JP7061289B2 - Barrel polishing method - Google Patents

Description

The present invention relates to a barrel polishing method capable of reducing damage generated on the surface of a workpiece when polishing a part (workpiece) composed of a hard and brittle material, a metal, a synthetic resin and a composite material.

As a barrel polishing machine that performs barrel polishing such as deburring, surface roughness adjustment, rounding, gloss finishing, etc. of the work piece, multiple barrel tanks loaded with mass are centered on the axis parallel to the ground. Rotating rotary barrel grinding machines and centrifugal barrel grinding machines are known. The rotary barrel grinding machine is a type that rotates the barrel tank, and is disclosed in, for example, Patent Document 1. The centrifugal barrel grinding machine is a type that causes the barrel tank to make planetary motions (rotation and revolution), and is disclosed in, for example, Patent Document 2.
Here, the mass is a general term for a work piece and a polishing medium to be charged into a barrel tank.

Japanese Unexamined Patent Publication No. 55-131464 Japanese Unexamined Patent Publication No. 57-173459 Japanese Unexamined Patent Publication No. 03-033023

When a workpiece made of a hard and brittle material (a material that is hard but vulnerable to impact and easily cracked) is polished by a rotary barrel grinder or a centrifugal barrel grinder, the corners and edges are cracked or chipped. Damage such as (chipping) occurs.

Hard and brittle materials are widely used as materials for various electronic components such as multilayer ceramic capacitors (MLCCs), inductors and crystal oscillators. Since electronic components are required to have high performance and miniaturization, there is a demand for a polishing device and a polishing method in which the workpiece does not crack or chip during polishing.

For example, Patent Document 3 discloses that an optical element such as a glass optical lens is smoothly processed by a barrel polishing method. However, the barrel polishing method that does not cause damage is not disclosed.

In the present technical field, a barrel polishing method capable of reducing damage such as cracks, chips, dents, deformations, scratches, etc., when polishing a work piece made of a hard and brittle material is desired. ing.

One aspect of the present invention is a barrel polishing method using a barrel polishing machine that polishes the workpiece by rotating the barrel tank itself into which a mass containing a workpiece and a polishing medium is charged.
This barrel polishing method includes the following steps (1) and (2).
(1) Step of putting mass containing work piece and polishing media into a sealable barrel tank (2) Rotate the barrel tank around the axis of rotation to fluidize the mass and put it into the work piece. On the other hand, the process of polishing the workpiece by rubbing the polishing media.
Then, in the step (2), the collision between the workpieces is controlled while the barrel tank is accelerated from the start of rotation until the rotation speed reaches a steady speed.

In one embodiment of the present invention, in the step (2) described above, the workpiece may be put into the barrel tank in a state where the workpiece is mixed in the layer formed as an aggregate of the polishing media.

In one embodiment of the invention, the mass further comprises abrasive grains, which grind the workpiece and are covered while the barrel tank is accelerated from the start of rotation until the rotational speed reaches its maximum. You may control the collision between the workpieces.

In one embodiment of the present invention, in the step (2) described above, the workpiece may be set between two layers formed as an aggregate of polishing media.

In one embodiment of the present invention, in the step (2) described above, the workpiece may be set in the layer formed by the abrasive grains located between the two layers formed by the polishing medium.

In one embodiment of the present invention, the workpiece may be a hard and brittle material.

According to one aspect and one embodiment of the present invention, it is possible to reduce damage to the workpiece and to polish the workpiece satisfactorily.

It is a schematic diagram which shows the barrel grinding machine used in one Embodiment of this invention. 1 (A) is a front view, and FIG. 1 (B) is a sectional view taken along the line AA in FIG. 1 (A). 2A, 2B, and 2C are schematic views for explaining a method of setting a workpiece in the barrel polishing method according to the embodiment of the present invention, and FIG. 2D is a conventional barrel polishing method. It is a schematic diagram for demonstrating the setting method of the workpiece in the above. It is a schematic diagram which shows the movement of mass in barrel polishing. It is a flowchart which shows the barrel polishing method of one Embodiment of this invention. It is a schematic diagram which shows the measurement point in the evaluation of the barrel polishing method of one Embodiment of this invention. It is a schematic diagram explaining another form of the barrel polishing method of this invention. It is a schematic diagram explaining another form of the barrel polishing method of this invention.

An embodiment of the present invention will be described with reference to the drawings. Here, a centrifugal barrel polishing machine will be described as an example as the barrel polishing machine. The "vertical, horizontal, and horizontal directions" in the following description refer to the directions in the figure unless otherwise specified.

