JPH0319020B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a work pallet used in a tact system-type assembly line operation in which the movement of a conveyance device is stopped during operation and is activated when the assigned operation is completed. To provide an unclamp holding operation after the end of assembly work and an unclamp release operation at the start of assembly work to be omitted to improve production efficiency and to eliminate an accompanying unclamp holding operation device.

<Background of the Invention> In a general tact system type assembly line conveyance device, a plate-shaped work pallet P is simply placed on a conveyance belt 17 made of a synthetic resin belt such as rubber and conveyed by friction. At times, the belt absorbs moisture and stretches, causing it to shift to the rear side of each station S (that is, to the front side that does not reach each station S).

Therefore, conventionally, in order to prevent this backward shift and to precisely align the center of the work pallet P with the center of each station S, the conveyor band 17 is fed in a larger tact depending on the distance between the stations S, and the work pallet P is In addition, the work pallet P that is about to be sent beyond the station S is stopped by a pallet stopping means attached to the center of two rubber belts. There is.

However, the above conventional technology has the following problems.

(1) In order to carry out surplus takt feeding, the takt time required for assembly line work itself becomes extra and productivity decreases.

(2) When a work pallet P is received by the pallet stopping means, the speed of the pallet P is not zero, so the work pallet P receives a stopping impact and the workpiece becomes misaligned with respect to the pallet P.

(3) If the conveyance speed or the weight of the work pallet P is large, there is a large possibility that the work pallet P will slide backward on the conveyance belt 17 due to static inertia and will not be able to stop accurately at a predetermined station S.

<Prior art> Therefore, the present applicant first proposed the invention related to Japanese Patent Application No. 1983-223336 (filed on September 19, 1988).
The above problems have been resolved.

That is, as shown in FIGS. 7 and 8, in the prior art, a clamp chamber 2 is formed in one side 1 of a work pallet P for tact system assembly line work, and a transportation clamp 3 is provided in the clamp chamber 2. , an unclamp device 4 and an unclamp holding device 100 are provided, and the transportation clamp 3 presses the clamp tool 5 with a pressing means 6.
The intermittent drive conveyance belt 17 of the assembly tact conveyance device 16 can be clamped and fixed between the clamping tool 5 and the receiving tool 7 by pressing the clamping device 4 toward the receiving tool 7 side. is configured to be pressed toward the unclamp F side against the pressing means 6, and its unclamp operation input part 18 is made to face the outer space of one side 1 of the work pallet P, and the unclamp holding device 100 is attached. The clamping tool 5 is pressed against the unclamp holding side K by the force tool 101.
When the unclamp holding position is reached from the clamping position to the unclamping position, the unclamping holding device is engaged and fixed to hold the unclamping holding position at the unclamping holding position, and the unclamping holding release operating section 102 of the unclamping holding device is connected to the workpiece pallet. One side of P 1
It was constructed so as to face the outside space of the building.

Therefore, when the above-mentioned work pallet P is applied to takt system type assembly line work, the following effects can be obtained.

(1) Since the work pallet P is integrally connected to the conveyance belt 17 by the conveyance clamp 3, the conveyance speed,
Or, regardless of the weight of the work pallet P,
The pallet P can be reliably moved along with the conveyance belt 17 to prevent it from slipping upward.

Therefore, the work pallet P is moved to the station S.
In addition to being able to accurately position the station at the center of the station, the tact feed length can be made equal to the distance between each station S, and the tact feed time can be shortened.

(2) When the work pallet P reaches each station S, the speed of the pallet P is 0, so the stopping impact caused by the pallet stopping means can be eliminated.

<Problems to be Solved by the Invention> However, the above prior art has room for improvement in the following points.

(1) When the work pallet P that has completed the specified work arrives at the terminal station Sn of the conveyance line, the clamp tool 5 is operated to the unclamp holding position by the external unclamp holding operation device 104, and the unclamp holding device 100 operates the clamp tool 5 to the unclamp holding position. If the clamping tool 5 is not held in this position to fix the workpiece pallet P in a free state from the conveyance belt 17, the empty pallet P will be transferred to the starting end station _S0 of the assembly tact conveyance apparatus 16, for example, through a circulation operation device. cannot be returned to the side of

Therefore, productivity is reduced by the amount of unclamping and holding operations required.

(2) Work pallet P is at the starting station S ₀
unclamp holding device 1.
The work pallet P cannot be clamped to the conveyance belt 17 again unless the unclamp holding/release operating section 102 of 00 is operated with the release tool 105 located outside.

Therefore, the productivity is reduced by the amount of unclamp holding release operation required.

(3) An unclamp holding device 100 must be attached to the clamp chamber 2 of the work pallet P,
The structure of pallet P becomes complicated.

