JPH0221602Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a device for controlling the supply and discharge of pressurized fluid to a fluid chamber formed in a fluid pressure controlled object, and is particularly applicable to a clamping force release device for a hob head equipped with a turning function. Therefore, it is suitable.

As shown in FIG. 1, which shows the appearance of a hobbing machine, when gear cutting is performed using the generation method on a gear material 4 that is fixed to a table 2 on a bed 1 via a fixture 3, a hob cutter attached to a hob head 5 is used. It is necessary to match the lead angle of 6 and the helix angle of the teeth formed on the gear material 4. For this reason, in the conventional hobbing machine, the hob head 5 can be rotated around an axis perpendicular to the rotation center of the table 2 relative to the hob saddle 8 supported by the column 7, and along with this, the hob head 5 can be rotated at any desired position. A clamping device that can be fixed in a pivoted position is also incorporated. In the conventional one shown in the figure, the turning position of the hob head 5 relative to the hob saddle 8 is set by turning a turning operation shaft 9 protruding from the hob saddle 8, and the hob head 5 is fixed to the hob saddle 8 by operating a bolt 10. There is.

In recent years, attempts have been made to simplify the setup work by shortening this series of operations through electrical or mechanical automation. For example, as shown in FIG. 2, which schematically shows the clamping mechanism of the hob head 5 to the hob saddle 8, a T bolt 12 protruding toward the hob head 5 is slidably inserted into a T groove 11 formed with a constant curvature in the hob saddle 8. A piston 14 that is slidably fitted into a cylinder 13 provided on the hob head 5 is integrally fixed to the T-bolt 12. A large number of disc springs 15 inserted into the T-bolts 12 are housed in the cylinder 13, and the spring force of these disc springs 15 abuts against the piston 14 and pushes the piston 14 upward in the figure. The hob head 5 is integrally fixed to the hob saddle 8. An oil passage 20 that communicates with a pressure increase chamber 18 of a pressure intensifier (booster) 17 and a check valve 19 is connected to an oil chamber 16 partitioned off by the piston 14 . A piston 22 with a piston rod 21 that partitions the
is slidably housed therein, and a pressurizing chamber 23 is formed by the piston 22 . This pressurized chamber 23
An oil drain pipe 27 and an oil supply pipe 29 for pressurized oil supplied by a hydraulic pump 28 are connected to the oil passage 24 communicating with the check valve 19 and the oil passage 26 to the pressure reducing valve 25 connected in series to the check valve 19 at two positions. It is connected via a switching valve 30, and when the hob head 5 is released from the hob saddle 8, a solenoid 31 is activated to open the oil path 2.
4, 26 and the oil drain pipe 27 and oil supply pipe 29 can be switched. In addition, pressure intensifier 1
7 is necessary because the cylinder 13 and piston 14 cannot be made too large due to the structure of the hob head 5, and a pressure reducing valve 25 and a check valve 19 are provided as a countermeasure against oil leakage.

That is, when releasing the fixation of the hobhead 5 to the hob saddle 8, the solenoid 31 is activated to supply pressure oil from the oil supply pipe 29 to the pressure chamber 23 of the pressure intensification chamber 17. The high-pressure oil inside is supplied to the oil chamber 16 to push the T-bolt 12 downward in the figure through the piston 14, and the clamping force by the disc spring 15 is released. in this case,
Low-pressure oil is supplied to the oil passage 20 side by the pressure reducing valve 25 to compensate for leakage of pressure oil between the pressure increasing chamber 18 and the oil chamber 16. On the other hand, when the hob head 5 is fixed to the hob saddle 8, the operation of the solenoid 31 is stopped and the oil passage 24 communicating with the pressurizing chamber 23 is connected to the oil drain passage 27. As a result, the pressure of the pressure oil in the pressure increase chamber 18 and the oil chamber 16 decreases, and the disc spring 1
The piston 14 is pushed upward in the figure by the spring force 5, and a clamping force is generated by the T-bolt 12.