First, the barrel grinding machine according to the embodiment of the present invention will be described. As shown in FIG. 1, the barrel grinding machine 10 includes four barrel tanks 11 into which masses are charged, four barrel tank cases 12 to which the barrel tanks 11 are detachably fixed, and a barrel tank case 12. A pair of turrets 13 (revolving disks) that rotatably fix the barrel, a revolving shaft 14 that is fixed to the center of the plane of the turret 13, a drive mechanism 15 that rotates the turret 13 about the revolving shaft 14 as an axis, and a turret 13. A driven mechanism 16 that rotates the barrel tank case 12 in accordance with the rotation of the barrel, a base 17 that fixes the revolving shaft, a control mechanism 18 that controls the operation of the barrel grinding machine 10, and a housing 19 that houses them. To prepare for. Note that FIG. 1 shows only the two barrel tanks 11 and the two barrel tank cases 12 for convenience.

The barrel tank 11 has a cylindrical space having a cross section (polygonal (octagonal in one embodiment) formed in the cross section (FIG. 1B) inside. The barrel tank main body 11a having an open upper surface and the opening thereof. It is composed of a barrel tank lid 11b that can seal the portion and seal the internal space, and a lid fixing mechanism (not shown) for fixing the barrel tank lid 1 to the barrel tank main body.

The barrel tank case 12 detachably fixes the barrel tank 11. The frame body 12a in which the barrel tank 11 is housed, the rotation shaft 12b fixed to both ends of the frame body 12a, and the barrel tank 11 housed in the frame body 12a are locked, and the barrel tank lid 11b is used as the barrel tank. It is provided with a locking mechanism 12c for being brought into close contact with the main body 11a.

The rotation shaft 12b pivotally supports the barrel tank case 12 on the turret 13 as described later.

The barrel tank fixing mechanism 12c is fixed so as to be erected on the frame body 12a, and is provided with a guide member 12d having a hole in which the support member 12e is loosely fitted in the upper portion and a screw hole penetrating in the center. A plate-shaped support member 12e, a screw member 12f screwed into the screw hole, a pressing handle 12g provided at the upper end of the screw member 12f for rotating the screw member 12f, and the screw member. It includes a pressing member 12h provided at the lower end of 12f for pressing the barrel tank lid 11b toward the barrel tank main body 11a.

After the barrel tank 11 is loaded into the frame body 12a, the support member 31d is idled so that the pressing member 12h is located in the vertical direction of the center of the barrel tank lid 11b (perpendicular to the top surface of the barrel tank lid 11b). Fit. Then, by rotating the pressing handle 31f, the pressing member 31g is advanced toward the barrel tank lid 11b. As a result, the barrel tank lid 11b is pressed against the barrel tank main body 11a to completely seal the internal space, and at the same time, the barrel tank 11 is fixed to the barrel tank case 12.

The turret 13 has a disk shape, a hole through which the revolution shaft 14 can be inserted is formed in the center of the plane of the turret 13, and a first bearing 13a capable of rotatably fitting the revolution shaft 14 is formed in each hole. It is provided. The turret 13 is rotatably supported by a revolution shaft 14 fixed to the base 17 via a first bearing 13a. Further, the turret 13 is provided with a plurality of second bearings 13b at equal intervals along the circumferential direction of the first bearing 13a. These second bearings 13b are individually fitted to the rotation shafts 12b of the plurality of barrel tank cases 12, and each barrel tank case 12 is rotatably supported. With this configuration, the four barrel tank cases 12 are arranged between the turrets 13 at equal intervals and rotatably relative to the turrets 13.

The revolution shaft 14 is pivotally supported by the base 17 so as to be tilted at a predetermined angle with respect to the ground. Similarly, the rotation shaft 12b pivotally supported by the second bearing 13b provided on the turret is also pivotally supported so as to have a predetermined angle with respect to the ground. That is, the barrel tank 12 is arranged so as to be tilted at an angle θ by the base 17.

The drive mechanism 15 includes a drive motor 15a, a motor pulley 15b, a revolution pulley 15c, and a drive belt 15d. The motor pulley 15b is fixed to the rotating shaft of the drive motor 15a. The revolution pulley 15c is provided on the outer periphery of one of the pair of turrets 13 (left side in FIG. 1). The drive belt 15d is bridged between the motor pulley 15b and the revolution pulley 15c.

The driven mechanism 16 includes a drive pulley 16a, a driven pulley 16b, and a driven belt 16c. The drive pulley 16a is fixed to the revolution shaft 14. The driven pulley 16b is fixed to the rotating shaft 12b. The driven belt 16c is bridged between the driving pulley 16a and the driven pulley 16b.

