JPH0481261A - Method for inspecting casting blow hole in cylindrical, hole of cylinder block - Google Patents

Abstract

PURPOSE:To improve inspection accuracy by inserting an air blow nozzle into a cylindrical hole, removing and cleaning foreign matter, inserting inspecting element rotated at high velocity, irradiating laser beam, receiving this reflecting beam and detecting the casting blow hole with deference of the reflecting ratio. CONSTITUTION:The air blow nozzle 20 for rotating at low velocity and blowing high pressure air, is inserted into the cylindrical hole 2 of a cylinder block 1 and reciprocated along axial direction of the cylindrical hole. The foreign matter of water drips, cutting powder, dust, etc., stuck to the surface of cylindrical hole is removed and cleaned. Successively, the inspecting element 36 rotated at high velocity is inserted and reciprocated along the axial direction of cylindrical hole. The laser beam irradiates on the surface of this cylindrical hole and also the reflecting beam of the irradiated laser beam is received to detect the casting blow hole formed on the surface of cylindrical hole with the difference of laser beam reflecting ratio between the normal surface and the casting blow hole. By this method, the inspection accuracy can be improved without sticking the foreign matter to inspection lens in the inspection element and lowering cycle time.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention relates to a cylinder block made of, for example, aluminum casting. The present invention relates to a method for inspecting cylinder holes in cylinder blocks to detect cavities that may otherwise occur.

(Prior Art) A cylinder block constituting an engine, together with a cylinder head, is made of, for example, aluminum casting.

To manufacture these, just like ordinary castings, a sand mold is formed, molten aluminum material (hot water) is injected, and after the hot water has cooled, the sand mold is destroyed and the casting is removed.

By the way, in the case of such cast products, for example, there may be problems with the shape of the sand mold, the state of pouring the hot water, or various other causes, which may cause gas pockets to form locally, resulting in molding without being filled with hot water. , so-called blowholes may be formed.

If an engine is constructed with the above-mentioned blowholes left unattended, there is a risk of problems such as cracks occurring from the blowholes, regardless of long-term or short-term use. Therefore, cylinder blocks with cavities must be disposed of.

If, for example, a cavity is formed on the outer surface during the manufacture of this cylinder block, it can be detected visually. However, when a knot is formed on the surface of a cylindrical hole, it is difficult to detect visually because the diameter of the hole is small and it is long in the axial direction to some extent.

Therefore, a cylinder block bore hole inspection device, which is a device specifically for inspecting the surface of knotholes, has been developed and put into practical use.

FIG. 6 shows an example of testing in the device.

That is, 1 is a cylinder block made of aluminum casting, for example, and at the same time as the cylinder block 1 is manufactured, a plurality of cylindrical holes 2 are provided at predetermined intervals.

Inspection cleaners a of the inspection device are inserted into these cylindrical holes 2 all at once, rotated at high speed, and then reciprocated along the axial direction of the cylindrical holes 2. The inspection cleaner a is provided with an air blow nozzle b that blows high-pressure air onto the surface of the knothole 2, and an inspection lens C that irradiates the surface of the knothole 2 with a laser beam and receives the reflected light.

The inspection cleaning element a is rotated at high speed and reciprocated along the axial direction of the cylindrical hole 2, and the high-pressure air blown from the air blow nozzle b collides with the surface of the nodal hole 2 in a spiral manner. Foreign matter such as water droplets of cooling water adhering to the surface of the joint hole 2, chips from cutting, and dust floating on the site are blown away by high-pressure air, and the surface of the tube hole 2 is cleaned. . On the other hand, at the same time, a laser beam is irradiated from the inspection lens C. This laser beam draws a spiral trajectory on the surface of the knothole 2 and receives its reflected light. The reflectance of the laser beam when it is irradiated to a completely normal surface area with no blow holes and the reflected light is received,
Naturally, the reflectance of the laser beam will be different when a part with a blow hole is irradiated and the reflected light is received. Therefore, the inspector who operates this device pays attention to changes in the pointer of the reflectance measuring instrument provided in the device and confirms the presence or absence of blowholes.

(Problem to be Solved by the Invention) However, since the diameter of the cylindrical hole 2 is small and long in the axial direction, the upper and lower opening surfaces of the cylindrical hole 2 are in a state similar to being closed to some extent. Since the air blow nozzle b rotates at high speed and blows air in such a substantially sealed area, the blown water droplets drift in the nodal hole 2 in the form of mist and are not immediately discharged. At the same time, the blown IJ powder and dust also float inside the knot hole 2 and are not immediately discharged.

Since the inspection lens C performs the blowhole inspection with these foreign substances such as water droplets floating in the cylindrical hole 2, some of the foreign substances will adhere to the inspection lens C.

