JPH0632897B2 - Polishing method in profile rotary sander - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Purpose of the Invention><Industrial Application Field> The present invention relates to a polishing method in a profile rotary sander for automatically polishing the periphery of a flat plate-shaped workpiece,
In particular, the pressing force of the presser pad is increased / decreased according to the magnitude of the curvature of the peripheral edge.

<Prior Art> Generally, a profile rotary sander is used for polishing a plate-like peripheral edge of a material for wooden furniture, a material for a wooden musical instrument, or the like. This is a kind of belt sander,
A sanding belt is suspended on a pulley arranged in a triangular shape, a presser pad is attached to the inside of the pulley, and the sander belt is pressed by the presser pad to a polishing target portion on the periphery of a workpiece to polish the sanding belt. . Of course, this device is an automatic machine, which consists of a sanding machine with a sanding unit as a main body and a holding device for the work piece, and while attaching the work piece to the holding device and rotating it, or The material is fixed, and the sanding unit is moved along the peripheral edge of the material to be processed while rotating the sanding board to polish the material.

By the way, in the belt sander, the presser pad is formed in an appropriate length, and the pressing surface has a shape corresponding to the shape of the surface to be polished of the workpiece, and the sanding belt makes surface contact with the surface to be polished. However, if there is a curved portion (corner portion) on the periphery of the work material, the shape of the pressing surface of the presser pad corresponds to the shape of the surface to be polished at that portion. As a result, the contact area of the sanding belt with the surface to be polished is reduced. In other words, in this portion, the pressure contact force per unit area of the sanding belt with respect to the polishing surface increases. Therefore, since the amount of polishing in this part is large,
There was a problem with the shavings.

In order to eliminate such a problem, conventionally, in the curved portion of the peripheral edge of the work material, a method of increasing the moving speed of the sanding unit with respect to the peripheral edge to shorten the polishing time has been attempted. However, in this method, it is extremely difficult to control the polishing amount and the polishing amount is not constant,
Moreover, it is unavoidable that the finish is rough and uneven.

Further, as an invention for facilitating the polishing process at the corner portion of such a work material, JP-A-51-43293.
No. "Pressure force automatic control device" exists. This product is configured so that the contact roll, in which the sanding belt comes into direct contact with the work material, is deflected when it reaches the corner, and when the deflected condition is seen, the cylinder that supports the entire sanding unit is driven. It is a method of adjusting the pressure contact force. However, with such a method,
In the sanding method using the sanding belt of this type, for example, the processing speed of the workpiece is 5 to 8 m / min, which is an extremely high feed rate. Therefore, the heavy sanding unit is entirely shifted. In the case of the mechanism, it cannot follow up completely and has not been practically used.

<Technical Items Attempted to Develop> The present invention has been made in consideration of such a conventional technique, and the polishing processing in the curved portion of the peripheral edge of the workpiece is uneven compared to other ranges. This is an attempt to develop a new polishing method that can prevent such a phenomenon.

<Structure of the Invention><Means for Achieving Object> A polishing method for a profile rotary sander of the present invention includes a work holding device and a sanding processing board provided near this work holding device, and the work holding device is a base. It has a work table attached to the base via a rotary support shaft, while the sanding machine has a movable base that can be moved back and forth with respect to the base, and a swing support shaft is centered on this movable base. A swivel base that can be swung freely, a mounting frame that is mounted to the pair of left and right support posts mounted on the swivel frame so that it can move back and forth, and can be raised and lowered, and a sanding belt that runs on a substantially planar triangular path. And a sanding unit that is tiltably attached to the attachment frame and has a part of the sanding belt. In a device that performs polishing by rubbing against a work material, the pressure contact state of the sanding belt with respect to the work material at the work site is set at the back of the work site by the pressing force of the presser pad, and the work material is bent. It is characterized in that the pressing force is adjusted according to the curvature of the formed portion to appropriately adjust the pressure contact force per unit area of the sanding belt with respect to the surface to be polished of the work material. Is what you are trying to do.