The control means 18 includes an input means 18a for inputting the operating conditions of the barrel polishing machine 10 and a storage means 18b for storing the input operating conditions and outputting a signal for operating the barrel polishing machine.

When the drive motor 15a is operated, the turret 13 rotates around the revolution shaft 14. Along with the rotation of the turret 13, the barrel tank 11 fixed to the barrel tank case 12 rotates (revolves) around the revolution shaft 14. Further, the driven mechanism 16 rotates (rotates) the barrel tank 11 in the direction opposite to the rotation direction of the turret 13 with the rotation shaft 12b as the axis.

At this time, the operation of the drive motor 15a is controlled by the signal from the storage means 17b so as to accelerate the rotation of the barrel tank to the optimum rotation speed for barrel polishing in a predetermined time.

As described above, the barrel tank 11 can rotate by its own rotation and revolve by the rotation of the turret 13, that is, it can perform planetary motion. These rotations are performed around the axis of rotation that is horizontal to the ground.

Next, the barrel polishing method will be described with reference to FIGS. 2 to 6. Here, a case where a 20 mm × 20 mm × t1.0 mm quartz plate is barrel-polished for the purpose of round chamfering of corners will be described as an example.

<S01: Mass input process>
First, the barrel tank lid 11a is removed, and the workpiece 20, the polishing medium 30, water, and the polishing aid (compound) are put into the barrel tank main body 11b. This charging method will be described later.

The polishing media 30 includes a type in which abrasive grains are bonded to each other with a vitrified binder (ceramics media), a type in which abrasive grains are bonded to each other with a resin (resin media), a type composed of metal (metal media), and a plant-based medium. It can be appropriately selected from a type (plant-based media) that is a crushed product such as seeds.

The type and amount of the compound can be appropriately selected depending on the purpose of the compound. The object can be any one of (1) to (10), for example.
(1) Improvement of polishing power (2) Cleaning of polishing media and maintenance of polishing power (preventing clogging of polishing media)
(3) Cleaning of the workpiece (4) Improvement of glossiness of the workpiece (5) Removal of scale of the workpiece.
(6) Removal of oils and fats on the work piece (7) Gives the work piece a rust preventive effect or prevents discoloration of the work piece (8) Prevents the formation of impact marks on the work piece surface (9) Water Softening (10) Suppression of chipping when the work piece is a hard and brittle material

After the mass is put in, the barrel tank lid 11b is placed on the barrel tank main body 11a and set in the barrel tank case 12. After that, the barrel tank 11 is sealed by the barrel tank fixing mechanism 12c and fixed to the barrel tank case 12.

After performing a series of operations for all the barrel tanks 11 and fixing all the barrel tanks 11 to the barrel tank case 12, the door 19a is closed and the barrel tank 11 into which the mass is put is housed in the housing 19. ..

<S02: Polishing process>
The operating conditions (operating time, rotation speed of the turret 13, etc.) are input to the storage means 17b in advance via the input means 17a of the control mechanism 17. Then, when the start button of the input means is turned "ON", the drive motor 15a is operated by the signal output from the storage means 17b, and the barrel tank makes a planetary motion.

The rotation of the barrel tank 11 accelerates based on the signal from the storage means 17b, and eventually reaches a steady speed. Inside the barrel tank 11 which has reached a steady speed, the mass is in a fluid state as shown in FIG. 3 (A). As a result, the polishing media 30 rubs against the workpiece 20, so that polishing proceeds.

When the mass is charged into the barrel tank, usually, a predetermined amount of the workpiece 20, the polishing medium 30, water, and the compound are charged together (FIG. 2 (D)). When the barrel grinding machine 10 is operated in that state, the workpiece 20 is in the initial stage of rotation of the barrel tank 11 (while the barrel tank 11 is accelerated from the start of rotation to the steady rotation speed). They collide with each other, causing damage such as cracks and chipping at the corners and edges of the workpiece 20. Therefore, it is preferable to control the collision between the workpieces 20 at that stage.

As a result of diligent research on the method of controlling the collision between the workpieces 20, it was found that the method can be controlled by the mass feeding method. In one embodiment, the workpiece 20 may be set so as to be mixed in the layer formed as an aggregate of the polishing media 30 in FIG. 2 (A). In one embodiment, the workpiece 20 may be set as shown in any of FIGS. 2A, 2B, and 2C.

