JPS6113238Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a workpiece changing device for a machine tool. After temporarily tightening the workpiece by supplying low fluid pressure to the workpiece fixing plate on the conversion table, the workpiece is fixed on the conversion table or the table of the machine tool. The purpose of this system is to supply high fluid pressure to the plate so that the workpiece can be fully tightened, and also to enable the workpiece fixing platen to be transferred onto the table with the fluid pressure supply hose etc. disconnected.

In high-performance NC machine tools such as machining centers, workpieces are exchanged using a workpiece fixing plate (workpiece exchange pallet) in order to increase the operating rate of the machine.

Most conventional workpiece fixing plates fixed the workpiece to the plate using bolt holes or slots on the top of the plate, which makes up the workpiece fixing plate. A type of fixing device that fixes a workpiece has also been put into practical use.

In the case of this hydraulic fixing device, hydraulic leakage is unavoidable, so after setting and fixing the workpiece on the workpiece fixing platen on the conversion table, move it onto the table of the machine tool with the hydraulic hose from the hydraulic supply source connected. As a result, handling of the hydraulic hose becomes complicated, which not only causes damage to the hydraulic hose, but also requires that the switching table be placed near the machine tool, which creates constraints on the layout.

In addition, the hydraulic fixing device was designed to fix the workpiece using approximately a predetermined hydraulic pressure, so after positioning the workpiece, pressure oil was supplied all at once to fix the workpiece.

In this case, there are problems in that the position of the workpiece is likely to shift, and it is difficult to finely adjust the position of the workpiece, resulting in lower workpiece positioning accuracy and lower work efficiency.

In order to eliminate the above-mentioned drawbacks, the present invention provides a non-leak type oil passage switching valve that does not leak pressure oil from the hydraulic fixing device of the work fixing platen, thereby maintaining the work fixed state while:
The hydraulic hose for oil supply can be disconnected to allow the work fixing plate to be transported, and a temporary fastening low fluid pressure supply device is provided on the conversion table side, and a final fastening high fluid pressure supply device is provided on at least one of the conversion table side and the machine tool side, so that the work can be temporarily fixed to the work fixing plate on the conversion table and its position accurately adjusted, and then the work can be final fastened to the work fixing plate on the conversion table or on the table of the machine tool.

Hereinafter, embodiments of the present invention will be described based on the drawings.

As shown in FIGS. 1 to 4, a horizontally rotating conversion table T is installed on the front side of the NC vertical machine tool M.
A pallet-type work fixing plate P placed on the table 1 of the machine tool M is transferred onto the switching table T via the delivery traveling rail 2, and another work fixing plate P on the converting table T is transferred onto the table 1. By replacing the workpiece on the machine tool M, the workpiece can be replaced with the workpiece fixing platen P.

Here, it is necessary to accurately position and fix the workpieces on each workpiece fixing platen P according to the design drawings, and it is necessary to accurately position and fix the workpiece fixing platen P on the table 1.

As shown in Fig. 4, table 1 of machine tool M
A travel guide rail 3, a travel rail 4, a support stand 5, a positioning device 6, and a clamp device 7 are attached on the top, and the workpiece fixing plate P is moved from the conversion table T to the table 1.
When transferring the workpiece onto the top, the running wheels of the traveling device 8 run on the traveling rail 4 and are stopped at a predetermined position on the table 1 via a stopper, where the connecting stopper 6a of the positioning device 6 is raised and the workpiece is transferred to the top. By fitting into the positioning hole 6b of the fixed platen P, the workpiece fixed platen P
is precisely positioned on the table 1.

Further, the clamp claws 7a of the clamp device 7 are loosely fitted into the grooves on the lower surface of the workpiece fixing platen P to allow the workpiece fixing platen P to travel back and forth.
The workpiece fixing platen P is placed and fixed on the support base 5 by moving the running wheel of the workpiece P into the square groove against its support spring (not shown).

