JP2004142013A - Preventative maintainable device in cylindrical grinding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a preventative maintainable device from a mechanical vibrational point of view which can be installed on one or several cylindrical grinding machines easily, and used to maintain highly accurate grinding work. <P>SOLUTION: The cylindrical grinding machine having a measuring device L for measuring the stock removal of a work being ground and emitting a grinding finishing signal when a finishing dimension is reached comprises a vibration sensor S installed on a rotation section such as a spindle 5, a grinding wheel spindle 15 and a vibration analyzing means installed in a measuring amplifier 32 of the device L and capable of analyzing vibrational data measured by the vibration sensor S. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention detects the deterioration or abnormality of rotating parts such as bearings mounted on a rotating part and notifies the worker, or, when an excessive vibration such as a strong earthquake occurs, stops the machine in an emergency, The present invention relates to a preventive maintenance device in a cylindrical grinder for ensuring the safety of a machine.
[0002]
[Prior art]
In a cylindrical grinder, a defect in a rotating part such as a spindle or a grinding wheel directly leads to a processing defect (a defect in roundness, a defect in surface roughness, a defect in dimensions). Therefore, what is called a “continuous monitoring system” has been considered as a device for monitoring the failure of rotating parts of a large number of processing machines in a large-scale factory including a cylindrical grinder.
[0003]
This "continuous monitoring system", as shown in FIG. 6, a number of machine _{(A 1, A 2 ·· An} ) respectively to the rotary part wearing the vibration sensor S of each machine _(A 1, _{A 2} .. An) The method of centralized management by monitoring the state of occurrence of the vibration by the monitor T and processing the state by the personal computer PC. Since this "continuous monitoring system" monitors a large number of machines, it is costly to install the machine, and it is not suitable for machines delivered in units of one or several units because the cost is high.
[0004]
For this reason, conventionally, machines that are delivered in a small number of units are delivered without a vibration analysis device, and it has not been possible to monitor the failure of the rotating part. Naturally, when an excessive vibration such as a strong earthquake occurs, there has been no device that recognizes an emergency from the vibration value and stops the machine in an emergency to ensure safety. .
[0005]
On the other hand, the cylindrical grinder is provided with a sizing device that measures the amount of grinding of the workpiece during grinding and issues a grinding end signal to stop the machine when the finished size is reached. For cylindrical grinders delivered in units of one or several units, the use of the above-mentioned sizing device enables maintenance of vibration surfaces even for cylindrical grinders delivered in small units. I got the idea.
[0006]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a preventive maintenance device on mechanical vibration that can be easily mounted on one or several cylindrical grinders and can maintain high-precision grinding.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 for solving the above-mentioned problem is a cylindrical grinding machine provided with a sizing device that measures a grinding amount of a workpiece during grinding and issues a grinding end signal when a finished dimension is reached, A vibration sensor mounted on a rotating part such as a main shaft and a grinding wheel shaft, and vibration analysis means incorporated in a measuring amplifier of the sizing device and capable of analyzing vibration data measured by the vibration sensor. And
[0008]
According to the first aspect of the present invention, the measuring amplifier constituting the sizing device attached to the cylindrical grinding machine has a built-in CPU (Central Processing Unit) and can install vibration analysis means (vibration analysis software). It is. For this reason, the vibration value, which is the detection data of the vibration sensor mounted on the rotating part of the cylindrical grinding machine, is analyzed and evaluated by vibration analysis means incorporated in the sizing device, and the evaluation result is output. For example, the vibration value is divided into several levels according to the strength of the vibration, and the content corresponding to the level (for example, allowable vibration, vibration requiring component replacement preparation, vibration requiring component replacement, etc.). Is displayed on the display screen of the sizing device. As a result, the worker can perform machining with knowledge of the strength of the vibration, and if damage to the rotating component is detected, it is possible to replace the component just before a machining failure occurs. , High-precision grinding becomes possible. In addition, since it is possible to know the content and the degree of deterioration or abnormality of the rotating component mounted on the rotating unit, it is possible to prepare for component replacement in advance.
