JP4628890B2 - Machining center pallet change mechanism - Google Patents

Description

  The present invention relates to a pallet change mechanism in a machining center (multi-task machine).

In general, in a horizontal machining center, a plurality of pallets are used, and a workpiece placed on one pallet is exchanged while a workpiece placed on one pallet is processed with a tool. Etc. are performed. Therefore, as this type of machining center, a machining center with a pallet changer as described in Patent Document 1 below has been conventionally known.
Patent Document 2 below discloses a chuck exchanging device for a pallet system configured so that various chucks can be attached and detached.
Japanese Patent Laid-Open No. 8-300245 Japanese Utility Model Publication No. 2-6943

When using a hydraulic chuck for a pallet changer, after setting the pressure of the hydraulic chuck of the pallet on the setup side, if the pallet is changed to the machine side, the pressure set on the setup side must be switched to the machine side. There is.
This requires individual pressure settings for each type of rough machining, finishing machining and workpiece.
However, in the conventional apparatus, since the individual hydraulic circuits are provided on the setup side and the machine side, switching cannot be performed automatically.
An object of the present invention is to provide a pallet exchange mechanism that solves the above-described problems.

In order to achieve the above object, the processing table and the setup table of the pallet exchanging mechanism of the present invention include a coupler that supplies hydraulic pressure to the hydraulic chuck pallet including the hydraulic chuck, and the hydraulic supply device is provided on the setup table. When the hydraulic chuck pallet to which the hydraulic pressure has been set is replaced on the processing table, a switching valve is provided for supplying the hydraulic pressure set on the setup table to the hydraulic chuck pallet on the processing table.
The hydraulic supply device includes a plurality of hydraulic control circuits corresponding to different set pressures, the hydraulic chuck pallet includes a hydraulic piston that operates the chuck pawl, and the machining table includes a position where the hydraulic piston of the hydraulic chuck pallet is in a normal position. It is equipped with a proximity sensor that confirms that

According to the present invention, the hydraulic pressure set on the setup table can be automatically reproduced on the machining table, and the machining efficiency is improved.
Further, since the machining table is provided with means for detecting misclamping of the hydraulic chuck, machining defects can be prevented.

  FIG. 1 is a perspective view showing an outline of a machining center to which the present invention is applied, FIG. 2 is a front view of the machining center, and FIG. 3 shows a pallet exchange mechanism.

The machining center generally indicated by reference numeral 1 includes a processing station K and a setup station D, and a pallet exchanging arm 30 for exchanging the pallet 20 between the two stations.
The processing station K and the setup station D are defined by a door 60, and the door 60 is opened only when the pallet is changed. The pallet exchange arm 30 has a hook 32, and the pallet 20 is exchanged by fitting the hook 32 into the groove 22 of the pallet 20.

In the machining station K, the pallet 20 on which the workpiece W is placed is fixed on the table 10 by the clamp device 11 and necessary machining is performed by the tool spindle 50. The table 10, the tool spindle 50, and the like are operated by the driving unit 40 of the machining center.
The machining center 1 has a door 70 for accessing the setup station D, and the operator opens the door 70 for setup.

FIG. 4 is an explanatory diagram of the table 12 disposed on the setup station D side, and FIG. 5 is an explanatory diagram of the table 10 disposed on the processing station K side.
The table 12 on the setup station D side has four clamping devices 120 for clamping pallets and hydraulic chucks. The clamp device 120 has a cone-shaped tapered portion having an opening at the center thereof, and engages with a pull bolt protruding from the center of a tapered hole provided on the back surface of the hydraulic chuck pallet. In the clamp device 120, a draw bar (not shown) arranged in the opening and moving up and down grips the hydraulic chuck pallet.
Two hydraulic couplers 130 are mounted on the table 12 and connected to the hydraulic circuit of the hydraulic chuck pallet.

The table 10 on the processing station K side shown in FIG. 5 also includes four clamping devices 120 and two hydraulic couplers 130.
A shaft 150 is provided at the center of the table 10 to confirm that the claw of the hydraulic chuck pallet 200 has stroked to grip the workpiece. When this shaft 150 is pushed in by the claw operating piston rod of the hydraulic chuck pallet 200, the proximity switch is operated to confirm that the hydraulic chuck is securely clamped.

FIG. 6 shows a state where the hydraulic chuck pallet 200 holding the workpiece W is clamped on the table 10 of the processing station K. Table 10 rotates, the tool T ₁ of the tool spindle 50 is subjected to cutting the workpiece W.
Various tools are automatically exchanged for the tool spindle 50, and necessary work such as turning or milling is performed on the workpiece W.

