JPH0325296B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a precision grinding method and a grinding device for the outer surface of a small-diameter cylindrical body. The present invention relates to a precision grinding method for the outer surface of a small-diameter cylindrical body, which has very high degree of accuracy, and is especially suitable for precision finishing of a small-diameter cylindrical body with a small inner diameter, and a grinding apparatus therefor.

[Technical background of the invention and its problems] Conventionally, when precision finishing the inner and outer circumferences of small diameter cylindrical bodies such as guide rollers used in audio products, video products, etc., it has been necessary to check the concentricity of the inner and outer circumferences. Extremely high accuracy is required.

However, although precision finishing has traditionally been performed using the following finishing methods, each has its own drawbacks.
It was not possible to obtain sufficient accuracy.

That is, in the centerless grinding method, as shown in FIG. 16, a cylindrical material 50 is placed on a blade 51, and a grinding wheel 52 and a regulating wheel 53 are moved from both sides of the cylindrical material 50 in the same direction. The grinding wheel 52 and the regulating wheel 53 are brought into contact with each other while being rotated, and grinding is performed by the difference in rotational peripheral speed between the grinding wheel 52 and the regulating wheel 53.

Therefore, since grinding follows the outer periphery of the cylindrical material 50, the difference in concentricity between the inner and outer diameters of the cylindrical material 50 remains as a difference in concentricity after finishing, so this is a machining method with high concentricity accuracy of the inner and outer peripheries. It was not suitable for all products, and it was impossible to obtain sufficient accuracy for all products to be offered as products.

As an example, Japanese Utility Model Publication No. 12913/1983 proposes a cylindrical thin-walled pipe grinding device for a centerless grinder.

This device is especially for centerless grinding of thin-walled cylindrical pipes, and includes a support means for supporting the thin-walled cylindrical pipe on its lower surface, which rotates under pressure between a grinding wheel and an adjustment wheel, and At least one presser roller that faces the upper surface of the cylindrical thin-walled pipe and presses the pipe, and a presser mechanism that regulates the amount by which the presser roller is pressed down in accordance with the grinding allowance of the cylindrical thin-walled pipe are provided. The pressing means for applying a pressing force to the roller is formed to have high rigidity.

However, this device performs centerless grinding while minimizing the crushing of thin-walled cylindrical pipes. The disadvantage that the difference in concentricity between the inner and outer diameters of the pipe remains as a difference in concentricity after finishing has not been resolved.

Therefore, Japanese Patent Laid-Open No. 48-32285 proposes a method and apparatus for polishing a hollow cylindrical work piece.

In this polishing method and device, a hollow cylindrical body as a workpiece is removably supported on a fixed support shaft provided in correspondence with a grinding wheel that can move forward and backward, and the hollow cylindrical body is pressed toward the grinding wheel by a drive roller. Further, a method of polishing the outer circumferential surface while actively rotating it through frictional contact, and an apparatus used therefor are disclosed.

In addition, in the case of this polishing method and device, the fixed support shaft is made considerably thinner with respect to the inner diameter of the hollow cylindrical body, so that there is considerable backlash when the hollow cylindrical body is fitted onto the fixed support shaft. .

Therefore, as shown in Figures 3a and 3b of the same publication, the hollow cylindrical body is sandwiched between the drive roller and the grindstone, and the fixed support shaft is brought to the side of the grindstone so that the grindstone and the fixed support shaft are separated. sandwich the meat of the hollow cylinder,
Polishing is performed by rotating a drive roller and a grindstone. Therefore, in such a loose state, even if a fixed support shaft is inserted, it only serves to support the grinding wheel in the vertical direction and to press the grindstone, and the outer diameter is not concentric with the inner diameter of the hollow cylinder. The degree of cylindricity cannot be ensured sufficiently, and even in terms of cylindricity, there is considerable backlash between the fixed support shaft and the hollow cylinder due to the hollow cylinder being sandwiched between the drive roller and the grindstone. If so, it would naturally be expected that it would bend, and it had the drawback that it was very difficult to ensure polishing accuracy, especially cylindricity.

Therefore, including such cases, JP-A-54-
In JP 16789, an automatic attachment/detachment device for a hole reference workpiece was proposed, in which an inflatable mandrel arbor and one end of this arbor were installed to ensure concentricity between the hole of the hole reference workpiece and the outer peripheral surface. A structure is disclosed in which it is fixed and the other end is supported by a tailstock.
In this device, the workpiece is fitted onto the arbor, and the arbor is expanded so that it comes into close contact with the inner periphery of the workpiece, and the workpiece is rotated together with the arbor to perform grinding. The concentricity between the inner diameter and the outer diameter at the stage is excellent.

