JPS5810004Y2 - Your Tsuki Rika Ben - Google Patents

Description

[Detailed description of the invention] Digital control has recently become popular as a means of automating machines and saving labor, and especially in machine tools, numerical control has made great progress.

Currently, numerical control has begun to be widely used in machine tools, gas cutting machines, etc., and is the most effective way to automate and save labor in all machines.

This invention relates to an electro-hydraulic pulse cylinder using a hydraulic switching valve, which was developed as a principle for servo equipment for digital control in order to develop numerical control. A screw having a hollow structure with the hollow part serving as an oil passage and whose end part is rotatably supported by one end of the cylinder is inserted into the piston and rod, and a plurality of screws are inserted into the piston and rod, and a plurality of A spool having an annular groove and screwed onto the outside of the screw is located in the piston, and the spool is engaged with the piston so that it can only move linearly by rotation of the screw, and the spool is fitted into the cylinder. , a supply oil port so that pressure oil always acts on one side of the piston, and a return oil port that communicates with the oil passage formed in the hollow part of the screw are provided, and one side of the piston and The piston is provided with an oil passage that communicates one surface of the piston with the spool portion and the other surface of the piston with the spool portion so that the other surface communicates with the spool portion through one annular groove on the outer periphery of the spool. The piston is provided with an oil passage that communicates between the other surface of the spool and the oil passage inside the screw through another annular groove on the outer periphery of the spool, and an electric wire connected to the end of the screw is provided. The present invention is characterized in that the spool is controlled by rotating the screw using a pulse motor, thereby controlling the flow of the supplied pressure oil and moving the piston.

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

Figures 1 and 2 show the principle of the hydraulic switching valve used to operate the electro-hydraulic pulse cylinder of the present invention.
A spool 1 having a threaded hole 2 along its axis and a rotation stopper pin 3 at its end is inserted into a sleeve 4 such that its axial position can be displaced, and the rotation stoppin 3 is provided in the sleeve 4. The spool 1 is engaged with the groove 5 so that only the rotation is restricted, and the engagement between the groove 5 and the rotation stopper pin 3 causes the spool 1 to rotate.
can reciprocate only in the axial direction, and a screw 6 is screwed into the axial center of the spool 1, and the rotation of the screw 6 causes the spool 1 to move in the axial direction and change the oil path, thereby causing the actuator to move. T is driven, and the spool 1 moved by the screw 6 is moved in the opposite direction by the displacement caused by the drive of the actuator I, so that negative feedback can be performed.

In the figure, 8 indicates a supply oil port, 9 indicates a return oil port, and 10 indicates an input end of the screw 6.

The principle structure of the hydraulic switching valve used to operate the electro-hydraulic pulse cylinder of the present invention is as described above, so that when the input end 10 of the screw 6 is rotated by a certain angle, the spool 1 is rotated by the detent pin. 3 so as not to rotate relative to the sleeve 4, it is displaced only in the longitudinal direction (axial direction).

When the spool 1 moves to the right in this manner, high pressure oil is introduced from the merged oil field 8 into the oil path A to the actuator 7, and the oil path B is guided to the return oil field 9 on the low pressure side.

Therefore, the actuator 7 is driven in a certain direction.

When the actuator 7 is driven, this drive displacement is negatively fed back to the sleeve 4, acting to move the spool 1 in the opposite direction to the left.

FIG. 3 shows an electro-hydraulic pulse cylinder of the present invention which uses the above-mentioned hydraulic switching valve, uses a piston 15 as the actuator 7, and further drives the screw 6 with an electric pulse motor 14. A piston 15 with a hollow rod 15a is housed inside the piston 15, and the rod 15a of the piston 15 is movably protruded from one end of a hydraulic cylinder 16 to be used as an actuator, and is fitted into the other end of the hydraulic cylinder 16. The rear end of the hollow screw 6 is supported by the hydraulic cylinder 16 via a bearing and a seal device, and its tip (front end) is connected to the piston 15 and rod 15.
The tip of the screw 6 is supported by a sealing piece so that it can slide against the inner wall of the rod 15a of the piston 15.

The spool 1 is screwed onto the outside of the screw 6,
A locking pin 3 provided at the end of the spool 1 is engaged with the piston 15 so that it can move only in the axial direction, so that the spool 1 can be displaced in the axial direction within the piston 15 by rotation of the screw 6. The screw 6 is rotated by an electric pulse motor 14 connected to the rear end of the screw 6 through gears 18 and 19.

The hydraulic cylinder 16 is provided with a supply oil port 8 that communicates with the front y side of the piston 15, and a return oil field 9 that communicates with the oil passage formed in the hollow part of the screw 6 at the distal end of the screw 6. As shown in the figure, the piston 15 is provided with an oil passage a which communicates the front y side of the piston 15 with the spool 1 part, an oil passage which communicates the rear X side of the cylinder 15 with the spool 1 part, and An oil passage C is provided to communicate between the spool 1 part and the inside of the rod 15a in order to communicate between the spool 1 part and the oil passage formed in the hollow part of the screw 6,
By controlling the spool 1, the high pressure oil supplied from the supply oil port 8 enters the rear surface X side of the piston 15 as shown by the arrow, and by controlling the spool 1, the high pressure oil supplied from the rear surface X side of the piston 15 enters the oil passage 1). -+ C, the oil passage inside the screw 6 as shown by the arrow is returned to be guided to the oil field 9, and the tip side of the piece at the tip of the screw 6 is the oil passage inside the screw 6,
The return oil field 9 communicates with the tank side so that the pressure is always low.

In addition, the difference in area between the front surface y and the rear surface X of the piston 15 is 7 characters 1/
It is 2x.

