. Sense resistor R2 And the voltage across the motion guiding device 3 as the resistance value of the motion guiding device 3. These resistors R1, R2 and the DC power source E1 constitute a resistance value detecting means. When the lubricant film is formed around the rolling elements, since the moving block 1 and the rail member 2 are insulated, current does not flow into the motion guiding device 3. Therefore, the detected voltage VLM is a voltage generated only by the resistor R2. The voltage VLM is expressed by the following formula. (Formula 1) VLM=E1/(R1+R2)×R2

On the other hand, when the lubricant film is not formed between the rolling elements and the rolling contact rolling surface, since the rolling elements form a metal contact with the moving block 1 and the rail member 2, the electric resistance of the motion guiding device disappears. The detected voltage VLM is also zero.

As the lubricant film is formed or not, the resistance value changes from zero to infinity. Along with this, the voltage VLM changes from zero to the value calculated by Equation 1. The change in voltage VLM has a relative relationship with the change in the resistance value of the motion guiding device. Therefore, by detecting the voltage, the resistance value of the motion guiding device can be detected.

2 and 3 are circuit diagrams showing a lubrication state detecting device in the first embodiment of the present invention. Fig. 2 shows a conceptual diagram of the detecting device, and Fig. 3 shows a detailed circuit diagram. As described above, the resistor R1 is connected in series to the motion guiding device, and the resistor R2 is connected in parallel. A DC power source E1 is connected to both ends of the resistor R1 and the resistor R2 connected in series. The voltage signal across the motion guiding device 3 is input to the comparator 4 as a comparison means. Further, the limit value set by the variable resistor 5 as the limit value setting means is input to the comparator 4. This limit value is a voltage signal generated based on the resistance value set by the variable resistor 5.

The comparator 4 compares the limit value set by the variable resistor 5 with the voltage signal of the motion guiding device 3, and when the voltage signal of the motion guiding device 3 is greater than the limit value, a signal of the comparison result is generated. After the signal is inverted in the NOT circuit 6, the LEDs 7a and 7b (light emitting diodes) as light-emitting elements are input. The LEDs 7a, 7b are composed of, for example, a first LED 7a that emits green light and a second LED 7b that emits red light. When the signal is generated by the comparator 4, that is, when the detected voltage signal (resistance value) of the motion guiding device 3 is greater than the limit value set by the variable resistor 5, the green first LED 7a emits light, and the red second LED 7b does not. Glowing. On the other hand, when the comparator 4 does not generate a signal, that is, when the detected voltage signal (resistance value) of the motion guiding device 3 is smaller than the limit value set by the variable resistor 5, the red second LED 7b emits light, and the green color One LED7a does not emit light. The lubrication state detecting means including the LEDs 7a, 7b is buried in the end plate 11 of the moving block 1 to be simplified (see Fig. 5).

In addition, instead of the first and second LEDs 7a, 7b, for example, a red-emitting LED is provided. When the voltage signal (resistance value) of the motion guiding device 3 is greater than the limit value set by the variable resistor 5, The LED does not emit light, and conversely, when less than the limit value, the LED emits light.

The moving block 1 displays red or green while traveling. When the lubrication state is good, a lubricant film is formed between the rolling elements and the rolling contact surface. Therefore, a signal is generated by the comparator 4, and the green first LED 7a emits light. On the other hand, if the lubrication condition is poor, the rolling element forms a metal contact with the rolling contact surface of the rolling element. The resistance of the moving guide 3 is zero, and the comparator 4 does not generate a signal. Therefore, the red second LED 7b emits light. When the lubrication state is good, the moving block 1 emits green light during traveling, and when the lubrication state is poor, the moving block 1 emits red light during traveling. Therefore, it is easy to judge whether or not the lubrication state is good only by visually moving the moving block 1.

The signal generated by the comparator 4 can also be output to the outside, using a signal for actuating the fuel supply pump. The timing of the oil supply varies depending on the travel time or load conditions of the motion guiding device 3. The method of supplying the oil pump at regular intervals is not directly related to the state of the lubricant film (oil film), so there may be a case where the oil supply is too much or too little. At the site where the motion guiding device 3 is used, in order to prevent the oil film from being exhausted, the timing of the operation of the oil supply pump is set to be shorter than necessary. However, in this case, the amount of lubricant used is increased, which is harmful to the environment. The oil supply pump is actuated by the signal generated by the comparator 4, and the oil supply pump is actuated only when the oil film is exhausted, etc., and can be an oil supply method directly related to the state of the oil film. Therefore, an appropriate amount of lubricant can be supplied at an appropriate timing.

