JP3585619B2 - Measuring instrument inspection method and inspection device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inspection method and an inspection apparatus for an inspection device for inspecting a measurement device for measuring a dimension of an object to be measured.
[0002]
[Prior art]
Conventionally, when measuring the bore diameter of an engine, as shown in FIG. 6, a measuring head 81 as a measuring device is used. The measuring head 81 includes a cylindrical neck portion 82 and a head portion 83 provided at a lower end of the neck portion 82. The head portion 83 has four electric micrometers 84 as detectors. Is provided.
[0003]
As shown in FIG. 7, the electric micrometer 84 includes a detector main body 85 and a probe 86 protruding from the detector main body 85. A core 88 is provided. The detector main body 85 is provided with a differential transformer 91 as detection means including a primary coil 89 and secondary coils 90 surrounding the core 88, and the differential transformer 91 includes: The displacement amount of the core 88 is converted into an electric signal, and is output via a cable 92 extending from a base end of the detector main body 85.
[0004]
The spindle 87 is provided with a stopper 93 at the distal end on the tracing stylus 86 side, and a nut 94 at the proximal end. The stopper 93 is provided with a diaphragm 95 whose edge is fixed to the detector main body 85, and an air chamber 96 is formed at the distal end of the diaphragm 95. The air chamber 96 communicates with a pipe 98 provided at the base end of the detector main body 85 via a communication path 97, and pressurized retract air flows through the pipe 98 and the communication path 97. A counter-biasing means is formed such that when sent into the air chamber 96, the measuring element 86 is retracted by the pressure of the retract air. Further, leaf springs 99, 99 as biasing members whose edges are fixed to the detector main body 85 are provided on the distal end side and the proximal end side of the spindle 87, respectively. It is biased toward the tip.
[0005]
Each of the leaf springs 99 has the same shape, and is formed of a disk-shaped member having a thickness of 0.15 mm as shown in FIG. In the leaf spring 99, a circular through hole 100 through which the spindle 87 penetrates is formed at the center, and first and second arc-shaped first and second arcs facing each other are formed on a concentric circle centered on the through hole 100. Slits 101 and 102, third and fourth slits 103 and 104, and fifth and sixth slits 105 and 106 are alternately formed at equal intervals. The first and second slits 101 and 102 and the fifth and sixth slits 105 and 106 define an X-axis 107 and a Y-axis 108 that divide the leaf spring 99 vertically and horizontally from the center. The third and fourth slits 103 and 104 are formed symmetrically with respect to the X axis 107 with the Y axis 108 interposed therebetween. Thereby, the spindle 87 is configured so as to prevent the spindle 87 from shifting in the left-right direction when moving in the up-down direction.
[0006]
When the measuring head 81 is used on a production line, inspection and adjustment are performed at predetermined time intervals. That is, retract air is sent from the pipe 98 into the air chamber 96, and the probe 86 is retracted by this pressure. Then, as shown in FIG. 5, after being inserted into the zero master 109 having the reference diameter C, the pressure of the retract air is reduced. In this state, the output of the differential transformer 91 is adjusted to be "0" so that a deviation of the reference value due to the use environment or the like can be eliminated.
[0007]
[Problems to be solved by the invention]
However, if the measurement is repeated 100,000 to 400,000 times by the measuring head 81, the leaf spring 99 of the electric micrometer 84 may cause metal fatigue and break. In this case, the output of the differential transformer 91 greatly deviates from "0", and this can be found by the above-described inspection method. However, when only one leaf spring 99 is damaged, When the leaf springs 99, 99 are deteriorated and the urging force is reduced, it is difficult to detect this. In this case, after taking out all the electric micrometers 84,... From the measuring head 81, each of the electric micrometers 84,. . Further, even when breakage or deterioration is found, time is required for repair, so that the downtime of the production line is prolonged and productivity is deteriorated.