However, in the case of this device, when grinding the outer diameter of a small-circumference cylindrical body such as a guide roller used in audio products, video products, etc. as mentioned above, the dimensions of such a guide roller must first be determined. However, since the inner diameter is small, for example, about 1.5 mm and the outer diameter is about 7 mm, it is impossible to use the above-mentioned inflatable mandrel arbor.

In addition, this type of guide roller is required to have strict concentricity on the order of μ when installed in audio products, video products, etc.
Moreover, since the guide roller is used with a cylindrical body rotatably fitted around the shaft, products that are ground using this method that uses an inflatable mandrel arbor are Because the arbor and workpiece are in close contact with each other, when the cylindrical body after grinding is released from the close contact state and fitted onto the shaft of audio equipment, etc., there are often variations in concentricity with the shaft, and in reality In this way, when the cylindrical body was ground in close contact with the mandrel arbor and the concentricity was measured by fitting it onto the shaft and rotating it, in most cases it was not possible to obtain accuracy in the μ unit. In other words, the result was a mental breakdown.

On the other hand, the internal grinding method is a method of grinding the inner periphery based on the cylindrical outer periphery. However, with this method, if the inner diameter is large to a certain extent, that is, if it is a large or medium-sized cylinder, it is possible to finish the concentricity of the inner and outer circumferences with general accuracy, but in the case of a small-diameter cylinder as mentioned above, it is not possible. Since the inner diameter is very small, the grinding wheel and grinding wheel shaft must be made very small, which poses problems in terms of strength and rigidity, and it is almost impossible to obtain a small diameter cylindrical body with high precision concentricity between the inner and outer circumferences. It was impossible. Further, even for large and medium-sized cylinders, it is extremely difficult and almost impossible to reduce the concentricity deviation to a value close to 0.

In addition, in the cylindrical grinding method, a mandrel with a center hole drilled at the center of both end faces is press-fitted into a cylinder.
This mandrel is pivoted at both centers and rotated, and a rotating grindstone is brought into contact with the outer peripheral surface of the cylinder to perform grinding. Therefore, although the concentricity of the inner and outer peripheries is finished with high precision, it is time-consuming and inefficient to attach (press-fit) and remove the mandrel. Furthermore, in the case of a small-diameter cylindrical body as described above, since the inner diameter is small, the core metal also has a very small diameter, so the core metal lacks rigidity, making it almost impossible. Furthermore, if the core metal itself has a deflection, the deflection has a negative effect on the concentricity.

Furthermore, in the cutting and finishing method using an automatic lathe, a cylindrical material is attached to the chuck of an automatic lathe, and both the inner and outer circumferences are finished and formed using a cutting tool. Therefore, once attached to the chuck, both the inner and outer peripheries can be finished, so concentricity can be achieved with good concentricity to some extent, but since it is finished with a cutting tool, highly hard materials cannot be processed. Moreover, in the case of small-diameter cylindrical bodies, the thickness of the boring tool used for finishing must be extremely thin.
There was also the drawback that the deflection of the pilot hole due to drilling could not be removed due to the lack of rigidity of the boring tool.

The machining method using the so-called ``open yato'' method, in which the inner periphery of the cylindrical body is fixed by dividing a cylindrical object into multiple parts and allowing them to move in the radial direction, is the core of the open yatoi. It is almost impossible to reduce the concentricity of the inner and outer circumferences to a value close to 0 because the vibration and the center vibration due to the fixation of the cylindrical body are added together. In addition, it takes time to tighten and untighten the opening and groove, making it unsuitable for mass production.Furthermore, in the case of small-diameter cylindrical bodies, the inner diameter is small, so the rigidity of the opening and groove itself is insufficient, making it impossible to achieve high-precision finishing. It was hot.

In this way, conventional finishing methods can provide highly accurate concentricity, if not satisfactory, in the case of cylindrical objects with relatively large inner and outer diameters.
This is not possible for products such as the small diameter cylindrical body mentioned above.
Now that such products are being used in large numbers, it has been desired to finish the concentricity of the inner and outer circumferences with extremely high precision, and to develop a processing method and equipment suitable for mass production.

[Object of the invention] Therefore, in view of the above-mentioned drawbacks, the present invention has been made to
The purpose is to finish the concentricity of the inner and outer circumferences of small-diameter cylindrical bodies with extremely high precision, and to make the finishing work easy and quick for anyone to do, making it suitable for mass production. It was created as a.