However, in the structure shown in FIG. 2, when the hob head 5 is fixed to the hob saddle 8, the oil passage 26
As a result, a surge pressure is generated and a small amount of pressure oil is replenished to the oil passage 20 side, and as a result, the pressure of the pressure oil in the oil chamber 16 becomes several times higher than the set value, and the clamping force is insufficient. It has become clear that there is a risk of not being able to obtain the

From this point of view, the present invention provides a control device that increases the pressure of pressure oil and supplies high-pressure oil to an oil chamber formed in a hydraulically controlled object, which includes a pressure oil replenishment mechanism and an oil chamber. It is an object of the present invention to provide a hydraulic device with a simple structure that can reliably reduce pressure.

The configuration of the fluid pressure control device of the present invention that achieves this object includes a first fluid chamber, a second fluid chamber communicating with the first fluid chamber, and a second fluid chamber communicating with the second fluid chamber. a cylinder block in which a third fluid chamber having a larger diameter than the second fluid chamber is sequentially formed in a straight line; and the first fluid chamber is slidably fitted into the first fluid chamber; a spool that partitions the first fluid chamber and the second fluid chamber; a fluid supply passage bored in the spool to constantly communicate the first fluid chamber and the second fluid chamber; a piston rod that is integrally formed with the piston that is slidably fitted to the piston and that is slidably fitted to the second fluid chamber to partition the second fluid chamber and the third fluid chamber; An opening/closing passage is formed in the piston rod and opens at the distal end surface and outer peripheral surface of the piston rod, and is closed by the spool when the piston rod is displaced toward the first fluid chamber, and an opening/closing passage is provided in the cylinder block. a control port connected to the fluid chamber of the fluid pressure controlled object and opened at an end of the second fluid chamber on the first fluid chamber side; and a control port provided in the cylinder block and connected to the fluid chamber of the fluid pressure controlled object; a depressurization supply and discharge port that opens at an end of the third fluid chamber on the side; and a depressurization supply and discharge port that is provided in the cylinder block and opens at an end of the third fluid chamber that is opposite to the depressurization supply and discharge port. and a pressurized supply/discharge port communicating with the opening/closing passage by displacement of the piston rod toward the third fluid chamber, the pressurized supply/discharge port, the depressurization supply/discharge port, a pressure fluid supply source, and a liquid storage tank. It is equipped with a two-position switching valve interposed between the

Therefore, according to the present invention, since the third fluid chamber is set to have a larger diameter than the second fluid chamber, when pressurized fluid is supplied to the pressurized supply/discharge port, the piston rod moves toward the first fluid chamber. The pressure of the fluid in the second fluid chamber can be significantly increased by the displacement to the second fluid chamber, and high-pressure pressurized fluid can be delivered to the fluid chamber of the fluid pressure controlled object. Also, even if pressure fluid leaks from the second fluid chamber or the fluid chamber of the fluid pressure controlled object at this time,
The first fluid chamber and the second fluid chamber are in communication via the fluid supply passage, and the first fluid chamber is pressed by the piston rod via the spool, so the pressure fluid is automatically transferred to the second fluid chamber. The first fluid chamber is replenished into the second fluid chamber. When removing pressure fluid from the fluid chamber of the fluid pressure controlled object, the second fluid chamber, the opening/closing passage, and the pressurized supply/discharge port communicate directly with the liquid storage tank, so that the fluid of the fluid pressure controlled object is removed. It is possible to reliably lower the pressure in the chamber to around atmospheric pressure. Furthermore, a check valve 19 as shown in FIG.
A pressure reducing valve 25 is not required, and a fluid pressure circuit with a simple structure and low cost can be obtained.

Hereinafter, an embodiment in which the fluid pressure control device according to the present invention is applied to the hobhead clamp mechanism of the hobbing machine shown in FIG. 1 will be described in detail with reference to FIG. 3, which shows the schematic structure thereof. Note that although oil is used as the pressurized fluid in this embodiment, it is of course possible to use water or the like. Furthermore, since the connection structure of the hob saddle, hob head, etc. may be the same as that shown in FIG. 2, the same reference numerals as in FIG. 2 will be used for these parts and the explanation thereof will be omitted.