[0009]
Further, according to the invention of claim 1, when the vibration value analyzed by the vibration analysis means exceeds the inoperable value due to the occurrence of a strong earthquake or the like, the measuring amplifier of the sizing device is used. , An emergency stop signal for stopping the cylindrical grinding machine is issued.
[0010]
According to the second aspect of the present invention, when a strong vibration that makes continuous operation of the machine impossible due to a strong earthquake or the like occurs, a vibration value exceeding a dangerous value for the continuous operation is transmitted to the emergency stop signal by the vibration analysis means. Is output to automatically stop the operation of the machine. As described above, since the operation of the machine is automatically stopped when a danger such as a strong earthquake occurs, the safety of the worker is ensured.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to embodiments. First, the outlines of the cylindrical grinding machine K mainly composed of a rotating unit and the sizing device L mounted on the machine will be described, and then the preventive maintenance device N according to the present invention will be described. 1 is a schematic plan view mainly showing a rotating part of a cylindrical grinding machine K, FIG. 2 is a partially cutaway view taken along the arrow U in FIG. 1, and FIG. It is. 1 to 3, on the upper surface of a base 1, a Z-axis carriage 2 is provided so as to be slidable in the Z-axis direction, and the Z-axis carriage 2 includes a headstock 3 and a tailstock 4. Are arranged facing each other along the Z-axis direction. Main shaft 5 in the headstock 3, both ends thereof is supported via a pair of bearings B _1, the main shaft 5, the driving force of the spindle drive motor M ₁ mounted on the carriage 2 is belt drive 25 and is driven and rotated. The Z-axis carriage 2 is guided by a V-shaped guide groove 6 provided on the base 1 and is slidable in the Z-axis direction. 7 are provided integrally. Bearing bases 10 are provided at both ends of a portion of the base 1 where the Z-axis ball screw 8 is arranged. Z-axis ball screw 8, both ends thereof are supported by bearings B ₂ attached to the bearing stand 10, the screwed with the ball nut 9 provided in the ball nut holder 7, Z-axis AC servomotor M ₂ , the Z-axis carriage 2 moves with the amount of movement along the Z-axis direction controlled. Workpiece W with a cylindrical shape, while being supported at both ends by the respective centers 11, 12 of the headstock 3 and the tailstock 4, the driving force of the spindle drive motor M ₁ is not the main shaft 5 and Kere acids (shown ), And is rotated at a low speed in the same direction as a grinding wheel 16 described later.
[0012]
In addition, on the upper surface of the base 1, beside the Z-axis carriage 2, a grindstone table 13 is disposed so as to be able to reciprocate along an X-axis direction orthogonal to the Z-axis direction. The wheel spindle support housing 14 of the wheel head 13, the wheel spindle 15 is disposed along the Z-axis direction, its both ends are supported by a pair of bearings B _3, projecting from the wheel head 13 in the grinding wheel shaft 15 A grinding wheel 16 is attached to the portion. The wheel head 13 is mounted wheel spindle drive motor M _3, the driving force is transmitted to the wheel spindle 15 through a belt drive 17. A ball nut holder 18 is integrally provided on the lower surface of the grindstone table 13, and bearing stands 21 are provided at both ends of a portion of the base 1 where the X-axis ball screw 19 is arranged. X-axis ball screw 19 has its opposite ends is supported by a bearing B ₄ attached to the bearing stand 21, the screwed with the ball nut 22 provided on the ball nut holder 18, X-axis AC servomotor M ₄ is controlled and rotated. Thus, the wheel head 13 is moved is controlled amount of movement in the X-axis direction by the X-axis AC servomotor M _4, giving a cut to the workpiece W. Each of the bearings B _{1 to} B ₄ described above has a structure capable of supporting both radial and thrust loads.
