JP3088577U - Hammering inspection system for mechanical parts - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To perform a non-destructive, simple, low-cost, and high-accuracy inspection of a connection state of a mechanical component. SOLUTION: A mechanical connection part (1 and 2 are connected in the figure below) to be inspected is placed on a support 3 having a small contact area using a material having a small elastic coefficient such as rubber, and a hammer 5 is provided.
Apply a shock with In this case, the mechanical coupling component continues its inherent free vibration on the support. The vibration is collected by a microphone 7 and the like, and a natural frequency, an attenuation rate, and the like are calculated by a computer 8. If the coupling strength is low, the natural frequency and the damping rate at the time of damping change, and the coupling state can be grasped, and the quality of the coupling section 11 can be determined.

Description

[Detailed description of the invention] [Industrial applications]

 Incorporating this inspection equipment into the production line of mechanical parts and electronic parts eliminates the need for destructive testing and has the advantage of time and economy. But there is an advantage

[Prior art]

 As a method of inspecting the joints on the production line, in the case of joining with screws, measure the change in total length before and after screw tightening, or measure the change in screw length with an ultrasonic axial force meter, etc. Managing power. For rivet, caulking, and bonding, samples are taken out and subjected to destructive inspection to guarantee the overall quality or to perform external inspection. In addition, several hitting tests have been devised, some of which use an accelerometer attached to the sample to measure the vibration and evaluate the maximum value of the vibration when hitting.

[Problems to be solved by the invention]

 The most reliable connection method on the production line is considered to be screw connection.However, the cost of the inspection equipment is high to grasp the accurate axial force, and the inspection time is long. At present, it is technically difficult to inspect the axial force of M6 or smaller screws, as well as there is a problem that inspection has not been performed. Rivets, caulking, and adhesives are inexpensive but require accurate destructive testing to accurately measure strength, in which case the sample product must be discarded, which is wasteful in terms of cost. Naturally, in the case of destructive inspection, 100% inspection is not possible. Therefore, considering production variations, quality cannot be guaranteed sufficiently and it cannot be applied to parts that require reliability. In addition, a method for impact testing has been devised, but the method of attaching an acceleration sensor or the like to a machine part to be inspected requires time and equipment to install the sensor on the machine part, which requires cost and time. In the case of a device that collects sound without installing a sensor on a mechanical part, a method of measuring the maximum value of impact and comparing it with a non-defective product is used for discrimination, but accurate data cannot be obtained. In the present invention, the measurement of free vibration can be performed with a simple measuring device by continuing the natural free vibration, and the value of the natural frequency and decay rate can be evaluated with high accuracy and reliability. Since high nondestructive inspection can be performed, cost can be reduced and quality can be improved. In addition, it has become possible to use inexpensive joining methods such as rivets, caulking, and bonding for parts that could not be used for important joints because of low reliability. It is also possible to inspect mechanical parts for which it was difficult to grasp the connection state of parts and the like.

[Means for Solving the Problems]

 In the present invention, a support 3 and a support made of a material such as rubber for supporting a part in which a mechanical part 1 and a mechanical part 2 to be inspected are connected (in this example, an example connected by a caulking 11) are used. It comprises a jig 4 to be mounted, a hammer 5 for generating an impact sound, a stopper 6 for adjusting the impact force, a microphone 7 for collecting the impact sound, and a computer 8 for analyzing the sound. A support made of a material such as rubber is provided with a projection 9 to reduce the contact area. The jig is used as an inspection jig or a transportation jig. Next, the principle of operation will be described. In such an inspection apparatus, when an impact is applied to a coupled mechanical component to be inspected by a hammer, the mechanical component to be inspected is compared with a mechanical component made of a material such as rubber. Because it is placed on a support table with a small contact area, the inherent free vibration continues more than when rigid support is used. The vibration characteristics of the mechanical parts change depending on the coupling condition. That is, if the coupling strength is low, the natural frequency and the attenuation rate at the time of attenuation change, and the coupling state can be grasped. In the present invention, a mechanical part can be made to continue its inherent free vibration by using a support made of a material having a small elastic modulus such as rubber and having a small contact area and applying a constant impact energy. This makes it easy to measure and obtain accurate and highly reliable data. In addition, the configuration of the apparatus is further simplified when the vibration sensor and the like are not installed on the target mechanical component.