FIG. 3 is a schematic diagram showing the movement of a mass. The mass set as shown in FIG. 3 (A) moves along the wall at the initial stage of rotation (FIG. 3 (B)), but when it moves to a certain height, it falls along the wall due to its own weight. (Fig. 3 (C)). Eventually, when the speed rises to the steady speed, the mass becomes in a fluid state as shown in FIG. 3 (D).

FIG. 2A shows a state in which the workpiece 20 is set so as to be sandwiched between the layers formed by the polishing media 30. When the mass moves in the initial stage of rotation, the workpiece 20 is prevented from freely moving due to the weight of the layer of the polishing media 30, so that the workpieces 20 can be prevented from colliding with each other.

FIG. 2B shows a state in which the workpiece 20 is set between the polishing media 30 in a mixed state. Since the mass is not fluidized at the initial stage of rotation, it can only move relative to the mass, so that it is possible to prevent the workpieces 20 from colliding with each other.

FIG. 2C further includes abrasive grains 40 as mass, a layer formed by the polishing medium 30, a layer formed by the abrasive grains 40, a workpiece 20, a layer formed by the abrasive grains 40, and the polishing media 30. Indicates the state in which they are set in the order of. The layer formed by the abrasive grains 40 further restricts the movement of the workpiece 20 as compared with FIG. 2A, and contributes to the improvement of the polishing ability in a steady state. Therefore, collisions between the workpieces 20 occur. While preventing it, the effect of improving the polishing ability can be obtained. The improvement of the polishing ability can shorten the time that the workpiece 20 is placed in an environment subject to an impact force, and as a result, contributes to the suppression of damage to the workpiece 20.

For the abrasive grains 40, the material and particle diameter are appropriately selected according to the physical characteristics of the workpiece. If the polishing force is too strong, the work piece will be polished more than necessary, which will affect the dimensional accuracy. Moreover, if it is too weak, it does not contribute to the improvement of polishing ability. The material of the abrasive grains 40 may be appropriately selected from known substances such as alumina and silicon carbide. The particle size of the abrasive grains 40 can be selected from F60 to F220 or # 240 to # 1000 specified in JIS R6001: 1998.

As described above, in one embodiment in which the mass is set as shown in FIGS. 2A, 2B, and 2C, while the barrel tank 11 is accelerated from the start of rotation until the rotation speed becomes a steady state, By controlling the movement of the workpiece 20, it is possible to control the collision between the workpieces 20.

In FIGS. 2A and 2C, the number of layers formed by the polishing media 30 is two, but it can be changed as needed.

<S3: Collect the work piece>
After the operation of the barrel grinding machine has elapsed for a predetermined time, the drive motor 15a is stopped by the signal from the storage means 17a. After that, the workpiece 20 and the polishing medium 10 are taken out from the barrel tank 11. After that, the workpiece 20, the polishing medium 30, and water (in the case of FIG. 3, further the abrasive grains 40) are separated, and the workpiece 20 is cleaned by ultrasonic cleaning or the like. At this time, if the workpiece 20 and the polishing media 30 are separated first and then the workpiece 20 and the water are separated, the workpiece 20 and the polishing media 30 are separated in water. Therefore, it is possible to prevent the workpiece 20 from being damaged in the process of separation.

Barrel polishing is completed through the above steps S1 to S3.

The effect of the barrel polishing method of one embodiment was confirmed. Fifty workpieces were set by the four methods shown in FIG. 2 and barrel-polished. After barrel polishing, the shapes (R-plane dimensions) of the six corners shown in FIG. 5 were measured with a surface shape measuring instrument for each of the five workpieces under each condition.

Furthermore, the presence or absence of chipping was confirmed with a microscope for all workpieces.

As shown in Table 1, FIGS. 2A, 2B, and 2C, which are the barrel polishing methods of one embodiment, generate more chipping than FIG. 2D, which is a conventional barrel polishing method. It is reduced, and it can be seen that the damage generated on the surface of the workpiece can be reduced by the barrel polishing method of one embodiment.

In one embodiment, the movement of the workpiece 20 is controlled while the barrel tank 11 is accelerated from the start of rotation until the rotation speed becomes a steady state by a mass charging method. However, this control can also be done in another way. Hereinafter, a modified example will be described.

<Change example 1>
To control the collision between the workpieces 20, the acceleration of rotation of the barrel tank 11 may be controlled. As shown in FIG. 6, the vehicle may be accelerated to a steady speed NS at a constant speed (Pattern A) or may be accelerated in multiple stages (Pattern _C ). Alternatively, the acceleration may be continuously changed so that the graph showing the time-rotational speed draws a gentle trajectory (Pattern C, Pattern C). By controlling the acceleration, it is possible to control the centrifugal force applied to the workpieces 20 so that the workpieces 20 do not collide with each other. Since the movement of the workpiece 20 with respect to the mass can be controlled by this centrifugal force, the collision between the workpieces 20 can be controlled.

