JPH0224551Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention is an improvement of a work lift device.

(Prior Art) Work lift devices are used in various fields, but an elevating device that raises and lowers an elevating table that receives the work is always required.

By the way, a welding station in a car body welding assembly line is equipped with a positioning unit on a lifting table to support the car body as a workpiece when the car body support jig, that is, lift table is raised, and also to position the car body. The welding robot then performs the welding work in this state. In the case of a workpiece lift device used in such a car body welding assembly line, etc., the workpiece and lifting table are quite heavy objects, so the load on the lifting device is unavoidable. Lifting and lowering is quite slow, and a fairly large lifting device is required. In particular, when attempting to use an air cylinder device as the lifting device, which is cheaper to install and easier to handle than a hydraulic cylinder device,
Another problem arises in that a large amount of air is consumed. For this reason, it may be possible to reduce the burden on the lifting device by providing a balance air cylinder device and having the weight of the lifting table itself be supported by this balancing air cylinder device.
In this case, a large space is separately required to install the air tank for the balance air cylinder device, resulting in a problem that the entire device becomes larger.

(Purpose of the invention) The present invention was created taking the above circumstances into consideration, and even when the load on the lifting device that lifts and lowers the lifting table is reduced using a balance air cylinder device, it is compact overall. The purpose of the present invention is to provide a work lift device that achieves the following.

(Structure of the device) In order to achieve the above-mentioned object, the present invention reduces the load on the lifting device by supporting the lifting table with a balance air cylinder device, and at the same time reduces the load on the lifting device by supporting the lifting table with a balance air cylinder device. That is, the reservoir tank is constituted by the reinforcing frame of the lift table, which has a sealed hollow structure.

(Example) Hereinafter, an example in which the present invention is applied to a welding station in a welding assembly line for vehicle bodies will be described based on the drawings.

In FIG. 1, A is a car body as a workpiece to be welded, and as shown in FIG. , so that it is conveyed from right to left in FIG.

Below the hanger rail 1, a plurality of welding stations _S1 to _S5 are arranged in series with each other. Each of these welding stations S ₁ to _{S 5} is
Each vehicle body A is sequentially welded by the welding robot 3 with the vehicle body A positioned as described below.
The assembly is performed. In addition, in the welding station _S3 , panels transported by a sub-transport line (not shown) are further added to the welding line, that is, assembled to the car body A, and welded to the car body A. , the other welding stations S ₁ , S ₂ , S ₄ , S ₅ are able to form a predetermined car body A without adding any additional panels.
All you have to do is weld the predetermined positions. Furthermore, among the welding robots 3, the welding robot 5 located between welding stations _S2 and _S3 is adapted to act on the vehicle body A located at both welding stations _S2 and _S3 , and The welding robot 3 is dedicated to each of the welding stations _S1 to _S5 .

Each of the welding stations _S1 to _S5 is broadly divided into a workpiece lift device B and a positioning unit C. First, the workpiece lift device B will be explained. Work lift device B is the third
As shown in FIGS. 4 and 4, a base 10 is fixedly installed on a floor surface F, and an elevating table 11 is disposed above the base 10. The base 10 and the lifting table 11 are connected by two links 12 and 13 arranged in an X shape.
Links 12 and 13 have a pin 14 between them.
The upper ends of the links 12 and 13 are rotatably connected to the lifting table 11 by pins 15 or 16, and the lower ends of the links 12 and 13 are rotatably connected to the base 10 by pins 17 or 18, respectively. There is. And pins 16 and 18
is slidable in a long hole 19 provided in the lifting table 11 or in a long hole 20 provided in the base 10. In this way, the base 10, the lifting table 11, and the two links 12 and 13 constitute a parallel link mechanism, and the lifting table 11 can be raised and lowered while always keeping parallel to the base 10, that is, keeping the horizontal state. It is said to be free. Note that a guide post 21 is provided upright on the base 10, and the engager 22 of the lifting table 11 is guided with respect to the guide post 21, so that the lifting table 11 is raised and lowered smoothly without rattling, and the engaging member 22 is guided to the guide post 21. 22 comes into contact with the stopper 23, thereby restricting the lifting table 11 from rising beyond a predetermined level.

The elevating table 11 is supported by the base 10 via a plurality of balance air cylinder devices 24, and the elevating table 11 is driven up and down by a mechanism installed between the base 10 and the elevating table 11. This is carried out by an air cylinder device 25 as a lifting device. Also,
As shown in FIGS. 5 and 6, the elevating table 11 includes a plate 26 and a plate 26 in the embodiment.
The first reinforcing frame 27 is fixed to the lower surface of the reinforcing frame 27, and the second reinforcing frame 28 is fixed to the lower surface of the first reinforcing frame 27. The second reinforcing frame 28 has a sealed hollow structure,
The hollow chamber inside the air tank 29 is configured as an air storage chamber, and such an air tank 2
A second reinforcing frame 28 , designated as 9 , is connected to the balance air cylinder device 24 .

The piping system between the cylinder devices 24, 25 and the air tank 29 will be explained with reference to FIG. In this Fig. 7, 30 is an air pump,
This air pump 30 is connected to a four-way electromagnetic switching valve 32 via a pipe 31. This switching valve 32
is connected to one chamber 25b of the air cylinder device 25 defined by the piston 25a via the piping 33.
It is also connected to the other chamber 25c of the air cylinder device 25 via a pipe 34, and a check valve 35 or 36 with a variable throttle is connected in the middle of both pipes 33 and 34. . Further, the air pump 30 is connected to an air tank 29 constituted by the second reinforcing frame 28 described above via a pipe 37 branched from the pipe 31, and this pipe 37 has a pressure regulating valve equipped with a pressure gauge 38a. 38
and a check valve 39 are connected. Further, a pipe 40 branched from the pipe 37 on the downstream side of the check valve 39 is connected to the balance air cylinder device 24, and an electromagnetic switching valve 41 is connected to the pipe 40.