[0008]
The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide an inspection method and an inspection apparatus for a measuring instrument that can easily detect abnormality of the measuring instrument.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, in the inspection method of the measuring instrument of the present invention, when measuring the dimensions of the object to be measured, a measuring element urged by an urging member abuts against the wall surface of the object to be measured, What is claimed is: 1. A method for inspecting a measuring instrument for measuring said dimension from the amount of protrusion of said tracing stylus, comprising: a first measuring step of performing measurement using a first master; and a measuring step of measuring the first master. The second measuring step of performing measurement using the second master in which the protruding amount of the child is increased is repeatedly performed at predetermined time intervals, and the first measuring step is repeated. When the amount of increase in the amount of protrusion when shifting to the second measurement step changes in each measurement step, the state of the urging member is determined based on the change amount.
[0010]
That is, the first measurement step by the first master and the second measurement step by the second master are continuously performed, and the measurement at the time of shifting from the first measurement step to the second measurement step is performed. The increase amount of the tracing stylus in the measuring instrument is defined as the first measurement result. Then, after a lapse of a predetermined time, the first step and the second step are continuously performed, and the amount of increase of the tracing stylus at the time of shifting from the first measurement step to the second measurement step is 2 The result of the first measurement is compared with the result of the first measurement.
[0011]
At this time, if the urging member for urging the tracing stylus is normal and its urging force does not change, the amount of protrusion of the tracing stylus matches in the first measurement and the second measurement. , Both measurement results have the same value. Further, when the urging member is damaged or deteriorated and the urging force is reduced at the time of the second measurement, the amount of protrusion of the tracing stylus is smaller than that at the time of the first measurement. For this reason, the second measurement result has a smaller value than the first measurement result. Thus, by measuring the change between the first measurement result and the second measurement result, the change with time of the urging member is determined based on the change amount of both measurement results.
[0012]
Further, when measuring the dimension of the object to be measured, the inspection device of the present invention abuts the measuring element urged by the urging member against the wall surface of the object to be measured, and measures the dimension from the protrusion amount of the measuring element. A first pre-measurement for performing measurement using a first master and an increase in the amount of protrusion of the tracing stylus in a state where the first master is measured. Storage means for storing an increase in the amount of protrusion between the first and second pre-measurements when the second pre-measurement of performing measurement using the second master is performed continuously; and After a lapse of a predetermined time, when a first post-measurement using the first master and a second post-measurement using the second master are continuously performed. The amount of increase in the amount of protrusion between the first and second post-measurements and stored in the storage means. Comparing means for comparing with the increasing amount, and when the increasing amount stored in the storage means and the increasing amount measured after a predetermined time do not match, the comparing means based on the difference between the two increasing amounts. Output means for outputting a notification signal indicating this.
[0013]
When the measuring device is inspected by this inspection apparatus, the first pre-measurement by the first master and the second pre-measurement by the second master are continuously performed at the first measurement. Then, the increment of the tracing stylus between the first and second pre-measurements is stored in the storage means. When the second measurement is performed after the elapse of the predetermined time, in detail, the first post-measurement by the first master and the second post-measurement by the second master are continuously performed. When the measurement is performed, the increase amount of the tracing stylus during the first and second post-measurements is compared with the increase amount stored in the storage unit by the comparison unit.
[0014]
At this time, if the urging member for urging the tracing stylus is normal and its urging force does not change, the amount of protrusion of the tracing stylus matches in the first measurement and the second measurement. The increase amount measured at the second time and the increase amount measured at the first time have the same value. Further, when the urging member is damaged or deteriorated and the urging force is reduced at the time of the second measurement, the protruding amount of the tracing stylus is smaller than that of the first measurement. Is smaller than the first increase. Thus, by comparing the change between the first increase and the second increase, the change with time of the urging member is determined based on the change, and the notification signal indicating the change is determined. Output from output means.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an inspection apparatus 1 according to an embodiment of the present invention. The inspection device 1 is connected to a sequencer that performs control when measuring a bore diameter of a manufactured engine, and is connected to a control device 2 connected to the sequencer (not shown) and to the control device 2. And an air circuit 3.
