JPS6126463B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a belt grinding device for grinding the body and sides of a rectangular wristwatch case using a grinding belt.

In addition to high-precision time display, wristwatches are also required to have more aesthetically pleasing cases and more diverse designs. With the diversification of case designs, there are cases with square or rectangular shapes, which are formed into a square shape by press processing and then finished into the final shape by grinding, but conventionally, it is based on the experience of the operator and the final shape. This was done manually by relying on intuition, that is, pressing the case against a grinding belt or whetstone by hand to grind it, so if one side was over-sharpened or bent, the balance between the left and right and top and bottom when viewed from the dial side could become unbalanced. The yield rate was poor due to the product being distorted and the shape of the product being inconsistent.

Therefore, the present invention provides a device in which a device chucking the case is mechanically operated and pressed against a grinding belt in order to grind the sides or the upper slope of a rectangular watch case. It is something to do.

The present invention will be explained below based on the illustrated embodiments. The overall structure of the belt grinding device of the present invention is shown in FIG.

The belt grinding device is equipped with a grinding belt A and a grinding belt B, and includes a grinding belt drive mechanism section 1 using a motor _M1 as a drive source, and a square processing case 9 chucked on a chuck 12 attached to a workpiece holding shaft 11. and a case drive mechanism section 2 configured for grinding into a desired shape, and both 1 and 2 are incorporated into the device main body 10 so as to face each other. The general configuration of the grinding belt drive mechanism section 1 includes a drive mechanism 39 that rotates two grinding belts A and B having different grain sizes using a motor _M1 as a common drive source. The structure of the case drive mechanism 2 is as follows: a workpiece holding shaft 11, a chuck 12, a lever 3;
A work holding device 3 consisting of a 0 etc., and a pulse motor for causing the work holding device 3 to perform reversal.
M ₃ , a reversing mechanism 4 consisting of a timing belt 15, etc., a motor M ₂ for reciprocating the work 9 of the work holding device 3 between the belt widths so as to effectively use the grinding belt width, a disc 17, and a connecting rod. A work holding device reciprocating mechanism 5 consisting of a work holding device 18, etc., a work holding device moving mechanism 6 consisting of an air cylinder L2, etc. for moving the work holding device 3 between grinding belts A and B, and a work holding device moving mechanism 6 consisting of an air cylinder _L2 , etc. for moving the work holding device 3 between grinding belts A and B, and a work holding device reciprocating mechanism 5 consisting of a work holding device 18, etc. It mainly consists of a table advancement/retraction mechanism 7 consisting of an air cylinder _L1 , etc., which moves the cable 21 to bring it into contact with the belt A or B. Further, a control device 8 is provided within the apparatus main body 10 to control the operations of the respective mechanisms 39, 4, 5, 6, and 7 of the grinding belt drive mechanism section 1 and the case drive mechanism section 2.

Next, the details of the configuration will be explained. First, the case drive mechanism section 2 will be explained.

The table 21 is attached to the main body 10 of the apparatus in the front and back direction (the direction of distance from and near the grinding belt drive mechanism section 1; the front direction is the side of the grinding belt drive mechanism section 1; the same applies hereinafter).
A piston rod of an air cylinder _L1 fixed to the main body 10, which serves as a mechanism 7 for advancing and retracting the table 21, is attached to the rear end, and also controls the amount of forward movement of the table 21. A stopper (not shown) is provided on the apparatus main body 10 in front of the table 21 in the moving direction. A work table 22 is placed on the table 21 in the left-right direction (in the direction perpendicular to the above-mentioned perspective direction, the left direction is the grinding belt A side,
The same applies hereinafter) Air cylinder L ₂ for left and right movement constitutes a work holding device moving mechanism 6 that is slidably mounted and has one end fixed to the left end of the table 21 and moves the work holding device 3 between the grinding belts A and B. A piston rod is attached, and the left end standing edge 22a is equipped with a motor _M2 for a workpiece holding device reciprocating mechanism 5 for reciprocating the workpiece holding device 3 via a bracket 23, and a disc 17 fixed to its drive shaft. . A work head stand 24 is mounted on the work stand 22 so as to be movable left and right by being fitted into two guide rods 25 and 26 extending between the right and left standing edges of the work stand 22. includes a connecting rod 1 having one end pivoted at an eccentric position of the disk 17.
The other end of 8 is pivotally connected. Note that the eccentric distance of the pivot point of the connecting rod 18 on the disk 17 side with respect to the center of the disk 17 is slightly smaller than the width W of the grinding belts A and B.
The work head stand 24 has two guide rods 27 and 28 placed between its front and rear edges, and a work head stand 29 is fitted and guided thereon. Work head 29
A spring 31 surrounded by each of the guide rods 27 and 28 is located between the erected edge of the rear end of the work head pedestal 24 and presses the work head 29 against the erected edge of the front end of the work head pedestal 24 at all times. When the case 9 is brought into contact with the grinding belts A and B for grinding, this urging force is used to press the case 9 against the grinding belts A and B. The work head 29 has a work holding shaft 11 at the front and a pulse motor at the rear.
Attach _M3 , workpiece holding shaft 11 and pulse motor
The drive shafts of M ₃ are arranged in parallel in the lateral direction, and are coupled to each other by a timing belt 15 via timing gears provided on both. pulse motor
_M3 is controlled by a pulse signal output from the pulse motor drive circuit of the control device 8, and the pulse signal is emitted so that the pulse motor _M3 for reversing the case 9 makes a half turn, that is, a rotation angle of 180°. . A chuck 12 is screwed onto the right end of the workpiece holding shaft 11 (on the side opposite to the engagement portion of the belt 15), and a well-known open chuck system is adopted so that the case 9 can be attached and fixed. The chuck part of the chuck 12 has a square shape when the chucked part of the case 9 has a similar shape to the square shape of the outer shape, and when chucking, the chuck part has a square shape. A43 and platen B46 are fixed at a position such that the sides of the case 9 are parallel to each other. Further, when the inner shape of the case 9 is round, the chucking part of the chuck 12 is round, and a part of the case 9 is arranged around the chucking part so that the side of the body of the case 9 is parallel to the platens A43 and B46. Install an adjustable pin, etc. to make it abut against the part.