Figure 4 shows a plurality of motion guiding device units mounted to the table 9. In this example, two rails 2 are arranged on the table 9 as the rail members 2, and two moving blocks 1 are assembled on the rails 2, respectively. Four moving blocks 1 are installed below the table 9. The lubrication state of the moving block 1 varies depending on each moving block 1. Since the lubrication state detecting device 10 is provided in each of the moving blocks 1, each moving block 1 emits red or green light during traveling. Therefore, it is possible to judge for each moving block 1 whether or not the lubrication state is good.

Figure 5 shows a perspective view of the motion guiding device 3. Motion guiding device 3 There are provided: a rail slide rail 2 extending in an elongated straight line, a moving block 1 movably assembled to the rail slide rail 2, and a rolling body rolling surface of the rolling element rolling surface and the moving block 1 interposed on the rail slide rail 2 Rolling bodies 12 such as a plurality of balls and rollers between the running faces.

The rail slide rail 2 is formed with a plurality of strips, for example, four rolling element rolling grooves 2a extending in the longitudinal direction. Further, the rail slide rail 2 is machined to mount the rail slide rail 2 to the attachment hole 2b of the target member such as the base, and is constituted by a counterbore.

The moving block 1 is saddle-shaped and spans the track 2. A rolling element rolling groove 1a is formed on the inner side surface of the moving block 1, and faces the rolling element rolling groove 2a of the track rail 2. The rolling element return passage 1b is machined in the moving block 1, and is formed by extending the through hole by the rolling element 2a. End plates 11 are attached to both ends of the moving block 1 in the moving direction. The end plate 11 is provided with a U-shaped direction changing passage, and the rolling element rolling groove 1a and the rolling body returning passage 1b which are extended to each other are connected. The rolling element rolling groove 1a, the rolling element returning passage 1b, and the direction changing path are configured to form a circulating rolling element circulation path.

A plurality of rolling elements 12 are arranged and accommodated in the rolling element circulation path. The rolling elements 12 can also be held in a series by the holder 14 in a rotatable and slidable manner. When the moving block 1 moves in the axial direction of the track rail 2 with respect to the track rail 2, between the rolling element rolling groove 1a of the moving block 1 and the rolling body rolling surface of the track rail 2, the rolling elements Rolling motion. The ball that moves to one end of the rolling element rolling surface of the moving block 1 is picked up in the direction changing path of the end plate 11, passes through the rolling body return passage, and ends from the opposite side The plate 11 is again returned to the rolling element rolling surface of the moving block 1. Above the moving block 1, a mounting thread 1c is machined for mounting the moving block 1 to the table 9.

Figure 6 shows a cross-sectional view of the motion guiding device 3 orthogonal to the axial direction of the track rail 2. A table 9 is placed on top of the moving block 1. The underside of the track rail 2 is in contact with the base. When the moving block 1 and the table 9, or the track rail 2 are electrically connected to the base, if a voltage is applied between the moving block 1 and the track rail 2, current will flow in the table 9 or the base. To prevent this, an insulating sheet 15 is provided between the upper surface of the moving block 1 and the table 9, or between the lower surface of the rail slide 2 and the base, so that the motion guiding device 3 is insulated from the table 9 or the base.

Even if the insulating sheet 15 is moved between the moving block 1 and the rail slide 2, if the bolts for mounting the moving block 1 and the rail slide 2 to the table 9 and the base are not insulated, the moving block 1 and the table are moved. 9. The track rail 2 and the base will be electrically connected through the bolts. In order to prevent such a phenomenon, as shown in Fig. 7, the periphery of the mounting hole 1c of the moving block 1 is constituted by an insulator 16. Further, as shown in Fig. 8, the periphery of the mounting hole 2b of the rail slide 2 is also constituted by an insulator 17.

FIG. 9 shows an example in which the table 9 is mounted on the moving block 1. The counterbore 9a is machined in the table 9. A bolt is inserted into the counterbore 9a, and the table 9 is attached to the moving block 1 by screwing the bolt to the mounting thread of the moving block 1. In order to prevent conduction between the bolt and the table 9, an insulating gasket 18 is provided on the seating surface 9c of the counterbore. Among them, the conduction between the moving block 1 and the table 9 via the bolt can be prevented by only using the insulating gasket 18. However, when When the bolt is in contact with the table 9 , it is not sufficiently insulated by the insulating gasket 18 alone. Therefore, it is necessary to provide the insulator 16 around the mounting thread 1c of the moving block 1.

