JPS6035003B2 - Screw inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for determining the quality of screws, such as the presence or absence of threads, the state of plating, and the length of screws.

For this type of device, throughput per hour is an equally important characteristic than sorting characteristics.

This is because the number of screws manufactured by automatic machines is enormous, and this type of equipment is relatively expensive, so if processing capacity is low, manufacturers will have to install a considerable number of inspection equipment. This would make it unprofitable. The present inventors developed an optical inspection method and succeeded in significantly speeding up the inspection time.

Therefore, if it were possible to process the screws by feeding them and taking them out, the processing capacity could be dramatically improved. In order to speed up screw feeding as much as possible, we developed a method in which a disk with notches at regular intervals on its outer circumference is continuously rotated, and the screws lined up in the notches of this rotating disk are inspected. With this method, as long as the screw is completely fed into the notch in the disk, the reliability of sorting is improved compared to any conventional method.
Additionally, processing power has also improved. However, it is extremely difficult to feed screws one by one into the notches of a continuously rotating disk. This is because the supply guide that feeds the screws into the disc has the screws lined up without gaps, so if the supply guide were connected directly to the outer periphery of the disc, the screws would get caught between the notches. It was. It is assumed that by shortening the interval between the notches, the feeding of the screw from the supply guide to the notch becomes smoother. is larger than the threaded portion, and is absolutely necessary in order to more clearly identify which thread is out of specification. If the disk is not rotated continuously, but rotated intermittently in synchronization with the feeding of the screw of the supply guide,
Although the screw can be fed smoothly into the notch, this method not only significantly reduces the processing capacity per unit of time, but also has the disadvantage that the device itself becomes significantly complicated.

The present invention was developed to eliminate these drawbacks at once.The important objectives of the present invention are to simplify the structure, provide high throughput, minimize screw clogging, allow extremely smooth transfer, and prevent failures. To provide a screw inspection device which requires less time and effort for maintenance.

Embodiments of the present invention will be described below based on the drawings.

The screw inspection device shown in FIGS. 1 to 3 has a rotating shaft 1
A disk 2 that is supported vertically and rotates continuously in a horizontal plane.
A guide member 3 disposed close to approximately half of the circumference of the disc 2, a supply guide 4 that feeds a screw between the guide member 3 and the disc 2, and a screw at the tip of the supply guide 4. 5
A nozzle 7 that accelerates and sends the screw 5 toward the notch 6 of the disk 2 with an air flow, and a screw inspection means that inspects and removes the screw 5 that is transferred between the disk 2 and the guide member 3. .
As shown in FIGS. 1 and 2, the disk 2 has the following shapes on its circumference:
Triangular notches 6 are formed in which screws are lined up at regular intervals, and the rotating shaft 1 is connected to a variable speed motor via a speed reducer, and is rotated to the right in the figure by the motor.

The spacing between each notch 6 is determined so that even if a screw is fed into an adjacent notch 6, some gap will be created between both screw heads. Therefore, the size of the notches 6 and the spacing thereof are determined to be optimum values depending on the size of the screw to be selected. Therefore, if you are selecting screws of several different standards, it is best to use a replaceable disc. When the guide member 3 approaches the outer periphery of the disc 2, the feeding edge 9 facing the outer periphery of the disc 2 is moved around the outer periphery of the disc 2 so that the screw fed into the notch 6 does not come out of the notch 6. They are curved to have equal or approximately equal radii of curvature, and the leading edges 9 of the brackets are fixed so as to create a gap between them and the outer periphery of the disk 2 that is narrower than the size of the screw. Although the feeding edge 9 of the guide member may contact the outer periphery of the disc 2, it is preferably in a non-contact state so that the disc 2 can rotate more smoothly.

The supply guide 4 has two parts so that the screws 5 can be transferred side by side.
The side walls 10 of the strips are formed in a straight line, narrower than the screw heads and widely spaced apart from the thread portions, and are vibrated to transport the screws 5 side by side. It is connected between the feeding green 9 and the disk 2. The linear supply guide 4 is arranged at an angle of 30 to 80 degrees, preferably 45 to 60 degrees, with respect to the tangential direction of the disk 2 so that the screw to be fed is fed into the notch more smoothly. In addition, the lower part of the side wall 10, as shown in FIG.
The notch is removed so that the threaded portion of the screw 5 can be pressed.

The nozzle 7 blows air onto the screw located at the leading edge of the supply guide to accelerate it, separates the screw at the leading edge from the next screw to be fed, and moves the screw at the leading edge with the air flow to the disk 2. The disk 2 rotates and the supply guide 4
When the notch 6 comes in front of the notch 6, the screw 5 is pushed into the notch 6, and air is injected in the direction of moving the screw 5 toward the notch 6.

The delivery end at the tip of the supply guide 4 is connected to the end of the guide member 3, as shown in FIG. The green feed 9 of the guide member 3 is pushed into the notch 6 by the flow.
sent in between.