As shown in Figures 3 to 5, the workpiece fixing plate P
In the center of the base plate 9, there is a reference frame 1 running in the left and right direction.
0 is fixedly installed, and in front and behind this reference receiving frame 10, workpiece holding frames 1 are placed facing each other with a work placement space 11 left open.
2 is fixed so that its position can be adjusted. This reference frame 10
A unit workpiece receiving surface S is formed by dividing the workpiece receiving surface S into a plurality of equal parts in the length direction, and a hydraulic syringe 13 of a hydraulic fixing device C is attached to the workpiece holding frame 12 at a position facing the unit workpiece receiving surface S. attached.

A clamping tool 15 is attached to the tip of the output shaft 14 of the hydraulic cylinder 13 so as to be able to swing in all directions through partial spherical contact, and supplies pressure oil to the hydraulic oil chamber 16 of the hydraulic cylinder 13 to move the output shaft 14 to receive the workpiece. The workpiece W is advanced toward the surface S side and is pressed and fixed to the unit workpiece receiving surface S using the clamp tool 15.

Incidentally, reference numeral 15b is a work holding width adjustment tool of the clamp tool 15, which is detachably fitted via an O-ring 15c. Further, the clamping tool 15 is urged toward the output shaft 14 by an elastic body 15a made of an O-ring or the like to prevent chips or the like from getting caught in the partially spherical contact portion. Further, reference numeral 18 is a rotation prevention plate for the workpiece W, and reference numeral 19 is a workpiece support height adjuster.

Here, the work fixing plate P is placed on the conversion table T, the work W is placed in the work placement space 11 on the table 9, and pressure oil is supplied to the hydraulic fixing device C to move the work fixing plate P. The hydraulic and pneumatic systems for transferring and fixing the machine tool M onto the table 1 will be explained based on FIG. 6.

First, the hydraulic oil chamber 16 of the hydraulic cylinder 13 of the hydraulic fixing device C of the work fixing platen P is connected to the work holding frame 12.
They are communicated and connected through an oil passage 17 provided therein.

The non-leak type oil passage switching valve V1 is mounted on the base plate 9.
An oil passage is provided from this oil passage switching valve V1 to the workpiece holding frame 12 via a hydraulic hose 17a, and is connected to the oil passage 17 inside the workpiece holding frame 12.
Further, a self-seal joint type fluid pressure input port 20 is formed in the oil passage switching valve V1. However, details of the non-leak type oil passage switching valve V1 will be described later.

Next, the following temporary tightening low fluid pressure supply device L and final tightening high fluid pressure supply device H are attached to the conversion table T.

That is, compressed air of about 7 kg/cm ² G is introduced from the pneumatic source 21 into the pneumatic passage 22, and the terminal end of the pneumatic passage 22 is connected to the primary side of the pneumatically driven hydraulic pump 24. The pressure path 22 includes a directional control valve U1, a low pressure regulator 23L (set pressure approximately 1 to 1.5 Kg/cm ² G), and a high pressure regulator 23H connected in parallel to the directional control valve U1.
(set pressure approximately 4 to 5 Kg/cm ² G).

In this way, the preliminary tightening low fluid pressure supply device L is composed of a low pressure hydraulic supply device consisting of the low pressure regulator 23L and the hydraulic pump 24, and the final tightening high fluid pressure supply device H is composed of the high pressure regulator 23H and the pneumatically driven hydraulic pump 24. It consists of a high-pressure hydraulic supply system consisting of:

However, without attaching the low pressure regulator 23L and the high pressure regulator 23H independently as described above,
One variable regulator (not shown) may be provided to serve both purposes.

In addition, a flow path 25 from the pneumatically driven hydraulic pump 24
A non-leak type oil passage switching valve V2 is interposed therein, and a self-seal joint type low fluid pressure output port 26 and high fluid pressure output port 27 are formed on the downstream side thereof.