FIG. 7 shows a state where the hydraulic chuck pallet 200 is clamped with respect to the table 10 in the processing station K.
The state where the hydraulic circuit 230 is formed by connecting the hydraulic coupler 230 of the hydraulic chuck pallet 200 to the joint 132 of the hydraulic coupler 130 provided on the table 10 is shown.
The shaft 150 for clamping confirmation attached to the center of the table 10 is pushed against the spring 152 when the piston for claw operation of the hydraulic chuck pallet 200 is lowered. The position of the shaft 150 is detected by the proximity sensors 160 and 161 to confirm the clamped state.

FIG. 8 is an explanatory view showing the overall configuration of the hydraulic chuck replacement system of the present invention.
The inner diameter of the work _{W 1} at the time of setup and chucking claws 210 of the first hydraulic chuck pallet 200a by setup station D side, for example, is grasped by the pressure set value _P 1 Kg / cm ^2.
When the first hydraulic chuck pallet 200a is replaced with the table 10 of the processing station K in the machine, the hydraulic circuit is configured so that the same pressure P ₁ Kg / cm ² is supplied to the claws 210 of the hydraulic chuck pallet 200a. Is done.
Similarly, when the pressure setting value P ₂ Kg / cm ² is used for the second hydraulic chuck pallet 200b in which the outer diameter of the workpiece W ₂ is grasped, the same pressure setting value is set for the hydraulic chuck pallet 200b. It is supplied to the table 12 on the D side and the table 10 on the processing station K side.

FIG. 9 shows an outline of a hydraulic circuit that connects the tables 12 and 10 and the hydraulic chuck pallet 200.
A first hydraulic chuck pallet 200 a is clamped on the table 12 of the setup station D, and the hydraulic pressure at the set pressure P ₁ is supplied via the hydraulic coupler 130. The hydraulic chuck pallet 200 a includes a hydraulic actuator 250 that operates the chuck claws 210. The hydraulic actuator has a piston rod 252, the chuck claws 210 hydraulic actuator is actuated when the inner diameter grasped workpiece W _1, the piston rod 252 is also moved.

During the hydraulic circuit of the hydraulic chuck pallet 200a, Yes and check valve 260 is provided, even when the hydraulic chuck pallet 200a is removed from the table 12 of the setup station D by the pallet changer, the workpiece W ₁ of the chuck claws 210 Grasping power is maintained.
When the first hydraulic chuck pallet 200a by the pallet changer is clamped on the table 10 of the processing station K, the hydraulic pressure supply device to be described later, from the table 10 side of the set pressure P ₁ oil pressure is supplied to the hydraulic chuck pallet .
Similarly, the second hydraulic chuck pallet 200b is a hydraulic chuck palette for the outer diameter grasping of the workpiece W _2, the chuck claws 210 outer diameter grasp the workpiece W _2.

The second hydraulic chuck pallet 200b clamped on the table 12 of the setup station D, it is supplied hydraulic pressure of the set pressure P _2, to the outer diameter grasp the workpiece W _2.
The second hydraulic chuck pallet 200b is conveyed onto the table 10 of the processing station K and clamped by the pallet changer.

Hydraulic pressure supply device to be described later, supplies the hydraulic pressure of the set pressure P ₂ from the table 10 to the hydraulic chuck pallet 200b.
In the hydraulic chuck pallets 200a and 200b, when the hydraulic actuator 250 is operated and the chuck claw 210 grasps the workpieces W ₁ and W ₂ , the lower end position of the piston rod 252 is within a predetermined range. is there.
The table 10 of the processing station K has a chuck misclamp confirmation shaft 150, and the shaft 150 is pushed against the spring 152 by the piston rod 252.
The pair of proximity sensors 161 and 162 detect the position of the shaft 150, and if the position of the shaft 150 is within a certain range, it is confirmed that the chuck pawl is normally grasping the workpiece. In other cases, it is determined that the gripping of the chuck pawl is not normal, and an alarm is sent to the control device side.

FIG. 10 is a circuit diagram showing the configuration of a hydraulic pressure supply apparatus applied to the hydraulic chuck pallet replacement mechanism of the present invention.
The hydraulic pressure supply apparatus generally indicated by reference numeral 400 includes a hydraulic control apparatus 410 for the first hydraulic chuck pallet and a hydraulic control apparatus 420 for the second hydraulic chuck pallet connected to the hydraulic supply source 405. The supply pressure of the hydraulic chuck pallet corresponding to the set pressure can be controlled.

The first hydraulic control device 410 includes a pressure adjustment valve 412 for the set pressure P _{1 of} the first hydraulic chuck pallet, a pressure gauge, and a switching valve 414.
The second hydraulic control device 420 includes a pressure adjusting valve 422 for the set pressure P2 of the _second hydraulic chuck pallet, a pressure gauge, and a switching valve 424.
The first and second hydraulic control devices 410 and 420 are connected to the hydraulic circuits 450 and 460 of the table 12 on the setup station D side and the table 10 on the processing station K side, respectively.