[0013]
The workpiece W rotates in the same direction as the grinding wheel 16 at a lower speed than the drive rotation of the spindle 5 in a state where both ends are supported by the centers 11 and 12 of the headstock 3 and the tailstock 4. Thus, the workpiece W is in a state of being rotated at a low speed in a predetermined direction, Z-axis carriage 2 is controlled by a Z-axis AC servomotor M _2, a longer stroke than the length of the workpiece W Thus, it reciprocates in the Z-axis direction. This causes the workpiece W to reciprocate in the Z-axis direction with the above stroke. On the other hand, the wheel head 13 by the X-axis AC servomotor M _4, every time the workpiece W is a half round trip, and moves in the X-axis direction toward the hand, given the cut to the workpiece W The workpiece W is cut by a predetermined amount by the grinding wheel 16. The cut amount is controlled by a sizing device L described later.
[0014]
Next, the sizing device L will be described with reference to the principle diagram of FIG. This sizing device L is called an “in-process gauge” and directly measures the outer diameter of the workpiece W during grinding, and when the measured value reaches a preset finishing dimension, the machining is completed. The measuring head 31 is for outputting an end signal and is mounted on the Z-axis carriage 2 and a measuring amplifier 32 for inputting processing data and outputting various signals. The measuring head 31 includes a pair of tracing styluses 33 for measuring the outer diameter of the workpiece W, and advances and retreats with respect to the workpiece W along a Z-axis direction orthogonal to the axis of the workpiece W. It is disposed so as to be capable of moving forward and backward by an air cylinder 34 which is a linear driving means. Further, the measurement amplifier 32 is “input / output connected” to the control unit 23 of the cylindrical grinding machine K, inputs predetermined processing data, and displays a processing state and a cylindrical state displayed on the display unit 35. It outputs various signals such as a processing end signal to the grinding machine K, and has a built-in CPU (Central Processing Unit).
[0015]
Then, after the rotation of the main shaft 5 is started, the measurement head 31 is advanced to start measuring the outer diameter of the workpiece W. The general processing steps in cylindrical grinding include rough grinding with a large cutting depth of the grinding wheel 16, fine polishing thereof, and spark-out in which the grinding wheel 16 is stopped to reduce the cutting depth to zero. In 32, signal points for starting fine polishing and spark-out are input and set according to the processing purpose. Specifically, when finishing the outer diameter of the workpiece W to (Dmm), the outer diameter of the material is [(D + α) mm], and for example, the outer diameter of the workpiece W is When it reaches (Dmm + 35 μm), a fine polishing signal for switching from rough grinding to fine grinding is issued, and when the outer diameter of the material reaches (Dmm + 5 μm), a spark-out signal is issued.
[0016]
As a result, until the outer diameter of the material reaches (Dmm + 35 μm) and the fine grinding signal is issued, the cutting amount of the grinding wheel 16 is increased to perform high-speed machining. The cutting amount of the grindstone 16 is reduced, and low-speed machining is performed. Further, when the outer diameter of the material reaches (Dmm + 5 μm) and a spark-out signal is issued, the grinding is continued with the cutting of the grinding wheel 16 stopped, and thereafter, when the outer diameter of the material reaches (Dmm). and processing end signal is issued to the cylindrical grinding machine K, the wheel head 13 after retracting the workpiece W, the drive motor M ₁ of the main shaft 5 is stopped.
[0017]
As described above, when the workpiece W is ground by the cylindrical grinder K, vibration is generated in the rotating portion. Here, the rotating part, the main shaft 5, Z-axis ball screw 8, a wheel spindle 15 and X-axis ball screw 19, both its ends is supported by a pair of bearings B ₁ ~B _4. Defects typical of the rotating portion, the wear of the bearing B ₁ .about.B _4, a deterioration, by the failure, the workpiece W is circularity defects, surface roughness defects, machining defects such as dimensional error It is easy to occur. And the defect of a rotating part appears first as a vibration.
