JPH0481126B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sizing device that is effective for measuring the outer diameter of a workpiece having a recessed portion in a portion of its circumferential surface.

[Conventional technology]

Conventionally, a sensor portion of a sizing device that comes into contact with a workpiece (hereinafter simply referred to as a workpiece) is configured as shown in a broken line frame 60 shown in FIG. That is, the main body 62
is provided with outer cylinders 61 and 63 that are moved up and down depending on the support position of the workpiece 97, and the outer cylinders 61 and 6
3, movable shafts 61 and 63 are inserted through them so as to be elastically movable up and down by springs 42 and 66, respectively. A contact portion 40 consisting of a pair of contacts 41 and 43 is attached to each tip of the movable shafts 61 and 62. The contact portion 40 includes contacts 41 and 43
The distance between them can be converted into an electrical signal and detected as outer diameter information of the workpiece 97. As a configuration for this purpose, a displacement detecting section 90 is provided on the base end side of the movable shafts 61, 63 to output a pulse signal in accordance with the relative displacement of the movable shafts 61, 63. The outer cylinder 65 is connected to a servo motor 79 for vertical driving via a ball screw 81.
Further, the outer cylinder 65 is coupled to an outer cylinder 67 through a series connection of gears 71, 73, and 75. 69
is a rack formed in the outer cylinder 65, on which the first stage gear 71 rolls, and 77 is a rack on which the final stage gear 75 rolls.

In such an apparatus, for example, the outer diameter φDO of a workpiece having a cross-sectional shape having recesses 54 to 57 as shown in FIG. 2a is measured by rotating the workpiece. In this case, the signal D output from the displacement amount detection section 90 has a signal voltage that is
43, that is, a pulse signal corresponding to the cross-sectional shape of the workpiece, and the outer diameter φDO is the distance between the recess 5
It is measured correctly at the position of the outer diameter portions 51 to 53 between 4 and 57.

[Problem that the invention seeks to solve]

For example, when measuring the outer diameter of a workpiece having the cross-sectional shape shown in FIG. 2A using the conventional apparatus described above, the following problem occurs.

When a workpiece 97 whose cross-sectional shape is shown in FIG. 2a is rotated, a signal D obtained from the displacement detection section 90
As shown in FIG. 1B, horizontal portions indicated by sections S1 to S4 and recessed portions indicated by sections F1 to F4 appear corresponding to the shapes 54 to 57 of the circumferential surface.
Therefore, the measurement of the true value φDO of the diameter shown in FIG.
There is a restriction that measurement must be performed at one of the following timings. Moreover, sections S1 and S2
changes when the rotational speed is changed depending on the material of the workpiece 97, and the number of recesses 54 to 57 may change depending on the type of workpiece. It becomes difficult to detect the position.

Therefore, even if the type of workpiece with recesses changes, the rotational speed changes, or the number of recesses changes, the timing of measurement can be easily determined using only the type data that determines the type of workpiece. The purpose of the present invention is to provide a sizing device that can detect and automatically measure the outer diameter accurately.

[Means for solving problems]

In the present invention, a circular workpiece having a predetermined number of recesses formed on its circumferential surface is rotated at a constant angular velocity around the center of the circle, and the outer circumference of the workpiece is measured to measure the outer diameter of the workpiece. a pair of contacts elastically in contact with the work piece; a displacement detection unit that detects the relative displacement of the pair of contacts and outputs a signal; A sizing device comprising: a signal processing section for determining an outer diameter; and a data input section for inputting type data corresponding to the type of the workpiece; a recess detection section that detects a fall or a rise of a signal at the recess by comparing the amount of change in the signal obtained by the amount detection section at a predetermined time interval with a preset setting value; and the recess detection section a period detection section that calculates the period between the recesses detected by the period detection section; and a period detection section that calculates the period between the recesses detected by the period detection section and the dimension measurement based on the recess according to the period determined by the period detection section and the type data inputted at the data input section. A sampling timing derivation unit that calculates a sampling timing; and a measurement unit that samples the signal from the displacement amount detection unit at the sampling timing of dimension measurement based on the recess determined by the sampling timing derivation unit. This is a sizing device characterized by the following.

