JPH0412875Y2 - - Google Patents

Description

[Detailed description of the invention] a. Industrial application field The present invention relates to a conveyance device for vertically conveying a workpiece such as an outer panel of an automobile body and transferring it to a jig, etc. The present invention relates to a conveyance device that transfers workpieces at an intermediate position of a frame.

b. Prior Art A conventional example of this type of conveyance device is shown in FIG. In the figure, 1 is a lifting frame for mounting the workpiece, 2 is a pinion, 3 is a lever, 4 is a link,
5 is a rack, and 6 is a drive cylinder. A plurality of such lifting drive devices are arranged below the lifting frame 1, and when the drive cylinder 6 is driven, the pinion 2
rotates to move the elevating frame 1 in the vertical direction.

c Problems to be solved by the invention In the conventional conveying device described above, the lifting speed is the lowest at the rising and falling ends of the lifting frame 1, and on the other hand, when the workpiece 1 is placed on the lifting frame 1. The lifting speed becomes maximum when the lifting frame 1 is transferred to a jig or the like (when the lifting frame 1 is located between the lifting end and the lowering end). For this reason, the workpiece is likely to be damaged or deformed due to collisions with the lifting frame 1, jigs, etc., which poses problems especially when this type of conveyance device is used to convey outer panels of automobile bodies. Ta.

To explain this point in more detail, in the conventional conveying device described above, in the welding process of the side body of an automobile, the workpiece, which is the object to be processed, is first set on a welding jig and the welding operation is performed. When the work in that process is completed, the workpiece is transported to the next process. The transport device used for this kind of transport is a so-called shuttle transfer device, and the lifting frame starts to rise as soon as the welding work is completed, so the workpiece is placed approximately in the middle of the lifting frame and placed on the workpiece receiver such as a jig. It is configured to pass the .

Therefore, in the above-mentioned conveying device, if the lifting speed of the lifting frame is high at an intermediate position, the workpiece may be deformed such as denting, and the workpiece may become unusable.

It should be noted that even if a soft material such as rubber is attached to the workpiece holder to prevent the deformation, this is not sufficient.

On the other hand, since work cannot be performed while the lifting frame is moving, there has been a demand for increasing the lifting speed of the lifting frame as much as possible.

The present invention has been made to satisfy both of the above contradictory demands.

That is, the present invention has been devised to effectively solve these problems, and its purpose is to prevent the lifting frame 1 from moving when the workpiece is transferred to and received from the lifting frame 1. The object is to prevent impact from acting on the workpiece by reducing the lifting speed as much as possible.

d. Means for Solving the Problems An embodiment of the present invention will be described below based on FIG. 1. In the figure, reference numeral 1 denotes a horizontal elevating frame, and the elevating frame 1 can move vertically in parallel while being guided by a plurality of guide rods 11 erected on a floor surface 10.
On the other hand, there is a drive cylinder 6 on the lower side of the lifting frame 1.
are arranged horizontally. One end of this drive cylinder 6 is connected to a pin 12 and a fixed bracket 13.
It is supported on the floor surface 10 by. Further, a connecting rod 15 is connected to the piston rod 14 of the drive cylinder 6, and this connecting rod 15 is connected to a connecting bracket 16.
It is connected to the cam arm 17 via. One end of the cam arm 17 is supported by a pin 18 on the floor surface, and when the drive cylinder 6 is driven, the cam arm 17 rotates vertically about the pin 18.

A link arm 19 is arranged on the outside of the cam arm 17. One end of the link arm 19 is supported on the floor by a pin 20, and the link arm 19 can rotate vertically about the pin 20. A roller is rotatably attached to the intermediate portion of the link arm 19, and the roller 21 rolls along a cam surface 17a formed on one side of the cam arm 17. A roller 22 is also attached to the tip of the link arm 19, and this roller 22 rolls along a pressed surface 23 formed on the lower surface of the elevating frame 1. Note that the cam arm 17 and link arm 19
A plurality of are arranged along the floor surface 10.

