JPH0419202Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an electro-hydraulic cylinder used for positioning machine tools, industrial machines, iron-making machines, etc.

[Conventional technology] Among conventional electro-hydraulic servo cylinders, electric motors (electric stepping motors, DC motors, AC
A rotary valve type electro-hydraulic servo cylinder in which the opening degree of a port is changed by rotating a spool with a motor, etc. has a configuration as shown in FIG. 2. That is,
On one side of the hydraulic cylinder 1 divided by the partition wall 2,
A cylindrical sleeve 3 is rotatably supported by a bearing 4 and built in, and a spool 5 having a hollow interior 6 is rotatably fitted inside the sleeve 3, with one end protruding from the hydraulic cylinder 1. The one end is rotatably supported by the hydraulic cylinder 1 with a bearing 7. On the sleeve 3 side of the hydraulic cylinder 1,
A port 9 communicating with the oil chamber 8 of the sleeve 3, a port 10 communicating with the oil chamber 12 outside the spool, and a port 11 communicating with the spool inner cavity 6 are provided respectively, and the spool 3 is provided with a port 9 communicating with the oil chamber 8 of the sleeve 3, a port 10 communicating with the oil chamber 12 outside the spool, and a port 11 communicating with the cavity 6 inside the spool, as shown in FIGS. 2 and 5. , ports 13 and 14 are provided at circumferential positions, respectively, and the spool 5 is provided with ports 13 and 14 of the sleeve 3.
A port 15 corresponding to the sleeve 3 is provided to open into the internal cavity 6, and a port 16 corresponding to the port 14 of the sleeve 3 is provided to open to the oil chamber 12. It is rotated by a motor 19. On the other hand, on the other side of the hydraulic cylinder 1, a piston 20 with a rod 21 whose tip protrudes outward is housed.The piston 20 and rod 21 are hollow, and a screw 22 inserted therein is inserted into the partition wall 2. A nut member 24 is rotatably supported through a bearing 23 and fixed to the sleeve 3, and a nut member 24 screwed to the screw 22 is fixed to the piston 20, so that the movement of the piston 20 in the axial direction The screw 22 rotates to rotate the sleeve 3. 25 is a port for supplying pressure oil to the rod side pressure chamber A of the piston 20, 26 is an oil passage provided in the partition wall 2 so as to open to the head side pressure chamber B of the piston 20, and 27 is a port for supplying pressure oil to the rod side pressure chamber A of the piston 20. This is piping that communicates with port 9.

In the conventional electro-hydraulic servo cylinder, when the electric motor 19 rotates the spool 5 by a predetermined angle and pressurized oil is supplied from the port 11 of the hydraulic cylinder 1 to the cavity 6 of the spool 5, the port 15
As it moves in the direction of arrow a in the figure and overlaps port 13, pressure oil enters pressure chamber B on the head side of piston 20 via ports 15, 13, oil chamber 8, port 9, piping 27, and oil passage 26. The hydraulic cylinder 1 then expands due to the difference in thrust between it and the pressure chamber A on the rod side.
At this time, the screw 22 screwed into the fixed nut member 24 rotates and the spool 3 is connected to the spool 5.
The movement of the piston 20 is transmitted to the spool 3 so that the overlap between the ports 15 and 13 becomes zero by rotating it in the same direction as the rotation direction of the spool 3. On the other hand, by rotating the spool 5 in the opposite direction to the above, pressure oil flows from the pressure chamber B on the head side to the oil passage 26, piping 27, port 9, oil chamber 8, ports 14, 16, oil chamber 12, and port 10. When it flows out to the tank port T, the hydraulic cylinder 1 is shortened due to the thrust difference between the pressure chamber A on the rod side and the pressure chamber B on the head side.

Thus, in the same manner as described above, the sleeve 3 is rotated in the same direction as the rotational direction of the spool 5 through the nut member 24 and the screw 22, and the movement of the piston 20 is transmitted to the sleeve 3.

[Problems to be solved by the invention] However, in the conventional electrohydraulic servo cylinder described above, the width W where the ports 15 and 16 of the spool 5 and the ports 13 and 14 of the sleeve 3 overlap each other is always constant. Therefore, when looking at the relationship between the rotation angle of spool 5 and the oil flow rate, the fourth
Only the curves shown in the figure are realized, and the curves,
, it was not possible to change the flow curve. In the conventional electro-hydraulic servo cylinder,
When changing the flow rate curve depending on the size, stroke, etc. of the hydraulic cylinder, each port is made to have a different width and ports 13 and 1 are used to change the width W.
Parts 4, 15, and 16 were newly made and replaced each time. Therefore, the work was difficult.

Therefore, the present invention aims to provide an electro-hydraulic servo cylinder in which the flow rate gain can be changed arbitrarily from the outside without having to recreate the port with a different width as in the conventional system.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the same configuration as the conventional electro-hydraulic servo cylinder described above, but has a large opening at the end of the hydraulic cylinder that supports one end of the spool. A slide member having a hollow shaft center portion and having one end of the spool fitted and supported in the hollow portion is fitted into the opening portion so as to be slidable in the axial direction, and the slide member and the spool A bearing is provided between one end of the
A seal device is provided between the slide member and the hydraulic cylinder, and the slide member is further provided with a slide adjustment device that acts on the end face of the hydraulic cylinder.

