JP2000210848A - Tube inner surface grinding machine - Google Patents

Abstract

(57) [Problem] A tube inner surface polishing apparatus which does not cause uneven polishing even when a grindstone imitates the inner surface of a work, and can increase a feed amount of a moving table per one rotation of a work to increase a grinding efficiency. The purpose is to provide. SOLUTION: A head base 21 of a grinding head 17 is attached to a front end of a support arm 4 provided on a moving base 3 via a four-node parallel link 18. In the grinding head 17, a driving pulley 24 made of an elastic body is mounted on a distal end of a driving shaft 23 supported on a head base 21, and a driven pulley 26 is mounted on a distal end of a driven shaft 25 parallel to the driving shaft 23. And
A polishing belt 27 is wound around a driving pulley 24 and a driven pulley 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding apparatus suitable for removing projections such as burrs formed on the inner surface of a tube-shaped work.

[0002]

2. Description of the Related Art When a cylinder such as a tube is extruded or injection-molded, so-called burrs are generated on the inner and outer surfaces of the molded article. In the case of impregnated ceramics, for example, silicon-impregnated silicon carbide, projection-like burrs are generated on the inner surface of a tube-shaped workpiece by blowing out an impregnating agent such as silicon. In order to commercialize these products, these burrs must be removed.Conventionally, a small hand grinder with a grinding wheel attached to the tip is used to grind and remove the burrs generated on the inner surface of the tube-shaped work. I was

However, in a manual grinding operation using a hand grinder, burrs remain by mistake because the inner surface of the work other than the burrs is accidentally cut off or the burrs cannot be completely removed. There was a technical problem that would. In addition, there is a problem that the finish of the grinding operation differs depending on the skill of the operation, a problem that the operation time varies, and a problem that the muscle fatigue of the operator is large and inefficient due to manual operation.

In order to solve the problem of such a manual polishing operation, the applicant of the present invention has previously disclosed in Japanese Patent Application Laid-Open No. 9-2859.
No. 60 has proposed the invention described therein. An outline of a grinding apparatus according to the present invention is shown in FIGS. 5 and 6 and will be described based on the drawings. FIG. 5 is a side view of the grinding apparatus, in which the work is shown in cross section. FIG. 6 is a front view of FIG. This grinding device is provided on a work turntable 2 on which a work W is mounted and rotated, and a worktable provided for moving forward and backward toward the work W (substantially the same as a worktable 3 in FIG. 4 described later). It comprises a support arm 4 projecting in the direction of W, and a grinding head 5 provided at the tip of the support arm 4.

[0005] A drive pulley 8 is mounted on the end of the output shaft of a motor 7 mounted on the gantry 6 on the work turntable 2, and two sets of bearings 9 are provided on the upper surface of the gantry 6. Assembled. A rotating roller 10 is supported on each set of bearings 9, and a belt 12 is attached to a driven pulley 11 and a driving pulley 8 provided at the end of each rotating roller 10.
Is wound. Therefore, when the motor 7 rotates, the two rotating rollers 10 rotate via the belt 12, and the work W placed on the rotating roller 10 rotates.

A bent base end of a cantilever 13 is fixed to the lower surface of the distal end of the support arm 4 extending in the direction of the work W. A head base 14 of the grinding head 5 is fixed to a tip of the cantilever 13. The output shaft of a motor 15 attached to the head base 14 has a whetstone 1
6 is detachably mounted. The grinding apparatus configured as described above advances the movable table while rotating the work W by the work rotating table 2 and grinds the inner surface of the work W with the grindstone 16. 5
Is formed, and the burr 1 is ground.
In addition, the solid line described in the hatched portion in FIG. 5 indicates a single feed amount of the grindstone.

[0007]

The copying mechanism of this tube inner surface polishing apparatus is constituted by a cantilever 13 which is elastically deformed and deformed.
6 follows the inner surface of the workpiece W. However, if the inner surface of the workpiece W has undulation, the amount of bending deformation of the cantilever 13 changes in accordance with the displacement of the grindstone 16 following the undulation surface, and the whetstone 1
6 is tilted. Due to the inclination of the grinding stone 16, the grinding stone 1
Since the corner where the end face of No. 6 intersects the grinding surface (outer peripheral surface) hits the inner surface of the work W, that is, the grinding surface (outer peripheral surface) of the grindstone 16 hits the inner surface of the work W, causing uneven polishing. There was a technical challenge. In addition, since the width of the grindstone 16 is generally small, there is a problem that a feed amount of the movable table per one rotation of the work W is small and a grinding time is long.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and does not cause uneven polishing even when a grindstone imitates the inner surface of the work, and increases the feed amount of the movable table per one rotation of the work. It is an object of the present invention to provide a tube inner surface polishing apparatus capable of improving the grinding efficiency.