[Summary of the Invention] In order to achieve the above objects, the precision grinding method of a cylindrical outer surface according to the present invention is used in audio products, video products, etc. at a grinding position between a grinding wheel and a regulating wheel. A small-diameter cylindrical body such as a guide roller is supplied and arranged, and then,
By inserting the mandrel into this small-diameter cylindrical body without play, similar to the state used in audio products, video products, etc., this small-diameter cylindrical body rotates relative to the mandrel with the inner circumference as a reference. After fixing the mandrel near both ends of the small-diameter cylindrical body in this pivotally supported state, the small-diameter cylindrical body is rotated by a grinding wheel and a regulating wheel. The grinding device consists of an audio product, which is arranged at a grinding position between a rotating grinding wheel and a regulating wheel, using a rotating circumferential speed difference between the rotating grinding wheel and the regulating wheel. A small-diameter cylindrical body grinder that grinds the outer surface of a small-diameter cylindrical body such as a guide roller used in video products, etc., and a small-diameter cylindrical body placed at a grinding position between a grinding wheel and a regulating wheel. The small-diameter cylindrical body is inserted into the body without any play, similar to the state used in audio products, video products, etc., and is pivoted so that the small-diameter cylindrical body can rotate freely with the inner circumference as a reference.
A mandrel that can be removed from the small diameter cylindrical body, a mandrel fixing device that fixes the inserted mandrel near both ends of the small diameter cylindrical body, and regulating the mandrel to the small diameter cylindrical body after fixing. Two interlocking mechanisms that operate the mandrel fixing tool and the regulating wheel to release the fixation of the mandrel after the wheels are brought into contact and the regulating wheel is separated from the small diameter cylindrical body after the external surface grinding is completed. The structure consists of a cam and a cam.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 15.

That is, the precision grinding method for the cylindrical outer surface is first carried out using a cylindrical outer surface grinding device that performs grinding by the difference in rotational circumferential speed between the grinding wheel 2 and the regulating wheel 3. A small diameter cylindrical body 1 is arranged at a grinding position between a grinding wheel 2 and a regulating wheel 3 in a grinding device.

This small-diameter cylindrical body 1, as shown in FIG.
For example, it is used in tape guide rollers for video equipment, and its dimensions are, for example, approximately 7 mm in outer diameter.
It has a small diameter cylindrical shape with an inner diameter of about 1.5 mm.

The small diameter cylindrical body 1 is arranged between the grinding wheel 2 and the regulating wheel 3 in this way.
As shown in FIG.
The small-diameter cylindrical body 1 is rotatably supported concentrically with respect to the inner circumference, and then the mandrel 4 is mounted near both ends of the small-diameter cylindrical body 1 using the mandrel fixture 5. Clamp and fix. This state of affairs is, after all,
This is a state in which the small-diameter cylindrical body 1 is pivotally supported on an audio device or the like.

This mandrel fixture 5 has clamping rods 5a and 5b each having a fixing groove 6 with a V-shaped cross section at the tip, which are arranged one above the other so that the fixing grooves 6 face each other to form a set, and the set is formed into a set with a small diameter. They are formed near both ends of the cylindrical body 1, respectively.

Incidentally, the mandrel fixture 5 is not limited to the structure described above, and may have any shape as long as it can clamp and fix the mandrel 4 near both ends of the small-diameter cylindrical body 1. Needless to say.

After fixing the mandrel 4 with the mandrel fixture 5, the regulating wheel 3 is brought into contact with the outer peripheral surface of the small diameter cylindrical body 1 as shown in FIG. 2, and then as shown in FIG. As shown, the grinding wheel 2 is brought into contact with the regulating wheel 3 from the opposite side, and the outer circumferential surface of the small diameter cylindrical body 1 is precisely ground by the difference in peripheral speed between the grinding wheel 2 and the regulating wheel 3. .

On the other hand, as shown in FIG. 5, the cylindrical external surface grinding device that performs grinding in this manner includes a cylindrical body support device 9 placed and fixed on a base 7, and a grinding wheel 2 that is driven and rotated. Consisting of

As shown in FIGS. 5 to 9, the cylindrical body support device 9 includes a support rod 11 whose base end is rotatably supported by a shaft support 10 on a base 7, and a support rod 11 attached to the tip of the support rod 11. Bearing 12 of regulating wheel 3
The regulating wheel 3 is rotatably supported by the bearing 12 and moves toward and away from the grinding wheel 2 by rotation of the support rod 11, and the regulating wheel 3 and the grinding wheel 2 are A mandrel fixture 5 disposed therebetween, an interlocking cam 13 for operating the mandrel fixture 5 and the regulating wheel 3, respectively, and a universal joint 14 for driving and rotating the regulating wheel 3. and a motor 16 connected to the rotating shaft 15 of the regulating wheel 3.