The present invention is an improvement on the above-mentioned prior art, and its technical problem is to improve production efficiency and simplify the structure of the work pallet P.

<Means for solving the problems> Means for achieving the above problems will be described below using drawings corresponding to embodiments.

That is, the present invention provides a clamp chamber 2 within one side 1 of a work pallet P for tact system type assembly line work.
A transport clamp 3 and an unclamp device 4 are provided in the clamp chamber 2, and the transport clamp 3 presses the clamp tool 5 with a pressing means 6.
The clamping rollers 10 and 12 are rotatably supported by the clamp parts 8 and 8 of the clamping tool 5 and the receiving tool 7, respectively, and the rotation of each clamping roller 10 and 12 is supported by the clamping rollers 10 and 12. Axis core 1
4 and 15 substantially parallel to the conveyance movement direction A of the intermittent drive conveyance belt 17 of the assembly tact conveyance device 16, the intermittent drive conveyance zone 1 of the assembly tact conveyance device 16 is
7 can be clamped and fixed between the clamping roller 10 of the clamping tool 5 and the clamping roller 12 of the receiver 7, and the unclamping device 4 moves the clamping tool 5 against the pressing means 6 to the unclamping F side. The unclamp operation input section 18 is configured to face the outer space of one side 1 of the work pallet P.

<Function> (1) Work pallet P is assembled by tact conveyance device 1
₆ , the work pallet P is pushed down by the transfer device toward the intermittent drive conveyance belt 17 of the conveyance device 16,
It is clamped against the conveyor belt 17.

In this case, the clamp 3 for transporting the work pallet P continues to be in a clamped state, but after being transferred by the transfer device, when the work pallet P is pushed down by a dedicated push-down device, the elastic force of the pushing means 6 increases. This pushing down force is overcome and the conveyor belt 17 is pushed between the clamping rollers 10 and 12 which are in elastic contact, and the workpiece pallet P is automatically clamped to the conveyor belt 17 without any unclamp release operation. be done.

Then, the work pallet P integrally clamped to the conveyance belt 17 is transferred to each station.
Sequentially transported to Sm.

(2) Next, when the work pallet P comes to each machine work station Sm, the external unclamp operating device operates the unclamping device 4 from the unclamping operation input section 18, and the pressing means 6
The clamping roller 10 of the clamping tool 5 is separated from the clamping roller 12 of the receiver 7 against the elastic force of , and the work pallet P is released from the unclamped state with respect to the conveyance belt 17.

At the same time, a workpiece pallet P is positioned at the center of the station Sm, and, for example, in the case of speaker assembly work, mechanical work such as gluing, assembling, crimping, caulking, etc. is performed on the workpieces on the pallet.

(3) When the workpiece pallet P that has completed the specified work arrives at the terminal station Sn of the conveyor line, the workpieces on the pallet P are moved to the downstream assembly block by the workpiece transfer device, and the pallet P is transferred to the terminal station Sn. It is lifted up by the device and placed on the circulation conveyance device, and then reassembled and conveyed to the conveyance device 16.
Return to the starting station _S0 .

In this case, the clamp 3 for transporting the work pallet P is still in the clamped state,
When the work pallet P is lifted up by the transfer device, the conveyance belt 17 is pulled out from between the clamping rollers 10 and 12 against the elastic force of the pressing means 6, so that the work pallet P is automatically lifted without an unclamping operation. It comes off from the conveyor belt 17.

(4) After that, when the workpiece pallet P returns to the start station _S0 of the assembly tact transport device 16 via the circulation transport device, the operation returns to the above (1) and the above operations (1) to (4) are performed. It will be repeated.

<Effects of the Invention> (1) The work pallet is automatically pulled up and removed from the conveyor band by omitting the work pallet unclamp holding operation at the end station of the assembly conveyance device and the work pallet unclamp release operation at the start end station. (In addition, in the present invention, instead of the conventional unclamp release operation, it is necessary to push down the work pallet with respect to the conveyor belt, but this push-down operation can be performed more quickly than the unclamp release operation. ), which can improve the efficiency of assembly line work.

(2) Compared to the prior art, the unclamp holding device can be omitted from the work pallet, so the pallet structure can be simplified.

(3) When performing maintenance on the work pallet, the work pallet can be pulled up from the conveyor belt or pushed back onto the conveyor belt without unclamping, so the maintenance can be performed easily and quickly.

<Example> Hereinafter, an example of a work pallet of the present invention and a circulating conveyance facility for tact system assembly line work using the work pallet will be described based on the drawings.

Fig. 1 is a plan view of the work pallet, Fig. 2 is a partially cutaway front view of the work pallet, Fig. 3 is an exploded perspective view of the main parts of the work pallet, and Fig. 4 is a schematic plan view of work pallet circulation conveyance equipment for speaker manufacturing. In the figure, the work pallet circulation conveyance equipment for speaker manufacturing is composed of an assembly tact conveyance device 16, an unloading conveyance device 20, a return conveyance device 21, and a loading conveyance device 22.