[Effect]

The displacement detecting section of the present invention rotates around the center of a circle of a circular workpiece, thereby producing a pulse signal corresponding to the circumferential cross-sectional shape of the workpiece. Since the low level side of this signal corresponds to the recess, the recess detecting section detects the fall of the low level of the pulse signal or the rise from the low level side to detect the recess. The period detecting section determines the period of the recess based on the time interval at which the recess is detected. On the other hand, since the data input section instructs the type of the workpiece using the type data, the sampling timing derivation section determines the type of the workpiece at a predetermined distance from the detection point of the concave portion based on the type data and the period of the concave portion. It is possible to find the sampling timing corresponding to

The workpiece type data is, for example, combination data of the period T1 of the recesses and the sampling timing, or the number or size of the recesses. The sampling timing is the rising start point or falling start point (hereinafter referred to as the UP point) of the signal D shown in Figure 2b.
The waiting time t (Fig. 2
In b, the rising edge is based on UP11). Such a waiting time t can be easily calculated by finding the period T1 of the low level signal corresponding to the recess. In the latter embodiment, a measurement condition setting table is used to tabulate the period T1 and standby time t for each rotation speed according to the type of workpiece. In addition, for example, the period T1 and the waiting time t
It is also possible to use the waiting time ratio R, which is the ratio of . In this case, the waiting time t can be found by multiplying the detected period T1 by the R described above.

The method of detecting the UP point and the DW point is as follows:
For example, when the levels of the signal D input at times TA and TB are SA and SB, the difference between SA and SB is
The absolute value of S0 is set in advance, and the judgment width SW (SW is a positive value) is used as a criterion for rising and falling.
It can be detected by checking the polarity of S0 and the polarity of S0.

The measurement unit corresponds to the dimensions of the workpiece by inputting the information on the sampling timing obtained by the derivation unit and inputting a signal from the displacement detection unit at the sampling timing based on when the recess is detected. Outputs the signal.

〔Example〕

Hereinafter, the present invention will be explained in detail based on specific examples. FIG. 1 is a block diagram illustrating a sizing device according to a specific embodiment of the present invention.

The slide device includes outer cylinders 65 and 67 that slide against the main body 62, and the outer cylinder 65 is connected to a ball screw 81.
a servo motor 79 for moving via the servo motor 79, and movable shafts 61, 63 that are elastically fixed to the outer cylinders 65, 67 by the tension of a spring 42, respectively.
and a gear 7 for moving the rack screws 69, 77 disposed outside the outer cylinders 65, 67 in relative directions.
1, 73, and 75. Also, the contact part 40
consists of contacts 41 and 43, which are disposed at the tips of movable shafts 61 and 63, respectively.

The displacement detection unit 90 detects the relative movement when a magnetic reader disposed on the bracket 64 that moves together with the movable shaft 61 and a magnet scale disposed on the movable shaft 63 move relative to each other. It is an electrical circuit that emits a signal in response to the

The signal processing section 10 includes a pulsing circuit 11 that shapes the waveform of the signal input from the displacement amount detection section 90.
, an up-down counter 12 that counts the pulse signal inputted from the pulse generator 11 including its sign, and an arithmetic processing section 13 having the functions of a period detection section, a derivation section, and a measurement section. .

The arithmetic processing unit 13 includes a CPU 131, a ROM1
32 and RAM 133.

A workpiece 97 is held in the chuck of the main shaft of the polishing machine, and its surface is being polished.

The operation of the sizing device with the above configuration is shown in Figures 2a and 2b.
This will be explained with reference to FIGS. 4a and 4b.

In this embodiment, the recesses 54 to 57 shown in FIG.
Measure the outer diameter φDO of the workpiece 97. FIG. 2b shows a signal D output from the displacement amount detection section 90 when the workpiece 97 is rotated,
The vertical axis shows the signal voltage corresponding to the diameter, and the horizontal axis shows the passage of time. The signal voltage D0 corresponds to the true value of the diameter of the workpiece 97, and two sections S1 and S2 appear during one revolution of the workpiece 97.

FIG. 3 is a measurement condition setting table showing the period T1 of the signal D determined from the rotation period of the workpiece 97 and the waiting time t. For example, when x11 is detected as the value of period T1 for a processed product of type W1, y11 is selected as the waiting time t.

The sizing device is activated by a measurement command from the numerical control device 20, and the slide device moves the contact portion 40 in the direction of contacting the outer diameter of the workpiece 97. After contacting the outer diameter, the movement is stopped at a position where the movable shaft 61 and the outer cylinder 69 reach a predetermined relative position.

The displacement detection section 90 outputs a signal corresponding to the displacement to the signal processing section 10 in accordance with the relative movement of the movable shaft 63 and the movable shaft 65.