- Once foreign matter adheres to the inspection lens C, since there is no means to remove it, the inspection lens C may become cloudy, resulting in a decrease and unevenness in the amount of laser beam irradiation and light reception, resulting in false detection. becomes a factor.

Furthermore, in order to irradiate the surface of the knot hole 2 with a laser beam from the inspection lens C, the inspection cleaner a must be rotated at a high speed of approximately 1200 rpm+ due to cycle time.

As a result, the high-pressure air blown from the air blow nozzle b may pass through the foreign matter such as water droplets without completely removing them, making it impossible to perform reliable cleaning. In order to improve this cleaning efficiency, it is desirable to slowly move the air blow nozzle b along the axial direction while rotating at an extremely low speed of about 1100 rpm or less. Due to its compact structure, low speed rotation is impossible.

The present invention has been made in view of the above circumstances, and by separating the air blow cleaning process and the laser beam inspection process, it is possible to prevent foreign matter floating inside the cylinder due to air blow from adhering to the inspection lens. A patent characterized in that it provides a method for inspecting cylinder block in-cylinder cavities, which can improve inspection accuracy by preventing air blow holes, and also improve cleaning efficiency by enabling low-speed rotation of an air blow nozzle. [Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a cylinder block in which, after manufacturing the cylinder block, an air blow nozzle that rotates at a low speed and blows out high-pressure air is inserted into the cylinder hole. By reciprocating along the axial direction of the hole, foreign matter such as water droplets, chips, and dust adhering to the surface of the knothole are removed and cleaned.
A high-speed rotating inspection element is inserted into the tube hole and reciprocated along the axis of the tube hole, and the surface of the tube hole is irradiated with a laser beam, and the reflected light of the irradiated laser beam is received to determine whether the surface is normal or not. This is a method for inspecting nodal holes in a cylinder block, which is characterized in that a blow hole formed on the surface of a cylinder hole is detected based on a difference in laser beam reflectance from the blow hole.

(Function) In this inspection method, the air blow nozzle is first rotated at low speed to completely remove and clean foreign matter such as water droplets and chips adhering to the surface of the knot hole. After the foreign matter has been discharged from the cylinder, the inspection element is inserted into the cylinder to detect the blowhole, so there is no foreign matter attached to the inspection element, and erroneous detection can be prevented.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, reference numeral 3 denotes a device main body constituting a nodal hole blowhole inspection device for a cylinder block. The main body 3 of the apparatus includes a supply section 4 for a cylinder block 1 as a workpiece, a cleaning section 5, and a blow hole inspection section 6.

The supply section 4 is arranged on the back side of the apparatus main body 1 and connected to the cleaning section 5. To explain, a plurality of rollers 7 are arranged at a predetermined height with extremely narrow intervals, and a conveyor 8 is hung on these rollers 7 so that they can run endlessly. will be stopped. The conveyor 8 supports the cylinder blocks 1 that are sequentially supplied and conveys the cylinder blocks 1 in this running direction. A conveyor drive unit 9 consisting of a motor as a drive source, a drive pulley, and a drive belt is located below the conveyor 8.
is placed. The drive belt of the conveyor drive unit 9 is engaged with a predetermined rollerf, and the conveyor 8 is driven to run endlessly in the direction of the washing section 5.

The cleaning section 5 is configured on the conveying end side of the conveyor 8 constituting the supply section 4, and is arranged at a predetermined interval between a plurality of rollers 0, which are aligned at the same height as the rollers 7... It is rotatably supported. A conveyor 11 is connected to these rollers 0 so that it can run endlessly. Further, a sprocket (not shown) is provided at one end of each roller 0, and a chain is connected to the sprocket. A drive chain of a roller drive unit 12 disposed below the rollers 0... is connected to a predetermined sprocket, and the conveyor 11 is rotated in the same direction via the rollers 10... It has become. To explain further, the supply section 4
The cylinder block 1 carried in from the conveyor 11
The paper is received on top and transported along the traveling direction, which is a direction perpendicular to the carrying direction. Above conveyor 1
A stopper cylinder and a sensor (not shown) are provided on the cylinder block 1 to detect the introduction of the cylinder block 1 and to reliably control the cylinder block 1 to a predetermined position.