[Action]

 Place the combined machine parts to be inspected on a support base made of rubber, etc., and apply an appropriate impact to the machine parts to be inspected with a hammer etc. and a stopper for adjusting the movement of the hammer. Performs free vibration. The vibration sound is collected by a microphone, the data is converted from analog to digital by a computer, and then the frequency analysis, the calculation of the attenuation rate, etc. are performed to determine the quality of the connection.

【Example】

 Place the combined machine part to be inspected on a jig with a small contact area rubber mounted on top. By using such a jig, it is possible to easily respond on the inspection table when the part to be inspected changes.Depending on the production method, such a jig can be placed on a transfer mechanism such as a belt conveyor and moved to be used as a transfer jig. Can be used. If silicone rubber or the like is used for the support base, molding can be easily performed even on site. The effect of the support is further reduced by using the upper protrusions of rubber. Alternatively, only the protrusions may be mounted on the table as small rubber parts. Next, a mechanism for applying an impact to the inspection target will be described. When the hammer is swung down by the rotary force of the rotary solenoid 10 using the rotary solenoid 10, the hammer handle portion hits the stopper and then the hammer handle portion is bent by the kinetic energy of the weight at the tip. The tip collides with the mechanical component to be measured. At this time, the position of the stopper should be adjusted so that the tip of the hammer collides with the mechanical parts only once without causing chattering in the event of collision with the mechanical parts. When a collision between a machine part and the tip of the hammer occurs, a sound is collected for a certain period of time by the microphone using the collision sound as a trigger. The collected sound is converted from analog to digital by a computer and then analyzed and the data is saved. Computers that use flash memory without mechanical moving parts are used to avoid the effects of vibration and dust in the factory. The computer is connected to a computer in the office by a LAN in the factory for remote monitoring. As another embodiment of the mechanism for giving a shock, there is an example using an electromagnet 12. A hammer 13 made of a magnetic metal is lifted up by applying a short-time current to the electromagnet, and when the current of the electromagnet is cut off, a spring 14 acts to move the hammer downward and the hammer handle becomes a stopper 15. When the handle hits, the tip of the handle flexes and the weight of the tip of the hammer collides with the machine parts, giving energy to the machine parts. In this case, the structure is simplified and the cost can be reduced. In some embodiments, a steel ball 16 and a slide 17 are used. When the steel ball is dropped at an appropriate position and then dropped, the potential energy is converted into kinetic energy, and the steel ball protruding from the tip of the slide hits mechanical parts and can give an impact. When a steel ball is used in this way, the magnitude of the impact can be easily adjusted by changing the height of the steel ball to be set first.

[Effect of the invention]

 1) The joint can be inspected without destructive inspection. 2) Inspection can be performed in a short time. 3) Judgment is made based on natural frequency and damping rate. 4) Non-destructive and simple test method. 5) The production cost of the inspection equipment is low. 6) The inspection time is short and the production cost of the equipment is low, so that the cost of the inspection work can be reduced. 7) Screws, rivets, caulking, welding, etc. It can be applied to various products such as bonding. 8) It can be monitored at a remote place because it is taken into a computer. 9) It is possible to save inspection data, so it is easy to manage historical data and it can be used from customers and markets. 10) The device according to the present invention can be easily integrated into the production line, so that the production line can be easily automated.

[Submission date] April 18, 2002 (2002.4.18)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents] [Detailed description of the invention] [Industrial applications]

 Incorporating this inspection system into production lines for mechanical and electronic components reduces inspection time, eliminates waste due to destructive inspections, and enables all-inspection, thereby providing an advantage in terms of quality assurance. .

[Prior art]

 Inspection of the caulking connection in the production line guarantees the overall quality by extracting the sample and performing torsion destruction inspection. Some hammering tests have also been devised, and an accelerometer is attached to the sample to measure vibration, and the maximum value of vibration at impact is evaluated.

[Problems to be solved by the invention]

 When inspecting the joints of mechanical parts in small-scale production, discarding destructive inspection samples directly increases production costs, so it is necessary to change destructive inspection to nondestructive inspection. It is hoped that inexpensive, reliable and versatile nondestructive inspection equipment will enable 100% inspection of a wide variety of products and reduce capital investment and production costs while ensuring product quality. Since the tapping sound of machine parts varies depending on the method of supporting the machine parts, it is necessary to ensure the reliability of the inspection data by devising the supporting method. It is also important to reduce the workability of inspection and the price of inspection equipment. The present invention has been made in view of the above-mentioned problems, and in non-destructive inspection based on the tapping sound of a mechanical part connection, the reproducibility of the tapping sound is ensured by an inexpensive and simple method to guarantee the inspection accuracy. It is intended to do so.

[Means for Solving the Problems]

 The hitting inspection device for a mechanical part coupling part of the present invention places the mechanical part on a rubber base having a projection. In addition, small protrusions are provided at the top of the rubber stand to minimize the contact area with the mounted mechanical parts. In order to apply impulse impact to mechanical parts, a rotary solenoid driven hammer and a stopper for adjusting the impact energy of the hammer are provided, and moderate and constant impact energy is applied to the mechanical parts to freely vibrate the mechanical parts. This vibration sound is collected by a microphone, and the data is converted from analog to digital by a computer, and then processed such as frequency analysis and calculation of the attenuation rate to determine the quality of the connection.

[Action]

 According to the above configuration, the operator performing the caulking connection can place the mechanical component on the rubber base and press the impact switch to generate free vibration unique to the mechanical component. In other words, nondestructive inspections can be performed with simple operations using inexpensive equipment, which reduces the time required for conventional destructive inspections. Quality assurance

【Example】

 Hereinafter, embodiments of the structure of the hammering sound inspection apparatus according to the present invention will be described with reference to the drawings. FIG. 1 shows a machine component to be inspected. This is a mechanical part in which the steel pin of the code is inserted into the hole of the steel plate of the code and the part of the code is swaged. FIG. 2 is a view showing a mechanical part mounted on a mechanical part holding jig using silicone rubber. A silicone rubber with a reference sign is attached to the upper part of the support of the reference sign to hold the mechanical parts at three or more points. FIG. 3 is a front view and a side view of a mechanical component holding jig and an impact mechanism according to the embodiment of the present invention. Attach the hammer arm of the code to the shaft of the rotary solenoid of the code. At the tip of the hammer arm, attach the hammer of the code. By passing a constant current through the rotary solenoid for a fixed time, the hammer arm is swung up and constant energy is applied to the hammer. Reference numeral denotes a hammer arm stopper made of silicone rubber, and reference numeral {circle around (10)} denotes a stopper mounting column. A hammer swinging with constant energy hits a stopper on its orbit. Since the stopper is made of soft silicone rubber, it absorbs the energy of the hammer while deforming. When the hammer head reaches the highest point, it applies a certain impact energy to the steel plate of the machine part. At this time, since no current flows through the solenoid, the hammer head immediately moves downward after the impact and does not strike twice. Reference numeral 11 denotes a microphone, and reference numeral 12 denotes its support. The acoustic signal is measured immediately after the hammerhead impacts the mechanical part. The microphone is connected to a computer or the like equipped with an AD converter and records sound data. The recorded acoustic data is analyzed to determine the quality of the caulking. By adopting such a structure, a constant energy impulse shock can be applied to the mechanical component, and the mechanical component freely vibrates, so that the measurement data is stabilized and accurate inspection can be performed. In addition, since the structure is simple, the operability and maintainability are good, and the manufacturing cost is extremely low.