An operating arm 17 is implanted in the bearing 12 so as to be substantially perpendicular to the supporting rod 11 in the direction opposite to the grinding wheel 2, that is, horizontally toward the front side. A coil spring 21 mounted substantially perpendicularly to the base 7 is brought into contact with the lower surface of the actuating arm 17, with the amount of upward movement adjustable by a screw 28, and the elastic force of the coil spring 21 causes the coil spring 21 to be actuated. arm 17
is constantly pressed to push up and rotate the regulating wheel 3 toward the grinding wheel 2.

On the other hand, the core metal fixture 5 has the fixing groove 6 as described above.
It is formed by clamping rods 5a and 5b having at their tips. Two lower clamping rods 5a of the clamping rods 5a and 5b are erected on the base 7 at an interval slightly wider than the length of the small diameter cylindrical body 1.

The fixing grooves 6 of the clamping rod 5a are arranged at the same height from above the base 7, open upwardly, and facing the same direction. The height and direction of this fixing groove 6 are determined by inserting the mandrel 4 into the small diameter cylindrical body 1 and
When placed over each other, the small diameter cylindrical body 1
As shown in FIG. 3, it is arranged at a slightly higher position than the line connecting the centers of the grinding wheel 2 and the regulating wheel 3, and its axis line is the same as the axis of the rotating shaft (not shown) of the grinding wheel 2. They are arranged parallel to each other. That is, the height and direction of the fixing groove 6 may be set so that the small-diameter cylindrical body 1 is placed at an appropriate grinding position between the grinding wheel 2 and the regulating wheel 3. Above the clamping rod 5a erected on the base 7, the same fixing groove 6 is positioned so as to face the same direction as the fixing groove 6 of the clamping rod 5a. are arranged respectively,
This upper clamping rod 5b is fixed to the tip of a lever rod 19 that rotates via a fulcrum 18, and operates to clamp and fix the mandrel 4 and to release the fixation as the lever rod 19 rotates. .

Further, a cam board 20 is provided upright on the base 7, and the interlocking cam 13 is pivotally supported on this cam board 20.

The interlocking cam 13 is configured such that the regulating wheel operating cam 13a and the mandrel fixing device operating cam 13b are connected to each other by a connecting shaft 13c so as to interlock with each other, and the connecting shaft 13c is passed through the cam base plate 20 to connect the regulating wheel operating cam 13a and the mandrel fixture operating cam 13b. A supporting regulating wheel operating cam 13a and a mandrel fixture operating cam 13b are arranged on both sides of a cam base plate 20.

On the other hand, a substantially middle portion of the lever rod 19 is rotatably supported on the cam base plate 20, and the supported portion serves as the fulcrum 18. As mentioned above, the upper clamping rod 5b is fixed to the tip of this lever 19, but a coil spring 22 is stretched across the lower part of the front side of the lever 19, and the lever 19 is moved by a tensile force. The tip is constantly pulled upward.

Furthermore, the mandrel fixing device actuating cam 13b is brought into contact with the lower surface of the front end of this lever rod 19, and,
A regulating wheel operating cam 13a is brought into contact with the upper surface of the front end of the operating arm 17. The regulating wheel actuating cam 13a and the mandrel fixture actuating cam 13b are formed so as to be rotatable together by a cam lever 23. By rotating the cam lever 23 approximately 90 degrees in one direction, the lever 19 is swung to clamp and fix the mandrel 4 with the mandrel fixing device 5, and the regulating wheel 3 is moved in the direction of the grinding wheel 2. The support rod 11 is moved by the actuating arm 17 to
Rotate. In addition, by rotating the cam lever 23 approximately 90 degrees to return the cam lever 23 to the opposite direction, the operating arm 17 moves the supporting rod 1 in order to move the regulating wheel 3 away from the grinding wheel 2.
1 and swing the lever lever 19 in order to release the clamping fixation of the mandrel 4 by the mandrel fixture 5.

In this case, as described above, the interlocking cam 13 is used to perform the clamping by the mandrel fixture 5 and the movement of the regulating wheel 3. The ridges 24 and 25 of the regulating wheel operating cam 13a and the mandrel fixture operating cam 13b are placed at appropriate positions for activation.

