JP3129503B2 - Dimension inspection method for ring-shaped seal members - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method and apparatus for measuring the inner diameter, outer diameter and sectional diameter of a ring-shaped seal member.

[0002]

2. Description of the Related Art As a method or apparatus for automatically measuring the inner diameter, outer diameter, and cross-sectional diameter of a ring-shaped seal member, a planar image of the ring-shaped seal member taken by a CCD (Charge Coupled Device) is image-processed. The CCD image processing and inspection device that measures the inner diameter, outer diameter, and cross-sectional diameter of the ring-shaped seal member, and the ring-shaped seal member that is placed and moved on a belt conveyor is measured by a CCD line sensor and detected by the line sensor. A method for measuring the inner and outer diameters of a ring-shaped seal member by measuring the maximum values of the inner and outer dimensions of a linear image of the ring-shaped seal member has been proposed or put into practice.

[0003] Further, as a device for measuring the size of a moving object in the moving direction by a conveyor device such as a belt conveyor,
Forming a laser light curtain with the laser light and a pair of plane mirrors,
An apparatus that detects an object by the light curtain and counts the number of pulses generated in proportion to the amount of movement of the transport device during the period in which the object is detected by the light curtain to measure the dimension of the object in the moving direction. Is disclosed in JP-A-51-24258.

[0004] Since only the outer diameter in the moving direction can be measured by this device, it is necessary to measure not only the outer diameter but also the inner diameter or the cross-sectional diameter or both dimensions at the same time. Cannot use this device.

[0005]

The CCD image processing and inspection apparatus described above is expensive, and a large number of CCD image processing and inspection apparatuses are used to measure the dimensions of a large number of ring-shaped seal members and judge the quality or detect different sizes. If such a device is installed, there is a regret that a large amount of equipment cost is required. In addition, handling when changing the size of the inspected ring-shaped seal member is troublesome, and in that case, there is a drawback that the lens system often needs to be changed, which is not suitable for dimensional inspection of small lot products. .

A dimensional inspection apparatus using the above-described CCD licensor can be assembled at a lower cost than the above-described CCD image processing inspection apparatus, but is expensive. In addition, handling at the time of size change is not easy, for example, the lens system needs to be changed.

Further, since both of the above-mentioned devices measure based on the video signal of the CCD, a method of illuminating the ring-shaped seal member also needs to be devised in order to measure with high accuracy.

The present invention has been made in view of the above points, and the present invention does not use a CCD image sensor.
The present invention proposes a novel method and apparatus for inspecting dimensions of a ring-shaped seal member which can be manufactured at low cost and which is easy to handle.

[0009]

In order to achieve the above object, a method for inspecting the size of a ring-shaped seal member according to the present invention is arranged such that the ring-shaped seal member is placed on a conveyor and moved, and is proportional to the amount of movement of the conveyor. Generate a number of pulses,
A belt-shaped laser parallel light beam having a width larger than the cross-sectional diameter of the ring-shaped seal member is projected at right angles to the moving direction of the conveyor and so that the width direction of the light beam is substantially perpendicular to the conveyor surface, and is projected onto the conveyor. The cross-sectional diameter of the ring-shaped seal member is detected from a change in the amount of light received on the light- receiving side of the light beam caused by a part of the laser parallel light beam being blocked by the mounted and moved ring-shaped seal member. The outer diameter of the ring-shaped seal member is detected by counting the number of pulses generated while a part of the light beam is blocked by the ring-shaped seal member.

The dimensional inspection apparatus for a ring-shaped seal member according to the present invention comprises a conveyor for placing and moving the ring-shaped seal member, and a belt-like laser parallel light beam having a width larger than the cross-sectional diameter of the ring-shaped seal member. A light projector that emits light at right angles to the moving direction of the light beam so that the width direction of the light beam is substantially perpendicular to the conveyor surface, and a light receiver that receives the laser parallel light beam facing the light emitter and the conveyor, A pulse generator that generates a number of pulses proportional to the amount of movement of the conveyor, and a ring formed from a change in the amount of light received by a light receiver that occurs when part of the laser parallel light beam is shielded by a ring-shaped seal member moved by the conveyor. A cross-sectional diameter detecting means for detecting a cross-sectional diameter of the ring-shaped sealing member, which is generated while a part of the laser parallel beam is shielded by the ring-shaped sealing member Is characterized in that consists of an outer diameter detecting means for detecting the outer diameter of the ring-shaped seal member by counting the number of serial pulses.

