JPH0451029Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a position indexing device in which a pressure tank is provided for a pneumatic balance cylinder that moves up and down.

(Prior Art) Conventionally, a position indexing device has been used in which a machining tool or the like is attached to a mounting base and the mounting base is moved vertically and horizontally to move the machining tool or the like to the correct position. This is as shown in Figs. 5 to 7. A pair of guide rails 2 are fixed to the position indexing device main body 1, and a horizontal movement table 3 slides on the rails 2 via a linear bearing 4. They are fitted and installed freely. A ball screw 5 is attached to the main body 1 by a bearing 6 in parallel with the guide rail 2, and a nut 7 screwed onto the ball screw 5 is fixed to the horizontally movable table 3. Further, a drive motor 8 that rotates the ball screw 5 and an encoder 9 that detects the number of rotations of the ball screw 5 are respectively connected to the main body 1.
installed on.

The vertical movement position indexing device 10 has a vertical guide rail 12 attached to a frame 11 fixed to the horizontal movement table 3.
is fixed, and the device mounting base 13 moves up and down.
is connected to the guide rail 1 via the linear bearing 14.
2 and is slidably fitted and attached. A ball screw 15 is connected to the frame 11 in parallel to the guide rail 12.
A nut 17, which is attached by a bearing 16 and screwed onto the ball screw 15, is fixed to the device mounting base 13. Further, a drive motor 18 for rotating the ball screw 15 and an encoder 19 for detecting the number of rotations of the ball screw 15 are attached to the frame 11. Further, in order to balance the weight of the device mounting base 13 which moves up and down, a pneumatic device 20 as shown in FIG. 8 is attached. As shown in the figure, the piston rod 22 of the air cylinder 21 is connected to the device mounting base 13 by a chain 24 via a group of pulleys 23.
It is connected with. Compressed air is supplied to the air cylinder 21 via the chain 24 in order to balance the weight of the device mounting base 13. That is, from the air source 25 to the stop valve 26
The pressure is reduced by the pressure reducing valve 27 through the cylinder 21, and the pressure becomes constant, and air pressure is supplied to the rod side of the cylinder 21 via the air hose 28. A safety valve 29 is installed in the middle of the air hose 28 between the pressure reducing valve 27 and the air cylinder 21. Also air source 2
5 to the downstream side of the valve 26, a filter 26a is attached to prevent dirt from entering.

In order to mount a machine tool etc. on the device mounting base 13 and position it, the motor 8 is used in the horizontal direction.
The horizontal movement table 3, which is slidable on the guide rail 2, is moved to a desired position by rotating the ball screw 5 by means of the encoder 9. Similarly in the vertical direction, the ball screw 15 is rotated by the motor 18 to vertically move the device mounting base 13 which is slidable on the guide rail 12. Air pressure is constantly applied to the rod side of the air cylinder 21 to balance a weight equal to the sum of the weight of the device mounting base 13 and the weight of the machine tool attached to it. Therefore, when the drive motor 18 is operated to raise the device mounting base 13, the air pressure inside the rod side of the air cylinder 21 and the total weight of the device mounting base 13 are balanced, and the piston rod 22 of the air cylinder 21 is moved by that amount. is descending. At this time, compressed air is supplied to the piston rod side of the air cylinder 21 from the air source 25 through the pressure reducing valve 27. When the device mounting base 13 is lowered, the piston rod 22 of the air cylinder 21 is connected to the device mounting base 13 via the chain 24 and the pulley group 23, so the piston rod 22 absorbs the air inside the rod side of the air cylinder 21. It rises while compressing. At this time, air cylinder 2
The air on the rod side of No. 1 is about to be discharged through the air hose 28, but since a constant air pressure is always supplied from the pressure reducing valve 27, the air pressure increases and is discharged to the atmosphere from the safety valve 29. .