As another method, a barrel polishing machine having a configuration in which the inclination angle θ of the barrel tank 11 can be arbitrarily changed may be used, and barrel polishing may be performed while changing the inclination angle θ according to the progress of polishing. In one embodiment of this method, as shown in FIG. 7, when the cylinder 17a is attached to the base 17 and the cylinder is expanded and contracted, the polishing unit (barrel tank 11, barrel tank case 12, turret 13, revolution shaft 14, drive mechanism 15) is used. , The driven mechanism 16, the base 17) is rotated around the bearing 17b. The inclination angle of the barrel tank 11 is arbitrarily adjusted by the length of the cylinder 17a. As the cylinder 17a, a known cylinder such as an air cylinder, a hydraulic cylinder, or an electric cylinder can be appropriately selected.

For example, when the barrel polishing machine 10 is started, the inclination angle θ of the barrel tank 11 is set to 90 ° to suppress the movement of the workpiece 20 in the initial stage of rotation of the barrel tank 11, and after reaching a steady speed, the barrel The polishing ability can be ensured by shortening the length of the cylinder 17a so that the inclination angle θ of the tank 11 becomes a predetermined angle. That is, by controlling the inclination angle of the barrel tank 11, it is possible to control the movement of the workpiece 20 and thereby control the collision between the workpieces 20.

One embodiment of the barrel polishing method provides a barrel polishing method that meets both productivity and quality requirements. In particular, when the workpiece is a hard and brittle material, damage such as chipping is remarkable, so that the barrel polishing method of one embodiment can be suitably applied to the processing of the hard and brittle material.

In one embodiment, barrel polishing using a centrifugal barrel grinding machine of a type in which the barrel tank is tilted has been described, but the barrel grinding machine is not limited to this type. Centrifugal barrel polishing machine that does not tilt the barrel tank (θ = 0 °, 90 °), barrel polishing machine that fluidizes mass by rotating the rotating disk provided at the bottom of the barrel tank, vibration force in the barrel tank The barrel polishing method of one embodiment can also be suitably used in a barrel polishing machine of a type in which mass is fluidized by adding the above, and a barrel polishing machine of a type in which a barrel tank is rotated.

10 Barrel grinding machine 11 Barrel tank 12 Barrel tank case 13 Turret 14 Revolution shaft 15 Drive mechanism 16 Driven mechanism 20 Work piece 21 Base 22 Leg 30 Polishing media

Claims (3)

A barrel polishing method using a barrel polishing machine that polishes the workpiece by rotating the barrel tank itself into which a mass containing a workpiece and a polishing medium is charged.
The process of putting the mass containing the workpiece and the polishing media into the barrel tank that can be sealed,
The process of rotating the barrel tank around the axis of rotation to fluidize the mass and scraping the polishing media against the workpiece to polish the workpiece.
Including
In the step of charging the mass, the workpiece is set between two layers formed as an aggregate of the polishing media, and the work piece is set.
In the step of polishing the work piece, while the barrel tank starts to rotate and is accelerated until the rotation speed reaches a steady speed, the work piece is prevented from freely moving due to the weight of the layer of the polishing media. This is a barrel polishing method characterized by suppressing collisions between workpieces. A barrel polishing method using a barrel polishing machine that polishes the workpiece by rotating the barrel tank itself into which a mass containing a workpiece and a polishing medium is charged.
The process of putting the mass containing the workpiece and the polishing media into the barrel tank that can be sealed,
The process of rotating the barrel tank around the axis of rotation to fluidize the mass and scraping the polishing media against the workpiece to polish the workpiece.
Including
The mass further contains abrasive grains having a particle size specified in F60 to F220 or # 240 to # 1000 specified in JIS R6001: 1998 .
In the step of charging the mass, the workpiece is set in the layer formed by the abrasive grains located between the two layers formed by the polishing medium.
In the step of polishing the work piece, while the barrel tank starts to rotate and is accelerated until the rotation speed reaches a steady speed, the work piece is prevented from freely moving due to the weight of the layer of the polishing media. This is a barrel polishing method characterized by suppressing collisions between workpieces while the barrel tank is accelerated from the start of rotation until the rotation speed reaches a steady speed. The barrel polishing method according to claim 1 or 2 , wherein the workpiece is a hard and brittle material.

Images