[0018]
Therefore, the present invention provides a vibration sensor S that is mounted on the rotating part and a vibration analysis that can be incorporated into the measuring amplifier 32 that constitutes the sizing device L and that can analyze the vibration data measured by the vibration sensor S. The preventive maintenance device N of the cylindrical grinding machine K is constituted by the software.
[0019]
Then, the attachment portion of the vibration sensor S in the rotating portion of the cylindrical grinding machine K, with respect to the main shaft 5, a both end bearing B ₁ portion of the main shaft 5 at the surface of the headstock 3 (P _1). As for the Z-axis ball screw 8, the surface portion (P ₂ ) of each bearing stand 10 incorporating the bearings B ₂ at both ends thereof, and the ball nut 9 incorporating the ball nut 9 screwed with the Z-axis ball screw 8. This is the surface portion (P ₃ ) of the holder 7. With respect to the wheel spindle 15, which is across the bearing _{B 3} parts of the wheel spindle 15 at the surface of the wheel spindle support housing 14 _{(P 4).} Furthermore, X-axis with respect to the ball screw 19, the surface portion of each bearing stand 21 incorporating a bearing B ₄ at both ends (P _5), and a ball nut, wherein the X-axis ball screw 19 screwed to the ball nut 22 is incorporated This is the surface portion (P ₆ ) of the holder 18. The vibration sensor S detects any one of displacement, speed, and acceleration of the vibration, and detects the magnitude (strength) of the vibration based on the value thereof. Alternatively, it is said that it is better to measure the acceleration. The vibration data detected by the vibration sensor S is input to the measuring amplifier 32 of the sizing device L (see FIG. 4).
[0020]
On the other hand, the measuring amplifier 32 of the sizing device L incorporates (installs) vibration analysis software for analyzing the vibration data detected by the vibration sensor S attached to the rotating part, and also provides the user with the information. By selection, each contact of a plurality of vibration levels proportional to the magnitude (strength) of the vibration is preset and input. That is, in the example shown in FIG. 5, the vibration level is divided into four stages. Levels 1 and 2 are all vibrations in the “tolerable range”. The difference between the levels 1 and 2 is that level 1 has less vibration than level 2, so there is no need for “parts replacement preparation” However, at level 2, this is a necessary point. In any case, an output display to that effect is displayed on the display unit 35 of the measuring amplifier 32, and the operation of the machine is continued. Level 3 is the magnitude of the vibration that requires “component replacement”, and the output is displayed on the display unit 35 of the measuring amplifier 32, and the operation of the machine is continued. Level 4 is a case such as when a strong earthquake occurs, and an emergency stop signal is output. This signal is input to the control unit 23 of the cylindrical grinding machine K, and the operation of the machine is stopped emergencyly. Is displayed on the display unit 35 of the measuring amplifier 32. The setting of each vibration level for the vibration analysis software can be set by selecting an optimum value for each user or for each workpiece.
[0021]
Thus, the level of vibration in rotating sites vibration sensor S is mounted, the display unit 35 of the measuring amplifier 32, and always appears in the machine of the display screen, in reality, the bearing B ₁ and the grindstone shaft of the spindle 5 damage of the bearings B ₃ 15 causes, most often frequent vibration may result. Thus, the operator, the rotating component is deteriorated, such as bearings B ₁ .about.B _4, when the damage occurs, since the effect can be detected in advance, performing the replacement of the defective parts before the processing failure occurs Therefore, high precision grinding can be maintained. When the vibration level is high, the content of the defect corresponding to the vibration level is displayed, so that preparation for component replacement or the like can be performed in advance. Further, when a strong vibration that makes it difficult or impossible to continuously operate the machine due to a strong earthquake or the like occurs, the vibration analysis software outputs the signal as an emergency stop signal and inputs the signal to the control unit 23 of the machine. The operation of the machine is automatically stopped. As described above, since the operation of the machine is automatically stopped when a danger such as a strong earthquake occurs, the safety of the worker is ensured.