[0009]

According to a first aspect of the present invention, there is provided a tube inner surface grinding apparatus for mounting a tube-shaped workpiece horizontally and rotatably. A work rotating table, a movable table having a support arm that is provided to be able to advance and retreat in parallel with the inner surface of the work, and has a support arm protruding in the work direction; The grinding head is mounted on the tip of the support arm via a four-node parallel link, a drive shaft supported by the head mount and rotated by a rotary drive source, and mounted on the drive shaft. A drive pulley made of an elastic body, a driven shaft supported by the head base and parallel to the drive shaft, a driven pulley mounted on the driven shaft, and a lap wound around the driven pulley and the drive pulley. A belt, is characterized in that the polishing belt and a copying mechanism is biased in a direction to contact the inner surface of the workpiece.

With the above configuration, even if the grindstone is displaced following the inner surface of the work, the head bar is not inclined by the four-node parallel link, so that the polishing belt is not inclined.
As a result, uniform grinding can be performed without causing unevenness in grinding on the inner surface of the work as in the related art. Further, since the polishing belt has a wide grinding surface, the moving amount of the grinding head per one rotation of the work can be increased, and the grinding efficiency is increased.

Here, as set forth in claim 2, the copying mechanism is preferably constituted by a balancer provided on the rear side of the four-node parallel link for supporting the polishing head.
Such a copying mechanism has a simple structure and can be configured at a low cost. Further, by changing the weight of the balancer, the grinding pressure can be set arbitrarily, and good grinding can be performed.

It is preferable that a plurality of grinding heads are provided at the tip of the support arm via the four-node parallel link. With this configuration, by simultaneously polishing the inner surface of the work with each grinding head, the grinding efficiency can be increased a plurality of times and the grinding operation can be made more efficient.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view of a grinding head in a tube inner surface grinding apparatus of the present invention, FIG. 2 is a side view of the grinding head during workpiece grinding, FIG. 3 is a front view of FIG. 2, and FIG. 4 is a side view of the entire tube inner surface grinding apparatus. It is. 2 and 4
The work is shown in section in FIG. As shown in FIG. 4, the tube inner surface grinding apparatus according to the present invention includes a work rotating table 2 on which a work W is placed, a movable table 3 that moves toward and away from the work W, and a grinding provided at the tip of the movable table 3. It is constituted by a head 17. The work rotating table 2 and the moving table 3 are the same as the conventional example, but the grinding head 17 described below is different from the conventional example.

The grinding head 17 is attached to the distal end of the support arm 4 of the movable table 3 via a four-node parallel link 18. The support arm 4 is provided in parallel with the inner surface of the work W (with respect to an axis passing through the rotation center of the work W). As shown in FIG. 1, the four-bar parallel link 18 includes a first arm 19 pivotally attached to the distal end of the support arm 4.
And a second arm 20, and a head base 21 of the grinding head 17 pivotally attached to the tip of the first arm 19 and the second arm 20.

The first arm 19 and the second arm 20 are parallel to each other, and the distance between the pivot points before and after the first arm 19 is equal to the distance between the pivot points before and after the second arm 20. The distance from the pivot point at the rear of the first arm 19 to the pivot point at the rear of the second arm 20 is the distance from the pivot point at the front of the first arm 19 to the second pivot point.
It is equal to the distance to the pivot point at the front of the arm 20. Therefore, even if the four-node parallel link 18 swings, the direction of the head base 21 does not change, and the head base 21 moves parallel to the support arm 4.
That is, a polishing belt 2 described later provided on the head table 21
7 moves in a direction perpendicular to the inner surface of the work W as shown in FIG. 2B, the polishing surface of the polishing belt 27 always hits perpendicularly to the inner surface of the work W.

A rear end of a drive shaft 23 supported on a vertical wall 21a of the head base 21 is connected to an output shaft of a motor (rotation drive source) 22 mounted on the head base 21. An elastically deformable drive pulley 24 is mounted. A driven shaft 25 parallel to the drive shaft 23 is supported by the vertical wall 21a of the head base 21 and is mounted on the front end of the driven shaft 25. A polishing belt 27 is wound around a driven pulley 26 and a drive pulley 24. I have. Thus, the grinding head 17 including the polishing belt 27 that grinds the inner surface of the work W by the rotation of the motor 22 is configured.

The four-node parallel link 18 is provided with a balancer 28 that generates a rotational moment in the direction to cancel the rotational moment because the rotational moment is generated by the own weight of the grinding head 17. The balancer 28 is the first
It comprises a lever 28a which is bent from the arm 19 and extends in the direction opposite to the grinding head 17, and a plurality of weights 28b which are detachably attached to the end of the lever 28a.

The rotational moment of the balancer 28 due to its own weight is slightly smaller than the rotational moment of the grinding head 17 due to its own weight.
A copying mechanism for urging in a direction in which the inner surface contacts the inner surface is configured. The contact pressure of the copying mechanism can be adjusted by adjusting the weight 28b.