In Figures 1 to 3, two nozzles 7 are arranged, the lower nozzle 7 blows air to the threaded part, the upper nozzle 7 blows air towards the screw head, and the upper and lower nozzles 7 also blow air. ,
Press the head of the screw and the threaded part. According to this structure,
Since the screw is fed into the notch 6 in a vertical position,
All the screws are fed into the locks 6 more smoothly. Particularly in the case of screws with long threads, by shifting the lower nozzle downwards, even fairly long screws can be fed out smoothly. The nozzle is connected to a compressor via a valve that adjusts the amount of air blown out.

The screw inspection means includes a thread inspection unit, a plating sensor that inspects the state of plating, and a length sensor that inspects the length of the screw.

As shown in FIG. 4, the thread inspection unit includes a position sensor 1 that is disposed below the guide member 3 and detects when the screw 5 has come to a position where the thread is detected; A photoreceptor 13 receives the light beam emitted from a light source 12 and reflected by the screw thread, which irradiates a light beam onto the thread of the screw 5 fed into a predetermined position at step 11; and a removal sensor 4 that is separated and detects passage of the screw.

The position sensor 1 includes a light source 11a that emits infrared rays or visible light in a direction perpendicular to the screw transport direction;
When the screw 5 comes to the thread detection device, the light beam emitted from the light source 11a is blocked by the screw 5.

Therefore, in a state where the photoreceptor 11b does not detect the incidence of light,
It is detected that the screw 5 has come to the normal position. That is, the light source 11
The light beam emitted from a is irradiated in the radial direction of the disc 2, and when the screw 5 is not between the light source 11a and the photoreceptor 11b, the photoreceptor 11b receives the light and issues a signal to that effect. A light source 12 for irradiating a light beam onto the thread is integrated with a photoreceptor 13, which in the vertical plane containing the position sensor 11 is aligned with the axis of the screw 5, i.e. in the vertical direction, as shown in FIG. The light source 12 irradiates the thread with a light beam from bottom to top.

Since the thread angle of most screws is 60 degrees, the light beam 15 incident on the thread surface at right angles is reflected by the thread surface and changes its direction by 180 degrees to form the incident light. The light beam is incident on the photoreceptor 13 in parallel, and the light beam is received by the photoreceptor 13.

If the screw is not threaded, the light beam 15 emitted from the light source will be reflected upwards on the surface of the screw, as shown by the chain line in FIG. 5, and will not be incident on the photoreceptor 13. Detects that the thread is defective.

The device shown in FIGS. 4 and 5 is configured such that the photoreceptor 13 receives the light beam from the light source 12 when a normally threaded screw is at the detection position. However, on the contrary, it is also possible to use a device in which the photoreceptor receives a light beam from a light source when a non-threaded screw comes to the detection position.

In that case, a light beam may be irradiated onto the thread from diagonally upward to downward, and a photoreceptor may be disposed in the path of the light beam reflected by the threadless surface of the thread. In this arrangement, the light beam will not be incident on the photoreceptor if there is a normal thread. The thread detection operation by the light source 12 and the photoreceptor 13 is controlled by the output of the position sensor 1.

That is, when the position sensor 11 detects that the screw 5 is at the detection position, it is detected whether the screw thread is normal. Therefore, the detection operation of the photoreceptor 13 is performed in synchronization with the output of the position sensor 11. The position sensor has
Anything that can detect whether a screw is in place or not can be used.

The light source can be anything that can emit light such as infrared rays or visible light, such as a light bulb, light emitting diode, laser, or EL lamp. Light-emitting diodes are ideal for this type of use because they are 4-inch, easy to focus a light beam, and have a long lifespan. Alternatively, an optical fiber may be connected to a light bulb or a light emitting diode, and a light beam may be irradiated from the tip of the optical fiber toward the screw.

As the photoreceptor, anything that can detect the light emitted by the light source, such as a phototube, CDS, phototransistor, etc., can be used.

The removal sensor 4 is used to remove a screw whose threads are detected to be defective by the photoreceptor 13 when the screw comes to the removal position.

That is, when transporting the screws 5 side by side, it is more convenient to transport the screws with defective threads by a predetermined distance and then remove them, rather than immediately removing them at the detection position. To achieve this, it is sufficient to detect how many screws are present at the detection position and the removal position, and determine how many screws pass through the removal position to be removed. Therefore, the number of screws that have passed through the position sensor 11 and the number of screws that have passed through the removal sensor 14 are counted separately, and the number of screws that are between the position sensor and the removal sensor is stored in a memory. When the thread sensor detects a thread with a defective thread, it is determined how many threads to pass through the removal sensor 14 to be removed.
The removal sensor 14 controls a valve 16 connected between the removal nozzle 8 and the air source and listens to the valve when the screw that needs removal passes in front of the air nozzle and is removed by the air flow. .

