JPS6015008Y2 - fluid pressure balance device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fluid pressure balance device suitable for use in industrial machinery.

In general, in industrial machines such as copy welding machines, automatic packaging machines, and automatic assembly machines, when a feed shaft is driven by a drive motor such as a pulse motor or a DC servo motor to drive and control a moving head such as a welding head, The drive motor is made smaller by using a balance device that cancels out the gravity acting on the moving head.

Such conventional industrial machinery employs a balance device that applies a spring force to a moving head, or a balance device that connects a weight to the moving head.

However, in a balance device that applies a spring force to the moving head, the spring force acting on the moving head changes as the length of the spring changes, and the load acting on the drive motor changes as the moving head moves. Therefore, it is not possible to apply an appropriate balance force over the entire stroke of the moving head.

In addition, in a balance device in which a weight is connected to a moving head, the moment of inertia of the moving head and driven objects such as the weight relative to the drive motor becomes large, and there is a problem that the drive motor cannot be sufficiently miniaturized. be.

This idea was made in view of the above-mentioned conventional problems, and it uniformly cancels out the gravity acting on the moving head over the entire stroke of the moving head without increasing the moment of inertia of the driven object such as the moving head. The object of the present invention is to provide a fluid pressure balance device that can perform the following tasks.

The fluid pressure balance device of the present invention is a fluid pressure balance device in which a motor-driven feed shaft is provided in a stationary part, and the gravity acting on a moving head supported movably in the vertical direction by the feed shaft in the stationary part is canceled out. A fluid pressure cylinder is interposed between the moving head and the stationary part, a piston rod of the fluid pressure cylinder is directly fixed to the moving head, and a piping system connecting the fluid pressure cylinder and a fluid supply source is provided. A pressure control valve is provided so that a constant pressure working fluid is supplied to the fluid pressure cylinder.

According to the above configuration, when the moving head is lowered by rotation of the feed shaft, the internal pressure of the fluid pressure cylinder increases, so the pressure control valve is actuated in response to this pressure, and the working fluid is released to the outside. By keeping the internal pressure of the pressure cylinder constant, the gravity acting on the moving head during its descent is canceled out.

On the other hand, when the moving head is raised, the internal pressure of the fluid pressure cylinder becomes low, so the pressure control valve operates in response to this pressure, and the fluid supply source is used to maintain the internal pressure of the fluid pressure cylinder constant. The pressure of the working fluid is adjusted to cancel out the gravitational force that acts on the moving head as it rises.

In this way, the pressure of the working fluid in the fluid pressure cylinder when the moving head moves up and down is controlled to a constant state by the pressure control valve, so the balance pressure acting on the moving head can be equalized, and the motor, etc. Load fluctuations in the drive section are eliminated.

Hereinafter, embodiments of this invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram showing a state in which an embodiment of the fluid pressure balance device according to the invention is applied to a copy welding machine.

A moving head 13 including a welding torch 12 is supported by the column 11 as a stationary part so as to be movable in the vertical direction via a bearing 14 .

A nut 15 is fixed to the back side of the moving head 13, and a male threaded feed shaft 16 rotatably supported by the upper end of the column 11 is screwed into the nut 15.

A drive motor 1 such as a pulse motor or an N servo motor fixed to the upper end of the column 11 is attached to the feed shaft 16.
7 output shafts are connected.

That is, the movable head 13 is movable up and down in the vertical direction along the column 11 through a threaded engagement between a feed shaft 16 rotated by the drive motor 17 and a nut 15.

Furthermore, a pneumatic cylinder 18 as a fluid pressure cylinder is interposed between the upper end of the column 11 and the moving head 13.

That is, the cylinder 19 of the pneumatic cylinder 18 is fixed to the upper end of the column 11, and the distal end of the piston rod 20 of the pneumatic cylinder 1B is connected to the moving head 13.

This pneumatic cylinder 18 has a filter 2 as a working fluid.
Compressed air from a pneumatic source 22 can be supplied via 1.

Here, the compressed air is supplied to the pneumatic cylinder 18 with its pressure regulated by the pressure control valve 23.

In the figure, 24 indicates a pilot pressure line for operating the pressure control valve 23, and 5 indicates a pressure gauge that allows confirmation of the pressure supplied to the pneumatic cylinder 18.

Next, the operation of the above embodiment will be explained.

By driving the drive motor 17 in one direction, the feed shafts 1;
When the moving head 13 rotates in one direction and descends from an arbitrary position, compressed air pushed out from the pneumatic cylinder 18 is discharged to the outside of the piping system via the pressure control valve 23.

Also, the drive motor 17 is driven in the other direction, and the feed shaft 16
When the moving head 13 rotates in the other direction and the moving head 13 rises from an arbitrary position, the pressure of compressed air from the pneumatic source 22 is adjusted to a constant pressure state at the pressure control valve 23, and acts on the moving head 13. The air is supplied to the pneumatic cylinder 18 at an appropriate pressure to counteract the force of gravity.

That is, according to the embodiment described above, the increase in the load torque on the drive motor 17 due to the gravity acting on the moving head 13 is eliminated without causing an increase in the moment of inertia of the driven object, and the waist drive motor 17 and its drive unit are made smaller. It becomes possible to convert into

In addition, since the pressure state of the compressed air acting on the pneumatic cylinder 18 is controlled to a constant state by the pressure control valve 23, the balance pressure acting on the moving head 13 is made uniform throughout the entire stroke of the moving head 13, No load fluctuation is applied to the drive motor 17.

In addition, when the weight of the moving head 13 changes, the pressure state of the compressed air acting on the pneumatic cylinder 18 is changed appropriately by operating the pressure control valve 23, so that an appropriate balance pressure is always applied to the moving head 13. It becomes possible to act.

Further, by reducing the size of the drive motor 17, it is possible to save energy such as power saving.

In addition, in the above embodiment, the case where the fluid pressure balance device according to this invention is applied to a copy welding machine is explained, but the fluid pressure balance device according to this invention can also be applied to an automatic packaging machine, an automatic assembly machine, etc. It is.

Further, in the above embodiment, a case has been described in which the pneumatic cylinder 18 is used as the fluid pressure cylinder, but it goes without saying that a hydraulic cylinder or the like may also be used.

As mentioned above, according to the present invention, the weight of the moving head can be accurately canceled out over the entire stroke of the moving head without increasing the moment of inertia of the moving head, so the driving force of the moving head can be reduced. Moreover, it can be done evenly, and the drive system can be downsized and economized.

Further, since the piston rod of the fluid pressure cylinder is directly fixed to the moving head, the piston rod does not affect the positioning of the moving head in response to changes in the weight of the moving head, and the structure is simple.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a fluid pressure balance device according to the invention. 13... Moving head, 16... Feed shaft, 17... Drive motor, 18... Pneumatic cylinder, 23... Curving/pressure control valve.

Claims (1)

[Scope of utility model registration request] A fluid pressure balance device in which a motor-driven feed shaft is provided in a stationary part and cancels gravity acting on a moving head that is vertically movably supported by the feed shaft in the stationary part,
A fluid pressure cylinder is interposed between the moving head and the stationary part, a piston rod of the fluid pressure cylinder is directly fixed to the moving head, and a piping system connecting the fluid pressure cylinder and a fluid supply source is provided. A fluid pressure balance device comprising a pressure control valve and configured to supply a constant pressure working fluid to the fluid pressure cylinder.