An air blow mechanism 13 is provided above the conveyor 11.
is provided. Next, this air blow mechanism 13 will be explained based on FIGS. 1 to 3. An LM guide 16 is provided on a plate 15 at the end of a pedestal 14 that constitutes a part of the apparatus main body 3, and a nozzle receiver is attached to the plate 1 on this LM guide 16.
7 are engaged so as to be movable in the vertical direction. Also,
A lift cylinder 18 made of, for example, an air cylinder is provided at the upper end of the pedestal 14, and its operating rod 18
a extends downward, and the nozzle receiver is fixed to the plate 17 via a mounting bracket 19. That is, by supplying and discharging a working medium to and from the lift cylinder 18, the nozzle receiver drives the plate 17 up and down. In the nozzle receiver, a plurality of (four in this case) air blow nozzles 20 are arranged at predetermined intervals on the plate 17, and bearings (not shown) are rotatably supported in a line through a tool. .

The pitch of these air blow nozzles 20... is the same as the pitch of the cylindrical holes 2... of the cylinder block 1.

At the tip of each air blow nozzle 20, a pair of nozzle holes 21, 21 are provided at different height positions in the axial direction facing each other across the axis. Furthermore, spur gears 22 are fitted to the ends of the nozzle receivers of the air blow nozzle 20 on the side of the plate 17, and these spur gears 22 mesh with each other to transmit driving force. The spur gear 22 at the minus side end is connected to a drive motor 24 via a reduction mechanism section 23 . The rotation of the drive motor 24 is decelerated and transmitted to the air blow nozzle 20 via the deceleration mechanism section 23 and the spur gear 22.
The rotation speed at zero is set to be a low rotation speed of about 100 rpI11. A rotary joint 25 is provided at the upper end of each spur gear 22 and communicates with the air blow nozzle 20 via the spur gear 22. Furthermore, air hoses 26 are connected to these rotary joints 25 and communicated with a high-pressure air supply source (not shown). For this reason, high-pressure air can be ejected from the nozzle holes 21 and 21 regardless of whether the air blow nozzle 20 stops rotating.

As shown again in FIGS. 1 and 2, the cavity inspection section 6 is comprised of an elevating support mechanism 27 and an inspection mechanism 28.

The lifting support mechanism 27 includes rollers 29 provided at exactly the same height and at the same interval as the rollers 10 provided in the cleaning section 5, and driven by the same drive source. rotationally driven in the direction. These rollers 2
A support plate 31 supported by a plurality of vertically movable guide shafts 30 is provided at a lower portion of the shaft 9 . This support plate 31 is also connected to the operating rod of an elevating cylinder 32, which is an air cylinder, for example, and is supported so as to be able to rise and fall freely. In the above-mentioned receiver, a plurality of support rods 33 are arranged on the upper surface of the plate 31, and these support rods 3
The upper end portions of rollers 29 . . . are capable of projecting and retracting upwardly from between the rollers 29 . That is, from the conveyor] 1 of the cleaning section 5 to the 0-ra 29 of the lifting support mechanism 27...
The support rods 33 can push the cylinder block 1, which is placed on top, upward from between the rollers 29.

The inspection mechanism 28 is arranged above the elevating support mechanism 27. That is, a fixed inspection plate 34 is provided above the rollers 29, and blocks the cylinder block 1 pushed up by the support rods 33 to check this height position. It is designed to always be held in a fixed position. Further, above the inspection plate 34, a plurality of (four in this case) inspection elements 36 are arranged in a row on the support plate 35.

The support plate 35 is connected to a drive source, for example, a servo motor 37, via a ball screw 38 connected to the rotating shaft of the servo motor 37, and a female threaded portion (not shown) that screws into the ball screw 38. . and support plate 35
is vertically driven by the amount of drive of the servo motor 37 while holding the tester 36 .

Here, a high-speed rotational drive mechanism (not shown) is used for each inspection element 36.
..., and each test element 36... is connected to about 120
It rotates at a high speed of about 0 rpm.

Three inspection lenses are provided on the circumferential surface of the lower end of the inspection element 36, from which a laser beam is irradiated and the reflected light is received. The pitch of each probe 36 is the same as the pitch of the cylindrical holes 2 of the cylinder block 1, and can be inserted into the cylindrical holes 2 all at once as the support plate 35 is vertically displaced. Further, a connection cord extends from the upper end of each tester 36 and is connected to a laser beam control circuit not shown here.

The cylinder blocks 1 that have just been cast and subjected to predetermined processing are supported in the supply section 4, driven in accordance with a drive signal, and delivered one by one to the cleaning section 5.

The cylinder block 1 is positioned on the conveyor 11 in the cleaning section 5, and the lift cylinder 18 is driven to open the air blow nozzle 20 from the lower end of the cylinder hole 2.
Insert gradually into... At the same time, the drive motor 24 is driven to rotate the air blow nozzles 20 at low speed.