The above is the explanation of the case drive mechanism section 2, including the table 21, work stand 22, work head stand 24,
The work head 29 has a four-layer structure that is slidable relative to each other.

Next, the structure of the grinding belt drive mechanism section 1 will be explained. A grinding belt A for rough grinding and a grinding belt B for finish grinding are provided in parallel, and the grinding belt A is wound around a drive pulley A41, an idle pulley 42, and a platen A43, and the grinding belt B is wound around a drive pulley B44 and an idle pulley B45. , platen B46
is wrapped around. (Figures 1 and 3). The drive pulley A41 and the drive pulley B44 (shown offset from the drive pulley A41 in FIG. 3 to make their presence clear) are each separately mounted on the main body 10 via a member, and both are fixed to a common shaft 49. The driving force of the motor _M1 is transmitted to rotate the grinding belts A and B by co-rotation. A pulley 41a is fixed to the common shaft 49 adjacent to the drive pulley A41, and a transmission belt 51 is stretched between this pulley 41a and an output pulley 48 fixed to the motor _M1 , and the driving force of the motor _M1 is is transmitted to grinding belts A and B. In addition, platen A43 and platen B
The contact surfaces of the grinding belts 46 and the grinding belts A and B are in the same plane parallel to the direction of movement of the work head 24.

In addition to the above, a control device 8 having a control circuit for controlling the motors _M1 and _M2 , the pulse motor _M3 , the air cylinders _L1 and _L2 , etc. is provided in the main body 10, and the details of the circuit are as follows. Although omitted, the block diagram includes a program setting section, a program storage section, and an output section.

Next, the operation of this device will be described.

(1) By pressing a start button (not shown), motor _M1 is activated, and grinding belt A and grinding belt B are rotated via transmission belt 51, pulley 41a, and drive pulleys A41 and B44.

(2) Attach the workpiece 9 to be processed to the chuck 12.

(3) When the cycle button (not shown) is pressed, the air cylinder _L1 is operated and the table 21 moves forward until it contacts the stopper. This movement is configured such that when the workpiece 9 comes close to the grinding belt A, the moving speed is slowed down. (For example, if a micro switch installed nearby is
Switch the movement speed by turning on. ) (4) When the workpiece 9 comes into contact with the grinding belt A, the motor _M2 starts and the workhead table 24 starts reciprocating within the belt width, and one side of the workpiece 9 makes effective use of the belt width. to be ground.

(5) After performing the required number of reciprocating movements, table 2
1 moves backward, and a pulse signal is input to the pulse motor _M3 to rotate and reverse the chuck 12.

(6) The table 21 moves forward again, and the other side of the workpiece 9 is ground in the same manner as described above.

(7) After reciprocating the required number of times, the air cylinder _L2 is activated and the workpiece 9 is transferred from the grinding belt A to the grinding belt B.

(8) Grinding belt B for finishing the above steps (4) to (6)
Do the same thing.

(9) After the grinding process on both sides of the workpiece 9 is completed, the table 21 is moved back by operating the air cylinder _L1 ,
Then, one cycle is completed by moving the grinding belt to its original position on the side of the grinding belt A.

The above is the explanation of the process performed by this apparatus.

Although the reversing mechanism 4 uses the pulse motor M ₃ in this embodiment, it is also possible to use a combination of other motors and mechanisms without using the pulse motor M ₃ . Also,
In this embodiment, the table 21 moves backward when the case 9 is reversed, and the work table 22 is provided with a cam follower, and the work head table 24 is connected to a motor, which is shaped so that the work 9 separates from the grinding belts A and B when the case 9 is reversed. A mechanism may also be used in which a cam is provided so that the work head stand 24 retreats when it is reversed.

As described above, the present invention provides the following effects. (1) By mechanizing manual work that relies on intuition, it is possible to improve the shape, precision, and yield of watch cases. (2) Items with uniform shapes can be mass-produced, labor can be saved through automation, and costs can be further reduced. (3) Since it is equipped with multiple different types of grinding belts, and the grinding process can be done in the same way without any unevenness, the processing cycle can be shortened and efficiency is high, and the number of grinding devices and manpower can be reduced. can. (4) Since the entire surface of the grinding belt is used by the reciprocating mechanism of the work holding device, the life of the belt can be extended.

[Brief explanation of the drawing]

1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a side view showing the grinding section shown in FIG. 1, FIG. 3 is a side view showing the grinding belt drive mechanism section shown in FIG. 1, and FIG.
FIG. 1 is a block diagram showing the system of FIG. DESCRIPTION OF SYMBOLS 1... Grinding belt drive mechanism part, 2... Case drive mechanism part, 4... Reversing mechanism, 5... Work holding device reciprocating movement mechanism, 6... Work holding device moving mechanism, 8... Control device.

Claims (1)

[Claims] 1. A belt grinding device for grinding a rectangular case of a wristwatch, which includes a grinding belt drive mechanism section having two grinding belts with different grain sizes, an inversion mechanism for inverting the grinding surface of the case, and a front case that rotates the front case from the width of the grinding belt. A case drive mechanism unit that includes a reciprocating mechanism that performs reciprocating motion with a small amount of movement and a movement mechanism that moves the case between the two grinding belts, and a control device that controls the operation of the drive unit. A belt grinding device for processing watch cases, which is characterized by: