JPH035396Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an arm balance device for a workpiece loading/unloading device.

(Prior Art) A workpiece loading and unloading device is known in which an arm is provided on a rotating shaft that is supported horizontally on a machine base and rotated by a predetermined angle by a drive device, and the arm is provided with a head that includes a holder that holds the workpiece. Conventionally, in order to maintain the balance of the moment caused by swinging of the arm, a weight was provided at the top of the arm or the arm was pulled by a hydraulic cylinder unit.

(Problems to be Solved by the Invention) However, since the weight increases the weight of the arm, the driving force required for swinging increases, and it is also necessary to provide a larger space above the arm. Furthermore, when the arm is pulled by the hydraulic cylinder unit, the piston stroke must be automatically adjusted, making control complicated.

(Means for solving the problem) In order to solve the problem, the present invention provides an arm 11 on a rotating shaft 7 that is supported horizontally on the machine base 1 and rotated by a predetermined angle by a drive device 5. , in a workpiece loading/unloading device in which the arm 11 is provided with a head 37 having a holder 41 for holding a workpiece W, a chain sprocket mechanism 51 is installed between the rotating shaft 7 and the machine base 1 side, and a sprocket 54 on the machine base side is installed. and the parallel link mechanism 61 on the machine side 1.
A vertical air cylinder 73 was installed on the parallel link mechanism 61, and a horizontal rail 4 was installed on the machine base 1 side, with which the piston rod 75 of the air cylinder 73 engaged.

(Function) When the arm 11 swings, the sprocket 54 on the machine base 1 side rotates in synchronization with the sprocket 52 on the rotating shaft 7 side, and the parallel link mechanism 61 also moves horizontally in synchronization, so that the machine base 1 side The air cylinder 73 is connected to the piston rod 75 that engages with the horizontal rail 4 of
moves up and down to pressurize or release the air in the air cylinder 73.

In particular, as the arm 11 swings from its original position, the air in the air cylinder 73 is compressed, and the load that compresses this air acts in the opposite direction to the swing of the arm 11, so it counteracts the moment of the arm 11. A moment will occur.

Therefore, the balance of the moment accompanying the swinging of the arm 11 can be automatically adjusted by the air cylinder 73.

In this way, since one air cylinder 73 is used as the source of the balance moment, it is possible to reduce weight and space, enable a compact device design, eliminate the need for complicated control, and drive required for swinging the arm 11. The force required is smaller than when using weights.

(Example) Examples will be described in detail below based on the accompanying drawings.

Figure 1 is a longitudinal side view of the main part of the workpiece loading/unloading device, and Figure 2 is its front view.A servo motor 5 is installed at one end of the horizontal cylindrical part 2 on the top of the machine stand 1, which is set up like a post. , a vertical plate 3 integrally extending to the left side is formed at the other end, and a horizontal rail 4 protruding forward at the lower edge of this plate 3.
will be permanently installed. A bearing holder 6 is fitted and fixed inside the cylindrical portion 2 on the plate 3 side, and an arm rotating shaft 7 connected to the output shaft of the servo motor 5 is supported in the bearing holder 6 via bearings 8, 8. An arm 11 is fixed to the protruding end of the rotating shaft 7.

The arm 11 extends from the vertically long rear wall 12 to the side walls 1
3 and 13 form an upper wall 14 and a lower wall 15, and a screw rod 16 is rotatably supported between the central portions of the upper wall 14 and the lower wall 15 via bearings 17 and 18, respectively. A belt pulley mechanism 22 is installed between the output shaft of the servo motor 21 and the upper end of the screw rod 16, which are vertically installed. Furthermore, a pair of lift rods 23, 23 are arranged on the left and right sides of the screw rod 16 as shown in FIG. Both lift rods 23, 23 penetrate the arm lower wall 15 and protrude downward. Both lift rods 2
A gear box 25 is fixed between the lower ends of the arms 3 and 23, and the open surface of the arm 11 is closed with a cover 26.

A rotating device 31 is incorporated into the gearbox 25. That is, a servo motor 32 is installed on the rear part of the gear box 25, and a horizontal head rotating shaft 35 that meshes with the output shaft of the servo motor 32 through bevel gears 33, 34 is supported within the gear box 25 via bearings 36, 36. gearbox 25
A work head 37 is fixed to the end of the rotating shaft 35 that projects forward.