The electro-hydraulic pulse cylinder of the present invention incorporates the spool 1 that engages with the screw 6 in the piston 15 of the hydraulic cylinder 16 as described above, and prevents it from rotating so that only linear displacement is possible within the piston 15. The pin 3 is engaged to control the pressure oil moving forward and backward of the piston 15. Therefore, the electric pulse motor 14 now applies a certain rotational displacement to the screw 6 to move the spool 1 straight in the right direction in the figure. When it is displaced, as a result, the supply oil port 8 and the rear surface X side of the piston 15 communicate with each other, and the high pressure oil piston 15 is constantly acting from the supply oil port 8 on the front surface Y side of the piston 15.
It enters the rear surface X side of the piston 15 through oil passages a and b.

At this time, the difference in area between the rear surface X and the front surface y of the piston 15 is the surface y.
Since the shape is 1/2 side X, if high-pressure oil enters the rear side X, the pressure balance on both sides of the piston 15 will be disrupted, causing the piston 15 to move forward in the cylinder 16, that is, to the right in the figure. It will be done.

When the piston 15 is displaced to the right, the position of the spool 1 returns to the origin between the oil passages a, b, and c provided in the piston 15, and negative feedback is provided to stop the piston 15.

Conversely, by applying a certain rotational displacement to the screw 6, the spool 1
When the piston 15 is linearly displaced to the left, the pressure oil on the rear surface Therefore, the piston 15 is displaced to the left due to the pressure difference with the supplied hydraulic pressure that is always acting on the front y side of the piston 15, and negative feedback is provided so that the relative position between the spool 1 and the piston 15 returns to the origin.

In the electro-hydraulic pulse cylinder of the present invention, as described above, the piston 15 is moved by the pressure difference acting on both sides of the piston 15 to generate an output, while the screw 6 is axially centered within the piston 15 and the rod 15a. The tip of the screw 6 is inserted so as to be movable in the direction, and the tip of the screw 6 is only located in the rod 15a of the screw I/N 15 and is not mechanically connected to the piston 15 and rod 15a, so there is no influence on the output. The screw 6 is not subjected to a corresponding reaction force, therefore, the screw 6 is always independent of the output, and the screw 6 can be rotated with a small servo input.

As a result, a thrust bearing for receiving the reaction force of the output is not necessary, and a bearing for fixing the movement of the screw 6 is sufficient to achieve the purpose.

In addition, since the screw 6 is made hollow to form a return oil path, the hydraulic pressure guided to the tip of the screw 6 is always low pressure and there is no force that compresses the screw 6, which simplifies the structure and makes it very easy to use. In addition, the screw 6 only needs to have a small diameter regardless of the magnitude of the supply pressure that generates the output, and since the screw 6 only rotates and does not move in the axial direction, communication with the return oil field 9 is improved. Not only is this convenient, but the seal for the screw 6 does not need to be complicated because the screw 6 does not move in a straight line, and a simple seal can be used.

As described above, according to the electro-hydraulic pulse cylinder of the present invention, (i) the spool is controlled by a screw that is rotated by input from an electric pulse motor, and the tip of the screw is located inside the piston in the cylinder; Since the screw is located without being fixed to the screw, the screw does not receive any reaction force depending on the output, and is always independent of the output.The control input to the screw is minimal, and a thrust bearing can be eliminated. .

(11) Feedback can be very simple, and especially when applied to a piston, a mechanical feedback mechanism is not required, and unstable elements in the control system can be reduced, stability can be improved, and it can be achieved at low cost.

(iii) Since the screw itself does not need to move from side to side and only needs to be rotated, its supporting method can be made very compact and the structure can be made simple.

(IV) Same The pitch of the output can be easily changed by changing the carrier ratio between the electric pulse smoke and the screw with the same screw.

Since the M screw is hollow and the hollow part is used as a pressure oil return oil path, there is no need to prepare a separate hose etc. as a return oil path, the structure is simple, manufacturing is easy, and the return pressure is reduced. This prevents the oil from acting on the tip of the screw and applying a force that would compress the screw, and it does not receive a reaction force depending on the output.

It can produce excellent effects such as

[Brief explanation of drawings]

Figure 1 is a sectional view showing the configuration of a hydraulic switching valve used to operate the electro-hydraulic pulse cylinder of the present invention;
The figure is a perspective view, and FIG. 3 is a sectional view of the electrohydraulic pulse cylinder of the present invention. 1... Spool, 3... Stopping pin, 4... Sleeve, 6... Screw 8... Oil supply port, 9... ... Return oil field, 15 ... Piston, 16 ... Hydraulic cylinder.

Claims (1)

[Scope of utility model registration request] A piston with a rond having a hollow structure is movably housed in a hydraulic cylinder, and a screw having a hollow structure with a hollow portion serving as an oil passage and whose end portion is rotatably supported at one end of the cylinder is attached to the piston and the rond. A spool is inserted into the piston and has a plurality of annular grooves on its outer periphery and is threaded onto the outside of the screw. is engaged with the piston, and further,
The above-mentioned cylinder is provided with a supply oil port so that pressure oil always acts on one side of the piston, and a return oil port that communicates with the oil passage formed in the hollow part of the screw, and one side of the piston. In order to communicate between the surface of the piston and the other surface through one annular groove on the outer periphery of the spool, oil passages are provided in the piston to communicate between one surface of the piston and the spool portion, and the other surface of the piston and the spool portion, respectively. An oil passage is provided in the piston to communicate the oil passage between the other surface of the piston and the spool portion and the oil passage inside the screw through another annular groove on the outer periphery of the spool, and the oil passage is connected to the end of the screw. 1. An electro-hydraulic pulse cylinder characterized in that it is configured to control a spool by rotating a screw using an electric pulse motor, thereby controlling the flow of supplied pressure oil and moving a piston.