That is, as shown in FIG.
When the mandrel 4 is clamped and fixed by the mandrels 4 and the regulating wheel 3 moves in the direction of the grinding wheel 2 and comes into contact with the small diameter cylindrical body 1 which is pivotally supported by the mandrel 4, for example, the cam lever 23 is moved. When tilted sideways, the crest 25 of the mandrel fixing actuating cam 13b engages the lever rod 19 and pushes up the front end of the lever 19, and then the ridge 24 of the regulating wheel actuating cam 13a comes off from the actuating arm 17. The ridges 24 and 25 are set so that the regulating wheel 3 comes into contact with the small diameter cylindrical body 1. Further, as shown in FIG. 9, when the cam lever 23 is returned to the vertical position, the regulating wheel operating cam 13a
The ridge 24 of the lever lever 19 separates the regulating wheel 3 from the small diameter cylindrical body 1, and then the ridge 25 of the mandrel fixing actuating cam 13b engages the lever 19.
The ridges 24 and 25 are set so that the front end of the lever rod 19 comes down and releases the fixation of the mandrel 4 by the mandrel fixing tool 5.

Therefore, by simply operating the cam lever 23 with one hand, the core metal fixture 5 and the regulating wheel 3 can be moved.
can be operated at the same time.

Small diameter cylindrical body 1 whose outer periphery has been ground in this way
The small diameter cylindrical body 1 is ground by inserting the mandrel 4 and fixing the mandrel 4, so even if the concentricity between the outer periphery and the inner periphery is misaligned in the pre-processing, the small diameter cylindrical body 1 can be ground with the mandrel 4 fixed.
Because it rotates around the axis, it is not ground along the outer periphery, but grounded based on the inner periphery, and the concentricity between the inner periphery and the outer periphery can be made with extremely high precision.

On the other hand, as shown in FIG. 4, instead of the grinding wheel 2, an end grinding wheel 26 whose peripheral surface is cut off diagonally to have a trapezoidal cross section is used, and the end grinding wheel 26 is placed on the opposite side of the end grinding wheel 26 with the mandrel 4 in between. The stopper 27 may be arranged so as to come into contact with the end surface of the small diameter cylindrical body 1. Then, in order to bring the bottom side of the trapezoidal cross section of the end face grinding wheel 26 into contact with the small diameter cylindrical body 1, the regulating wheel 3 is slightly tilted to generate a thrust in the direction of the stopper 27. The body 1 moves back toward the axis of the small-diameter cylindrical body 1 using the moving force in the direction of the stopper 27.
comes into contact with. Then, the end face of the small diameter cylindrical body 1 is ground by the end face grinding wheel 26 by the amount of retraction of the stopper 27. In this case, the end face grinding wheel 26
If the bottom side of the small diameter cylindrical body 1 is arranged at right angles to the axis of the small diameter cylindrical body 1, the end face of the small diameter cylindrical body 1 can be formed at right angles to the inner peripheral surface of the small diameter cylindrical body 1. can.

Next, an automatic cylindrical outer surface grinding device that performs the above-described grinding as a continuous series of steps will be described below.

This device has a frame 3 as shown in FIG.
A grindstone cutting slide 33 is placed on the grindstone 2 via a slide receiving plate 34, and a grindstone mount 35 and a grindstone drive motor 36 are placed thereon. Similarly, a traversing table 8 is placed on the frame 32, and the cylindrical body support device 9 is attached to the base 7 on the table 8. The grinding wheel 2, which is covered more than half by a grinding wheel cover 37, is rotatably mounted on the grinding wheel mount 35, and is driven and rotated by a grinding wheel drive motor 36, and is controlled by a positioning handle 38. It is formed to adjust the depth of cut.

Further, a supply chute 2 is provided above the portion where the mandrel 4 is held by the mandrel fixture 5 in the cylindrical body support device 9.
9 is arranged, and a discharge chute 3 is placed below the clamping part.
9 is arranged, and the 12th
As shown in the drawings and FIG. 13, a mandrel 4 that can be freely retracted and retracted is arranged in this clamping portion. Furthermore, a pedestal 31 is disposed below the clamping portion, and as shown in FIGS. 11 and 14, the small diameter cylindrical body 1 supplied from the supply chute 29 is received and placed at the appropriate grinding position. It is formed so that it rises so as to hold it in place, while the other parts are formed so that it retracts downward.