When clamping the workpiece W to the workpiece fixing plate P on the conversion table T, connect the low fluid pressure output port (high fluid pressure output port 27) on the conversion table T side and the fluid pressure input port 20 with a hydraulic hose 28, Connect the fluid pressure outlet 29 and the fluid pressure return port 30 with a hydraulic hose 31, switch the oil passage switching valve V1 to return the pressure oil to the oil tank 32,
After removing the processed workpiece W and setting a new workpiece W to be processed and roughly positioning it, after switching the oil passage switching valves V1 and V2, a low pressure of about 40 to 80 kg/cm ² G is applied from the low pressure oil pressure supply device L. Apply pressure oil to each hydraulic cylinder 1
3, each workpiece W is temporarily tightened at the same time with a force of about 500 to 1000 kg. If each workpiece W is accurately positioned by a method such as tapping lightly under this temporarily tightened state, the position of each workpiece W can be set with high precision without shifting.

After completion of this positioning work, high pressure oil of approximately 250 kg/cm ² G is supplied from the high pressure hydraulic supply device H to the hydraulic cylinder 13 to fully tighten each workpiece W at the same time with a force of approximately 33000 kg.

After this final tightening, the hydraulic hoses 28 and 31 are removed and the workpiece fixing platen P is transferred to the machine tool M side.

The machine tool M includes a back-up and hydraulic clamp device 7 in case of pressure oil leak from the hydraulic cylinder 13.
A high fluid pressure supply device H for final tightening is attached for driving. This final tightening high fluid pressure supply device H consists of a small capacity high pressure hydraulic supply device, and compressed air of approximately 7 kg//cm ² G from the pneumatic supply source 33 is supplied to the high pressure regulator 2.
The pressure is adjusted to about 4 to 5 Kg/cm ² G for 3 hours, and then supplied to the pneumatically driven hydraulic pump 24 to generate high pressure oil of about 250 Kg/cm ² G. V3, is connected to the fluid pressure input port 20 via the high fluid pressure output port 27 and the hydraulic hose 34.

In addition, the flow path 25A is connected to a non-leak type oil path switching valve V.
4 to the hydraulic cylinder 7b of the clamp device 7.

Furthermore, the positioning device 6 consists of a pneumatic cylinder with a built-in shutoff valve 6c as shown in FIG.

After roughly positioning the workpiece fixing plate P on the table 1, when the directional switching valve U2 is switched to the position shown, air pressure is supplied to the working chamber 6d of the positioning device 6, the piston 6e rises, and the connecting plug at the upper end of the platen P is moved upward. 6a is fitted into the positioning hole 6b of the workpiece fixing platen P to accurately position it. At this time, the shutoff valve 6c opens and air pressure is propagated to the pneumatic pressure confirmation indicator 36, pushing up the coloring indicator therein and displaying it through the transparent window. Thereby, it is confirmed that the fitting plug 6a of the positioning device 6 has been fitted into the positioning hole 6b.

With the fitting plug 6a fitted and positioned in this way, the oil passage switching valve V4 is switched to the illustrated position to supply high-pressure oil to the hydraulic cylinder 7b of the clamping device 7, and the workpiece is fixed by lowering the clamp claw 7a. The board P is attracted and fixed onto the support stand 5.

The reference numeral 37 is a pressure switch for detecting a drop in the hydraulic pressure of the hydraulic cylinder when the workpiece is fixed, and the reference numeral 38 is a pressure switch for detecting a drop in the oil pressure of the clamping device 7.

The oil passage switching valves V1 and V3 are electromagnetic switching valves, and when the oil pressure of the hydraulic cylinder 13 decreases, the pressure switch 37
It is also possible to configure the oil passage switching valves V1 and V3 to be automatically switched to the illustrated positions based on a signal from. Similarly, when the oil pressure of the clamp device 7 decreases, the oil passage switching valve V4 alone can be automatically switched to the illustrated position based on the signal from the pressure switch 38.

