JPS6335468B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a transport pallet used for transporting parts, jigs, etc., and in particular improves the durability of a transport pallet equipped with a friction clutch using a coil spring. It is the daily goal to do so.

This type of pallet conveyor is installed so that it can run freely on a conveyor frame that forms the pallet track, and has a sprocket wheel that is attached via a clutch to a fixed shaft installed at the bottom of the pallet.
It is locked to a drive chain that circulates at a constant speed along the conveyor frame, and when traveling, the clutch is fixed and the sprocket wheel is fixed to a fixed shaft, and the sprocket wheel is fixed non-rotatably to the fixed shaft. , the propulsion force from the drive chain is transmitted and the pallet travels together with it, and the clutch is released at a predetermined position to allow the sprocket wheel to rotate freely relative to the fixed shaft, thereby transmitting the propulsive force from the drive chain. It is configured to cut the transmission and stop running.

By the way, many of the clutches installed in the conventional pallets are friction clutches that utilize frictional force.

1 and 2 are drawings showing an example of a conventional friction clutch. The friction clutch shown in the figure supports a rotating drum 2 to which a sprocket 1 is fixed on a fixed shaft 3. As shown in FIG. 2, a coil spring 4 having a diameter slightly smaller than the outer diameter of the rotating drum 2 is fitted, and one end of the coil spring 4 is locked to the release lever 5, and the other end is locked to the fixing member 7 of the mounting table 6. , a striker 9 that rotates against the stopper 8 is provided so as to be able to engage with the release lever 5.

In the figure, 10 is a first return spring for pressing the striker 9 in a counterclockwise direction, and 11 is a first return spring.
12 is a second return spring for pressing the release lever 5 clockwise, and 12 is a drive chain that engages with the sprocket wheel 1 to transport the pallet.

In the normal state, one end is the release lever 5.
The coil spring 4 locked on the spring 4
It comes into pressure contact with the surface of the rotating drum 2 by its own elasticity and prevents the rotation of the rotating drum 2. Therefore, the sprocket wheel 1 fixed to the rotating drum 2 also does not rotate, and the sprocket wheel 1 is connected to the drive chain 1.
2, the pallet moves together with the drive chain 12.

Moreover, when the pallet 1 is conveyed to a predetermined position, the striker 9 comes into contact with the stopper 8 again,
The striker 9 is the first return spring 10
The release lever 5, which is engaged with the striker 9, also rotates counterclockwise against the elasticity of the second return spring 11. Therefore, the coil spring 4, whose one end is locked to the release lever 5, is rotated in the diametrically expanding direction, so that the rotary drum 2 can freely rotate. Therefore, the sprocket wheel 1 fixed to the rotating drum 2 idles as the drive chain 12 moves, so that the drive chain 12
The propulsive force from the pallet is no longer transmitted to the pallet, and the pallet stops at that position.

However, when the friction clutch is configured as described above, the coil spring 4 fitted into the rotating drum is always in pressure contact with the rotating drum 2 due to the elasticity of the spring 4 itself. When the part in contact with the surface wears out, the binding force of the coil spring 4 to the rotating drum 2 becomes weak, and the rotating drum 2 cannot be completely fixed, which is a drawback.

In view of the above-mentioned conventional drawbacks, the present invention provides a pallet equipped with a clutch mechanism that prevents the binding force of the coil spring to the rotating drum from decreasing even if the coil spring wears out. The configuration will be described below according to the embodiment shown in the drawings.

3 to 6 are drawings showing a pallet according to the present invention, in which 20 is a mounting table on which parts, jigs, etc. are placed, and 21 and 21 are parallel support frames that support the mounting table 20. , both support frames 21, 2
Axles 22 and 23 are passed through and fixed in the front and rear spaces between the rollers 1 and 2, and rolling rollers 24, 24, . These rolling rollers 24, 24... are installed in rail grooves 26, 26 of parallel conveyor frames 25, 25 constituting a track, and these rail grooves 26, 24...
26, the pallet is transferred to the conveyor frame 2.
It runs guided by 5, 25. 27 is a fixed shaft horizontally suspended in the center between both support frames 21, 21, 28 is a rotating drum rotatably inserted into the fixed shaft 27, and 29 is a sprocket wheel fixed to the side surface of the rotating drum 28. , a part of which is engaged with a drive chain 30 which is arranged in parallel along the conveyor frames 25, 25 and circulates at a constant speed. 31 is a coil spring inserted into the outer periphery of the rotating drum 28, and this coil spring 31
For this purpose, use one whose inner diameter is slightly larger than the outer diameter of the rotating drum 28 in its natural state. 32 is a spring locking drum fitted on the outer periphery of the rotating drum 28. This spring locking drum 32 is rotatably supported by a fixed shaft 27, and a coil is provided on the inner peripheral surface of the spring locking drum 32. One end 31a of the spring 31
Keep it locked. Reference numeral 33 denotes a release lever that is rotatably fitted into the side part of the outer periphery of the spring locking drum 32, and the release lever 33 includes:
A coil spring 3 protrudes outward from an opening 32a provided on the side of the spring locking drum 32.
1 is engaged with the other end 31b. A striker 34 is connected to the release lever 33 via a pin 35, and is rotatably supported by the axle 22 mentioned above. A return spring 36 is press-fitted between the striker 34 and the mounting table 20, and applies a counterclockwise rotational force to the striker 34. A connecting rod 37 has one end connected to the striker 34 via a spring 38 and the other end connected to the spring locking drum 32 via a pin 39. By the action of the connecting rod 37, the spring locking drum 32 is prevented from rotating beyond a certain angle. Further, a counterclockwise rotational force is applied to the spring locking drum 32 by a spring 38 press-fitted between the striker 34 and the connecting rod 37. The elastic force of the spring 38 and the length of the connecting rod 37 can be adjusted by rotating a nut 40 screwed into the end of the connecting rod 37.