<Example> A polishing method in the profile rotary sander of the present invention will be specifically described below. In the following description, the structure of the profile rotary sander for carrying out the present invention will be described, and the operating state thereof will be described, as well as the method of the present invention.

In the figure, reference numeral 1 is a work holding device provided in the central portion of the device for holding a work material A, and one or more sanding worktables 2 are provided near the side of the work holding device. It is provided so as to face the device 1. The figure shows an example of a method of polishing the outer peripheral edge of the work material A while rotating the work material A. Therefore, the work holding device 1 is provided with a mechanism for turning the work material A,
On the other hand, the sanding board 2 is provided with an advancing / retreating mechanism and a swinging mechanism of the sanding unit. This device will be described in more detail.

First, the work holding device 1 will be described. Reference numeral 10 is a base on which a boss 11 is erected at the center thereof, and a work table 12 is rotatably supported by the boss 11. A rotary shaft 13 is attached to the lower surface of the work table 12, and a drive motor 14 is connected to the rotary shaft 13 via a rotation transmission mechanism such as a worm gear.
The rotation of the drive motor 14 is transmitted to the work table 12.

Further, above the work table 12, the work holding plate 15
Is provided. This is for fixing the workpiece A by pressing it on the work table 12, and
Rotatably at the tip of the support frame 16 extending from the corner of
Moreover, it is attached so that it can be raised and lowered.

By the way, since the workpiece A is subjected to a lateral pressure of a considerably strong force during machining, it is important to mount the workpiece table 12 so as to withstand the lateral pressure and not shift on the work table 12.

Next, the sanding processing board 2 will be described. Although two sanding processing boards 2 are provided on both sides of the work table 12 in the figure, the sanding processing board 2 is not limited to this, and one or three or more sanding processing boards 2 may be provided. The sanding processing board 2 is composed of a base, a support and a sanding unit 21.
According to the shape of the surface to be polished, the polishing surface of the sanding unit 21 can be inclined to process the surface to be polished into a desired shape, and according to the turning of the material A to be processed. It is configured to always face the surface to be polished while advancing and retreating. Reference numeral 22 is a fixed mount,
23 is a movable mount, and 24 is a swivel mount. These are the bases that support the sanding unit 21, and are used to cause the sanding unit 21 to perform a forward / backward movement and a swinging motion.The swivel base 24 is swingably supported by the movable base 23, The board 23 is supported by a fixed base 22 so as to be movable back and forth. That is, the work holding device 1 is provided on the upper surface of the fixed base 22.
There are two rails 25 facing toward.
A movable base 23 is slidably attached to 25. A male screw rod 26 is attached to the fixed base 22 in parallel with the rail 25, while a female helix 27 is attached to the movable base plate 23, which is screwed to the male screw rod 26 and has a drive motor. 28
By moving the male screw rod 26 forward and backward, the movable base 23 is moved forward and backward. The movable base 23 has a rear end formed in an arc shape, a rail 29 is attached to the movable base 23, and a swing support shaft 30 is erected at the center of the movable base 23. It is attached freely. A drive wheel 31 that meshes with the rail 29 is attached to the rear end of the swivel base 24. The drive wheel 31 is further connected to a drive motor 32 via a bevel gear or the like, and the drive wheel 31 is normally or reversely rotated. By doing so, the swivel base 24 is swung around the swivel support shaft 30.

Next, the support base will be described. The support base is composed of a support post 33 and a mounting frame 34, and the sanding unit 21 is mounted on the mounting frame 34. Since these are similar to those of an ordinary profile rotary sander of this kind, detailed description of the structure will be omitted, but the support post 33 is reciprocally attached to the swivel base 24 left and right, while the support post 33 is attached. The frame 34 is supported by a support post 33 so as to be able to move back and forth and to move up and down. The sanding unit 21 is mounted on the mounting frame 34 so that the elevation angle can be adjusted, and the sanding unit 21 can be positioned in accordance with the thickness of the workpiece A, the surface angle of the surface to be polished, or the shape of the presser pad described later. The depression / elevation angle is adjusted so that the polishing surface of the sanding unit 21 matches the surface to be polished.