The switching valve 32, in accordance with its switching, supplies air to the chamber 25c of the air cylinder device 25 (chamber 25b is open to the atmosphere) - raises the lifting table 11, seals both chambers 25b and 25c - lifts the table 11 - Maintaining the raised position of the lifting table 11 and supplying air to the chamber 25b (chamber 25c is released to the atmosphere) - lowering the lifting table 11 and releasing both chambers 25B and 25C to the atmosphere - maintaining the lowering position of the lifting table 11. People are starting to do this. Further, the switching valve 41 seals the balance air cylinder device 24 and switches the communication with the air tank 29, and is linked to the switching valve 32, so that the sealing is performed when the lifting table 11 is in a stopped state. The communication with the air tank 29 corresponds to when the lifting table 11 is being raised or lowered. Furthermore, the pressure regulating valve 38 is
In cooperation with the check valve 39, air is supplied from the air pump 30 into the air tank 29 when the pressure in the air tank 29 falls below a predetermined pressure. Note that the balance air cylinder device 24 includes a cylinder 24a and two pistons 24b, 2
4c, and the entire structure is telescopically expandable and retractable.

In this way, in the work lift device B,
The lifting table 11 is held stationary by the action of the balance air cylinder device 24 when no external force is applied to the lifting table 11. By the communication action of the balance air cylinder device 24 with the air tank 29 described above, the amount of air (air pressure) is adjusted according to its expansion and contraction, and the air pressure inside the air tank 29 itself is adjusted by the action of the pressure regulating valve 38. maintained at a given level.

Next, an example of the positioning unit C will be explained with reference to FIGS. 3 and 4. A bracket 5 is placed on (the plate 26 of) the lifting table 11.
0, each extending in the transport direction of the vehicle body A 2
A book rotation shaft 51 is rotatably held, and a plurality of jig mounting plates 57, 5 are attached to this rotation holding shaft 51.
7' is fixed. A jig is attached to each of the mounting plates 57, 57'.
And again, set the clamp arm at 53 and 53',
Furthermore, the bearings are designated by reference numerals 54, 54';
In FIG. 4, these jigs are omitted. In addition,
Among the above-mentioned jigs, the (positioning) pin 52, clamp arm 53, and support base 54 are used for, for example, a hatchback-shaped vehicle body A shown in FIG. is for a sedan type car body A, and the jigs 52, 53, 54 and 52' for this slightly different car body A are
Switching between 53' and 54' is performed by rotating the rotary shaft 51 in the forward and reverse directions by 180 degrees using a rotary drive device 55, such as a motor or rotary actuator, provided on the lifting table 11. And each jig 52, 53, 54, 52', 53', 5
4' is the vehicle body A due to the lifting of the lifting table 11.
The (positioning) pin 52 is inserted into the positioning hole formed in the vehicle body A to perform its positioning, and the clamp arms 53, 53'
actuated by air cylinder devices 56, 56';
The predetermined position of the vehicle body A thus positioned is clamped and held without wobbling, and the supporting bases 54, 5
4' partially supports a predetermined position of the vehicle body A. Of course, in such a positioning state, the welding robot 3 welds the vehicle body A and assembles it, and when the lifting table 11 is in the raised position, the rotation axis 5
1 will lift the vehicle body A from the hanger 2.

In the above embodiments, a work lift device for a car body welding line has been described, but the work lift device can also be used for other purposes. In addition to the air cylinder device 25, a hydraulic cylinder device or a motor may be used as the lifting device.

(Effects of the invention) As is clear from the above, the invention has the following effects:
Since the elevating table is supported by a balance air cylinder device, the burden on the elevating device that drives the elevating table up and down can be extremely reduced.As a result, the elevating table can be made smaller and the elevating speed of the elevating table can be increased. In particular, when an air cylinder device is used as the lifting device, the amount of air consumed can be extremely small.

In addition, in the present invention, the air tank for the balance air cylinder device is constructed using the reinforcing frame of the lifting table, so there is no need for a separate space for installing this air tank, and the device as a whole can be made more compact. can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a simplified plan view showing a car body welding assembly line to which the present invention is applied. FIG. 2 is a simplified side view of FIG. 1. FIG. 3 is a side view showing details of a welding station in which the work lift device according to the present invention is used. FIG. 4 is a sectional view taken along the line shown in FIG. 3. FIG. 5 is an enlarged cross-sectional view of the main part of the lifting table. Figure 6 is the 5th
- Line sectional view of the figure. FIG. 7 is a system diagram showing an example of an air piping system. A: Vehicle body (work), B: Work lift device,
11: Lifting table, 24: Balance air cylinder device, 25: Air cylinder device (lifting device),
28: Reinforced frame, 29: Air tank.

Claims (1)

[Scope of utility model registration request] A balance air cylinder device that supports an elevating table that receives a workpiece, and an elevating device that drives the elevating table up and down, and a reinforcing frame of the elevating table is connected to the balance air cylinder device as an air tank with a sealed hollow structure. A work lift device characterized by: