JP2005161423A - Hydraulic device of machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic device of a machine tool for preventing operational failure of hydraulic equipment such as a hydraulic pump and a solenoid valve, by preventing reduction in lubricatability and a deposit of sludge, when a coolant generated in processing work of a workpiece is mixed in a hydraulic fluid supplied for operating a hydraulic cylinder from the hydraulic pump. <P>SOLUTION: An active cylinder 31 for constituting a hydraulic fluid dividing mechanism 57 is arranged on a side surface of a processing table 13, and a passive cylinder 37 is arranged on a side surface of a pallet 15. The hydraulic fluid supplied from the hydraulic pump 52 is supplied via a pipe 54 and a solenoid selector valve 55 to a cylinder chamber R1 on the piston 33 side of the active cylinder 31. The hydraulic fluid of a cylinder chamber R2 of the passive cylinder 37 is supplied to a piston 45 side cylinder chamber R3 of a cylinder 44. A piston rod 40 and a piston 39 of the passive cylinder 37 are moved upward by upwardly moving the piston rod 34 of the active cylinder 31, and the hydraulic fluid in the cylinder chamber R2 is supplied to the cylinder 44. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hydraulic device for a machine tool, and more particularly to a hydraulic device for a machine tool for operating a hydraulic cylinder for various jigs such as a jig for clamping a workpiece provided near a processing table.

  A workpiece is mounted on a machining table of a machine tool, and the workpiece is machined by a tool such as a drill. In order to efficiently process multiple types of different types of workpieces with a single machine tool, four chuck mechanisms are mounted on the upper surface of the processing table, and the pallet that supports the workpiece by this chuck mechanism is located above the processing table. The pallet is detachably mounted at a predetermined position, and this pallet is exchanged by an automatic pallet exchange device. In addition, hydraulic fluid pumped up from an oil tank by a hydraulic pump rotated by an electric motor is supplied to a hydraulic cylinder for clamping a workpiece provided on the pallet side to clamp the workpiece. Further, a coupler for connecting and disconnecting the hydraulic fluid path is provided between the processing table and the pallet when the pallet is exchanged.

  However, in the conventional automatic pallet changer, the coolant adheres in the form of droplets on the connecting surface of the lower coupler on the processing table side when the coupler is disconnected. The adhering coolant enters the lower coupler when the coupler is connected during chucking of the pallet. The intruding coolant droplets cause a failure inside the hydraulic fluid path. That is, when the coolant is mixed into the hydraulic oil, the lubricity and rust prevention properties are impaired, and foreign matters such as contamination increase. If the lubricity is impaired, there is a risk that hydraulic equipment such as a hydraulic pump and a solenoid valve will not function. Moreover, even if the rust prevention property is impaired, the hydraulic equipment does not function as well. Furthermore, foreign matters such as contamination can be an obstacle to the operation of hydraulic equipment. In either case, there was a problem that the performance and durability of the hydraulic equipment were hindered.

  The present invention eliminates the above-described problems in the prior art and eliminates the mixing of coolant generated during the work of the workpiece into the hydraulic oil supplied to operate the hydraulic cylinder from the hydraulic pump. It is an object of the present invention to provide a hydraulic device for a machine tool that can prevent such troubles and improve the durability of hydraulic equipment.

  In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that hydraulic oil is supplied from a hydraulic pump to a hydraulic cylinder via a hydraulic path, and a jig provided near the processing table is operated by the hydraulic cylinder. In the machine tool, a hydraulic oil dividing mechanism is provided to prevent the hydraulic oil from being directly supplied to the hydraulic cylinder in the middle of the hydraulic path and to indirectly transmit the power of the hydraulic oil to the hydraulic cylinder. This is the summary.

  According to a second aspect of the present invention, in the first aspect, a pallet having a hydraulic cylinder is removably mounted at a predetermined upper position of the processing table, and the hydraulic oil dividing mechanism is provided between the processing table and the pallet. This is the summary.

  According to a third aspect of the present invention, in the second aspect, the hydraulic oil dividing mechanism is provided on the processing table side, and an active cylinder provided with a cylinder chamber for storing hydraulic oil in a lower portion is provided on the pallet side. And a passive cylinder provided with a cylinder chamber for storing hydraulic oil in the upper part, and the lower end surface of the piston rod of the passive cylinder is pushed upward by the upper end surface of the piston rod of the active cylinder. It is a summary.