When a liquid lubricating oil is used as the lubricant, when the moving block 1 is stopped, an oil film is not formed between the rolling elements 12 and the rolling element rolling grooves 1a, 2a, and the rolling elements 12 and the rolling elements are rolled away. A metal contact is formed between them. Therefore, the resistance value between the moving block 1 and the track rail 2 becomes zero, and the moving block 1 emits red light. When the moving block 1 is actuated and the speed is increased, an oil film is formed between the rolling elements 12 and the rolling element rolling grooves 1a and 2a, and the rolling elements 12 and the rolling element rolling grooves 1a and 2a are insulated. Therefore, the resistance value between the moving block 1 and the track rail 2 is greater than the limit value, and the moving block 1 emits green light. The inventors have experimentally confirmed that if all the lubricating oil of the motion guiding device 3 is removed, even if the moving block 1 is moved at a high speed, the LED of the moving block 1 remains red. In other words, it is understood that the rolling element 12 and the rolling element rolling grooves 1a and 2a are not insulated between the rolling elements 12 and the rolling element rolling grooves 1a and 2a due to the high-speed movement of the moving block 1, but there is a difference between the rolling elements 12 and the rolling element rolling grooves 1a and 2a. The oil film is in an insulated state between the rolling elements 12 and the rolling element rolling grooves 1a and 2a.

When a liquid lubricating oil is used, the thickness of the oil film formed between the rolling elements 12 and the rolling element rolling grooves 1a and 2a varies depending on the moving speed of the moving block 1 and the type of the lubricating oil. The most appropriate oil film thickness also varies depending on the moving speed of the moving block 1 and the type of the lubricating oil. Since the limit value of the resistance can be changed without cutting off the circuit to which the variable resistor is connected, the limit value of the resistance can be changed in the case where the motion guiding device 3 is actually used. Therefore, the most appropriate limit can be set according to the moving speed of the moving block 1 and the type of the lubricating oil. value.

There is also a case where a solid lubricant represented by molybdenum disulfide or PTFE is used instead of the liquid lubricating oil. A solid lubricant is used in an environment where a liquid lubricating oil cannot be used in a vacuum environment or the like. The solid lubricant is applied to the rolling elements 12 or the rolling element rolling grooves 1a and 2a by splashing or the like. When the solid lubricating film is peeled off, it causes contact between metals. Liquid lubricants can be replenished after the start of operation, but solid lubricants cannot be recoated. Since the solid lubricant is peeled off at the time of reaching the life of the motion guiding device, it is necessary to know the state of the solid lubricating film.

When a voltage is applied to the motion guiding device 3 in which the rolling element 12 is covered with the solid lubricant, the motion guiding device is in an insulated state (i.e., the green LED emits light) during the stop and movement of the moving block 1. After the solid lubricant is peeled off, the motion guiding device 3 is in an on state. The motion guiding device 3 is in an insulated state because the solid lubricant has the function of an insulator. When the solid lubricant is peeled off, the motion guiding device 3 is turned on because the rolling elements 12 are in metal contact with the rolling element rolling grooves 1a, 2a. Therefore, if the resistance value of the motion guiding device 3 is detected, compared with the limit value, it is also possible to directly know whether or not the solid lubricant is peeled off.

Fig. 10 is a circuit diagram showing a lubricating state detecting device in a second embodiment of the present invention. In the circuit of the present embodiment, counting means 31, 32, 33 are provided to accumulate time-dependent indicators of the signals generated by the comparator 4, and signals are generated when the accumulated values are equal to or higher than a predetermined value.

The voltage signal across the motion guiding device 3 is input to the comparator 4. The comparator 4 compares the limit value set by the variable resistor 5 with the motion guiding device 3 The voltage signal, when the voltage signal of the motion guiding device 3 is greater than the limit value, generates a signal of the comparison result, and conversely, when it is less than the limit value, no signal is generated. This signal is inverted in the NOT circuit and input to the LED 7 and the AND circuit 32. When there is a signal input from the comparator 4, that is, when the comparator 4 determines that the lubrication is abnormal, the LED 7 emits red light. The photoelectric crystal outputs a signal to the outside when the lubrication is abnormal.