Next, the structure of the non-leak type oil passage switching valve V1 will be explained.

The non-leak type oil passage switching valve V1 is a directional switching valve having the structure shown in FIGS. 8 and 9, for example, by rotating the operating shaft 40 with the manual operating rod 39, and opening the inclined grooves 41a and 42a of the operating rod 39. via rod 4
1 and 42 are moved up and down to switch the supply/discharge direction. That is, an oil supply passage 45 connecting the oil supply port 43 and the output port 4 is provided with a check valve 46 and an oil supply valve 47 facing in the opposite direction. is equipped with an oil drain valve 50.

At the time of refueling, the operating rod 39 is pulled up to open the refueling check valve 47 with the refueling rod 41, and the oil draining rod 42 is pulled down to close the oil draining valve 49, thereby supplying pressure oil. When draining oil, the operating rod 39 is lowered as shown in the figure to close the oil supply valve 47, and the oil draining rod 42 opens the oil drain valve 50 to drain the oil.

Incidentally, reference numeral 20A denotes a self-sealing joint, the inside of which constitutes the fluid pressure input port 20, into which a self-sealing joint at the tip of the hydraulic hose 34 is detachably attached.

Similarly, on the oil drain port 48 side, reference numeral 29A is a self-seal joint, reference numeral 35 is a hydraulic hose for draining oil, and reference numeral 51 is a wire mesh filter.

Unlike a normal spool valve, the non-leak type oil passage switching valve V1 is a directional switching valve that fully utilizes the features of a check valve, so it can almost completely shut off pressure oil.

Here, the above non-leak type oil passage switching valves V2, V
3 and V4 are also similar to the above.

It should be noted that the non-leak type oil passage switching valve V1 does not necessarily have to have the above-described structure, and may have any structure as long as it can almost completely block the leakage of pressure oil.

The output port 44 of this non-leak type oil passage switching valve V1 and the oil passage 17 of the front and rear workpiece holding frames 12
and are connected by a oil supply hydraulic hose 17a.

A part of the above embodiment can be modified as follows.

B As shown in Fig. 10, the fluid pressure input port 20 of the workpiece fixing plate P and the non-leak type oil passage switching valve V1
A pneumatically driven hydraulic pump 24A is interposed between the two.

A low-pressure pneumatic supply device consisting of a low-pressure regulator 23L connected to the pneumatic supply source 21 is provided as a temporary tightening low fluid pressure supply device L on the conversion table T side, and as a final tightening high fluid pressure supply device H on the machine tool M side. A high-pressure pneumatic supply device consisting of a high-pressure regulator 23H connected to a pneumatic supply source 33 is provided.

(b) The hydraulic fixing device C is not limited to the structure that fixes the workpiece W using hydraulic pressure as described above, but may have a structure that fixes the workpiece using a spring force and releases the fixation using hydraulic pressure.

Since the present invention is configured as described above, it has the following effects.

1 The pressure oil supplied to the hydraulic fixing device of the workpiece fixing plate can be shut off by the non-leak type oil passage switching valve and maintained in a leak-free state, so when the workpiece is temporarily fixed on the workpiece fixing plate on the conversion table or temporarily. After stopping and final tightening, the workpiece fixing platen can be transferred from the conversion table to the machine tool with the fluid pressure hose disconnected from the workpiece fixing platen. This not only simplifies and improves the efficiency of transporting the workpiece fixing plate, but also eliminates the need to place the switching table near the machine tool, increasing the degree of freedom in terms of layout.

Of course, damage to the fluid pressure supply hose and the like and burnout caused by chips and the like are also alleviated.