The hydraulic circuit 450 on the setup station D side includes a switching valve that is switched according to whether the chuck claw of the hydraulic chuck grasps the inner diameter or outer diameter of the workpiece or holds the current hydraulic state for a while (neutral state). .
Similarly, the hydraulic circuit 460 on the processing station K side is also switched according to whether the chuck claw of the hydraulic chuck grasps the inner diameter or outer diameter of the workpiece or holds the current hydraulic pressure state for a while (neutral state). Provide a valve. The hydraulic circuit 460 includes a pressure switch 464 that is operated by hydraulic pressure.

FIG. 11 is a flowchart of the operation of the hydraulic chuck pallet replacement mechanism of the present invention.
In the hydraulic chuck pallet exchange started in step S10, the pallet clamped on the table 12 on the setup station D side and the pallet clamped on the table 10 on the processing station K side are unclamped in step S11.
In step S12, the hook of the pallet changer is engaged with the groove of the hydraulic chuck pallet, and the hydraulic chuck pallet is lifted from the table. In step S13, the arm of the pallet changer is turned 180 degrees. In step S14, the hydraulic circuit of the hydraulic chuck pallet is switched between the setup station D side and the processing station K side.
Specifically, the supply pressure of the hydraulic chuck pallet is switched between the table 12 of the setup station and the table 10 of the processing station by operating the switching valves 414 and 424. In step S15, the clamp of the hydraulic chuck is neutralized by operating the switching valves 452 and 462, the hydraulic chuck pallet is lowered onto each table in step S16, and the clamp mechanism of the table is operated in step S17 to operate the hydraulic chuck. Clamp the pallet.
In step S18, the switching valves 452 and 462 are operated to clamp the hydraulic chuck to grasp the outer diameter or inner diameter of the workpiece, and the operation ends in step S19.
Although explanation is omitted, the grasping direction (obtaining outer diameter or inner diameter grasping) of pallet 1 or pallet 2 is separately selected by an electrical switch, and the switching valve is operated according to the state of the switch.

The perspective view which shows the outline | summary of the machining center to which this invention is applied. 1 is a front view of a machining center to which the present invention is applied. The figure which shows a pallet exchange mechanism. Explanatory drawing of the table arrange | positioned at the setup station side. Explanatory drawing of the table arrange | positioned at the process station side. Explanatory drawing which shows the state by which the hydraulic chuck | pallet pallet which hold | gripped the workpiece | work was clamped on the table of the processing station. Explanatory drawing which shows the state by which the hydraulic chuck | pallet pallet was clamped with respect to the table within a processing station. BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the whole structure of the exchange system of the hydraulic chuck | zipper of this invention. Explanatory drawing which shows the outline | summary of the hydraulic circuit which connects a table and a hydraulic chuck | pallet pallet. The circuit diagram which shows the structure of the hydraulic supply apparatus applied to the replacement mechanism of the hydraulic chuck pallet of this invention. The flowchart of the action | operation of the exchange mechanism of the hydraulic chuck | zipper pallet of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Machining center 10 Processing table 12 Setup table 20 Pallet 30 Pallet exchange arm 50 Tool spindle 60 Door 120 Clamping device 130 Hydraulic coupler 150 Clamp confirmation shaft 161, 162 Proximity sensor 200 Hydraulic chuck pallet 210 Chuck claw 230 Hydraulic coupler 250 Hydraulic actuator 400 Hydraulic pressure Supply device

Claims (3)

A mechanism for exchanging pallets between a machining table and a setup table of a machining center,
The processing table and the setup table have a coupler that supplies hydraulic pressure to the hydraulic chuck pallet with a hydraulic chuck, and the hydraulic supply device replaces the hydraulic chuck pallet with the hydraulic pressure set on the setup table on the processing table. A pallet exchanging mechanism for a machining center, comprising a switching valve for supplying the hydraulic pressure set on the setup table to the hydraulic chuck pallet on the processing table when it is done. The pallet exchanging mechanism for a machining center according to claim 1 , wherein the hydraulic pressure supply device includes two hydraulic pressure control devices corresponding to two kinds of set pressures to supply hydraulic pressure to the setup table and the processing table . The pallet exchanging mechanism for a machining center according to claim 1, wherein the hydraulic chuck pallet includes a hydraulic piston for operating the chuck claw, and the processing table includes a proximity sensor for confirming that the hydraulic piston of the hydraulic chuck pallet is in a normal position.

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