The process of grinding the outer periphery of the small-diameter cylindrical body 1 using this device will be described below. First, as shown in FIG.
In order to place and hold the small-diameter cylindrical body 1 at a proper position for grinding the small-diameter cylindrical body 1 between the two, the pedestal 31 rises and stops between the two clamping rods 5a. Then, the stopper pin 30 is retracted from the inside of the supply chute 29, thereby placing one small-diameter cylindrical body 1 on the pedestal 31.

Next, as shown in Fig. 12, the mandrel 4 is
advances and passes through the small-diameter cylindrical body 1 on the pedestal 31, and at the same time draws the pedestal 31 downward. Then, as shown in FIG. 13, the mandrel 4 inserted into the small diameter cylindrical body 1 is clamped and fixed by the mandrel fixtures 5 near both sides of the small diameter cylindrical body 1, and the mandrel 4 is secured to the small diameter cylindrical body 1 by a leg. Bring the cycling wheel 3 into contact. Thereafter, the grinding wheel 2 is advanced to come into contact with the outer circumferential surface of the small-diameter cylindrical body 1 to perform finish grinding.

After grinding the outer circumferential surface of the small diameter cylindrical body 1, as shown in FIG. The small diameter cylindrical body 1 is released from the clamping and fixed state, and is pulled out and discharged through the discharge chute 39. In this case, the discharge chute 39 is retracted downward when it is not needed.

Then, the pedestal 31 is raised again, the stopper pin 30 is retracted, and the small-diameter cylindrical bodies 1 are fed from the supply chute 29 onto the pedestal 31, and the above-mentioned process is repeated again to sequentially supply the small-diameter cylindrical bodies 1 one by one. It grinds continuously. In this case, since the lower clamping rod 5a of the mandrel fixture 5 is fixed and does not move, the discharge chute 39 is moved by the clamping rods 5a, 5b.
The pedestal 31 is also placed between the two, and when inserting or removing the mandrel 4 from the small-diameter cylindrical body 1, the two lower clamping rods are used. 5
Either one of a serves to hold down the small-diameter cylindrical body 1, so that the mandrel 4 can be easily inserted and removed.

At this time, the core metal 4 moves in and out, the pedestal 31 moves in and out, the discharge chute 39 moves in and out, the regulating wheel 3 moves, the interlocking cam 13 moves, and the grinding wheel 2 rotates. All movements, etc., are operated by servo motors, hydraulic or pneumatic cylinders, solenoid valves, other limit switches (both not shown), etc.
These are controlled by a control device (not shown) to perform the operations described above.

The small-diameter cylindrical body 1 whose outer circumferential surface has been ground partly manually or fully automatically in this way is used as a guide roller for video equipment, for example, as shown in FIG. 15. In this guide roller, a small diameter cylindrical body 1 is fitted onto a roller shaft 40, and a fixed flange 41 sets the position of the small diameter cylindrical body 1 and holds it rotatably. Therefore, if the accuracy of concentricity is poor, rotational blurring will occur, which will have an adverse effect on video recording, playback, etc., so concentricity must be highly accurate on the order of μ.

However, if the small-diameter cylindrical body 1 is ground as described above, the concentricity can be improved by setting the outer diameter of the mandrel 4 so as to eliminate play between the mandrel 4 and the small-diameter cylindrical body 1. It is possible to provide a small-diameter cylindrical body 1 that can suppress runout to almost 0 and that can sufficiently satisfy the requirement for high precision in μ units. Further, if the end face of the small diameter cylindrical body 1 is also made square as described above, it is possible to provide an excellent small diameter cylindrical body 1 with less rotational wobbling.

[Effects of the Invention] The precision grinding method according to the present invention configured as described above uses a guide roller used in audio products, video products, etc. at the grinding position between the grinding wheel 2 and the regulating wheel 3. A small diameter cylindrical body 1 as shown in FIG.
By inserting the mandrel 4 through the mandrel 4 without play, similar to the state used in audio products, video products, etc., the cylindrical body 1 can freely rotate relative to the mandrel 4 with respect to the inner periphery. Pivotally supported so that
After fixing the mandrel 4 near the center of both ends of the small-diameter cylindrical body 1 in this pivotally supported state, the cylindrical body 1 is The first major effect of grinding the outer surface is that the mandrel 4 can be inserted into the small-diameter cylindrical body 1 without play in the same state as the small-diameter cylindrical body 1 is placed in an audio product, etc. Therefore, if centerless grinding is performed in this state, the grinding will not follow the outer circumference of the small diameter cylindrical body 1, but will actually be ground around the axis called the core metal 4, based on the inner circumferential surface. Since it is used in audio products in the same state as the one in use, highly accurate concentricity can be obtained during use. Moreover, the second major effect is that the core amount is 4.
After inserting the mandrel 4, the mandrel 4 is fixed near both ends of the small-diameter cylindrical body 1, so even if the mandrel 4 has some deflection, the mandrel 4 will be fixed and will not rotate. During grinding, the small-diameter cylindrical body 1 can maintain a stable grinding state without wobbling, and the finish of the ground surface is also very good, making it possible to provide a high-quality product. The third major effect is that it is now possible to easily finish the small-diameter cylindrical body 1 to a value close to 0 with concentricity, which was almost impossible in the past. That's true.