Next, the sanding unit 21 attached to the attachment frame 34 will be described. First, the drive motor 36 is attached to the rear of the substrate 35, the pulley 37 is attached to the output shaft thereof, and the pair of left and right guide pulleys 38 are attached to the front of the substrate 35.
Install 39. One of these guide pulleys 38 is the substrate
On the other hand, the guide pulley 39 is fixedly attached to the base plate 35, and the guide pulley 39 is attached to the base plate 35 via the revolving arm 40 so that the guide pulley 39 is always biased outward by compressed air or the like. This drive motor 36 pulley 37 and guide pulley 38,
A sanding belt 41 is stretched around a track formed by 39 and forming an approximately isosceles triangle. The sanding belt 41 is formed by fixing abrasive grains to the surface of a base belt material, and the surface of the workpiece A is polished on the polishing surface. A presser pad 42 is applied to the sanding belt 41 between the guide pulleys 38 and 39 and on the back of the guide pulleys 38 and 39 to obtain a desired processed cross-sectional shape. That is, the front surface shape of the presser pad 42 has a shape substantially similar to the cross-sectional shape required for processing the work material A, and the sanding belt is guided and deformed along the shape to obtain a desired processed shape. Of. Since such a point is the same as that in the already known sander, further detailed description will be omitted.

Next, the shift mechanism of the presser pad will be described. Reference numeral 43 is a pair of left and right guide rails attached to the board 35, and is a support bracket that is raised from the board 35.
It is horizontally attached to the tip of 44. A slider 45 is attached to this guide rail, and the presser pad 42 is attached to the front center of the slider 45. Note that the presser pad 42 is exchanged in order to appropriately change the processing shape, and therefore is bolted exchangeably. A cylinder 46 for controlling a standby state and an operating state of the presser pad 42 is attached to the slider 45. This cylinder 46 is
When the contracted state is released to be in a free state, the presser pad 42 integrated with the slider 45 is allowed to move freely. The slider 45 receives the shift arm 48 of the actuator 47 at the rear thereof.
That is, an actuator is provided on the side surface of the substrate 35 as an example.
47 units are attached, and a shift arm 48 is attached to the output shaft.
Of the shift arm 48 is connected to the arm receiving portion 49 of the slider 45. With such a configuration, the slider 45 that can freely move in a state where the contraction of the cylinder 46 is released, and the presser pad integrated with the slider 45.
The actuator 42 is constructed so as to always be projected forward with a cushioning effect in response to the forward movement tendency due to the rotation of the shift arm 48 of the actuator 47. The above is the mechanical configuration of the work holding device 1 and the sanding processing board 2. In the present invention, the workpiece A is rotated and the sanding unit 21 is moved forward and backward and while swinging. It is configured to polish the peripheral edge of the material A,
In particular, these are provided with a CNC control device such as a numerical control driver box and a control box with a built-in computer. The rotary movement of the work material A and the forward / backward movement of the sanding board 2 and the sanding unit are carried out according to pre-input numerical values. Twenty-one swinging movements are automatically performed. Therefore, the drive motor 14,
28 and 32 are connected to a CNC controller and rotate automatically. An example in which two sanding boards 2 are symmetrically provided on the left and right of the work holding device 1 is shown, but in most cases, a chamfering cutter unit is additionally provided.
Needless to say, this is also numerically controlled like the sanding board 2.