[Operation] When the slide adjustment device is operated to move the slide member in the axial direction, and at the same time the spool is moved in the axial direction, the spool is simultaneously moved in the axial direction, and the port of the spool and the sleeve are moved. The opening area communicating with the port can be changed arbitrarily. In this state, if the spool is rotated by a predetermined angle using an electro-hydraulic servo cylinder, the flow rate curve with respect to the rotation angle can be arbitrarily changed.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment of the present invention, in which the partition wall 2
A large opening 28 is provided in the end surface of the hydraulic cylinder 1 on one end side, and a slide member 29 having a hollow shaft center and a flange 30 at one end is slidably fitted from the outside into the opening 28. Arrived,
One end of the spool 5 is fitted into the hollow portion of the slide member 29, one end of the spool 5 is made to protrude outward from the slide member 29, and is connected to the electric motor 19 via gears 17 and 18.

A bearing 31 for rotatably supporting the spool 5 is provided between the slide member 29 and the outer surface of one end of the spool 5 so as to be integral with the slide member 29 in the axial direction. A port 32 is provided for communicating the pressure oil supply port 11 provided in the hydraulic cylinder 1 with the cavity 6 of the spool 5, and in order to prevent the oil flowing through the ports 11 and 32 from leaking, the slide member 29 and the hydraulic pressure are connected. A sealing device 33 is provided between the inner surface of the opening 28 of the cylinder 1 and the inner surface of the opening 28 of the cylinder 1 . Further, the flange portion 30 of the slide member 29 is provided with an adjustment bolt 34 for adjusting the amount of axial movement of the slide member 29.

The rest of the structure is the same as that of the electrohydraulic servo cylinder shown in FIG. 2, and the same parts are given the same reference numerals.

When the spool 5 is rotated by a predetermined angle by the electric motor 19 in the state shown in FIG. 1, the oil flow rate is determined by the opening area of ports 13 and 15 or ports 14 and 16, and the flow rate curve is as shown in FIG. 4. When it is desired to change the flow rate curve, etc., the slide member 29 is moved outward or inward by the adjustment bolt 34, and at the same time, the spool 5 is moved slightly to the right in the figure. If they are moved outward, the overlapping width W of ports 13 and 15, 14 and 16 becomes smaller, and the opening area of ports 13 and 15 or 14 and 16 can be changed smaller when the spool 5 is rotated. The flow rate can be reduced, and the curve shown in FIG. 4 can be realized. Conversely, when the slide member 29 is pushed inward into the hydraulic cylinder 1 by the adjustment bolt 34, the spool 5 is also simultaneously moved to the left in the figure, and the widths W of each of the overlapping ports 13 and 15 and 14 and 16 are increased. Become. This increases the opening area of the ports 13 and 15 or 14 and 16 when the spool 5 is rotated.
5 or ports 14 and 16, the flow rate curve can be raised higher than the flow rate curve in FIG. 4, and a curve can be realized.

By moving the spool 5 in the axial direction in this way, the area of the port 13 or 14 of the sleeve 3 and the port 15 or 16 of the spool 5 can be changed, and the flow rate gain can be changed arbitrarily from the outside. .

[Effects of the invention] As described above, according to the electro-hydraulic servo cylinder of the invention, a large opening is provided in the end face on one end side of the hydraulic cylinder, and a slide member having a hollow shaft center is installed in the opening. The spool is slidably fitted from the outside, one end of the spool is fitted into the hollow part of the slide member, and one end of the spool protrudes outward from the slide member, thereby moving the slide member in the axial direction. The rotary spool can be moved in the axial direction with a simple and reliable operation, and the areas of the sleeve port and spool port can be changed arbitrarily, making it possible to change the flow rate curve against the rotation angle of the sleeve. can be changed arbitrarily, the valve capacity can be arbitrarily determined by the size and stroke of the electro-hydraulic servo cylinder, and the flow rate gain can be arbitrarily changed from the outside without having to recreate the conventional port with a different width. This excellent effect can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the electro-hydraulic servo cylinder of the present invention, Fig. 2 is a sectional view of a conventional electro-hydraulic servo cylinder, Fig. 3 is an expanded view of the sleeve, and Fig. 4 is a rotation of the spool. FIG. 5, which is a diagram showing the relationship between angle and flow rate, is a developed view of the conventional system corresponding to FIG. 3. 1... Hydraulic cylinder, 2... Bulkhead, 3... Sleeve, 5... Spool, 6... Cavity, 13,1
4, 15, 16... port, 20... piston,
22... Screw, 28... Opening, 29...
Slide member, 31...Bearing, 33...Seal device, 34...Adjustment bolt.

Claims (1)

[Scope of utility model registration request] A hydraulic cylinder that supports one end side of the spool in an electro-hydraulic servo cylinder that rotates a spool by an electric motor to communicate a port of the spool with a port of a sleeve, and moves a piston forward and backward as oil flows through these ports. A slide member having a large opening in an end face on one end side, a hollow shaft center portion, and a flange portion at one end is fitted into the opening from the outside so as to be slidable in the axial direction, and the slide member One end of the spool is fitted into the hollow part so that the one end of the spool protrudes outside the slide member to be connected to the electric motor, and a bearing is provided between the slide member and the one end of the spool. and a sealing device for sealing between the sliding member and the hydraulic cylinder, and further comprising a sliding adjusting device on the flange portion of the sliding member to move the sliding member in the axial direction. Electro-hydraulic servo cylinder.