The cam surface 17a of the cam arm 17 has a recess 24 formed in a detailed dogleg shape in a part thereof, and the elevating frame 1 is at the position shown by the solid line in FIG. The roller 21 of the link arm 19 is configured to pass through this recess 24 when the following steps are performed.

e. Effect The conveyance device is constructed as described above, and when the drive cylinder 6 is driven to move its piston rod 14, for example, in the direction of the arrow in FIG. 1, the cam arm 17 is rotated counterclockwise. Cam arm 17
When the link arm 19 rotates counterclockwise, the roller 21 of the link arm 19 is pressed against the cam surface 17a of the cam arm 17, and the link arm 19 also rotates counterclockwise. As a result, the lifting frame 1 is
It rises while being pressed by the roller 22 of 9.

At this time, when the elevating frame 1 rises to the position shown by the solid line in FIG.
Since the link arm 19 passes through the concave portion a, the rotational speed of the link arm 19 at this time becomes very small, and as a result, the rising speed of the elevating frame 1 temporarily becomes almost 0.
decreases to Therefore, the workpiece can be transferred to and from the lifting frame 1 very quietly, and damage or deformation of the workpiece can be prevented. Similarly, when the lifting frame 1 is lowered to transfer the workpiece to a jig or the like, the descending speed of the lifting frame 1 decreases to almost 0 at one point, causing damage or deformation to the workpiece. It can be transferred to a jig etc. quietly without any trouble.
Further, wear of the jig receiver and the lifting frame 1 can be prevented.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified in various ways. For example, in the above embodiment, the cam arm 17 is driven to rotate by the drive cylinder 1, but the cam arm 17 may be driven to rotate directly by a motor or the like. Further, the shape of the cam surface 17a of the cam arm 17 may be modified as necessary, thereby making it possible to control the change in the elevation speed of the elevating frame 1 to a desired state.

f. Effects of the invention As explained above, according to the conveyance device according to the invention, the link arm is rotatable in the vertical direction while the distal end is in sliding contact with the lifting frame, and the link arm is in sliding contact with the intermediate part of the link arm. The link mechanism is constituted by a cam arm having a cam surface and rotated by the drive cylinder, and a recess is provided in a part of the cam surface, so that the elevating frame can be moved in the vertical direction. When passing approximately an intermediate position of By appropriately determining the speed of the elevating frame at the intermediate position, it is possible to optimally set the speed of the elevating frame at the intermediate position.

For this reason, the workpiece can be transferred to and from the lifting frame and the jig etc. quietly, thereby preventing damage or deformation to the workpiece. At the same time, wear of the jig receiver and the lifting frame can be reduced, and the durability of the conveying device can be improved.

Further, since this device does not use a rack, pinion, etc. as in the conventional device, it can be constructed in a simple and compact structure.

Therefore, a large installation space for a welding machine, a jig, etc. can be provided around the device, and design and construction can be facilitated.

This eliminates the need to dig a pit when installing the line, and it is possible to shorten the line construction period in cases such as changing the model of an automobile. In other words, when digging a pit, the old line was removed, the pit was filled in, the pit was dug, cement was poured, it was allowed to cure, and then a new line was installed, which took about two weeks. If there is no need to dig a pit, line removal work and other such work becomes unnecessary, and the line construction period is shortened.

In addition, with conventional equipment, a very high workbench was required to carry out transport work without digging a pit, but with the device of this invention, a pit is not required in the first place, so the workbench is also very high. It is possible to make layout changes such as model changes and shorten the period.

[Brief explanation of drawings]

Figure 1 is a side view of the conveyance device according to the present invention, Figure 2
The figure is a side view of a conventional conveyance device. 1... Lifting frame, 6... Drive cylinder, 1
7...Cam arm, 17a...Cam surface, 19...
Link arm, 21, 22...roller, 24...
recess.

Claims (1)

[Scope of utility model registration request] A conveyance device comprising: an elevating frame that is capable of moving vertically with a workpiece placed thereon; a drive cylinder that moves the elevating frame up and down; and a link mechanism that transmits the driving force of the drive cylinder to the elevating frame. The link arm has a link arm whose tip portion is slidable on the elevating frame and can be rotated in the vertical direction, and a cam surface that slides in contact with an intermediate portion of the link arm, and is rotated by the drive cylinder. The link mechanism is constituted by a cam arm, and a recess is provided in a part of the cam surface, so that when the elevating frame passes through a substantially intermediate position in the vertical direction, the intermediate portion of the link arm A conveying device characterized in that the vertical movement speed of the vertical frame is temporarily reduced by passing through a recessed portion of a cam arm.