The assembly tact transfer device 16 connects a chain 17 made of metal material to a drive source 2 via an intermittent drive device 23.
4, the work pallet P placed on the chain 17 is sequentially and intermittently conveyed between each station S and then stopped.

At this time, while the workpiece pallet P is tact-fed through the conveyance device 16, the workpieces W on the pallet P are subjected to assembly work, and then moved to the assembly block on the downstream side.

At the same time, the empty pallet P is circulated again to the conveying device 16 via the devices 20→21→22 (see FIG. 4).

The work pallet P is a substantially cylindrical upper pallet 25.
is constructed by removably fixing it integrally to a substantially prismatic lower pallet 26 with screws, two positioning holes 27 are made in the bottom of the upper pallet 25, and one side 1 of the lower pallet 26 is cut out in the shape of a rectangular parallelepiped. A clamp chamber 2 is formed, and a transportation clamp 3 and an unclamp device 4 are provided in the clamp chamber 2.

Incidentally, a vertically elongated chain guide groove 40 is formed in the wall near one side 1 of the lower pallet 26 along the conveyance movement direction A (see FIG. 3).

The transportation clamp 3 includes a clamping tool 5 pivotably supported on a support plate 28, and bases 30 on both sides.
It is composed of a receiver 7 formed between the clamping member 7 and a plate spring 6 that presses the clamping member 5 toward the clamping side C.

The support plate 28 is arranged in a horizontal direction, and support arms 31 connected to both sides of the clamp tool 5 are connected to the support plate 28 via a fulcrum 33 provided at an upper part 32 of the support arm 31.
It is supported by 8.

Further, the leaf spring 6 is bent into a substantially dogleg shape and fixed to the back surface of the support plate 28, and its tip 6a is brought into elastic contact with the clamping tool 5 to push it toward the receiving tool 7 (i.e., arrow C direction) to press.

Of the clamp tool 5, a U-shaped support groove 5a is formed across the support arms 31 on both sides of the clamp part 8 facing the receiver 7, and the clamp roller 10 can be freely rotated along the support groove 5a. The rollers 10 are fitted in such a manner that the arc portion of the roller 10 protrudes from the smooth surface of the clamp portion 8.

On the other hand, a U-shaped support groove 7a is also formed in the clamp part 8 of the receiver 7 on the side facing the clamp tool 5, and the clamping roller 12 is freely rotatable along the support groove 7a. The circular arc portion of the roller 12 protrudes from the smooth surface of the clamp portion 8 and is arranged so as to be able to come into contact with the clamp roller 10.

In this case, the rotational axes 14 and 15 of the clamping rollers 10 and 12 are oriented parallel to the conveyance movement direction A of the conveyance chain 17 (note that both rollers 10 and 12 are in the unclamped state). Even if they are separated, the separation distance is set so as to maintain a narrow enough distance that these rollers cannot escape from the support grooves 5a, 7a).

In addition, an input hole 18 for unclamp operation is formed in the center of the receiver 7, and the unclamp pin 4 can be inserted into the input hole 18 so as to be able to slide forward and backward, and can come into contact with the clamp part 8 of the clamp tool 5. Configure.

The support plate 28 is arranged so as to be fitable between the inner sides of the bases 30 located on both sides of the receiver 7, and the clamp rollers 10 and 12 are brought into elastic contact with each other at the clamp parts 8 and 8.

Further, after setting both outer sides of the base 30 to match the width of the clamp chamber 2, and assembling the support plate 30, the clamp tool 5, and the receiver 7 into the base 30,
All of these are accommodated in the clamp chamber 2.

At this time, the chain guide groove 3 is placed below the base 30.
5 is formed and communicated with the chain guide groove 40 formed in the lower pallet 26, and these chain guide grooves 35, 40 are positioned along the clamp portion 8 where the clamp rollers 10, 12 face each other.

2 running along the chain guide grooves 35 and 40
As shown in FIGS. 1, 2, 5, and 6, the metal chain 17 of the book has one end as a normal chain 17a and the other end as a chain 17b with an attachment 36. When the attachment 36 is clamped by the conveying clamp 3, the work pallet P is tact-fed together with the conveying chain 17, and when the conveying clamp 3 is unclamped with the unclamp pin 4 and the attachment 36 is separated, the work pallet P is is released from the conveyance chain 17 to a free state.

The functions of this work pallet P when applied to a circulation conveyance facility for speaker manufacturing will be described below.