Further, the equipment used in the precision grinding method described above also includes a rotating grinding wheel 2 and a regulating wheel 3.
A cylindrical body grinding machine that grinds the outer surface of a small-diameter cylindrical body 1 such as a guide roller used in audio products, video products, etc., which is placed at a grinding position between the two and The cylindrical body 1 is inserted into the cylindrical body 1 placed at the grinding position between the grinding wheel 2 and the regulating wheel 3 in the same state as when installed in an audio product, etc., without play. A mandrel 4 that supports the body 1 rotatably and is detachable from the cylindrical body 1.
Then, the mandrel fixing tool 5 fixes the inserted mandrel 4 near both ends of the small-diameter cylindrical body 1, and the regulating wheel 3 is brought into contact with the small-diameter cylindrical body 1 after hardening near the core 4, and the outer surface Two interlocking cams 13 actuate the mandrel fixing device 5 and the regulating wheel 3 to release the fixation of the mandrel 4 after separating the regulating wheel 3 from the cylindrical body 1 after completion of grinding. Since the structure is simple, it can be formed by improving a grinding machine or the like that has been used conventionally, and the equipment investment can be kept at low cost.

Since the operation of the mandrel fixture 5 and the regulating wheel 3 is performed by the interlocking cam 13, even if it is done manually, it can be done with one touch, which is extremely convenient for automation. Moreover, in this device, the operation of the grinding wheel 2 and the regulating wheel 3, the insertion and removal of the mandrel 4,
If all the operations of the interlocking cam 13 are controlled by the control device, the external surface grinding can be performed completely automatically with almost no human intervention, and thus costs can be reduced.

As explained above, according to this invention, concentricity (center wobbling), which was almost impossible in the past, can be reduced to zero.
It is possible to easily and inexpensively grind the outer periphery of a small diameter cylindrical body used for guide rollers, etc. of audio products, which has a value close to . This method has various excellent effects, such as requiring less investment in equipment, and allowing anyone to carry out high-precision grinding without any variation in accuracy without requiring skilled workers.

[Brief explanation of the drawing]

1 to 14 show an embodiment of the present invention, and FIG. 1 is a perspective process diagram when the mandrel is clamped and fixed;
Fig. 2 is a plan process diagram when the regulating wheel is in contact with the cylindrical body, Fig. 3 is a front process diagram when grinding the outer periphery, Fig. 4 is a plan process diagram of another embodiment, and Fig. 5 is a plan process diagram when the regulating wheel is brought into contact with the cylindrical body. The figure is a partially cutaway perspective view of the main part of the cylindrical external surface grinding device, Figure 6 is a front view with the motor removed, Figure 7 is a plan view, Figure 8 is a side view, and Figure 9 is the same cylinder. FIG. 10 is a front view of the cylindrical outer surface automatic grinding device, FIGS. 11 to 14 are schematic process diagrams during automatic grinding, and FIG. The figure is a perspective view showing the state in which the molded cylindrical body is used.
The figure is a schematic front view of the main parts of the centerless grinder. 1... Cylindrical body, 2... Grinding wheel, 3... Regulating wheel, 4... Core metal, 5... Core metal fixture, 5a... Lower clamping rod, 5b... Upper clamping rod. , 6... Fixed groove, 7... Base, 8... Table, 9... Cylindrical body support device, 10... Pivotal support,
11... Support rod, 12... Bearing, 13... Interlocking cam, 13a... Regulating wheel operating cam, 13b... Core metal fixture operating cam, 13c...
...Connection shaft, 14...Universal joint, 1
5... Rotating shaft, 16... Motor, 17... Operating arm, 18... Fulcrum, 19... Leverage rod, 20... Cam board, 21... Coil spring, 22... Coil spring, 23... Cam lever , 24...
Mountain, 25... Mountain, 26... End face grinding wheel, 27...
...stopper, 28...screw, 29...supply chute, 30...stopper pin, 31...cradle,
32... Frame, 33... Grindstone cutting slide, 34... Slide receiving plate, 35... Grindstone mounting base, 36... Grindstone drive motor, 37... Grindstone cover, 38... Positioning handle, 39... Discharge chute, 40... Roller shaft, 41... Fixed flange, 50... Material cylindrical, 51... Blade,
52... Grinding wheel, 53... Regulating wheel.