[0011]

The operation of the method and the apparatus for inspecting the dimensions of the ring-shaped seal member of the present invention having the above-described structure will be described with reference to FIGS. 2, 3, 4 and 5. FIG. 2 is an explanatory diagram illustrating light blocking by an O-ring, which is an example of a ring-shaped sealing member for a laser parallel light beam.

As described above, the laser parallel light beam L is a belt-like parallel light beam having a width b larger than the cross-sectional diameter W of the O-ring, and is perpendicular to the moving direction of the conveyor 2 indicated by an arrow A and perpendicular to the direction. The light beam L is projected so that the width b of the light beam L is substantially perpendicular to the conveyor surface 21.

The O-ring 1 placed on the conveyor and moving in the direction of arrow A crosses the curtain of the projected laser parallel light beam L as shown in FIG. 2, FIG. 3, FIG. 4, and FIG. From the time when the leading end in the moving direction of the O-ring 1 starts traversing the light beam L as shown in FIG. 3 until the rear end in the moving direction of the O-ring 1 traverses the light beam L as shown in FIG. In other words, while the O-ring 1 moves a length corresponding to the outer diameter OD, a part of the laser parallel light beam L is shielded by the O-ring 1.

Therefore, it is detected that the amount of light received by the optical receiver, for example, the amount of received laser parallel light, has changed due to light blocking by the O-ring, and the amount of movement of the conveyor during the period of light blocking by the O-ring is measured. Thus, the outer diameter OD of the O-ring can be measured. In the present invention, the above-described measurement of the amount of movement of the conveyor is performed by transmitting a number of pulses proportional to the amount of movement of the conveyor and counting the number of pulses transmitted during the light-shielding period by the O-ring. . In order to improve the accuracy of the outer diameter measurement described above, it is desirable to reduce the lateral dimension (thickness) t of the laser beam L as can be understood from FIGS.

Next, the measurement of the cross-sectional diameter W of the O-ring will be described. The amount of light received before the O-ring 1 shown in FIG. 2 starts traversing the laser beam L and a part of the laser beam L shown in FIG. Since the difference from the light reception amount when the light is completely shielded by the O-ring 1 is an amount proportional to the cross-sectional diameter W of the O-ring 1, the difference is detected and measured to determine the cross-sectional diameter W of the O-ring. Can be measured. In the simplest case, the sectional diameter W is determined by the difference between the maximum (FIG. 2) and the minimum (FIG. 4) of the received light amount.
Can be measured.

If the outer diameter OD and the cross-sectional diameter W of the O-ring are measured as described above, the inner diameter ID of the O-ring can be calculated from the relation of ID = OD−2W. By providing a circuit and performing calculations, the inner diameter of the O-ring can also be measured.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in more detail below by way of example and with reference to the drawings. FIG. 1 is an explanatory view illustrating an embodiment of an O-ring dimension inspection apparatus which is an example of a ring-shaped seal member of the present invention.

In FIG. 1, reference numeral 1 denotes an O-ring whose size is to be inspected, which is mounted on a belt conveyor 2 made of, for example, a steel belt, and is moved in the direction of movement of the belt conveyor 2 as indicated by an arrow A. Drive wheels 3 of the belt conveyor are driven by a pulse motor 5 via a speed reducer 4. 6
Is a pulse oscillator for generating a pulse for driving a pulse motor.