(1) When the work pallet P is transported to the transport start station _S0 by the transfer device, a dedicated push-down device lowers the work pallet P toward the transport chain 17, and
The attachment 36 protruding from 7b is attached to the plate spring 6.
The clamping rollers 10 and 12
and clamp the work pallet P to the chain 17.

The work pallet P integrated with the chain 17 is intermittently transported with the work W on it, and is transferred to each station Sm (consisting of a work station where mechanical work or manual work is performed and a free station where no work is performed). It is stopped every time the takt feed is carried out.

(2) Work pallet P is a mechanical work station
When Sm is reached, the tact feed is stopped, and at the same time, the unclamp operation device 50 is activated, and the operation pin 51 that protrudes forward enters the input hole 18 for unclamp operation made in the work pallet P, and the unclamp operation device 50 is activated. Push the clamp pin 4 in the unclamp direction F.

As a result, the unclamping pin 4 swings the clamping tool 5 in the direction of arrow F against the pressing force of the leaf spring 6, separating the clamping roller 10 from the clamping roller 12 of the holder 7, and releasing the workpiece pallet P. The transport chain 17 is released from the free state.

In this case, the tip of the operating pin 51 is machined into a triangular shape so that it can engage with the input hole 18 for unclamping operation of the workpiece pallet P machined into a conical shape, and the input hole 18 is positioned and engaged. The hole is also used.

Therefore, when the unclamping operation device 50 is operated on the unclamping operation input hole 18, the workpiece pallet P can be unclamped, and at the same time, the workpiece pallet P can be accurately positioned at the station Sm of the assembly tact transfer device 16. , enables proper mechanical work such as gluing, crimping, caulking, and assembling.

(3) For example, in the case of circulation equipment for field assembly work, when the workpiece pallet P arrives at the transport terminal station Sn after completing the prescribed field assembly,
The transfer device lifts up the work pallet P.

At this time, the clamping rollers 10 and 1 are attached to the attachment 36 of the conveyance chain 17b.
Since the elastic clamping force of 2 is overcome by the lifting force, the conveying clamp 3 releases the attachment 36, and the work pallet P is separated from the conveying chain 17 and transferred to the unloading conveying device 20.

(4) After this, the work pallet P is transferred from the unloading transport device 20 to the return transport device 21 to the loading transport device 2.
2, return to the starting station _S0 of the assembly tact conveyance device 16, and return to the operation (1) above, thereby repeating the operations (1) to (4) below.

As described above, the present invention is a work pallet used in tact system assembly line work, and is not limited to the manufacture of speakers as in the above embodiment, but is also applicable to home appliances such as watches, telephones, kettles, etc., or automobile parts. It can be applied to any product that can be manufactured using the tact system method, such as the following.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention.
2 is a partially cutaway front view of the work pallet, FIG. 3 is an exploded perspective view of the main parts of the work pallet, and FIG. 4 is a schematic plan view of work pallet circulation conveyance equipment for speaker manufacturing. Fig. 5 is a plan view of the main part of a conveyance chain with an attachment, Fig. 6 is a front view of the main part of the same chain, Fig. 7 is a cross-sectional plan view of the main part of a work pallet showing the prior art, and Fig. 8 is a cross-sectional view of the main part of the same work pallet. It is a longitudinal sectional front view of the main part. P...Work pallet, A...Transfer movement direction,
1... One side of P, 2... Clamp chamber, 3... Transportation clamp, 4... Unclamping device, 5...
Clamp tool, 6... Pressing means, 7... Receiver, 8...
...clamping section, 10...5 clamping rollers,
12...7 clamping rollers, 14...10 rotational axes, 15...12 rotational axes, 16...assembly tact conveyance device, 17...intermittent drive conveyance belt,
18...Input section for unclamping operation.

Claims (1)

[Claims] 1 A clamp chamber 2 is formed in one side 1 of a work pallet P for tact system type assembly work, a transport clamp 3 and an unclamp device 4 are provided in the clamp chamber 2, and the transport clamp 3 is connected to a clamp tool 5.
is pressed toward the receiver 7 side by the pressing means 6, and the clamp rollers 10 and 12 are rotatably supported by the clamp portions 8 and 8 of the clamp tool 5 and the receiver 7, respectively. , 12 are oriented substantially parallel to the conveyance movement direction A of the intermittent drive conveyance belt 17 of the assembly tact conveyor 16, the intermittent drive conveyor belt 17 of the assembly tact conveyor 16 is clamped. The unclamping device 4 is configured to be clamped and fixed between the clamping roller 10 of No. 5 and the clamping roller 12 of the receiver 7, and the unclamping device 4 is configured to press the clamping tool 5 toward the unclamping F side against the pressing means 6. A work pallet for assembly line work using a tact system, characterized in that the unclamp operation input section 18 is configured to face the outer space of one side 1 of the work pallet P.