[0016]
As shown in FIGS. 6 to 8 of the conventional example, the inspection apparatus 1 includes an electric micrometer 84 (detector) incorporated in a measuring head (measuring device) 81 for measuring the bore diameter,. Is connected. The electric micrometer 84 includes a detector main body 85 and a measuring element 86 protruding from the detector main body 85. A spindle 87 connected to the measuring element 86 has a leaf spring 99 as an urging member. 99 urges the distal end. At the center of the spindle 87, a core 88 is provided. On the detector main body 85, a differential transformer as a detecting means comprising a primary coil 89 and secondary coils 90, 90 surrounding the core 88 is provided. A vessel 91 is provided. The differential transformer 91 converts the displacement amount of the core 88, that is, the protrusion amount of the tracing stylus 86 into an electric signal, and converts the electric signal via a cable 92 extending from the detector main body 85. It is configured to output to the control device 2 of the inspection device 1.
[0017]
A diaphragm 95 whose edge is fixed to the detector main body 85 is provided at the tip of the spindle 87, and an air chamber 96 is formed at the tip of the diaphragm 95. The air chamber 96 communicates with a pipe 98 provided at a base end through a communication passage 97 formed in the detector main body 85, and the pipe 98 is connected to the air circuit 3 of the inspection device 1. ing.
[0018]
The control device 2 includes a CPU 4, a ROM 5, a RAM 6, and a control circuit 7, and the CPU 4 is configured to operate according to the contents of the ROM 5. Further, the CPU 4 is configured to be able to read and write contents stored in the RAM 6 at any time during operation.
[0019]
The air circuit 3 is provided with a branch point 9 for branching the retracted air sent from the air pump 8 into two circuits. A first regulator 11 for reducing the pressure and a first solenoid valve 12 for opening and closing the flow of air sent from the first regulator 11 in response to a drive signal from the control device 2 are provided. Have been. A second solenoid valve 14 that opens and closes the flow of the incoming air in response to a drive signal from the control device 2 is provided to a low-pressure supply circuit 13 as a supply unit that forms the other circuit. A second regulator 15 for reducing the pressure of the air sent from the second solenoid valve 14 is provided. The second regulator 15 joins the high-pressure supply circuit 10 and is connected to the electric micrometer 84.
[0020]
The first regulator 11 is set so as to reduce the pressure of the flowing air to 1.5 to 2.0 kg / cm. When the air is sent to the electric micrometer 84, the first regulator 11 operates normally. The tracing stylus 86 can be retracted against the urging force of the leaf springs 99 in the state. As a result, when measuring the bore diameter of the engine with the measuring head 81, the first electromagnetic valve 12 is opened and the measuring element 86 of the electric micrometer 84 is retracted, so that the measuring head 81 It is configured to be easily inserted into the bore.
[0021]
Further, the second regulator 15 is set so as to reduce the pressure of the flowing air to 0.5 to 0.7 kg / cm, and when the two leaf springs 99 are in a normal state. Is configured such that even when this air is sent to the electric micrometer 84, the probe 86 cannot be retracted. On the other hand, if the two leaf springs 99, 99 are deteriorated, or if one of the leaf springs 99 is damaged by metal fatigue and the urging force is reduced, the tracing stylus 86 resists the urging force. Is configured to be retracted.
[0022]
As shown in FIG. 2, the inspection apparatus 1 configured as described above is configured to perform inspection using a machine master 18 including a zero master 16 and a sensitivity master 17 laminated on the zero master 16. Have been. The inner diameter of the zero master 16 is set to a reference dimension A that matches the design value of the bore diameter at which measurement is performed by the measuring head 81, and the inner diameter of the sensitivity master 17 is an allowable error Is set to a large diameter dimension B slightly larger than the dimension obtained by adding.
[0023]
A specific operation in the present embodiment having the above configuration will be described with reference to the flowchart shown in FIG. The ROM 6 of the control device 2 incorporates a control program for measuring the bore diameter of the engine conveyed on the production line, and a program for automatic operation processing for controlling the inspection device 1. The operation processing routine is configured to be called every hour from the main routine.
[0024]
That is, when the automatic operation process is called, first, a pressure inspection process is performed (S1). As shown in FIG. 4, the output of the differential transformer 91 of each of the electric micrometers 84,... The amount is stored in the RAM (S2), and in the next step S3, a drive signal is output to the second solenoid valve 14 of the low-pressure supply circuit 13 to open the second solenoid valve 14 and set to 0.5 to 0.7 kg / cm. The retracted air is output to each electric micrometer 84,. Then, after inputting the amount of protrusion of the tracing stylus 86 of each electric micrometer 84,... (S4), the low-voltage supply circuit 13 compares the amount of protrusion with the amount of protrusion stored in the RAM. It is determined whether or not the amount of protrusion has changed before and after the output of the retract air (S5).