The comparator 4 determines that the signal when the lubrication is abnormal is input to the AND circuit 32. Further, the pulse wave signal of a certain time interval generated by the pulse wave transmitter 33 and the external device synchronization signal are input to the AND circuit 32. The AND circuit 32 produces a pulse wave signal of the logical product of the signals. The pulse wave signal generated by the AND circuit 32 is input to the counter 31. The counter 31 outputs a lubrication abnormality warning signal when the count value reaches a predetermined value or more. After the lubrication state detecting device outputs the lubrication abnormality warning signal, the user of the motion guiding device 3 can confirm the lubrication state of the motion guiding device 3, supply oil to the motion guiding device 3, supply grease, or operate the fuel supply pump.

Figure 11 shows a timing diagram of the signal. Comparator 4 produces an opposite comparator signal when lubrication is abnormal and when lubrication is normal. The pulse wave transmitter 33 generates a pulse wave signal of a certain time interval. The AND circuit 32 takes the logical product of the comparator signal and the pulse signal to produce a pulse signal to the counter. The counter 31 accumulates the pulse wave signal generated by the AND circuit 32 and sent to the counter, and outputs a lubrication abnormality warning signal when the accumulated value reaches a predetermined value (for example, 9) or more.

Further, in the circuit diagram of the present embodiment, the time during which the signal of the lubrication abnormality is generated by the comparator 4 is replaced with a pulse wave signal, and the pulse is accumulated by the counter 31. The wave signal, but it is also possible to directly measure the time during which the comparator 4 generates a signal of lubrication anomaly. Further, while the comparator 4 generates a signal indicating that the lubrication is abnormal, the total time for generating the lubrication abnormality signal is accumulated even if a signal indicating that the lubrication is normal is generated. However, it is also possible to reset the integrated value when the comparator 4 generates a signal indicating that the lubrication is normal. In this way, the motion guiding device with a high stopping frequency can also correctly grasp the lubrication state.

Fig. 12 is a circuit diagram showing a lubrication state detecting device according to a third embodiment of the present invention. In the circuit of the present embodiment, the first variable resistor 5-1 that sets the upper limit of the limit value and the second variable resistor 5-2 that sets the lower limit of the limit value are provided as the limit value setting means. Further, the first comparator 4-1 and the second comparator 4-2 are provided as comparison means. The voltage signals across the motion guiding device 3 are input to the first comparator 4-1 and the second comparator 4-2, respectively.

The second comparator 4-2 compares the lower limit value of the limit value set by the second variable resistor 5-2 with the voltage signal of the motion guiding device 3, and generates a signal when the voltage signal is greater than the lower limit value of the limit value, Conversely, no signal is generated when the voltage signal is below the lower limit of the limit.

The first comparator 4-1 compares the upper limit value of the limit value set by the first variable resistor 5-1 with the voltage signal of the motion guiding device 3, and generates a signal when the voltage signal is less than the upper limit value of the limit value, Conversely, no signal is generated when the voltage signal is above the upper limit of the limit.

The signals generated by the first comparator 4-1 and the second comparator 4-2, respectively, are input to the AND circuit 19. The AND circuit 19 generates a signal when a signal is generated by each of the first comparator 4-1 and the second comparator 4-2. After the signal is inverted in the NOT circuit 6, the LEDs 7a and 7b as light-emitting elements are input. The LED is composed of a second LED 7a that emits green light and a second LED 7b that emits red light (a color different from the color emitted by the first LED 7a), and is the same as the lubrication state detecting device of the first embodiment.

In the lubrication state detecting device of the present embodiment, when the electric resistance of the motion guiding device 3 is within the range of the upper limit value and the lower limit value of the limit value, the green LED 7a having a good lubrication state is illuminated. On the other hand, when the resistance value of the motion guiding device 3 is less than the lower limit value of the limit value or greater than the upper limit value, the red LED 7b emits light. In order to make the lubrication state good, the film thickness of the lubricant also needs to be within an appropriate range. By setting the upper limit value and the lower limit value of the limit value, it is possible to know whether or not the film thickness is within an appropriate range.