The work head 37 has a center of rotation C.
A pair of work holders 41 with a phase difference of 180°,
42 are provided. That is, the work head 37 has a horizontally elongated shape, and as shown in FIG. 6, air cylinders 38,
38 is built in horizontally, and work holders 41 and 4 are installed in the lower right half and upper left half with respect to the rotation center C, respectively.
Incorporate 1. The work holder 41 consists of a pair of left and right chuck arms 42, 42, both chuck arms 42, 42 are pivotally supported on the head 37 by pivot shafts 43, 43, and are connected to respective sector gears 44, 4.
4 mesh with each other, and are normally biased in the expansion direction by a return spring 45 installed between them. A lever portion 46 is formed at the base of one arm 42, and a lever portion 46 is formed at the base of one arm 42, and the lever portion 46 is connected to the piston rod 3 of the air cylinder 38.
9 is in contact with this lever portion 46, and when air is supplied into the cylinder 38, the piston rod 3
9 moves forward and presses the lever part 46, and both arms 4
2 and 42 resist a return spring 45 and perform a chucking operation synchronously by sector gears 44 and 44.

Further, a chain sprocket mechanism 51 is installed between the arm rotating shaft 7 and the plate 3 fixed to the machine base 1. That is, a drive sprocket 52 is fixed on the arm rotation shaft 7, and a support shaft 53 is fixed horizontally in the middle on the left side of the plate 3 as shown in FIG. A sprocket 54 is supported via bearings 55, 55, and a chain 56 is hung between both sprockets 52, 54.

A parallel link mechanism 61 is installed between the driven sprocket 54 and the plate 3. That is, the support shaft 5
A pair of front and rear links 62, 62 are supported on the plate 3 via bearings 63, 63, respectively, and a support shaft 64 is also provided in the middle of the plate 3, parallel to and at the same height as the support shaft 53, as shown in FIG. A pair of front and rear links 65,
65 are supported via bearings 66, 66, respectively. Also, connect the driven sprocket 54 and the link 62 facing inside thereof with the bolt 6 as shown in FIG.
7. They are integrally connected by a nut 68, and a cylinder bed 71 is pivotally connected horizontally between the left and right links 62 and 65, respectively, via bearings 72.

An air cylinder 73 is vertically installed in the center of this cylinder bed 71. Air is sealed in this air cylinder 73, and a piston 7 compresses this air.
A piston rod 75, which is integral with the piston rod 4, projects above the bed 71, and an L-shaped bracket 76 is fixed to the upper end of the piston rod 75, as shown in FIG. A pair of rollers 77, 77 that engage with the upper and lower sides of the rail 4 are pivotally supported on the vertical surface of the L-shaped bracket 76.

In the above, the servo motor 5 on the machine base 1 causes the arm 11 to reciprocate within a predetermined angle range as shown in FIG.
1 moves the work head 37 back and forth within a predetermined range from the arm 11, and a servo motor 32 on the gear box 25 rotates the work head 37 every 180 degrees. Also, work head 37
Air is supplied and discharged into the air cylinders 38, 38 from an air supply source (not shown), and each operation of the servo motors 5, 21, 32 and the air supply source is performed by a control device.

Next, the functions of the above workpiece loading/unloading device will be explained.
Here, in the example, the crankshaft of an internal combustion engine was used as the workpiece W, as shown in FIG.

First, in the original position, the arm 11 and the parallel link mechanism 61 are in a vertical state as shown in FIGS. 1 and 2.
One work holder 41 of the work head 37 faces downward, and the other work holder 41 faces upward. A work loading chute (not shown) is provided below the downward holder 41, and a processing machine (not shown) is provided to the right of the work loading/unloading device.

At the start of work, the work head 37 is moved forward from the arm 11 downward by the operation of the servo motor 21, and after holding the workpiece W to be processed in the downward facing work holder 41, the head 41 is moved back upward, and then the next work is started. The servo motor 32 is operated to move the head 3.
7 by 180 degrees, and the head 37 is moved forward again to hold the workpiece W in the other holder 4.
Similarly, the head 37 is moved back. At the same time, the head 37 is moved forward toward the processing machine by the operation of the servo motor 5 while swinging the arm 11 as shown in FIG. 37 is moved backward, and the arm 11 is left on standby.