[Effect of the invention]

 1) The joint can be inspected without destructive inspection. 2) It can be inspected in a short time. 3) Judgment is made based on natural frequency and damping rate. 4) Non-destructive and simple test method. 5) Low production cost of inspection equipment 6) Short inspection time reduces cost of inspection work 7) Applicable to various products such as screws, rivets, caulking, welding and bonding 8) Since the device according to the present invention can be easily incorporated into a production line, it is easy to automate the production line.

[Brief description of the drawings]

FIG. 1 is a front view

FIG. 2 is a right side view

FIG. 3 is a left side view.

FIG. 4 is a side view of a stopper.

FIG. 5 is an enlarged view of a support portion.

FIG. 6 is a hammering mechanism using a spring mechanism and an electromagnet.

FIG. 7: Impact mechanism using a slide

[Explanation of symbols]

 1. Machine parts 2. Mechanical parts 3. Supports such as rubber 4. Jig 5. Hammer 6. Stopper 7. Microphone 8. Computer 9. Protrusion 10. Rotary solenoid 11. Caulking 12. Electromagnet 13. 13. Hammer of magnetic metal Spring 15. Stopper 16. Steel ball 17. slide

[Procedure amendment]

[Submission date] April 18, 2002 (2002.4.1
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Name of device] Inspection device for mechanical parts coupling

[Utility model registration claims]

[Brief description of the drawings]

FIG. 1 is a diagram of a machine part to be inspected.

FIG. 2 is a front view and a side view in which machine parts are mounted on a machine part holding jig using silicone rubber.

FIG. 3 is a front view and a side view of a mechanical component holding jig and an impact mechanism according to the embodiment of the present invention.

[Explanation of symbols] Steel pin Steel plate Caulked portion Silicone rubber with projections Rotary solenoid hammer arm Hammer head Silicone rubber hammer stopper ▲ 10 ▼ Hammer stopper mounting support ▲ 11 ▼ Microphone ▲ 12 ▼ Microphone support

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction contents]

FIG.

FIG. 2

FIG. 3

Continued on the front page (72) creator Masaomi Sada 158-17 Haritacho, Kodaira-shi, Tokyo 206 206 Corp Yamada (72) creator Kazunari Matsuda 324-10 Naraharacho, Hachioji-shi, Tokyo (72) creator Kazuo Igawa Ome, Tokyo 1-96-6, Iwada-cho, Ichikawa (72) Inventor Ken Fukuda 4-58-4, Zanbori, Musashimurayama-shi, Tokyo (72) Inventor Ken Wakabayashi 3117-3 Mannohara Nitta, Fujinomiya-shi, Shizuoka (72) Inventor Sasakawa Hiroyuki 3-17-2-108 Shinbori, Higashiyamato-shi, Tokyo (72) Inventor Fumio Sakuma 4-9-11 Oyuminochuo, Midori-ku, Chiba-shi, Chiba

Claims (4)

[Utility model registration claims] 1. Vibration energy when vibration is generated by placing a mechanical part joined by screws, rivets, caulking, bonding, welding, etc. on a support base made of a material having a small elastic coefficient such as rubber. To reduce the absorption of the vibrations into the support base and maintain the inherent free vibration, and measure and analyze the vibration generated by applying an impact force with a hammer, etc. in a simple and accurate manner to achieve the natural vibration. A hammering sound inspection apparatus characterized in that the connection state is inspected from the values of the number and the attenuation rate. 2. The apparatus according to claim 1, wherein a projection made of a material such as rubber is provided on the supporting base to reduce an area in contact with the mechanical component, thereby maintaining free vibration inherent to the mechanical component and facilitating measurement. A hammering inspection device shown in Item 1 3. The hitting sound inspection apparatus according to claim 1, wherein the apparatus has a structure in which an adapter or a jig is used and a base made of rubber or the like is provided thereon to cope with production of various types. 4. Use of recoil by providing a spring characteristic to a handle portion and providing a stopper in the middle of the handle.
2. The hitting sound inspection apparatus according to claim 1, further comprising a mechanism for applying a constant impact energy by colliding a steel ball or the like from below and preventing chattering.