The pulsing circuit 11 of the signal processing section 10 converts the input signal D into a pulse signal having a predetermined shape, and outputs the pulse signal to the up-down counter 12. The up-down counter 12 counts the input pulses, and the count result is output to the arithmetic processing section 13.

The process by which the arithmetic processing unit 13 detects the true value φDO, which is the outer diameter of the workpiece 97, will be explained with reference to the flowchart of FIG. 4 showing the computer processing.

In response to a measurement command from the numerical control device 20, the CPU 131 of the sizing device starts execution from step 100.

In step 100, the up-down counter 12 is activated, and in the next step 102, the CPU 131
The type number Wm being processed is input from the numerical control device 20. Steps 104 to 110 are a routine for detecting the period of the input signal.

In step 104, for example, one DW point caused by the recess 54 is detected, and in step 106, a measurement counter is started. Then step 108
When two points DW are detected at , the value of the measurement counter at that time gives the period T1 of the recess.
Therefore, in the next steps 110 and 112, a waiting time t corresponding to T1 is selected and set from the ROM 132 to prepare for sampling. Step 114 resets the measurement counter.

Steps 116 to 122 are steps for finding the sampling timing, and after detecting the UP point, the waiting time t is counted. In steps 124 to 128, the signal D is sampled, the finishing target DS is inputted from the RAM 133, the D and the DS are compared, and when it is determined that the value of the D is equal to the true value DS, , the process proceeds to the next step and a processing completion signal is output, but when it is determined that the D and the DS are not equal, the process jumps to step 132, and in steps 132 to 138, the value of the counter is used, After intermittent counting and detecting the period for the next sampling, the process jumps to step 116.

In this way, in this embodiment, the diameter of a workpiece having a recess on its circumferential surface can be determined without changing the rotational speed or data, and after detecting the rising point or falling point, the rotational position at which accurate measurement can be performed is indicated. Therefore, measurements can be made accurately and quickly.

〔Effect of the invention〕

According to the present invention, the data input unit inputs type data corresponding to the type of workpiece, and the amount of change in the signal obtained by the displacement detection unit due to rotation of the workpiece is set in advance at a predetermined time interval. a recess detection section that detects a fall or a rise of a signal at the recess by comparing it with a set value set by the recess; a period detection section that calculates a period between the recesses detected by the recess detection section; a sampling timing derivation unit that calculates a sampling timing for dimension measurement based on the concave portion according to the period determined by the period detection unit and the type data inputted by the data input unit; By including a measurement unit that samples the signal from the displacement amount detection unit at the sampling timing of dimension measurement based on the determined recess, the workpiece can be machined even if the workpiece has a recess on the circumferential surface. By simply inputting the type of workpiece, it is possible to measure the outer diameter of a specific location on the workpiece, regardless of the rotation speed, and in the case of mass production, the diameter can be measured quickly, improving machining efficiency.

[Brief explanation of drawings]

Figure 1 is a block diagram showing the configuration of a sizing device according to a specific embodiment of the present invention, Figure 2a is a sectional view of the workpiece used in the above embodiment, and Figure 2b is the Fig. 3 is an explanatory diagram of the signals detected from the workpiece in the embodiment, Fig. 3 is an explanatory diagram of measurement condition settings used in the above embodiment, and Fig. 4 a and b are flowcharts showing an example of the operation of the present invention. It's a chat.

Claims (1)

[Claims] 1. A circular workpiece having a predetermined number of recesses formed on its circumferential surface is rotated at a constant angular velocity around the center of the circle, and the workpiece is rotated at a constant angular velocity to measure the outer diameter of the workpiece. a pair of contacts that elastically contact the outer periphery of an object; a displacement detection section that detects a relative displacement amount of the pair of contacts and outputs a signal; and in response to a signal from the displacement detection section, A signal processing unit for determining an outer diameter of a workpiece; In the sizing device, the signal processing unit includes a data input unit for inputting type data according to the type of the workpiece, and a data input unit for inputting type data according to the type of the workpiece. a recess detection section that detects a fall or a rise of a signal at the recess by comparing the amount of change in the signal obtained by the displacement amount detection section at a predetermined time interval with a preset value; a period detection section that calculates a period between the recesses detected by the recess detection section; and a period detection section that determines the period between the recesses detected by the recess detection section; a sampling timing derivation unit that obtains a sampling timing for dimension measurement; and a measurement unit that samples a signal from the displacement amount detection unit at a sampling timing for dimension measurement based on the recess determined by the sampling timing derivation unit. A sizing device characterized by comprising the following.