When the machining is completed, the head 37 is moved forward to hold the machined workpiece W in the same holder 41 on which it was mounted, and the head 37 is moved back to hold the machined workpiece W.
is removed from the processing machine, the servo motor 32 is operated to rotate the head 37 by 180 degrees, and the head 37 is rotated again.
is moved forward and the workpiece W held by the other holder 41 is mounted on the processing machine.

After that, the head 37 is moved back to return the arm 11 to its original position, and then the head 37 is moved forward to hold the workpiece W on the input chute in the same holder 41 that was used for the second time. Then, the head 37 is rotated 180 degrees while moving backward again, and the head 37 is moved forward to discharge the processed workpiece W held by the other holder 41 onto the input chute. Then, at the same time as the head 37 is retreated again, the arm 1 is
1 to the processing machine side, move the head 37 forward and take out the machined workpiece W by holding it in the same holder 41 that was used to take out the machined workpiece, then rotate the head 37 by 180 degrees and move it forward to remove the other workpiece. The workpiece W held in the holder 41 is mounted on a processing machine. After that, repeat the same procedure.

In such a workpiece loading/unloading device, when the arm 1 swings, the drive sprocket 52 on the rotating shaft 7
The driven sprocket 54 on the plate 3 side synchronizes with
rotates via the chain 56, and the parallel link mechanism 6
1 also swings horizontally in synchronization. When the parallel link mechanism 61 horizontally swings, the piston rod 75 engages with the horizontal rail 4 fixed to the lower edge of the plate 3 on the machine base 1 side via the upper and lower rollers 77, 77. A piston 74 within the air cylinder 73 moves up and down relatively.

Therefore, when the arm 11 swings toward the processing machine,
The parallel link mechanism 61 also swings in the same direction and moves forward almost below the arm rotation axis 7 as shown in FIG. 3, and at the same time the air cylinder 73 rises relative to the piston rod 75 that engages with the rail 4 and moves to the right. Therefore, the air in the air cylinder 73 is compressed by the piston 74. The load that compresses this air acts in the opposite direction to the swinging of arm 11, so arm 1
Generate a moment that opposes the moment of 1.

When the arm 11 returns to its original position, the parallel link mechanism 61 also moves to the left side of the rail 4, the piston 74 rises relatively, and the air in the air cylinder 73 is decompressed.

In this way, the balance of the moment accompanying the swinging of the arm 11 is automatically adjusted by the air cylinder 73.

Incidentally, the workpiece W is not limited to the crankshaft as in the embodiment, but any other workpiece may be employed, and it goes without saying that the present attachment/detachment device is applied not only to the machining process but also to the assembly process.

(Effects of the invention) As described above, according to the invention, since the balance of the moment caused by the swing of the arm is automatically adjusted by the air cylinder, it is possible to achieve lightweight and space saving, and also eliminates the need for complicated control. Furthermore, the arm driving force can be made smaller than when a weight is provided.

[Brief explanation of drawings]

Figure 1 is a vertical sectional side view of the main parts of the workpiece loading/unloading device, Figure 2 is a front view of the main parts, Figure 3 is a front view of the main parts showing the operating state, and Figures 4 to 6 are the lines shown in Figure 1. ,
- line and - line cross-sectional views, Figures 7 and 8
The figure is each sectional view taken along the lines -- and -- in Figure 3. In the drawing, 1 is a machine base, 3 is a plate, 4 is a rail, 7 is an arm rotation axis, 11 is an arm, 16 is a screw rod, 21 is a servo motor, 22 is a belt pulley mechanism, 23 is a lift rod, 25 is a gearbox, 31 is a rotating device, 32 is a servo motor, 35 is a head rotation shaft, 37 is a work head, 41 is a work holder, 51 is a chain sprocket mechanism, 61 is a parallel link mechanism, 73 is an air cylinder, 75 is a piston rod, 77 is Laura,
W is work.

Claims (1)

[Claims for Utility Model Registration] A workpiece attachment/detachment device in which an arm is provided on a rotating shaft that is supported horizontally on a machine base and rotated by a predetermined angle by a drive device, and the arm is provided with a head equipped with a holder that holds the workpiece. In the device, a chain sprocket mechanism is installed between the rotating shaft and the machine base side, a parallel link mechanism is installed between the machine base sprocket and the machine base side, and a vertical air cylinder is installed in the parallel link mechanism. An arm balance device for a workpiece loading/unloading device, characterized in that, on the machine side, a horizontal rail is installed with which the piston rod of the air cylinder engages.