Since the grinding head 17 has a simple structure by adopting the above-described structure, it can be made compact. When the inner diameter of the work W is large, a plurality of grinding heads 17 (two in FIG. 3) can be arranged as shown in FIG. In this case, each of the grinding heads 17 is separately provided with a four-node parallel link 1.
8 can be provided, but it is preferable to mount a plurality of grinding heads 17 on one four-node parallel link 18 in order to simplify the structure of the grinding head 17.

Next, the work of grinding the work W by the tube inner surface grinding apparatus configured as described above will be described with reference to FIGS. The work W is placed on the rotating roller 10 of the work rotating table 2 and the work W
Rotates counterclockwise as shown in FIG. On the other hand, the polishing belt 27 of the grinding head 17 is rotated clockwise.

When the movable table 3 is moved while the polishing belt 27 is in contact with the inner surface of the end of the work W, the inner surface of the work W is polished in a spiral shape (shaded portion in FIG. 2).
The polishing belt 27 rotates while contacting the inner surface of the work W with a constant contact pressure, and when there is undulation on the inner surface of the work W, the driving pulley 24 elastically deforms and the ground surface follows the undulation. There is no wobble of the grindstone as in the conventional example.

In addition, when the height of the inner surface of the work W is higher than the moving direction of the moving table 3, the four-node parallel link 1
Since the polishing belt 27 follows the inner surface of the work W by the copying mechanism constituted by the balancer 8 and the balancer 28, there is no possibility that the grinding pressure becomes too large or too small. Also, even if the four-node parallel link 18 operates, the direction of the polishing belt 27 does not change,
Since it moves parallel to the support arm 4, the grinding surface does not hit one side. Thus, the burrs 1 protruding from the inner surface of the work W are removed.

[0023]

Since the present invention is configured as described above, it has the following effects. (1) Since the tube inner surface grinding device according to the present invention uses a polishing belt, the grinding width is wide, and therefore, the grinding feed amount per one rotation of the work can be increased. (2) Since the tube inner surface grinding apparatus according to the present invention uses an elastic body for the driving pulley of the polishing belt, even if the inner surface of the work has undulation, the grinding surface can be adjusted to undulation, and the grinding wheel piece can be formed. Uniform grinding can be performed without hitting. (3) In the tube inner surface grinding apparatus according to the present invention, since the grinding head does not tilt even if the grinding head is displaced following the inner surface of the work, it is possible to prevent the grinding head from hitting one side by the copying operation, and to achieve uniformity. Grinding can be performed. (4) The tube inner surface grinding apparatus according to the present invention is inexpensive and compact because the structure of the grinding head is simple. Therefore, the tube inner surface grinding device can be equipped with a plurality of grinding heads according to the inner diameter of the tube inner surface, and the grinding efficiency can be increased.

[Brief description of the drawings]

FIG. 1 is a perspective view of a grinding head which is a main part of a tube inner surface grinding apparatus according to the present invention.

FIG. 2A is a side view of a grinding head during work grinding, and FIG. 2B is an enlarged view of a circle in FIG.

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a side view of the entire tube inner surface grinding apparatus.

FIG. 5 is a main part side view showing a conventional example of a tube inner surface grinding apparatus.

FIG. 6 is a front view of FIG. 5;

[Explanation of symbols]

 W Tube-shaped work 1 Burr 2 Work turntable 3 Moving table 4 Support arm 5 Grinding head 17 Grinding head 18 Four-node parallel link 19 First arm 20 Second arm 21 Head table 24 Drive pulley 27 Polishing belt 28 Balancer

Claims (3)

[Claims] 1. A work rotation table on which a tube-shaped work is horizontally and rotatably mounted, and a support arm provided so as to be able to advance and retreat in parallel with an inner surface of the work, and protruding in the work direction. A moving table, and a grinding head provided at a tip of the support arm, wherein the grinding head is mounted on a tip of the support arm via a four-node parallel link; A drive shaft supported by the rotary drive source and rotated by a rotary drive source, a drive pulley made of an elastic body mounted on the drive shaft, a driven shaft supported by the head base and parallel to the drive shaft, and mounted on the driven shaft. A driven pulley, a polishing belt wound around the driven pulley and the driving pulley, and a copying mechanism for urging the polishing belt in a direction of contacting an inner surface of the work. Tube internal grinding device. 2. The copying mechanism is a balancer provided on the rear side of the four-node parallel link, and the moment of the four-node parallel link due to the weight of the balancer is opposite to the moment due to the weight of the grinding head. 2. The tube inner surface grinding apparatus according to claim 1, wherein the weight is slightly smaller due to its own weight on the grinding head side. 3. The tube inner surface grinding apparatus according to claim 1, wherein a plurality of grinding heads are provided at a tip of the support arm via the four-node parallel link.