Next, a work procedure for polishing the peripheral edge of the work material A will be described. First, a program corresponding to the work material A is input to the computer to adjust the attitude of the sanding unit 21. This adjustment is performed so that the polishing surface of the sanding unit 21 is brought into proper contact with the surface to be polished of the work material A. The support post 33 is moved to the left and right, the mounting frame 34 is moved up and down, and moved back and forth. Sanding unit 21
In addition, the tilt angle of the position is adjusted. At this time, the cylinder 46 contracts and the slider 45 is pulled back rearward. Therefore, the presser pad 42 attached to the slider 45 is also pulled back, the sanding belt 41 is on the straight line connecting the guide pulley 38, and even if the sanding unit 21 advances to a predetermined position, the sanding belt 41 Does not come into contact with the work material A. Next, the work material A is attached at a predetermined position on the work table 12 in a predetermined posture, and is pressed and fixed by lowering the work pressing plate 15 from above. And finally, the control device is started. Then, the drive motor 36 is activated to rotate the sanding belt 41, and the drive motors 28 and 32 are activated to advance the sanding unit 21 to a predetermined position and face the surface to be polished of the workpiece A. . Subsequently, the drive motor 14 is activated to rotate the workpiece A, the cylinder 46 extends, and the slider 45 advances to a certain position. Then, the presser pad 42 projects the sanding belt 41 from the inner side, and further the sanding belt 41 is brought into contact with the surface to be polished to polish it. By the way, in this apparatus, the contact area of the polishing action surface of the sanding unit 21 with respect to the surface to be polished is different between the linear portion and the curved portion of the workpiece A, and the contact area becomes smaller as the radius of curvature becomes smaller. . Therefore, in the portion where the peripheral edge of the work material A is curved, the pressing force of the presser pad 42 is adjusted according to the curvature, and the pressing force per unit contact area is stretched,
This prevents excessive cutting of this part. As a method of adjusting the pressing force, a pressure regulator is attached between a compressor (not shown) and the actuator 47, and the air pressure is adjusted according to the curvature of the portion to be polished by communicating this with a control device. Alternatively, two or more regulators with different adjustment pressures are connected in parallel to the actuator 47, and an on-off valve is attached to each, and these are connected to a control device to open any one of the on-off valves for adjustment. .

<< Effects of the Invention >> The present invention has the configuration as described above, and by adjusting the pressing force of only the presser pad 42 having a relatively small mass, the rubbing pressure of the sanding belt 41 on the workpiece A is adjusted. Therefore, the pressure setting to be adjusted can be instantaneously changed.

[Brief description of drawings]

FIG. 1 is a plan view showing an outline of a polishing operation state, FIG. 2 is a side view of the same as above, and FIG. 3 is a plan view showing essential parts. 1; Work holding device 2; Sanding machine 10; Base 11; Boss 12; Work table 13; Rotating shaft 14; Drive motor 15; Work holding plate 16; Support frame 21; Sanding unit 22; Fixed frame 23; Movable table Board 24; Revolving mount 25; Rail 26; Male screw 27; Female spiral 28; Drive motor 29; Rail 30; Revolving spindle 31; Drive wheel 32; Motor 33; Support post 34; Mounting frame 35; Board 36; Drive motor 37; pulley 38; guide pulley 39; guide pulley 40; swivel arm 41; sanding belt 42; presser pad 43; guide rail 44; bracket 45; slider 46; cylinder 47; actuator 48; shift arm

Claims (1)

[Claims] 1. A work holding device, and a sanding processing board provided near the work holding device, wherein the work holding device has a work table attached to a base via a rotary support shaft. On the other hand, the sanding machine is a movable base that can be moved forward and backward with respect to the base, a swing base that is rotatable on the movable base around a swing support shaft, and the left and right mounted on this swing base. A mounting frame that is attached to the pair of support posts so as to be able to move forward and backward and to be raised and lowered, and a sanding unit that has a sanding belt that travels in a substantially planar triangular path, and that is tiltably attached to the mounting frame. In an apparatus for polishing by rubbing a part of the sanding belt against a material to be processed, The pressure contact state of the workpiece with respect to the work material is set by the pressing force of the presser pad provided on the rear part of the processing site, and the pressing force is adjusted according to the curvature of the curved part of the work material to adjust the work material. A polishing method for a profile rotary sander, which is characterized by appropriately adjusting a pressure contact force per unit area of a sanding belt with respect to a surface to be polished.