  According to a fourth aspect of the present invention, in the first aspect, a pallet having a hydraulic cylinder is detachably mounted at a predetermined position on the upper part of the processing table, and a lower part connecting and disconnecting a hydraulic path between the processing table and the pallet The gist is that an upper coupler is provided, and the hydraulic oil dividing mechanism is provided in a hydraulic path between the hydraulic pump and the lower coupler on the processing table side.

  The invention according to claim 5 is summarized in that, in claim 4, the hydraulic oil dividing mechanism is a free piston.

  According to the present invention, since the hydraulic oil supplied from the hydraulic pump is separated from the hydraulic cylinder hydraulic oil by the hydraulic oil dividing mechanism, the vapor lock phenomenon can be prevented without the coolant entering the hydraulic oil passage of the hydraulic pump. This can be prevented and the durability of the hydraulic equipment can be improved.

Hereinafter, a first embodiment of a hydraulic device for a machine tool embodying the present invention will be described with reference to FIGS.
FIG. 4 shows a schematic front view of the machine tool. A processing table 13 is mounted on the upper surface of the bed 11 via a Z-axis guide rail 12 so as to be capable of reciprocating in the Z-axis direction. A pallet 15 is mounted on the processing table 13 via a plurality of (four in this embodiment) chuck mechanisms 14. A column 17 is mounted on the right upper surface of the bed 11 via an X-axis guide rail 16 so as to be capable of reciprocating in the X-axis (paper surface orthogonal) direction. A Y-axis saddle 19 is mounted on the front surface of the column 17 via a Y-axis guide rail 18 so as to be able to reciprocate in the Y-axis (up and down) direction. The workpiece 21 clamped on the upper surface of the pallet 15 is processed by a clamping jig (not shown).

  FIG. 5 is a front view in which the processing table 13 and the pallet 15 are separated, and FIG. 6 is a right side view of the same. FIG. 7 is a plan view of the processing table 13, and FIG. 8 is a plan view of the pallet 15. As shown in FIGS. 5 to 8, the plurality of chuck mechanisms 14 provided on the upper surface of the processing table 13 are configured in the same manner, and therefore, one chuck mechanism 14 will be briefly described. This chuck mechanism 14 is formed on the pedestal 22 supported on the upper surface of the processing table 13 and fixed with bolts, a chuck pin 23 attached to the pedestal 22, and the pallet 15. It is comprised by the engagement hole 24 for engaging. As shown in FIG. 5, when the pallet 15 is moved downward by an automatic pallet changer (not shown) while the pallet 15 is spaced upward from the chuck pin 23 of the chuck mechanism 14, the lower surface of the pallet 15 is moved to the base 22. The chuck pin 23 is fitted into the engagement hole 24 while being supported by the upper surface. In this state, the pallet 15 is chucked at a predetermined position on the processing table 13 by the chuck pins 23.

Next, the configuration of the main part of the present invention will be described.
As shown in FIG. 1, an active cylinder 31 is mounted on the side surface of the processing table 13. The active cylinder 31 includes a bottomed cylindrical case 32, a piston 33 accommodated in the case 32, and an upward piston rod 34 connected to the piston 33. The active cylinder 31 is fixed to the lower surface of the mounting plate 35, and the mounting plate 35 is fastened and fixed to the upper surface of the processing table 13 by bolts 36. The piston rod 34 protrudes upward through the mounting plate 35.

  On the other hand, a passive cylinder 37 is mounted on the side surface of the pallet 15. The passive cylinder 37 includes a case 38 having a cylindrical shape with a lid, a piston 39 accommodated in the case 38, and a piston rod 40 connected to the lower surface of the piston 39. The passive cylinder 37 is fixed to the lower surface of the attachment plate 41, and the attachment plate 41 is attached to the upper portion of the pallet 15 with bolts 42.

  A cylinder 44 is connected to the passive cylinder 37 via a pipe 43. The cylinder 44 includes a piston 45 and a piston rod 46, and operates a workpiece clamping jig (not shown).

  A hydraulic pump 52 operated by an electric motor 51 is connected to the cylinder chamber R1 on the piston 33 side of the active cylinder 31. The hydraulic oil pumped up from the oil tank 53 by the hydraulic pump 52 is supplied to the cylinder chamber R1 via the pipe 54. An electromagnetic switching valve 55 is connected in the middle of the pipe 54. The electromagnetic switching valve 55 can be switched between a drain port 55a and a hydraulic oil supply port 55b. The drain port 55 a is always switched and held by a spring, and the hydraulic oil in the cylinder chamber R 1 is returned to the oil tank 53 by the drain passage 56.