The coil spring 31 described above is configured such that its diameter decreases when the release lever 33 with which the end 31b is engaged is rotated clockwise, and the diameter of the coil spring 31 is reduced when the release lever 33 is engaged with the end 31b. The diameter is also reduced when the spring locking drum 32 rotates counterclockwise.

To explain the operation of the pallet with the above configuration, in a normal state where no upward force is applied to the tip of the striker 34, a counterclockwise rotational force is applied to the striker 34 by the elasticity of the return spring 36. Therefore, a clockwise rotational force is applied to the release lever 33 connected to the striker 34. Therefore, the coil spring 31 whose end portion 31b is engaged with the release lever 33
is wound and contracted in a direction in which its diameter is reduced, and the coil spring 31 is pressed against the outer periphery of the rotating drum 28. Therefore, the rotating drum 28 and the rotating drum 2
The sprocket wheel 29 fixed to the conveyor frame 8 is fixed so as not to rotate, and the propulsion force from the drive chain 30 is transmitted to move the pallet to the conveyor frames 25, 2.
It travels guided by 5 and transports parts, jigs, etc. When the striker 34 is pushed up against the elasticity of the return spring 36 by the stopper 41 or the like at a predetermined position, the release lever 33 connected to the striker 34 rotates counterclockwise, causing the end of the release lever 33 to Since the tightening force on the coil spring 31 to which the coil spring 31b is locked is released, the diameter of the coil spring 31 expands due to the elasticity of the spring 31 itself. Therefore, the rotating drum 28 and the sprocket wheel 29 fixed to the rotating drum 28 rotate freely with respect to the fixed shaft 27, and the propulsive force from the drive chain 30 is not transmitted to the fixed shaft 27, and the pallet remains at that position. It stops, and parts, jigs, etc. on the mounting table 20 are taken out or transferred.

At this time, the end 31 of the corulu spring 31
Spring locking drum 32 to which a is locked
, a counterclockwise rotational force is applied by a spring 38 fitted into the connecting rod 37, and a force is applied to the coil spring 38 in a direction to reduce its diameter. Therefore, even if the striker 34 is pushed up, the binding force exerted by the coil spring 31 on the rotating drum 28 is not completely released, and the rotating drum 28 rotates with some resistance. Therefore, the striker 34 is the stopper 41
When the pallet comes into contact with the pallet, the pallet does not stop abruptly but stops gradually, so when the pallet stops, it is possible to prevent impact from being applied to the parts, jigs, etc. on the mounting table 20.

When the upward force on the striker 34 disappears, the striker 34 rotates counterclockwise again due to the pressure of the return spring 36, and the release lever 33 connected to the striker 34 rotates clockwise, causing the coil spring 31 to rotate. Wrap it tightly,
The rotating drum 28 is prevented from rotating, the sprocket wheel 29 is fixed unrotatably, and the drive chain 3 is fixed.
The propulsion force from 0 is transmitted and the pallet travels again.

As explained above, in the clutch equipped on the pallet according to the present invention, a coil spring having a diameter slightly larger than the outer diameter of the rotating drum is fitted around the outer periphery of the rotating drum, and one end of the coil spring is locked. Since the striker connected to the release lever is rotated by the return spring in the direction of tightening the coil spring, even if the part of the coil spring that contacts the rotating drum wears out, the coil spring will still maintain the specified pressure. The striker rotates under the force of the return spring until it comes into pressure contact with the rotating drum. For this reason,
The binding force to the rotating drum no longer decreases due to wear of the coil spring, and the durability of the clutch can be improved.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of a pallet equipped with a conventional friction clutch, Fig. 2 is a perspective view showing a state in which a coil spring is fitted into a rotating drum, and Fig. 3 is a plan view of a pallet according to the present invention. Figure 4 is the third
FIG. 5 is a cross-sectional view taken along the line -- in FIG. 3, and FIG. 6 is a cross-sectional view taken along the line -- in FIG. 3. 20... Mounting table, 21... Support frame, 2
2, 23...Axle, 24...Rolling roller, 25,
25...Conveyor frame, 27...Fixed shaft, 2
8... Rotating drum, 29... Sprocket wheel, 30... Drive chain, 31... Coil spring, 32... Spring locking drum, 33
...Release lever, 34...Striker, 3
6...Return spring, 37...Connecting rod, 4
1...stopper.

Claims (1)

[Claims] 1 A rotating drum with a sprocket wheel fixed to its side, which is rotatably inserted into a fixed shaft that is horizontally suspended between parallel support frames that support a mounting table on which parts, jigs, etc. are placed, and a rotating drum. A coil spring with a diameter slightly larger than the outer diameter of the rotating drum is fitted around the outer periphery of the rotating drum, a spring locking drum that locks one end of the coil spring is placed on the outer periphery of the rotating drum, and a spring locking drum is placed on the outer periphery of the rotating drum to lock one end of the coil spring. A release lever that locks the other end of the coil spring,
It is equipped with a striker that is rotatably supported by an axle horizontally suspended between support frames and that engages with the release lever, and a return spring that applies a winding force to the coil spring via the striker and the release lever. A wrap spring clutch type palette.