2. After temporarily tightening the workpiece by supplying low fluid pressure to the workpiece fixing plate on the conversion table, the workpiece can be accurately and easily positioned by tapping the workpiece, etc., and then high fluid pressure can be supplied for final tightening. As a result, the work efficiency and positioning accuracy for positioning and fixing the workpiece can be improved, and as a result, the dimensional accuracy of the product can be significantly improved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Figs. 1 and 2 are side and plan views of a machine tool and a transfer table, Figs. 3 and 4 are plan and front views of a work fixing plate,
FIG. 5 is a partially enlarged side view of a hydraulic fixing device;
The figures are hydraulic and pneumatic system diagrams, Fig. 7 is a vertical cross-sectional side view of the positioning device, Figs. 8 and 9 are a partially cutaway vertical cross-sectional side view and a partially cutaway vertical cross-sectional rear view of the non-leak type oil passage switching valve, respectively, and Fig. 10 is a partial view of a modified example corresponding to Fig. 6. M...machine tool, T...switch table, P...work fixing platen, C...hydraulic fixing device, W...work,
V1: Non-leak type oil passage switching valve, L: Pre-tightening low fluid pressure supply device, H: Final fastening high fluid pressure supply device, 1: Table M, 9: Base plate P, 13
……C hydraulic cylinder, 20……Fluid pressure input port,
24A: air-driven hydraulic pump, 26: low fluid pressure output port, 27: high fluid pressure output port.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A conversion table T is installed on the front side of the machine tool M, and the workpiece fixing plate P placed on the table 1 of the machine tool M is transferred to the conversion table T.
The workpiece fixing plate P is configured so that it can be transferred to the table 1 of the machine tool M. The hydraulic cylinder 1 of the hydraulic fixing device C is provided with an input port 20.
3 is communicated with the fluid pressure input port 20 via the non-leak type oil passage switching valve V1, and a pre-tightening low fluid pressure is supplied to the hydraulic cylinder 13 to temporarily fasten the workpiece W to the hydraulic fixing device C. A pressure supply device L is provided on the conversion table T side, and a final tightening high fluid pressure supply device H is provided to supply final tightening high hydraulic pressure to the hydraulic cylinder 13 in order to final tighten the workpiece W temporarily fixed to the hydraulic fixing device C. Provided on at least one of the conversion table T side and the machine tool M side, the low fluid pressure output port 26 of the pre-tightening low fluid pressure supply device L and the high fluid pressure output port 27 of the main tightening high fluid pressure supply device H are provided respectively. A workpiece changing device for a machine tool, characterized in that it can be connected to and separated from a fluid pressure input port 20 of a workpiece fixing platen P. 2. Scope of Utility Model Registration Claims In the workpiece changing device for a machine tool described in paragraph 1, a final tightening high fluid pressure supply device H is provided on the conversion table T side. 3. Scope of Utility Model Registration Claims In the workpiece changing device for a machine tool described in paragraph 1, the final tightening high fluid pressure supply device H is provided on both the conversion table T side and the machine tool M side. 4. Scope of Utility Model Registration Claims In the workpiece changing device for a machine tool described in paragraph 1, a final tightening high fluid pressure supply device H is provided on the machine tool M side. 5. In the workpiece changing device for a machine tool described in any one of claims 1 to 4 of the claims for utility model registration, the temporary tightening low fluid pressure supply device L
consisting of a low-pressure hydraulic supply device. 6. In the workpiece changing device for a machine tool described in any one of claims 1 to 4 of the claims for utility model registration, the final tightening high fluid pressure supply device H
consisting of a high-pressure hydraulic supply device. 7. In the workpiece changing device for a machine tool described in any one of claims 1 to 4 of the utility model registration claims, the fluid pressure input port 20 of the workpiece fixing platen P and the non-leak type oil passage switching valve V1 A pneumatically driven hydraulic pump 24A is interposed between the workpiece fixing platen P and the workpiece fixing platen P is supplied with low-pressure compressed air and high-pressure compressed air from the temporary tightening low fluid pressure supply device L and the final tightening high fluid pressure supply device H, respectively. .