  The cylinder chamber R2 on the piston 39 side of the passive cylinder 37 is filled with hydraulic oil in advance, and the hydraulic oil is supplied to the cylinder chamber R3 on the piston 45 side of the cylinder 44 through the pipe 43 as the piston 39 rises. It has become.

  In this embodiment, the hydraulic oil supplied from the hydraulic pump 52 by the active cylinder 31 and the passive cylinder 37 is supplied to the cylinder chamber R2 on the piston 39 side of the passive cylinder 37 and the cylinder chamber R3 on the piston 45 side of the cylinder 44. The hydraulic oil dividing mechanism 57 is divided.

Next, the operation of the machine tool hydraulic device configured as described above will be described.
FIG. 1 shows a state where the pallet 15 is separated upward from the processing table 13 and the piston rod 40 of the passive cylinder 37 is separated from the piston rod 34 of the active cylinder 31. The electromagnetic switching valve 55 is switched to the drain port 55a, the piston 33 is held at the unclamping position which is the lower limit, the piston 39 is also held at the unclamping position which is the lower limit, and the cylinder 44 is also a jig for clamping the workpiece. Is held at the unclamping position. In this state, when the pallet 15 is moved downward by an automatic pallet changer (not shown), the chuck pins 23 are inserted into the engagement holes 24 of the pallet 15 as shown in FIG. As a result, the pallet 15 is chucked at a predetermined position above the processing table 13, and the lower end surface of the piston rod 40 is brought into contact with the upper end surface of the piston rod 34.

  In this state, when the electromagnetic switching valve 55 is switched from the drain port 55a to the hydraulic oil supply port 55b, the hydraulic oil assembled by the hydraulic pump 52 is supplied into the cylinder chamber R1 of the active cylinder 31 via the pipe 54. Therefore, the piston 33 and the piston rod 34 of the active cylinder 31 are lifted upward, and the piston rod 40 and the piston 39 of the passive cylinder 37 are moved upward by the piston rod 34. Therefore, as shown in FIG. 3, the volume of the cylinder chamber R2 is reduced by the piston 39, and the hydraulic oil in the cylinder chamber R2 is supplied into the piston 45 side cylinder chamber R3 of the cylinder 44 via the pipe 43. As a result, the workpiece clamping jig is switched to the clamping position by the piston 45 and the piston rod 46, and the workpiece is clamped.

  When the workpiece is processed by the tool 21 and it is desired to replace the pallet 15 with another pallet, the electromagnetic switching valve 55 is switched to the drain port 55a in FIG. Then, the hydraulic oil in the cylinder chamber R 1 of the active cylinder 31 is returned to the oil tank 53 through the drain passage 56. For this reason, the piston 33 and the piston rod 34 are lowered, and the piston 39 and the piston rod 40 of the passive cylinder 37 are also lowered. As a result, the hydraulic oil in the cylinder chamber R3 on the piston 45 side of the cylinder 44 is returned to the cylinder chamber R2 through the pipe 43. Accordingly, the workpiece clamping by the cylinder 44 is released. In this state, the pallet 15 is raised by an automatic pallet exchanging device (not shown), and after moving the pallet 15 to the storage position, it is exchanged with another pallet.

According to the hydraulic device of the machine tool of the above embodiment, the following effects can be obtained.
(1) In the above embodiment, the active cylinder 31 is provided on the processing table 13, the passive cylinder 37 is provided on the pallet 15, and the active cylinder 31, the piston rod 34 of the passive cylinder 37, and the piston rod 40 are connected to each other in the clamped state of the pallet 15. I made it correspond. The active cylinder 31 and the passive cylinder 37 are operated by supplying hydraulic oil from the hydraulic pump 52 into the cylinder chamber R1 of the active cylinder 31. As a result, even if the coolant adheres to the upper end of the piston rod 34 in the state where the active cylinder 31 and the passive cylinder 37 are separated, the coolant does not enter the cylinder chamber R1. Thus, the coolant does not enter the hydraulic circuit, the rise in the boiling point of the hydraulic oil is suppressed, and the durability of the hydraulic equipment such as the hydraulic pump 52 can be improved.

  (2) In the above embodiment, since the active cylinder 31 and the passive cylinder 37 are used as the hydraulic oil dividing mechanism 57, the lower end surface of the piston rod 40 only needs to be in contact with the upper end surface of the piston rod 34. It is possible to omit the lock mechanism for maintaining the seal state of the coupler, which has been necessary in the past for securing. As a result, the number of parts can be reduced, manufacturing and assembling work can be easily performed, and cost can be reduced.