(Problem to be solved by the invention) When moving the device mounting base 13 up and down in this way, compressed air flows into the air cylinder 21 and is discharged into the atmosphere every time it moves up and down. Compressed air consumption is extremely high. In addition, in order to minimize the amount of air consumed, it is possible to install an air pressure tank outside the position indexing device body and connect this pressure tank to a cylinder. This has the disadvantage that the entire device becomes large. The present invention was made to solve the above problem, and it ensures the function of the position indexing device to balance the weight of the device mounting base when the position indexing device moves up and down, and furthermore, when the position indexing device moves up and down, To provide a position indexing device that reduces the amount of air consumed and is compact.

(Means for Solving the Problems) As a means for solving the above-mentioned problems, the present invention provides a vertically movable positioning unit that has a device mounting base that moves up and down on a horizontally movable base provided on the position indexing device main body. In a position indexing device provided with an indexing device and an air cylinder for balancing the weight of the device mounting base, a pressure tank having a volume larger than a displacement volume of the piston of the air cylinder in the position indexing device body; The pressure tank and the working chamber of the air cylinder are connected by an air hose, and the rod of the air cylinder and the device mounting base are connected by a chain via a pulley. .

(Function) By configuring the present invention in this way, the vertical movement of the device mounting base is performed not by the air cylinder but by the vertical movement position indexing device, so that the air pressure in the action chamber of the air cylinder and the movement of the device mounting base are controlled. It becomes possible to balance the total weight. The position indexing device body is equipped with a pressure tank having a volume larger than the piston movement volume of the air cylinder, and the pressure tank and the working chamber of the air cylinder are connected with an air hose, thereby controlling the vertical movement of the device mounting base. In this case, the air corresponding to the volume moved by the piston can be transferred via the air hose between a pressure tank having a volume larger than the volume moved by the piston and the working chamber of the air cylinder. Therefore, air is not released to the outside, and the pressure inside the air cylinder can be maintained at a pressure commensurate with the total weight of the device mounting base. Furthermore, since the pressure tank is built into the main body of the position indexing device, it is possible to make the position indexing device compact. In addition, since the equipment mounting base and the air cylinder rod are connected by a chain via a pulley, the vertical movement position indexing device can be used while balancing the pressure inside the air cylinder and the total weight of the equipment mounting base. It becomes possible to move the device mounting base up and down.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 to 4 show the conventional position indexing device shown in Figures 5 to 8 with the pressure tank of the present invention added, and the same parts as the device in Figures 5 to 8 have the same reference numerals. It is assumed that most of the parts shown in FIGS. 5 to 8 are reproduced in the apparatus shown in FIGS. 1 to 4 and have similar functions.

The device mounting base 13, which moves up and down, is connected to the piston rod 22 via a chain 24 and a group of pulleys 23 in order to balance its movement.
and a pressure tank 30 provided within the position indexing device main body 1 are connected by an air hose 31. Moreover, the pressure tank 30 is fixed to the main body 1, and the air cylinder 21 is fixed to the frame 11 on the horizontally movable table 3, which is a horizontally movable base, so that it performs relative movement. Therefore, the air hose 31 passes through a flexible cable duct 32, and one end 32a of the flexible cable duct 32 is fixed to the main body 1, and the other end 32b is fixed to the frame 11 on the horizontal movement table 3. has been done. Therefore, even if the cylinder 21 moves relative to the pressure tank 30, the air hose 31 serves to stably connect the two. Note that the safety valve 29 is attached to the middle of the air hose 31, and the pressure tank 30 is attached to a drain valve 30a.

