JPH0627386Y2 - Lifting device for large tables - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement of a device suitable for raising and lowering a large rectangular table such as a die lifting table in a vacuum forming machine.

(Prior art and problems) Conventionally, hydraulic cylinders or electric cylinders have been generally used as lifting devices for large tables that require an intermediate stop at an arbitrary position. However, in the former case, there is a problem that the stopping accuracy of the large table is poor.

The present invention has been made for the purpose of solving the above problems.

(Means for Solving the Problems) In order to achieve the above object, the lifting device for a large table according to the present invention is provided with a piston rod of a downward electric cylinder in the vicinity of both ends of a diagonal line of a large table having a rectangular upper surface. The lower end and the lower end of the piston rod of the air cylinder are fixed near both ends of the other diagonal line, respectively, and these four cylinders are installed on the ceiling of the gate frame, and the rod cover side of the air cylinder is provided with pressure adjusting means. It is connected to a compressed air source through the head cover side and is open to the atmosphere on the head cover side.

(Operation) The weight of the large table and the mold that moves up and down together with the large table are supported by the force of the air cylinder, and the lifting / stopping control of the large table is performed only by the extension / contraction drive of the electric cylinder.

(Example) An example will be described with reference to the drawings. In FIG. 1, (1) is a portal frame having a rectangular ceiling (1a), which is installed on the foundation (S). Further, two electric cylinders (2) and (2) are mounted downwardly near both ends of a diagonal line in the ceiling (1a) of the gate-shaped frame (1), and the electric cylinders (2) and (2) are attached downward. On the lower end of the piston rod (2a) (2a), a large table (3) having a rectangular upper surface is fixed near both ends of the diagonal line, and a mold for vacuum forming is mounted on the large table (3). (Not shown) is attached.
Further, two air cylinders (4) and (4) are mounted downward near the opposite ends of the other diagonal line in the ceiling (1a) of the gate-shaped frame (1), and the air cylinders (4) and (4) are attached downward. To the lower ends of the piston rods (4a) (4a) of the large table (3) are fixed near both ends of the other diagonal line. Further, the rod cover side of each air cylinder (4) is connected to a compressed air source (6) through a pressure adjusting means (5) capable of highly accurately adjusting the pressure of a relatively large amount of compressed air, The pressure adjusting means (5) includes a main pressure reducing valve (7) for adjusting the pressure of compressed air supplied to the air cylinder (4), and the main pressure reducing valve (7).
Pilot pressure reducing valve to adjust pilot air pressure to (8)
It consists of and. The head cover side of each air cylinder (4) is open to the atmosphere via a silencer (9). Further, four cylindrical guide rod holders (10) and (10) are fixed near the piston rods (2a) and (4a) fixed on the large table (3).
0) and (10) are four guide rods erected on the foundation (S).
(11) (11) is fitted through so that it can slide up and down. Further, on the right side surface of the large table (3), as shown in FIG.
(13) is rotatably mounted via (13), the pinion (14) (14) is fitted to both ends of the rotary shaft (12), the pinion (14) (14), The racks (15) and (15) fixed to the columns (1b) and (1b) of the gate-shaped frame (1) and extending in the vertical direction are engaged with each other. Thus, guide rods (11) (11)
With the racks (15) (15) and the pinions (14) (14), the large table (3) can be surely moved up and down.

Next, the operation of the apparatus thus configured will be described. Adjusting the pressure adjusting means (5) in advance, the lifting force by the two air cylinders (4) and (4) and the large table
(3) and the weight of the mold that moves up and down together with it should be almost the same, and the weight of the large table (3) and the mold should be supported by the force of the two air cylinders (4) and (4). Control for lifting and lowering large tables (3) type, etc. with two electric cylinders (2)
Make it possible to carry out only by the operation of (2). Under this condition, when the electric cylinders (2) (2) are driven to contract, the large table (3) will move to the guide rods (11) (11) and the racks (15) (15).
・ The pinion (14) (14) lifts while preventing rolling and twisting. Further, when the electric cylinders (2) and (2) are driven to extend, the large table (3) is lowered while preventing the rolling and twisting in the same manner as the upward movement. Furthermore, by appropriately stopping the driving of the electric cylinders (2) and (2), it is possible to stop the vertical movement of the large table (3) at an arbitrary position.

(Effect) As is apparent from the above description, according to the present invention, the weight of the large table (3) and the mold that moves up and down together with the large table (3) are set to the two air cylinders (4) (4). ), And the lifting / stopping control of them is performed only by the two electric cylinders (2) (2), so there is no need for a hydraulic device or a large electric cylinder like this type of conventional device. Thus, the facility cost is significantly reduced, and moreover, the excellent practical effect such as the stopping accuracy of the large table (3) is improved as compared with the case of using the hydraulic cylinder.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a partially longitudinal front view, and FIG. 2 is a view taken along arrows AA of FIG. (1): Gate type frame (1a): Ceiling (2): Electric cylinder (2a), (4a): Piston rod (3): Large table (4): Air cylinder (5): Pressure adjusting means

Claims (1)

[Scope of utility model registration request] 1. A gate-type frame having a rectangular ceiling (1a).
(1) is installed, and the two electric cylinders (2) and (2) are mounted downwardly near both ends of a diagonal line in the ceiling (1a), and the piston rods (2) and (2) of the electric cylinders (2) and (2) are installed. 2a) (2a)
A large table (3) with a rectangular upper surface is erected near the ends of the diagonal line at the lower end of the, and two air cylinders (4) (4) face downward near the ends of the other diagonal line in the ceiling (1a). Then, the lower ends of the piston rods (4a) and (4a) of the air cylinders (4) and (4) are fixed near both ends of the other diagonal line of the large table (3). ) Each rod cover side of (4) is connected to the compressed air source through pressure adjusting means (5), and the air cylinder (4) is connected.
A lifting device for a large table, wherein each head cover side of (4) is open to the atmosphere.