Next, another embodiment of the present invention will be described with reference to FIG.
In this embodiment, a lower coupler 61 is provided on the side surface of the processing table 13, and an upper coupler 62 is provided on the side surface of the pallet 15. And the fitting hole 63 of the lower coupler 61 and the connection port 64 of the upper coupler 62 are made to correspond so that contact / separation is possible. Further, a free piston 65 is connected to the pipe 54 between the electromagnetic switching valve 55 and the lower coupler 61. The free piston 65 is constituted by a case 66 and a piston 67 accommodated in the case 66, and a cylinder chamber R4 and a cylinder chamber R5 are defined in front and rear of the piston 67.

  Therefore, in this embodiment, when the electromagnetic switching valve 55 is switched to the hydraulic oil supply port 55b with the upper coupler 62 joined to the lower coupler 61, the hydraulic oil is supplied to the cylinder chamber R4 and the piston 67 moves forward. Then, the hydraulic oil in the cylinder chamber R5 is supplied to the cylinder 44 via the lower coupler 61 and the upper coupler 62.

  In this embodiment, since the free piston 65 is interposed in the pipe 54, even if coolant enters the fitting hole 63 of the lower coupler 61 in a state where the upper coupler 62 is separated from the lower coupler 61, the inside of the cylinder chamber R5. It is possible to eliminate the above-described adverse effects caused by coolant entering the hydraulic circuit of the hydraulic pump 52 without entering the cylinder chamber R4.

In addition, you may change the said embodiment as follows.
The configuration of the hydraulic oil dividing mechanism 57 may be, for example, a diagram mechanism or another mechanism instead of the active cylinder 31 and the passive cylinder 37.

  As the jig operated by the cylinder 44, for example, a cleaning jig for cleaning the work surface of the workpiece can be considered in addition to the clamping jig.

The circuit diagram of the hydraulic device in the machine tool which actualized this invention. The circuit diagram which shows the non-operation state of a hydraulic apparatus. The circuit diagram which shows the operating state of a hydraulic apparatus. FIG. 3 is a schematic side view showing the entire machine tool. The front view which shows the separation state of a process table and a pallet. The side view of a process table and a pallet. The top view of a process table. The top view of a pallet. Explanatory drawing of the hydraulic circuit which shows another embodiment of this invention.

Explanation of symbols

  R1, R2, R4, R5 ... cylinder chamber, 13 ... machining table, 15 ... pallet, 31 ... active cylinder, 34, 40, 46 ... piston rod, 37 ... passive cylinder, 52 ... hydraulic pump, 57 ... hydraulic oil dividing mechanism , 65 ... Free piston.

Claims (5)

In a machine tool that supplies hydraulic oil from a hydraulic pump to a hydraulic cylinder via a hydraulic path and operates a jig provided near the processing table by the hydraulic cylinder,
A machine comprising a hydraulic oil dividing mechanism for preventing hydraulic oil from being directly supplied to the hydraulic cylinder in the middle of the hydraulic path and for indirectly transmitting hydraulic oil power to the hydraulic cylinder. The hydraulic system of the machine. 2. The hydraulic apparatus for a machine tool according to claim 1, wherein a pallet having a hydraulic cylinder is detachably mounted at a predetermined upper position of the processing table, and the hydraulic oil dividing mechanism is provided between the processing table and the pallet. 3. The hydraulic oil dividing mechanism according to claim 2, wherein the hydraulic oil dividing mechanism is provided on the processing table side, and an active cylinder provided with a cylinder chamber for storing hydraulic oil in a lower part thereof, and provided on the pallet side and storing hydraulic oil in an upper part thereof. And a passive cylinder provided with a cylinder chamber, and the lower end surface of the piston rod of the passive cylinder is pushed upward by the upper end surface of the piston rod of the active cylinder. 2. The hydraulic pump according to claim 1, wherein a pallet having a hydraulic cylinder is detachably mounted at a predetermined upper position of the processing table, and a lower and upper coupler for connecting and disconnecting a hydraulic path is provided between the processing table and the pallet. And a hydraulic device for a machine tool in which the hydraulic oil dividing mechanism is provided in a hydraulic path between the lower coupler on the processing table side. 5. The hydraulic apparatus for a machine tool according to claim 4, wherein the hydraulic oil dividing mechanism is a free piston.

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