Fig. 13 is a perspective view showing the screw device 25 in which the lubrication state detecting device is incorporated. The screw device 25 includes a screw 22 and a nut 22 that is assembled to the screw 21 by interposing the rolling elements 23 . A spiral rolling element rolling groove 21a is formed on the outer circumferential surface of the screw 21. A spiral rolling element rolling groove 22a that faces the rolling element rolling groove 21a is formed on the inner circumferential surface of the nut 22. The nut 22 is provided with a returning tube 24 that connects the one end of the rolling element 22a of the nut 22 to the other end. Between the rolling element rolling groove 21a of the screw 21 and the rolling element rolling groove 22a of the nut 22, the rolling elements 23 composed of a plurality of balls are arranged and accommodated.

When the screw 21 is relatively rotated with respect to the nut 22, the rolling elements interposed between the nut 22 and the screw 21 perform a rolling motion. The rolling element 23 which is rolled to one end of the rolling element rolling groove 22a of the nut 22 is picked up in the return pipe 24, and after passing from the one end to the other end through the return pipe 24, the rolling element which is returned to the nut 22 is rolled away again. The other end of the groove 22a.

The lubrication state detecting device 10 is the same as the lubrication state detecting device assembled to the motion guiding device 3. A voltage was applied between the screw 21 and the nut 22, and the resistance value between the screw 21 and the nut 22 was measured. Moreover, the resistance value is compared with the limit value, and when it is greater than the limit value, the LED is illuminated. The lubrication state detecting device 10 is embedded in the nut 22. The nut 22 shows whether the lubrication state itself is good during the movement.

The present invention is not limited to the embodiments described above, and various embodiments can be implemented without departing from the scope of the invention. For example, the motion guiding device may use a ball bolt slot or a linear bush in addition to the linear guide rail formed by the above-mentioned rail slide rail and the saddle-shaped moving block. In the ball stud groove and the linear bearing, the cylindrical moving block covering the track shaft slides with respect to the track axis as the rail member.

Further, the screw device may be a screw device such as an end cap type or a steering plate type, in addition to the return type screw device.

Further, in addition to the battery, the power source of the lubrication state supply device can also use the power generated by the generator when the commercial power source or the moving block is installed in the factory. A light bulb can also be used instead of an LED.

Further, when the lubricating oil most suitable for the motion guiding device or the screw device is selected, the appropriateness of the lubricating oil can be evaluated by the lubrication state detecting device of the present embodiment. If the improper lubricating oil can be removed before the endurance test is applied to the motion guiding device or the screw device, the time for the endurance test can be saved.

This specification is based on Japanese Patent Application No. 2007-21315 filed on January 31, 2007. This content is all included here.

1‧‧‧moving block

1a‧‧‧ rolling elements rolling

1b‧‧‧ rolling element return channel

1c‧‧‧Installation thread

2‧‧‧Track slides (track members)

2a‧‧‧ rolling elements rolling

2b‧‧‧ mounting holes

3‧‧‧Sports guide

4‧‧‧ comparator (comparative means)

5‧‧‧Variable resistors (limit value setting means)

6‧‧‧NOT circuit

7, 7a, 7b‧‧‧ LED (light-emitting elements)

9‧‧‧Workbench

9a‧‧‧ countersunk hole

10‧‧‧Lubrication state detecting device

11‧‧‧End board

12‧‧‧ rolling elements

15‧‧‧Insulation sheet

16, 17‧‧‧Insulators

18‧‧‧Insulation washers

21‧‧‧ screw

21a‧‧‧ rolling elements rolling

22‧‧‧ Nuts

22a‧‧‧ rolling elements rolling

23‧‧‧ rolling elements

24‧‧‧Return tube

25‧‧‧ screw device

31‧‧‧Counter (counting means)

32‧‧‧AND circuit (counting means)

33‧‧‧ Pulse Transmitter (counting means)

E1‧‧‧DC power supply (resistance value detection means)

R1, R2‧‧‧ resistance (resistance value detection means)

1 is a circuit diagram of a resistance value detecting circuit for detecting a resistance value of a motion guiding device.

Fig. 2 is a circuit diagram (conceptual view) of a lubrication state detecting device in the first embodiment of the present invention.

Fig. 3 is a circuit diagram (detail view) showing a lubrication state detecting device in the first embodiment of the present invention.

4 is a perspective view of a plurality of motion guiding device units mounted to a table.

Figure 5 is a perspective view of the motion guiding device.

Figure 6 is a cross-sectional view of the motion guiding device orthogonal to the axial direction of the track rail.

Figure 7 is a cross-sectional view of the mounting thread of the moving block.