[0025]
At this time, if both leaf springs 99, 99 for urging the tracing stylus 86 of the electric micrometer 84 are deteriorated, or if one leaf spring 99 is damaged by metal fatigue and its urging force is reduced, Since the tracing stylus 86 is retracted by the retract air supplied from the low-pressure supply circuit 13, it is determined in step S5 that the protrusion amount has changed (YES), and in this case, in the next step S6 It is determined whether or not this variation exceeds 3 μm. If the variation does not exceed 3 μm, that is, if it is within the range of normal operation (YES), a prediction signal indicating that the leaf spring 99 is deteriorating is output to the sequencer (S7), and the next On the other hand, if the change amount exceeds 3 μm, that is, if the change amount is out of the range of the normal operation (NO), the flow branches to step S9 to output a failure signal to the sequencer, and to execute the automatic operation processing routine. Return to
[0026]
Further, when the both leaf springs 99 and 99 are in a normal state, even when the retract air is supplied from the low pressure supply circuit 13, the tracing stylus 86 does not move. In step S5, it is determined that the projection amount does not change (NO), and the process branches to step S8.
[0027]
In step S8, a drive signal is output to the first solenoid valve 12 of the high-pressure supply circuit 10 to open the first solenoid valve 12, and the retract air set to 1.5 to 2.0 kg / cm is supplied to each of the electric micrometers 84, Output to. After inputting the amount of protrusion of the tracing stylus 86 of each electric micrometer 84,... (S10), the amount of protrusion is compared with the amount of protrusion stored in the RAM, and the high voltage supply circuit 10 It is determined whether or not the amount of protrusion has changed before and after the output of the retract air (S11).
[0028]
At this time, if the two leaf springs 99 are normal, the probe 86 is retracted by the pressure of the retract air from the high-pressure supply circuit 10, so that the amount of protrusion changes in step S11. Is determined to have occurred (YES), and the process returns to the automatic operation processing routine. If the protruding amount has not changed, that is, if the tracing stylus 86 does not retreat (NO), some failure has occurred, so the process branches to step S9 and outputs a failure signal to the sequencer. Return to the automatic operation processing routine.
[0029]
In this automatic operation processing routine, it is determined in step S12 whether or not a failure signal has been output. If a failure signal has been output, that is, if a failure has occurred in the electric micrometer 86 ( NO), returning to the main routine. If no failure has occurred (YES), a master measurement process (S13) is executed.
[0030]
In the master measurement process, as shown in FIG. 5, in step S14, the measurement head 84 from which the tracing stylus 86 has been retracted in the pressure inspection process is inserted into the machined master 18 and set on the zero master 16. (See FIG. 2). Then, the pressure of the retract air sent to the electric micrometer 86 is reduced to bring the measuring elements 86,... Into contact with the inner wall surface of the zero master 16 (S15). The amount of protrusion, that is, the output of each of the differential transformers 91, is adjusted to be "0" (S16). As described above, by performing the “0” adjustment every hour, it is possible to eliminate a deviation of the reference value due to a change in the use environment over time.
[0031]
Next, the measuring head 84 is set on the sensitivity master 17 (S17). After calculating the sensitivity position from the amount of protrusion of the tracing stylus 86 at this time (S18), it is determined whether or not the sensitivity position is stored in the RAM. A judgment is made (S19). In the first determination, since the sensitivity position is not stored in the RAM (NO), the process branches to step S20, stores the calculated sensitivity position in the RAM, and returns to the automatic operation process. On the other hand, in the second determination, that is, when the process passes through step 19 after one hour, the sensitivity position calculated from the protrusion amount measured one hour before is stored in the RAM (YES). Then, the process proceeds to the next step S21, where the sensitivity position one hour ago stored in the RAM is compared with the sensitivity position calculated from the protrusion amount at the current time.
