JPH0637015B2 - Work feeder retractable work misalignment prevention mechanism - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work feeder arranged for feeding and discharging a work to a machine tool or the like. More specifically, the present invention relates to a work feeder that can feed and discharge a work between a work feeder and a robot provided between machine tools in a precisely positioned state.

Conventional technology and its problems In a conventional work feeder for a machine tool such as a lathe in which a work is fed and discharged by a robot, when a pallet moves on the top surface of the feeder, vibration and impact during driving cause
The work is misaligned. So, to deal with this,
There is one in which a plurality of support rods are fixed on a pallet so as to position a work and prevent displacement due to vibration or impact.

However, since such a supporting rod is provided on the pallet, there is a problem of interference between the robot hand and the supporting rod when the work is fed or discharged. In order to avoid this interference, it is generally necessary to make the robot's hand special, or to set new restrictions on the movement of each axis of the robot.

FIG. 8 is a diagram showing the interference between the support rod S and the robot hand H described above. The work W is held by a support rod S protruding above the pallet P. The hand H of the robot cannot hold the work W because the support rod S interferes with it. In addition, if each axis of the robot is inadvertently operated, it may come into contact with the support rod.

In view of the above-mentioned problems, the present invention aims to provide a work feeder capable of removing the support rod from the pallet when the robot is operated.

Means for Solving the Problems The present invention is a work feeder configured to prevent displacement of a work loaded on a pallet by at least three work positioning support members, the support member moving together with the pallet. As described above, the base plate disposed on the lower side of the pallet is provided so as to extend upward through the pallet, and the supporting member is projected and retracted with respect to the pallet at a work feeding / discharging position. The problem is solved by a retractable work deviation prevention mechanism having a lifting means for lifting the base plate.

The work placed on the pallet of the work work feeder is held at its position by the support member and is transferred to a fixed point where it is fed and discharged. At this fixed point, the support member that can be retracted and retracted from the pallet is pulled downward from the pallet in order to avoid interference with the hand of the robot that feeds and discharges the work with the machine tool.

Therefore, the hand of the robot can surely grip the workpiece positioned on the pallet without interference with the support member and supply / discharge the workpiece to / from the machine tool.

Then, when the supply and discharge of the work with the pallet is completed,
The support member again projects onto the pallet and can function as a work positioning support member.

Examples The present invention will be described below with reference to the drawings. FIG. 1 is a front view of a work feeder 10 equipped with a work shift prevention mechanism of the present invention, and FIG. 2 is a top view thereof.

A plurality of pallets 20 for mounting the work W are continuously attached to the endless chain C, and are intermittently driven on the upper surface 18 of the work feeder 10. Then, at the position where the robot (not shown) feeds and discharges the work W from the work feeder 10, that is, at the fixed point 12,
The elevator 16 of the elevator 14 is arranged on the same horizontal plane as the upper surface 18 of the work feeder 10.

3 and 4 show the pallet 20 stopped at the fixed point 12.
Is shown. The pallet 20 is attached to the chain C through the adjusting collar 22 and the attaching bolts 24. A pin guide 26 is press-fitted into a hole in the center of the pallet 20, and a pulling pin 36 of the base plate 30 is removably inserted into the pin guide 26. Also, pallet 2
0 has three long holes 28 in the radial direction centered on the pin guide 26.

An eccentric caster 32 is attached to the lower surface of the base plate 30, and the base plate 30 freely moves on the upper surface 18 of the work feeder 10. The above-mentioned tow pin 36 is fixed to the center,
In the engaged state with the pin guide 26, it is driven by the chain C together with the pallet 20. Further, on the upper surface of the base plate 30, three synchronous sprockets 38 centering on the tow pin 36 and bolts 34 integrally formed with this are provided.
The stay base 40 is attached rotatably.

Each stay base 40 has a long hole 28 of the pallet 20.
At least three work stays (that is, a work positioning support member) 48 that are inserted into the upper part and project upward are fixed to the synchronous sprocket 38.
2, the respective synchronous sprockets 38 are connected, and the work stay 48 can be expanded / contracted at equal pitch circles around the tow pin 36.

The work stay 48 is provided on the base plate 30 via the synchronous sprocket 38 and the stay base 40, which is also referred to in the claims as "the base plate,
Needless to say, it corresponds to "equipped".

At the fixed point 12 of the work feeder 10, the base plate 3
An elevator 14 for raising and lowering 0 etc. is arranged,
The lifting platform 16 is located on the same horizontal plane as the upper surface 18 of the work feeder 10. The elevating table 16 is connected to a rod of a linear actuator 19 and is vertically moved from the upper surface 18 of the work feeder 10 by this operation. Further, the lifting table 16 is provided with a hook 44 that ensures the lowering of the base plate 30.

The elevator 14, the elevating table 16 and the linear actuator 19 compose "elevating means" in the claims.

The load of the work W up to the fixed point 12 is the pallet 20.
The stay base 40, which is in contact with the lower surface of the, receives. When the elevator 14 descends at a fixed point, the work feeder 1
The support roller 46 provided at 0 supports the pallet 20.