In the cylinder block 32, a first oil chamber 33, a second oil chamber 34, and a third oil chamber 35 having a larger diameter than the second oil chamber 34 are formed in order in a straight line. 33 is sealed by a plug 36 screwed into the cylinder block 32, and the third oil chamber 3
5 is sealed by an end cap 37 that is integrally fitted to the cylinder block 32. A spool 38 that can change the volume of the first oil chamber 33 is slidably interposed between the first oil chamber 33 and the second oil chamber 34, and is housed in the first oil chamber 33. This spool 38 is always pressed toward the second oil chamber 34 by the spring force of the compression coil spring 39.
An oil replenishment passage 40 that communicates the first oil chamber 33 and the second oil chamber 34 is bored. A piston 41 that is slidably fitted into the third oil chamber 35 is integrated with a piston rod 42 that partitions the third oil chamber 35 and the second oil chamber 34 and can change the volume of the second oil chamber 34. This piston rod 42
An opening/closing passage 43 is bored in the piston rod 42 and opens at the distal end surface and the outer circumferential surface of the piston rod 42. The opening end of this opening/closing passage 43 on the second oil chamber 34 side faces the tip of the spool 38 that protrudes into the second oil chamber 34, and the tip of this spool 38 is tightly fitted to the opening/closing passage 43. The opening end on the opposite side of the opening/closing passage 43 is connected to a pressurized supply/discharge port 44 formed in the cylinder block 32 when the piston 41 is displaced to the right end in the figure. It's starting to communicate. A control port 45 communicating with the second oil chamber 34 is bored in the cylinder block 32.
is connected to the cylinder 13 of the hob head 5 via the oil passage 46.
It is connected to an oil chamber 16 formed in . Second oil chamber 3
A pressurization supply/discharge passage 47 connecting the end of the third oil chamber 35 on the opposite side to the third oil chamber 4 and the pressurization supply/discharge port 44 is bored in the cylinder block 32. A reduced pressure supply/discharge port 48 communicating with the end of the third oil chamber 35 on the second oil chamber 34 side is bored. Oil passages 49 and 50 connected to the reduced pressure supply/discharge port 48 and the pressurized supply/discharge port 44 are connected to the oil tank 51 via a two-position switching valve 30.

Therefore, when the hob head 5 is clamped to the hob saddle 8, the two-position switching valve 30 is in the normal state as shown in the figure, and the pump 2 is disconnected from the oil tank 51.
The oil pumped up by 8 flows from the oil supply pipe 29 through the oil passage 49 into the third oil chamber 35 via the reduced pressure supply and discharge port 48, and the pressurized supply and discharge port 44 communicates with the oil discharge pipe 27 via the oil passage 50. In order to do this, in the figure,
Pressure oil in the third oil chamber 35 on the right side of the piston 41 is returned to the oil tank 51 from the pressurized supply/discharge passage 47 through the pressurized supply/discharge port 44 and the oil passage 50 via the oil drain pipe 27, and further through the opening/closing passage. 43 to the second oil chamber 34
and the pressurized supply/discharge port 44 are brought into communication. As a result, the T-bolt 12 is pushed upward in the figure by the spring force of the disc spring 15, and the oil in the oil chamber 16 is drained from the oil passage 46 and the control port 45 to the second oil chamber 3.
4. The oil is returned to the oil tank 51 through the opening/closing passage 43, the pressurized supply/discharge port 44, the oil passage 50, and the oil drainage passage 27, and the pressure inside the oil chamber 16 becomes almost equal to atmospheric pressure, and the pressure of the disc spring 15 increases. All spring force acts effectively as clamping force.