Claims (1)

[Claims] 1. A small-diameter cylindrical body such as a guide roller used in audio products, video products, etc. is supplied and arranged at the grinding position between the grinding wheel and the regulating wheel, and then By inserting the mandrel into this small-diameter cylindrical body without play, similar to the state used in audio products, video products, etc., this small-diameter cylindrical body can be inserted into the mandrel with the inner circumference as a reference. The small-diameter cylindrical body is rotatably supported, and the mandrel is fixed near both ends of the small-diameter cylindrical body in this supported state, and then the small-diameter cylindrical body is attached to a grinding wheel and a regulating wheel. A precision grinding method for the outer surface of a small-diameter cylindrical body, which is characterized by grinding the outer surface using a difference in rotational circumferential speed. 2. The precision grinding method for the outer surface of a small-diameter cylindrical body according to claim 1, wherein the mandrel is fixed by being held by opposing V-shaped fixing grooves of the mandrel fixture. 3 The regulation wheel is brought into contact with the small diameter cylindrical body and the mandrel is fixed by using two interlocking cams to bring the regulating wheel into contact with the small diameter cylindrical body after the mandrel is fixed. Precision grinding of the outer surface of a small-diameter cylindrical body according to claim 1 or 2, wherein the fixing of the mandrel is released after the regulating wheel is separated from the small-diameter cylindrical body after the completion of external surface grinding. Method. 4. Supplying the small diameter cylindrical body to the grinding position between the grinding wheel and the regulating wheel, inserting the mandrel into the small diameter cylindrical body supplied and arranged at the grinding position, fixing the mandrel, and grinding the grinding wheel. Grinding the outer surface of a small-diameter cylindrical body due to the difference in peripheral speed between the rotating wheel and the regulating wheel.
Claim 1, in which the operations of releasing the fixation of the mandrel after grinding the outer surface, removing the mandrel from the small-diameter cylindrical body, and discharging the small-diameter cylindrical body are performed in a series of sequential automatic steps. Or the precision grinding method for the outer surface of a small-diameter cylindrical body according to item 2 or 3. 5. A small-diameter cylindrical body such as a guide roller used in audio products, video products, etc., which is placed at the grinding position between the rotating grinding wheel and regulating wheel due to the difference in rotational circumferential speed between them. A small-diameter cylindrical body grinding machine that grinds the outer surface of a small-diameter cylindrical body, and a small-diameter cylindrical body placed at a grinding position between a grinding wheel and a regulating wheel, similar to the condition used for audio products, video products, etc. The small-diameter cylindrical body is inserted without any play, and is pivoted so that the small-diameter cylindrical body can rotate freely based on the inner periphery. After the mandrel is fixed near both ends of the cylindrical body, the regulating wheel is brought into contact with the small-diameter cylindrical body, and after the outer surface has been ground, the regulating wheel is removed from the small-diameter cylindrical body. Used for precision grinding of the outer surface of a small-diameter cylindrical body, characterized by comprising two interlocking cams that operate a mandrel fixing tool and a regulating wheel to release the fixation of the mandrel after they are separated. Device. 6. The device used for precision grinding of the outer surface of a small-diameter cylindrical body according to claim 5, wherein the mandrel fixing tool is formed to be clamped and fixed by opposing V-shaped fixing grooves. 7 The grinding machine, mandrel, and interlocking cam are used to place the small-diameter cylindrical bodies supplied one by one from the supply chute to the grinding position, insert the mandrel, and then insert the mandrel into the mandrel fixture. After the small-diameter cylindrical body is fixed, a grinding wheel and a regulating wheel are brought into contact with the small-diameter cylindrical body to perform external grinding.After grinding is completed, the grinding wheel and regulating wheel are separated from the small-diameter cylindrical body, and then the small-diameter cylindrical body is The small-diameter cylindrical body according to claim 5 or 6, which is controlled by a control device to automatically extract the mandrel from the cylindrical body and discharge the small-diameter cylindrical body from the discharge chute. A device used for precision grinding of the external surface of the body.