A light projector 7 and a light receiver 8 are provided on both sides of the belt conveyor 2 so as to oppose each other with the belt conveyor interposed therebetween. From the projector 7, a band-shaped laser parallel light beam L having a width larger than the cross-sectional diameter of the O-ring 1 whose size is to be inspected is in a direction perpendicular to the moving direction of the conveyor indicated by an arrow A and in a direction of the width b of the light beam L. Is the conveyor surface 2 of the belt conveyor 2
1 (FIG. 2).

The above-mentioned laser beam L is converted from a laser beam emitted from a semiconductor laser in the light projector into a parallel beam by a lens unit and passed through an elongated slit provided substantially perpendicular to the conveyor surface 21. Can be obtained by For example, the vertical dimension of the slit is 1
0 mm and the lateral dimension is 1 mm or less, preferably 0.5 mm or less.

The light receiver receives the above-mentioned laser beam L, detects a change in the amount of light received when a part of the beam L is blocked by the O-ring 1 on the belt conveyor 2, and outputs the detection output. Control the opening and closing of the gate 9. That is, as shown in FIG. 3 described above, when the O-ring 1 starts to block a part of the parallel laser beam and the amount of received light decreases, this is detected and the gate 9 is opened, and as shown in FIG. When the amount of received light is increased after the interruption of the light beam L due to this, the gate 9 is closed by detecting this.

Therefore, the pulse generated by the pulse oscillator 6 is input to the counting circuit 10 only while a part of the laser beam L is shielded by the O-ring 1. Since the belt conveyor 2 is driven by the pulse motor 5 driven by the pulse of the pulse oscillator 6, the amount of movement of the belt conveyor is proportional to the number of pulses. Outer diameter OD of 1
Is measured and displayed and recorded on the display / recorder 11.

The light receiving signal of the light receiver 8 is transmitted to a section diameter measuring circuit 12.
In the circuit, the difference between the amount of light received before the laser beam L is blocked by the O-ring 1 and the amount of light received when the beam L is blocked by the O-ring 1 is detected. The sectional diameter W of the ring is measured, and this is displayed and recorded by the display / recorder 11. The detection of the difference in the amount of received light can be easily performed by means such as delaying the received light signal before the light is shielded.

A signal relating to the outer diameter OD of the O-ring, which has been counted by the above-described counting circuit 10, and a signal relating to the cross-sectional diameter of the O-ring, which has been measured by the above-described cross-sectional diameter measuring circuit, are input to a calculation circuit 13. , O-ring inner diameter ID
Is calculated, displayed on the display / recording device 11, and recorded.

In the above description, the outer diameter of the O-ring,
The inner diameter and cross-sectional diameter were measured individually and displayed and recorded. However, when dimensional inspection of a large number of O-rings, the outer diameter, inner diameter and cross-sectional diameter of each O-ring were measured and displayed and recorded. However, it is not always necessary to determine whether or not these dimensions are within the allowable tolerance. Alternatively, in addition to such determination, for example, one O-ring is sampled for every 50 O-rings, and the outer diameter, the inner diameter, and the cross-sectional diameter of the sampled O-ring are measured and displayed / recorded. You can also do so. Further, when the apparatus of the present invention is used to detect and remove a different size product that may be mixed,
The calculation circuit 13 can be omitted. The counting circuit, the measuring circuit, and the like can be appropriately designed according to the above-described purpose or mode of use.

In the above embodiment, the device or circuit for measuring the outer diameter of the O-ring, the device or circuit for measuring the cross-sectional diameter, and the device or circuit for calculating the inner diameter of the O-ring are respectively provided. Although provided independently, these devices or circuits can be combined into a single device or circuit. In short, according to the above, means to measure the outer diameter from the received light signal,
Means for measuring the cross-sectional diameter and means for calculating the inner diameter may be provided mechanically, and it does not matter in what form they are provided.

Further, in the above embodiment, the pulse for measuring the outer diameter of the O-ring is supplied from the pulse oscillator 6 for driving the pulse motor 5, but the pulse is attached to the rotating shaft of the driven rotary pulley of the belt conveyor. Alternatively, a pulse output of a rotary encoder may be used, or a simple clock pulse that is not related to the operation of the belt conveyor may be used if a constant speed operation of the belt conveyor can be guaranteed. However, if the pulse of the pulse oscillator for driving the pulse motor is used as in the above-described embodiment, a special device and circuit for generating the pulse are not required, so that the device can be manufactured at a lower cost.