Figure 8 is a cross-sectional view of the mounting hole of the rail slide.

Figure 9 is a cross-sectional view of the motion guiding device mounted to the table.

Figure 10 is a circuit diagram of a lubrication state detecting device in a second embodiment of the present invention.

Figure 11 is a timing diagram of the signal.

Figure 12 is a circuit diagram of a lubrication state detecting device in a third embodiment of the present invention.

Figure 13 is a perspective view of the screw device.

1‧‧‧moving block

2‧‧‧Track slides (track members)

3‧‧‧Sports guide

4‧‧‧ comparator (comparative means)

5‧‧‧Variable resistors (limit value setting means)

E1‧‧‧DC power supply (resistance value detection means)

R1, R2‧‧‧ resistance (resistance value detection means)

Claims (9)

A lubrication state detecting device for movably assembling a moving block through a rolling body to a rail member, and a rolling guide for rolling motion of the rolling body when the moving block relatively moves in an axial direction of the rail member, or a nut passing through the rolling body a screw device that is rotatably assembled to the screw and detects a lubrication state thereof; the lubrication state detecting device includes: a resistance value detecting means that is applied between the rail member and the moving block or between the screw and the nut a voltage, detecting a resistance value between the track member and the moving block, or between the screw and the nut; a variable resistor for setting a limit value of the resistance and changing the limit value; and comparing means, Comparing the limit value set by the variable resistor and the resistance value detected by the resistance value detecting means to generate a signal of a comparison result; the variable resistor having an upper limit value and a lower limit value respectively capable of setting a limit value a first variable resistor and a second variable resistor that can change the upper limit and the lower limit of the limit value, respectively The comparison means is for comparing an upper limit value and a lower limit value of a limit value set by the first variable resistor and the second variable resistor, and a resistance detected by the resistance value detecting means value. The lubrication state detecting device according to claim 1, wherein the lubrication state detecting device further includes a light emitting element, wherein the light emitting element is provided in the moving block of the motion guiding device or the screw device The nut is illuminated by a signal generated by the comparison means. The lubrication state detecting device according to claim 1 or 2, wherein the lubrication state detecting device further includes a counting means for accumulating a time-dependent index of the signal generated by the comparing means, and when the cumulative value reaches a predetermined value The above signal is generated. The lubrication state detecting device according to claim 3, wherein the counting means includes: a pulse wave transmitter that generates a pulse wave signal at a certain time interval; and an AND circuit that receives a signal generated by the input of the comparison means and the pulse a wave signal; and a counter that accumulates signals generated by the AND circuit described above. The lubrication state detecting device according to claim 1 or 2, wherein in the motion guiding device or the screw device, a mounting hole or mounting for mounting the motion guiding device or the screw device to a target component is provided. Thread, the mounting hole or the circumference of the mounting thread is composed of an insulator. A motion guiding device or a screw device is assembled with the lubrication state detecting device of claim 1 or 2. A lubrication state detecting method for moving a moving block through a rolling body to be movably assembled to a rail member, and a rolling guide for rolling movement of the rolling element when the moving block moves relative to an axial direction of the rail member, or a nut passing through the rolling body a screw device that is rotatably assembled to the screw and detects a lubrication state thereof; the lubrication state detecting method includes: a resistance value detecting step between the rail member and the moving block, Or applying a voltage between the screw and the nut to detect a resistance value between the rail member and the moving block or between the screw and the nut; a limit value setting step by changing a limit value of the resistor a variable resistor that sets a limit value of the resistance; and a comparison step of comparing the limit value set in the limit value setting step with the resistance value detected in the resistance value detecting step to generate a signal of a comparison result; The variable resistor includes a first variable resistor and a second variable resistor that can respectively set an upper limit value and a lower limit value of the limit value, and can change the upper limit value and the lower limit value of the limit value, respectively; In the comparison step, the upper limit value and the lower limit value of the limit values set by the first variable resistor and the second variable resistor, and the resistance value detected in the resistance value detecting step are compared. The method for detecting a lubrication state according to claim 7, wherein the lubrication state detecting method further includes a light emitting step of causing the motion guiding device to be provided according to a signal generated in the comparing step. The moving block or the light-emitting element of the nut of the screw device emits light. The lubrication state detecting method according to claim 7 or 8, wherein the lubrication state detecting method further comprises a counting step of accumulating the signal-time-related index generated in the comparing step, when accumulating A signal is generated when the value is above a predetermined value.