As shown in FIG. 4, high-pressure air is blown out from the nozzle hole 21.21 of the air blow nozzle 20 and blows the surface of the knot hole 2 with air. Droplets of cooling water, cutting chips, and floating dust attached to the surface of the knot hole 2 due to predetermined machining are removed and cleaned by air blowing. In particular, the air blow nozzle 20 is rotating at a low speed, the insertion speed is set along the two axial directions of the nozzle holes in accordance with the rotation of the air blow nozzle 20, and the positions of the nozzle holes 21 and 21 are shifted vertically. Air blow cleaning can be carried out reliably because the conditions such as the provision of two air blowers are met.

After cleaning is completed, the lift cylinder 18 is driven to raise the air blow nozzle 20 and remove it from the knot hole 2. After returning to the predetermined height, cylinder block 1 is transported next.
wait.

The roller drive unit 12 is driven again to transport the cylinder block 1 that has undergone air nib blow to the rollers 29 of the inspection mechanism 28. A position regulating switch (not shown) detects that the cylinder block 1 is supported at a predetermined position.

Next, the lifting cylinder 32 is raised and the support rod 3
3..., the cylinder block 1 is pushed up, and the cylinder block 1 is brought into contact with the inspection plate 34 and held at a predetermined height. Furthermore, the servo motor 37 is driven at the right timing to lower the tester 36 along with the support plate 35, and each tester 36 is inserted into the node hole 2 of the cylinder block 1 while being driven to rotate at high speed. do. The rotational speed of the tester 36 is set (approximately 120 Orpm) in consideration of the cycle time, as in the conventional case.

As shown in FIG. 5, the inspection element 36 irradiates a laser beam from an inspection lens 39 provided on its circumferential surface. This laser beam irradiates the surface of the tube hole 2 so as to draw a spiral trajectory, and receives the reflected light. The reflectance of the laser beam when there is a blowhole on the surface of the cylindrical hole 2 is different from the reflectance of the laser beam at a normal surface area where there is no blowhole. Therefore, the inspector who operates this device pays attention to changes in the pointer of the reflectance measuring instrument provided in the device and confirms the presence or absence of blowholes. Since the blow holes are inspected by the inspection element 36 after a certain time lag after the air blowing action of the cleaning section 5 is finished, all the foreign matter removed by the air blowing action is naturally removed from the outside of the knot hole 2 during this inspection. It is being discharged.

Therefore, no foreign matter adheres to the inspection lens 39, making it possible to prevent lens fogging and providing extremely high detection accuracy.

Once the three inspection lenses have inspected the entire surface of the tube hole 2, the servo motor 37 is driven again to drive the inspection elements 36 upward, and the lifting cylinder 32 is driven to drive the cylinder block 1 downward. Each tester 36... is a node hole 2...
・Cylinder block 1 that has been removed from the cylinder block, returned to its original position, and finished air blow cleaning from the cleaning section 5, and will be transported next.
wait. The cylinder block 1, which has been inspected for blowholes on the surface of the cylinder hole 2, is carried out from the rollers 29 to a predetermined location.

〔Effect of the invention〕

As explained above, according to the present invention, after manufacturing the cylinder block, the surface of the knot hole is cleaned with air blow, and then the inspection element is used to detect the porosity on the surface of the knot hole. This saves time and completely removes foreign matter, improving the cleaning efficiency of the surface of the knot hole. Also, since foreign matter does not adhere to the inspection lens of the tester, it is possible to improve inspection accuracy without reducing cycle time. Effects such as

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention, and FIG. 1 is a schematic front view of a cylinder block nodal hole blowhole inspection device;
Fig. 2 is a side view thereof, Fig. 3 is a schematic side view of the cleaning section which is the main part, Figs. FIG. 2 is a diagram illustrating a conventional inspection method. ]... Cylinder block, 2... Node hole, 20...
Air blow nozzle, 21... Nozzle hole, 36...
Tester, 39... test lens. Applicant's agent Patent attorney Takehiko Suzue 1 cylinder block 7 13 [Figure

Claims (1)

[Claims] After the cylinder block is manufactured, an air blow nozzle that rotates at low speed and blows out high-pressure air is inserted into the cylinder hole, and is driven back and forth along the axis of the cylinder hole to remove water droplets, chips, and dust that adhere to the surface of the cylinder hole. After cleaning and removing foreign matter, a high-speed rotating tester is inserted into the tube hole and driven back and forth along the axial direction of the tube hole, and a laser beam is irradiated onto the surface of the tube hole. A method for inspecting a cavity in a cylinder block, the method comprising detecting a cavity formed on the surface of the cavity by receiving reflected light from the cavity and detecting a cavity formed on the surface of the cavity based on the difference in laser beam reflectance between the normal surface and the cavity.