The work feeder 10 as described above operates as follows. The pallet 20 on which the work W whose position is prevented by the work stay 48 is placed is driven by the chain C. When the pallet 20 stops on the lifting table 16 at the fixed point 12, the linear actuator 19 operates and the lifting table 16 and the hook 44 descend. At the same time, lift 16
The base plate 30 located above also descends. At this time,
The pulling pin 36 is removed from the pin guide 26, the work stay 48 moves downward from the long hole 28 of the pallet 20, and only the work W is placed on the pallet 20 in a positioned state. The stay base 40 that receives the load on the pallet 20 also descends, but the position of the pallet 20 is held by the support rollers 46, so that a stable loading state is maintained even if a heavy load is placed. . When the works W are stacked, the actuator 19 may be operated stepwise.

Then, a robot (not shown) operates to pick up the work W and supply it to a machine tool (not shown).

On the other hand, even when the work W that has been machined by the machine tool is placed on the pallet 20, the work stay 48 that interferes
Since the robot is retracted, the robot hand can operate without obstacles.

After the operation of placing the work on the robot is completed, the linear actuator 19 is actuated upward, and the lifting platform 16 is lifted until it coincides with the upper surface 18 of the work feeder 10. As a result, the pulling pin 36 is inserted into the pin guide 26 and the work stay 48 is inserted into the elongated hole 28, respectively, and the work W is held by the work stay 48 and can be prevented from being displaced.

Then, the pallet 20 is driven by the chain C, and the next pallet comes to the fixed point to perform the next feeding / discharging work.

The PCD of the work stay 48 is the work W to be processed.
It can be adjusted from the outside according to the size of. Fifth
As shown in FIGS. 6 and 6, the work stay 48 of the present invention can be used both when the work W1 is supported from the outer peripheral surface and when the annular work W2 is supported from the inner peripheral surface.

The PCD of the work stay 48 is adjusted by a set bolt 50 and an adjusting rod 54 provided on the outer peripheral surface of the cylindrical portion of one synchronous sprocket 38.

First, the set bolt 50 is loosened to release the bolt 34. Then, the adjusting rod 54 is inserted into the insertion hole 52, and one synchronous sprocket 38 is rotated. Since the respective synchronous sprockets 38 are connected by the synchronous chain 42, the work stays 4 attached to the stay base 40 are
8 expands and contracts while maintaining a uniform pitch circle. After adjusting to PCD corresponding to the work W, tighten the set bolt 50,
Fix the bolt 34.

As schematically shown in FIG. 7, the work stay 48
PCD of the bolt 34 PC on the base plate 30
D. is D, work stay 4 centered on stay base 40
When the radius of 8 is r, the expansion / contraction is possible within the range of D ± 2r. Here, if the diameter of the rod-shaped work stay is d,
When gripping the outer peripheral surface as shown, the diameter is D-2r-
When gripping a workpiece in the diameter range of d to D + 2r-d from the inside as shown in FIG. 6, the inner diameter is D-
It can be used in the range of 2r + d to D + 2r + d.

When the adjusting rod 54 is inserted into the insertion hole 52 and the stay base 30 is rotated by the angle θ, the work stay 48 moves from A to A ′ and PCD becomes Dp. Dp is expressed as a function of θ by the following equation.

^{Dp = (D 2 -4Dr cosθ +} 4r 2) 1/2 Further, the n-number of workstations provided, tension without loosening the n-number of synchronization sprocket, in order to scaled each of workstation at equal pitch, the following equation Just satisfy.

n · D cos θ (n−2 / 2n) π = N · P where P is the chain pitch and N is an integer.

In this way, the PCD of the work stay 48 is attached to the pallet 20.
Can be adjusted between the long holes 28 in the radial direction, and the number thereof can be changed according to the size and shape of the work W.

When the work W is supplied and discharged at different positions, similar elevators may be provided at a plurality of locations.

As a result, the work placed on the pallet is prevented from being displaced by the support member and is driven on the work feeder. Therefore, even if vibration or impact occurs when the work feeder is driven, the supply position of the work to the robot can be reliably positioned at the fixed point.

When the work is supplied to the hand of the robot, the work stay is lowered by the elevator and the supporting member disappears from the pallet, so that the hand and the supporting member do not interfere with each other.

Therefore, it is not necessary to reshape the hand of the robot to have a special shape in order to avoid interference with the support member, or to restrict the movement of the hand.

[Brief description of drawings]

FIG. 1 is a front view showing in section a part of a work feeder equipped with a retractable work deviation prevention mechanism of the present invention, FIG. 2 is a top view of FIG. 1, and FIG. FIG. 4 is a top view of FIG. 3, FIG. 5 and FIG. 6 are plan views showing the relationship between the work and the work stay, and FIG. 7 is a schematic view showing the adjustment range of the work stay. FIG. 8 is a plan view showing interference between a hand of a robot and a support rod according to a conventional technique. 10 ... Work feeder 12 ... Fixed point (feed / discharge position) 14 ... Elevator 16 ... Elevating table 20 ... Pallet 48 ... Work positioning support member (work stay) W ... Work

Claims (1)

[Claims] 1. A work feeder in which at least three work positioning support members prevent positional displacement of works stacked on the pallet, wherein the support member is located below the pallet so as to move together with the pallet. A base plate arranged on the base plate and extending upward through the pallet, and elevating means for elevating and lowering the base plate so that the support member appears and disappears with respect to the pallet at a work feeding / discharging position. Equipped with a retractable work slip prevention mechanism for the work feeder.