[0028]

The method and apparatus for inspecting dimensions of a ring-shaped seal member according to the present invention do not require image sensing and image processing by a CCD or the like, as is apparent from the detailed description of the structure and operation thereof, and the laser parallelism. It can be configured using only elements and functions that can be formed relatively easily and inexpensively, such as detection of a change in light reception due to light being blocked by a moving ring-shaped seal member and oscillation and counting of pulses. Therefore, it can be manufactured at a remarkably low cost as compared with the conventional ring-shaped seal member size inspection apparatus, and the handling when the size of the ring-shaped seal member is changed is simple. The present invention can also be advantageously applied to the dimension inspection of a small lot of ring-shaped seal members.

[Brief description of the drawings]

FIG. 1 is an explanatory view illustrating an embodiment of a dimension inspection device for a ring-shaped seal member of the present invention.

FIG. 2 is an explanatory diagram for explaining light blocking of a laser parallel light beam by an O-ring.

FIG. 3 is an explanatory diagram illustrating light blocking of a parallel laser beam by an O-ring.

FIG. 4 is an explanatory diagram illustrating light blocking of a laser parallel light beam by an O-ring.

FIG. 5 is an explanatory diagram illustrating light blocking of a laser parallel light beam by an O-ring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 O-ring 2 Belt conveyor 5 Pulse motor 6 Pulse oscillator 7 Emitter 8 Receiver 10 Counting circuit 11 Display / recorder 12 Section diameter measuring circuit 13 Calculation circuit L Laser parallel beam

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01B 11/00-11/30

Claims (4)

(57) [Claims] 1. A ring-shaped sealing member is mounted on a conveyor and moved to generate a number of pulses proportional to the amount of movement of the conveyor, and a belt-shaped band having a width larger than the cross-sectional diameter of the ring-shaped sealing member. The laser parallel light beam is projected at right angles to the moving direction of the conveyor and the width direction of the light beam is substantially perpendicular to the conveyor surface, and the laser light is mounted on the conveyor and moved by the ring-shaped seal member. The cross-sectional diameter of the ring-shaped sealing member is detected from a change in the amount of light received on the light- receiving side of the light beam caused by a part of the parallel light beam being blocked, and a part of the laser parallel light beam is blocked by the ring-shaped sealing member. Detecting the outer diameter of the ring-shaped seal member by counting the number of pulses generated during the operation of the ring-shaped seal member. 2. The method according to claim 1, wherein the inner diameter of the ring-shaped seal member is detected from the detected outer diameter and cross-sectional diameter of the ring-shaped seal member. Dimension inspection method for ring-shaped seal members. 3. The method according to claim 1, wherein the pulse proportional to the amount of movement of the conveyor is a drive pulse of a pulse motor for driving the conveyor. 4. A conveyor on which a ring-shaped sealing member is placed and moved, and a belt-shaped laser parallel light beam having a width larger than the cross-sectional diameter of the ring-shaped sealing member is perpendicular to the moving direction of the conveyor and in the width direction of the light beam. Are projected so as to be substantially perpendicular to the conveyor surface, a light receiver facing the light emitter and the conveyor and receiving the laser parallel light beam, and a number of pulses proportional to the amount of movement of the conveyor. A cross-sectional diameter for detecting a cross-sectional diameter of a ring-shaped seal member from a change in the amount of light received by a light-receiving device that is generated when a part of the laser parallel light beam is shielded by a generated pulse generator and a ring-shaped seal member moved by the conveyor. Detecting means;
Outer diameter detecting means for detecting the outer diameter of the ring-shaped seal member by counting the number of pulses generated while a part of the laser parallel light beam is shielded by the ring-shaped seal member. Dimension inspection device for ring-shaped seal members.