On the other hand, to release the fixation of the hob head 5 from the hob saddle 8, the solenoid 31 is energized to switch the position of the two-position switching valve 30, the oil passage 49 is connected to the oil drain pipe 27, and the pressure oil from the pump 28 is removed. It is supplied from the oil passage 50 to the pressurized supply/discharge port 44 . As a result, relatively low-pressure oil is first filled into the second oil chamber 34 and the oil chamber 16 through the opening/closing passage 43, and then from the pressurized oil supply/discharge oil passage 47 due to the difference in pressure receiving area between the piston rod 42 and the piston 41. Pressure oil is gradually fed into the third oil chamber 35, and the piston rod 42 is displaced to the left in the figure together with the piston 41.
Accordingly, the oil in the third oil chamber 35 on the left side of the piston 41 in the figure is returned to the oil tank 51 from the reduced pressure supply/discharge port 48. As the piston rod 42 is displaced, the opening/closing passage 43 is first closed by the tip of the spool 38 and the pressurized supply/discharge port 44 and opening/closing passage 4 are closed.
3 is cut off, and the piston rod 42 pushes back the spool 38 and moves to the left in the figure, so the pressure of the pressure oil in the first oil chamber 33, the second oil chamber 34, and the oil chamber 16 increases. , the piston 14 is pushed down in the figure against the spring force of the disc spring 15, and the fixation of the hob head 5 to the hob saddle 8 is released. In this case, the second oil chamber 34 or the oil chamber 16
Even if there is a leakage of pressure oil, the leakage is supplied from the first oil chamber to the second oil chamber 34 via the oil supply passage 40, so no inconvenience will occur.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the external appearance of the hobbing machine that is the object of the present invention, Fig. 2 is a mechanical conceptual diagram showing the conventional clamping mechanism of the hob head, and Fig. 3 is the fluid pressure control device according to the present invention as described above. This is a conceptual diagram of an example of a mechanism applied to a clamping mechanism of a hob head. In the figure, 5 is a hob head, 8 is a hob saddle, and 11 is a T.
Groove, 12 is T bolt, 13 is cylinder, 14,4
1 is a piston, 15 is a disc spring, 16 is an oil chamber, 27
is an oil drain pipe, 28 is a pump, 29 is an oil supply pipe, 30 is a two-position switching valve, 32 is a cylinder block, 33 is a first oil chamber, 34 is a second oil chamber, 35 is a third oil chamber, 3
8 is a spool, 40 is an oil supply passage, 42 is a piston rod, 43 is an opening/closing passage, 44 is a pressurized supply/discharge port, 45 is a control port, 48 is a reduced pressure supply/discharge port,
51 is an oil tank.

Claims (1)

[Scope of utility model registration request] A first fluid chamber, a second fluid chamber that communicates with the first fluid chamber, and a third fluid chamber that communicates with the second fluid chamber and has a larger diameter than the second fluid chamber are aligned in a straight line. a spool that is slidably fitted into the first fluid chamber and partitions the first fluid chamber from the second fluid chamber; and a spool that is bored in the spool. a fluid replenishment passage provided therein that constantly communicates the first fluid chamber and the second fluid chamber; and a piston that is slidably fitted into the third fluid chamber; A piston rod is slidably fitted into the second fluid chamber and partitions the second fluid chamber from the third fluid chamber; an opening/closing passage that opens and is closed by the spool by displacement of the piston rod toward the first fluid chamber; a control port that opens at the end of the second fluid chamber on the fluid chamber side; and a depressurization supply provided in the cylinder block and opens at the end of the third fluid chamber on the second fluid chamber side. a discharge port, which is provided in the cylinder block and opens at the end of the third fluid chamber on the opposite side to the depressurization supply and discharge port, and is opened and closed by displacement of the piston rod toward the third fluid chamber. A fluid pressure system comprising a pressurized supply/discharge port communicating with the passage, and a two-position switching valve interposed between the pressurized supply/discharge port and the reduced pressure supply/discharge port, a pressure fluid supply source, and a liquid storage tank. Control device.