[0022]
Further, the cylindrical grinding machine K of the above embodiment grinds the outer periphery of the cylindrical workpiece W, and the sizing device L mounted on the cylindrical grinding machine K moves the workpiece W outside the workpiece W during grinding. In this configuration, the diameter is directly measured by the pair of tracing styluses 33 of the measuring head 31. In contrast, a sizing device mounted on a cylindrical grinder that grinds the inner circumference of a workpiece is referred to as a “single-point measurement method,” and during processing of the workpiece, one point on the inner circumferential surface thereof is processed. Only the internal diameter is measured by measuring only the internal diameter.If vibration analysis software is incorporated into this type of sizing device, the vibration state during processing can be understood in the same Can be performed.
[0023]
【The invention's effect】
The preventive maintenance device according to the present invention incorporates vibration analysis means into a sizing device which is always used for grinding by a cylindrical grinder, and the vibration analysis means allows a vibration sensor mounted on a vibration generating portion of a machine to vibrate. Analyzes the data and knows the failure of the rotating parts in advance, or outputs an emergency stop signal when a strong earthquake or the like occurs and automatically stops the machine, so it is delivered in units of one or several units It can be easily and inexpensively incorporated into a cylindrical grinder to be used.
[0024]
Also, by incorporating the preventive maintenance device according to the present invention into the cylindrical grinder, the damage of the rotating part, or the state of deterioration is displayed on the measurement amplifier of the sizing device on the screen, so that the worker or the person in charge of machine maintenance, It is possible to plan the preparation for component replacement (replacement schedule), and to maintain high-precision grinding without causing processing defects. In particular, when machinery exports are large recently, maintenance of machinery in foreign countries is the biggest issue as a manufacturer, but in such a situation, machine maintenance is the responsibility of local maintenance staff. As a result, the number of dispatch opportunities for manufacturers is reduced.
[0025]
Further, if excessive vibration occurs due to a strong earthquake or the like, the emergency stop signal is output by the vibration analysis means and input to the control unit of the machine, so that the machine is emergency stopped. Grinding can be performed with care.
[Brief description of the drawings]
FIG. 1 is a schematic plan view mainly showing a rotating part of a cylindrical grinding machine K.
FIG. 2 is a partially cutaway view as seen from the direction of the arrow U in FIG. 1;
FIG. 3 is a view taken in the direction of the arrow V in FIG.
FIG. 4 is a principle diagram of a sizing device L in which a preventive maintenance device N according to the present invention is incorporated.
FIG. 5 is a diagram showing a relationship between a vibration level and an output display.
FIG. 6 is a conceptual diagram of a “continuous monitoring system”.
[Explanation of symbols]
B _{1 to} B ₄ : Bearing K: Cylindrical grinder L: Sizing device N: Preventive maintenance device P _{1 to} P ₆ : Attachment site of vibration sensor S: Vibration sensor W: Workpiece 5: Spindle (rotating part)
8: Z axis ball screw (rotating part)
15: Grinding wheel shaft (rotating part)
19: X-axis ball screw (rotating part)

Claims (2)

Measure the amount of grinding of the workpiece during grinding, and in a cylindrical grinding machine equipped with a sizing device that issues a grinding end signal when it reaches the finish dimensions,
It is characterized by comprising a vibration sensor attached to a rotating part such as a main shaft and a grinding wheel shaft, and vibration analysis means incorporated in a measuring amplifier of the sizing device and capable of analyzing vibration data measured by the vibration sensor. Preventive maintenance device for cylindrical grinders. When the vibration value analyzed by the vibration analysis means is an excessive value including the time of occurrence of a strong earthquake, an emergency stop signal for stopping the cylindrical grinding machine is issued from the measuring amplifier of the sizing device, Preventive maintenance device for cylindrical grinders.

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