FIG. 6 shows a plating sensor 8 that detects the plating state of a screw, and this plating sensor 18 includes a light source 18a that irradiates a light beam to the center of the groove of the screw head that is least likely to be plated, and a light beam emitted from the light source 18a. The light beam has a photoreceptor 18b that receives the reflected light beam at the bottom of the groove, and a position sensor 19 that detects when the screw has come to the detection position. When the amount of light exceeds a certain amount, it is detected that the screw is completely plated.

Further, FIG. T shows a screw length sensor 17 for detecting the length of the screw, and the length sensors 17 are arranged in two stages, vertically shifted. The length sensor 17 includes a light source 17a and a photoreceptor 17b, and detects the length by detecting whether the screw 5 blocks the light beam. That is, when a screw blocks the light beams of both the upper and lower length sensors 17, it is detected that the screw 5 is too long, and when both light beams are not blocked, it is detected that the screw 5 is too short, and only the upper light beam is blocked. It detects that the length is normal when the The removal process after the plating sensor and length sensor detect a defective screw is that it is removed when it comes to the removal sensor 14, similar to when the thread sensor detects a defective screw.

Therefore, how many screws are present between the removal sensor 14 and the removal sensor 14 is detected by each path sensor and memory. As described above, the screw inspection device according to the present invention uses a nozzle to blow air onto the screw at the tip of the supply guide, the airflow also presses the screw against the outer periphery of the disc, the disc rotates, and the supply guide The screw is pushed into the notch when the notch is engaged in front of the notch, and is then fed between the guide members while being pushed inside the notch, so the screw is inserted into the disc that rotates extremely smoothly and continuously. It is fed into the notch.

In other words, the screws that are fed side by side by the supply guide are
Only the most advanced screws are accelerated by the airflow, separated from the next screw, and sent into the disk one by one.
Furthermore, the screw that comes into contact with the outer circumference of the disc is pushed through the cushioned airflow until it is fed into the notch, so it is smoothly fed into the notch in the disc. For this reason, the screws are fed into the continuously rotating disk without stopping the rotation of the disk, significantly increasing the throughput per hour, and simplifying the overall structure, and also preventing problems such as screw jamming. It has many advantages, such as greatly reducing the amount of water and making maintenance and handling easier.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view of a screw inspection device showing an embodiment of the present invention, Fig. 2 is an enlarged plan view of main parts of a supply guide and a disk, and Fig. 3 is a diagram showing the supply guide with the guide member removed. Figures 4 and 5 are a cross-sectional view and an enlarged front view of the main parts showing the thread inspection unit, Figure 6 is a cross-sectional view of the plating sensor, and Figure 7 is the length sensor. FIG. 1...Rotating axis, 2...Disc, 3...
... Guide member, 4 ... Supply guide, 5 ... Screw, 6 ... Notch, 7 ... Nozzle, 8 ...
... Removal nozzle, 9 ... Green feeding, 10 ... Side wall, 11 ... Position sensor, 12 ... Light source, 13 ... Photoreceptor, 14 ... Removal sensor, 15...Light beam, 16...Valve, 17...Length sensor, 18...Plating sensor, 19...Position sensor, 20...Position sensor. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1. A disk in which a notch into which a screw is fitted and is transferred is formed on the circumference, and a rotating shaft is vertically supported and rotates continuously, and a part of the circumference of this disk. The feeding edge facing the circumference of the disk is curved to the same or the same radius of curvature as the circumference of the disk, and there is a thread between the feeding edge and the outer circumference of the disk. a guide member forming a gap narrower than the outer diameter of the disk, and a screw supply guide in which a feeder is disposed close to the end of the feed edge to feed the screw between the guide member and the disk. The screw detection device is configured to inspect the quality of the screw when the screw is fed from the supply guide into the notch of the disk and moves along the feeding edge of the guide member, the screw detection device comprising: A nozzle for blowing out air is disposed at the tip of the supply guide, and this nozzle blows out air in the direction of transferring the screw from the delivery end of the supply guide to the end of the feeding edge, and also blows air out from the supply guide. The screw fed into the notch is pressed into the notch by the air flow blown out from this nozzle, and air is blown out in the direction between the guide member and the air flow blown out from this nozzle. The screw is pressed against the outer periphery of the continuously rotating disk, and when the disk rotates and the notch comes to the front of the supply guide, the screw is pushed into the notch, and while it is pushed into the notch, it is fed between the supply guides. A screw inspection device characterized in that it is configured to 2. The screw inspection device according to claim 1, which includes a plurality of nozzles and is configured such that the head of the screw and the threaded portion are pressed separately by the air flow blown out from the nozzles. 3. The screw inspection device according to claim 1, wherein the supply guide is linear and transports the screws by vibration. 4 The supply guide is attached to the disc at a angle of 45 to 8 in the tangential direction.
Claim 1 connected to form an angle of 0 degrees
Screw inspection device as described in section.