A case will be described in which a welding gun unit (not shown) is attached as a working device to the device mounting base 13 of the position indexing device 1 to perform welding work. First, in FIG. 1, the ball screw 5 is rotated and the horizontal movement table 3 is moved to perform positioning in the AA' direction. Next, by the vertical movement position indexing device 10,
Although positioning is performed in the BB′ direction, the device mounting base 13
When the piston rod 22 is raised by rotating the ball screw 15, the piston rod 22 connected by the chain 24 and the pulley group 23 is lowered, and air flows from the pressure tank 30 into the rod-side working chamber 21a of the air cylinder 21. . However, since the volume ratio between the pressure tank 30 and the movement volume of the piston of the air cylinder 21 is quite large, the amount of air that moves from the pressure tank 30 to the action chamber 21a of the air cylinder 21 is small compared to the volume of the pressure tank. It does not affect the air pressure much. Also, when the device mounting base 13 is lowered, the piston rod 22
rises, and the air in the action chamber 21a flows into the pressure tank 30.
move towards. At this time, the air pressure increases slightly, but the volume of the pressure tank 30 and the piston rod 2
Since the ratio of the displacement amount due to the increase in 2 to 2 is large, the rate of increase in pressure is small. Therefore, if the set pressure of the safety valve 29 is set slightly higher than the air pressure of the pressure tank 30, the safety valve 29 is unlikely to operate due to the pressure increase in this case. However, when the device mounting base 13 descends excessively and the piston rod rises to near the final stroke, the air pressure inside the air hose 31 becomes excessive and the safety valve 29 operates, and only in this case a small amount of air is discharged. . In this way, the air exhausted is only from the safety valve in this case and from leakage from the piping system, and the conventional device
The amount of air consumed is extremely small compared to the fact that the entire amount of displacement required for the stroke is exhausted by moving up and down.

(Effect of the invention) As mentioned above, in this invention, the vertical movement of the equipment mounting base is performed not by the air cylinder but by the vertical movement position indexing device, so the total weight of the equipment mounting base and the air in the action chamber of the air cylinder are The pressure can be balanced, and the above-mentioned balanced function of the position indexing device can be ensured.

Since the position indexing device body is equipped with a pressure tank having a larger volume than the piston movement volume of the air cylinder, and the pressure tank and the working chamber of the air cylinder are connected with an air hose, the device mounting base can be moved up and down. In this case, the air only moves between the pressure tank, which has a volume larger than the moving volume of the piston, and the working chamber of the air cylinder, and is not released to the outside. As a result, the amount of air consumed can be made extremely small compared to the conventional method, and the amount of energy consumed can be significantly reduced. Furthermore, since the pressure tank is built into the main body of the position indexing device, the position indexing device can be made compact.

Since the equipment mounting base and the air cylinder rod are connected by a chain via a pulley, the pressure inside the air cylinder can be controlled by moving the equipment mounting base up and down using the vertical movement position indexing device. The total weight can be reliably balanced. Another feature of the present invention is that, despite this, the main body of the device can be made compact and not much different from conventional devices.

[Brief explanation of the drawing]

FIG. 1 is a side view of an embodiment of the present invention, FIG. 2 is a plan view thereof, FIG. 3 is a sectional view of FIG. 1, and FIG. 4 is a system diagram of a pneumatic device. FIG. 5 is a side view of a conventional position indexing device, FIG. 6 is a sectional view of FIG. 5, FIG. 7 is a sectional view of FIG. 5, and FIG. 8 is a system diagram of a pneumatic device. DESCRIPTION OF SYMBOLS 10... Vertical movement position indexing device, 13... Device mounting base, 21... Air cylinder, 21a... Air cylinder action chamber, 30... Pressure tank, 31...
...air hose.

Claims (1)

[Scope of utility model registration request] A position indexing device in which a vertically movable position indexing device having a device mounting base that moves up and down is provided on a horizontally movable base provided on the main body of the position indexing device, and an air cylinder is provided to balance the weight of the device mounting base. In the apparatus, a pressure tank having a volume larger than a moving volume of the piston of the air cylinder is installed in the position indexing device main body, the pressure tank and the working chamber of the air cylinder are connected with an air hose, and the air cylinder A position indexing device characterized in that the rod and the device mounting base are connected by a chain via a pulley.