[0032]
At this time, if the leaf springs 99 and 99 are normal and the urging force does not change as compared with one hour before, the sensitivity master is determined from the amount of protrusion of the tracing stylus 86 when the zero master 16 is measured. Since the amount of increase in the amount of protrusion of the tracing stylus 86 at the time of measuring 18 coincides with the current time one hour ago and the present, the RAM from which the deviation of the reference value has been eliminated by performing the “0” adjustment, respectively. And the current sensitivity position have the same value. Therefore, in the comparison in step S21, (sensitivity position stored in RAM) = (current sensitivity position) (NO), and the sensitivity position calculated by branching to step S20 is stored in RAM. Return to the automatic operation processing.
[0033]
If the two leaf springs 99, 99 are deteriorated, or if one of the leaf springs 99 is damaged by metal fatigue and the urging force is lower than one hour before, the sensitivity from the zero master 16 is reduced. Since the current increase amount of the tracing stylus 86 at the time of shifting to the master 18 is smaller than one hour before, in the determination of the step S21, (the sensitivity position stored in the RAM)> (the current sensitivity) Position) (YES), and in the next step S22, it is determined whether or not this difference is shifted by 4 μm or more. When the difference is less than 4 μm, that is, within the error range of the measuring instrument (YES), the calculated sensitivity position is stored in the RAM in step S20, and the process returns to the automatic operation process. If it is 4 μm or more, that is, if it exceeds the error range of the measuring instrument (NO), the leaf springs 99, 99 have deteriorated, or dust or the like has adhered to either of the masters 16, 17. Is output to the sequencer (S23), and the process returns to the automatic operation processing routine. When the difference is largely (for example, 10 μm or more), a failure signal may be output to the sequencer.
[0034]
By outputting the failure signal or the prediction signal to the sequencer in this way, not only the damage of the leaf springs 99, 99 but also the deterioration state of the leaf springs 99, 99 can be transmitted. Can be easily recognized. Therefore, even when one of the leaf springs 99 is broken or the biasing force of one of the leaf springs 99 is reduced, the measuring head 81 and the electric micrometer incorporated in the measuring head 81 are not affected. 84,... Can be found without disassembly.
[0035]
Further, by comparing the sensitivity position one hour ago stored in the RAM with the current sensitivity position, the deterioration of the leaf springs 99 over time can be inspected. Thereby, the degree of this deterioration can be determined to predict the time of breakage of the leaf springs 99, 99, and a new measuring head 81 or a new electric micrometer 84,. Can prevent the production line from being stopped for a long time due to the failure of the electric micrometers 84,.
[0036]
In the present embodiment, the method of inspecting the measuring head 81 including the electric micrometer 84 for measuring the bore diameter of the engine has been described. For example, the electric micrometer is arranged so as to surround the object to be measured. In the case of a measuring instrument for measuring the external dimensions, the inspection can be performed using a first master and a second master having a smaller diameter than the first master.
[0037]
In this embodiment, the method of updating the sensitivity position stored in the RAM every hour and comparing the sensitivity position one hour ago with the current sensitivity position has been described. The sensitivity position at the start of the measurement may be stored in the RAM, and this sensitivity position may be compared with each sensitivity position measured every hour thereafter.
[0038]
Further, in the present embodiment, in the automatic operation process, a pressure inspection process for supplying low-pressure retract air to the electric micrometer 84 and a master measurement process for performing measurement using the masters 16 and 17 are performed. Although the abnormality of the leaf springs 99, 99 of the electric micrometer 84 was more accurately inspected, the inspection may be performed only by the master measurement process.
[0039]
【The invention's effect】
As described above, in the inspection method of the measuring device of the present invention, the measurement process in which the first measurement process and the second measurement process are continuously performed is repeated at predetermined time intervals, and the measurement process is performed in each measurement process. The amount of increase in the measuring element of the measuring instrument is measured, and when these measurement results change, it is possible to judge the change over time of the urging member based on the change amount. That is, when the variation is within the error range of the measuring instrument, the biasing member is deteriorated, and when the variation greatly exceeds the error range of the measuring instrument, the biasing member is damaged. Therefore, not only when the urging member is damaged but also when the urging force is reduced due to the deterioration of the urging member, this can be easily found.
[0040]
Therefore, when inspecting a measuring device in which the tracing stylus is urged by a plurality of urging members, when one urging member is damaged or when the urging force of one urging member is reduced Even this can be discovered without disassembling the measuring instrument. In addition, when the measuring device is used in a production line, an abnormality due to the deterioration of the urging member can be found before the urging member is broken, so that a new measuring device is ordered according to the degree of deterioration. This can prevent the production line from being stopped for a long time due to a failure in the measuring instrument.
[0041]
Further, in the inspection device of the present invention, the comparison unit compares the first measured increase amount and the second measured increase amount stored in the storage unit, and based on the difference between the two increase amounts. The change with time of the biasing member is determined, and a notification signal indicating this is output from the output means. For example, if the difference between the two increments is within the error range of the measuring instrument, a notification signal indicating that the biasing member has deteriorated, and the difference between the two increments greatly increases the error range of the measuring instrument. If it exceeds, a notification signal indicating that the urging member has been damaged is output from the output means. Thus, as described above, not only when the urging member is broken and the urging force is lost but also when the urging member is deteriorated and the urging force is reduced, it can be easily found. it can.
[0042]
Therefore, when inspecting a measuring device in which the tracing stylus is urged by a plurality of urging members, when one urging member is damaged or when the urging force of one urging member is reduced Even this can be discovered without disassembling the measuring instrument. In addition, when the measuring device is used in a production line, an abnormality due to the deterioration of the urging member can be found before the urging member is broken, so that a new measuring device is ordered according to the degree of deterioration. This can prevent the production line from being stopped for a long time due to a failure in the measuring instrument.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is a partial cross-sectional view showing a state of an inspection in the embodiment.
FIG. 3 is a flowchart showing an operation in the embodiment.
FIG. 4 is a flowchart showing a pressure inspection process of the embodiment.
FIG. 5 is a flowchart showing a master measurement process of the embodiment.
FIG. 6 is a side view showing a conventional inspection method.
FIG. 7 is a cross-sectional view showing an electric micrometer of a conventional example and the present embodiment.
FIG. 8 is a plan view showing a leaf spring of a conventional example and the present embodiment.
[Explanation of symbols]
1 inspection device 2 control device 4 CPU
5 ROM
6 RAM
7 control circuit 13 low voltage supply circuit (supply means)
16 Zero Master (First Master)
17 Sensitivity master (second master)
81 measuring head (measuring device)
84 Electric micrometer (detector)
86 Contact point 91 Differential transformer (detection means)
99 Leaf spring (biasing member)
A Standard dimensions C Large diameter dimensions

Claims (2)

When measuring the dimensions of the object to be measured, the measuring element urged by the urging member is brought into contact with the wall surface of the object to be measured, and the inspection method of the measuring device for measuring the dimension from the protrusion amount of the measuring element. So,
A first measurement step of performing measurement using a first master, and a second measurement of using a second master in which the amount of protrusion of the tracing stylus in a state where the first master is measured is increased. The measurement step is continuously performed and the measurement step is repeatedly performed at a predetermined time,
When the amount of increase in the amount of protrusion when shifting from the first measurement step to the second measurement step changes in each measurement step, the state of the urging member is determined based on the change amount. A method for inspecting a measuring instrument, characterized in that: When measuring the dimensions of the object to be measured, the measuring element urged by the urging member is brought into contact with the wall surface of the object to be measured, and the inspection device of the measuring device that measures the dimension from the protrusion amount of the measuring element. So,
A first pre-measurement in which measurement is performed using the first master, and a second pre-measurement in which measurement is performed using the second master such that the amount of protrusion of the tracing stylus in a state in which the first master is measured is increased. Storage means for storing the amount of increase in the protrusion amount between the first and second pre-measurements when the pre-measurement is continuously performed;
After a predetermined time, when the first post-measurement using the first master and the second post-measurement using the second master are continuously performed, Comparing means for comparing the amount of increase in the protrusion amount between the first and second post-measurements with the amount of increase stored in the storage means;
When the increase amount stored in the storage unit does not match the increase amount measured after a predetermined time, the comparing unit outputs a notification signal indicating the increase based on the difference between the two increase amounts. Output means;
An inspection device for a measuring instrument, comprising:

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