JPH0415055B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a table for holding a pallet on which a workpiece to be machined is mounted relative to a machine tool, and particularly relates to a table that is capable of changing the inclination of the pallet. The present invention relates to a pallet clamp mechanism applied to a tilt table.

(b) Prior Art Normally, this type of tilt table requires a means to prevent the clamp mechanism from being erroneously activated to the unlock side due to an operational error when the table is tilted. circuits etc. have been used.

(c) Problems to be Solved by the Invention However, using electrical means for such means has the disadvantage that it may stop working in the event of a power outage. Therefore, there was a desire to develop a clamping mechanism that would ensure that pallets would never fall off the table.

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned drawbacks, the present invention aims to provide a pallet clamping mechanism for a tilt table in which a pallet will never fall off the tilt table as long as the tilt table is tilted. .

(d) Means for solving the problem That is, the present invention provides a method for clamping a pallet by using a clamp plate on a frame and a hydraulic drive means.
The pallet is movably provided so that it can be unclamped, and a hydraulic supply means is connected to the hydraulic drive means via a hydraulic circuit, and a pallet locking means is provided.
It is provided so that it can freely engage and lock against the pallet in such a way that it is always biased toward the locking side of the pallet by an elastic means.
A mechanical detection supply cutoff means is provided in the hydraulic circuit to detect the inclination of the frame with respect to the floor surface and to cut off the connection between the hydraulic pressure supply means and the hydraulic drive means when the frame is tilted.

(e) Effect With the above-described configuration, the present invention provides that when the tilt table is tilted, the mechanical detection supply cutoff means cuts off the connection between the hydraulic pressure supply means and the hydraulic drive means, and the hydraulic drive means is driven to the unclamping side. Further, the locking means is always urged by the elastic means so as to be able to engage with the pallet, and the locking state of engagement between the pallet and the locking means is maintained even in the event of a power outage.

(f) Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a hydraulic circuit diagram showing an embodiment of the pallet clamping mechanism according to the present invention, FIG. 2 is a front view showing an example of a tilt table to which an embodiment of the pallet clamping mechanism according to the present invention is applied, and FIG. 3 is a side view of the tilt table shown in FIG. 2, FIG. 4 is an operation diagram showing how the cylinder is driven when clamping a pallet, and FIG. 5 is a diagram showing how the pallet is clamped by the pallet clamping mechanism according to the present invention. It is an operation diagram.

The tilt table 1 has a frame 2, as shown in FIGS. 2 and 3, and arms 2a, 2a are provided on both sides of the frame 2 in FIG. A tilt shaft 3 is fitted into each arm 2a, and by rotating the tilt shaft 3 over a predetermined angle range, the tilt table 1
It rotates through a predetermined angle (usually 90 degrees) in the directions of arrows A and B in FIG. 3 about the center. In frame 2,
A clamp mechanism 5 is provided in the center thereof,
The clamp mechanism 5 has a rectangular clamp plate 6. As shown in FIG. 1, the clamp plate 6 is provided with a main cylinder 7 for clamping at its center, and a fixed piston 7a fixed to the frame 2 is attached to the main cylinder 7. On the other hand, they are fitted and engaged so as to be relatively slidable in the directions of arrows C and D. The fixed piston 7a has
A cylinder 7b is provided, and a lock pin 7e is engaged with the cylinder 7b so as to be slidable in the directions of arrows C and D. Fixed piston 7a and lock pin 7
A coil spring 7c is compressed between the pins 7e and 7e, and the coil spring 7c always biases the lock pin 7e in the direction of arrow C, that is, toward the lock side of the pallet 13, which will be described later. Further, four sub-cylinders 9 are formed around the main cylinder 7, and each sub-cylinder 9 has a fixed piston 9a fixed to the frame 2.
They are fitted and engaged so as to be relatively slidable in the D direction.
Note that hydraulic circuits 10 and 11 are connected to the main cylinder 7, cylinder 7b, and sub-cylinder 9, and a tilt detection pulp 15 is connected to the hydraulic circuit 10. As shown in FIG. 3, the tilt detection pulp 15 has a detection bar 15a provided in a shape that protrudes downward from the frame 2 in a manner that can come into contact with the floor surface 16 on which the tilt table 1 is installed. The detection bar 15a is supported so as to be movable in the directions of arrows E and F, and is always urged in the direction of the floor surface 16, that is, in the direction of arrow E, by a coil spring 15b.
The detection bar 15a has a notch 15 at its upper part in FIG.
A is formed in the notch 15a, and a control valve 15c is engaged with the notch 15a via an actuator 15d. A switching valve 17 is connected to the control valve 15c, a hydraulic circuit 11 and a hydraulic pump 19 are connected to the switching valve 17, and a drain tank 20 is connected to the hydraulic pump 19 via a filter 21.

A plurality of guide rollers 6a are rotatably provided on the surface and side surfaces of the clamp plate 6, and in a position facing the periphery of the clamp plate 6 of the frame 2, there are rollers shown in FIGS. As shown, four seating blocks 12 are provided.

On the other hand, the clamp mechanism 5 causes the tilt table 1 to
As shown in FIG. 5, the pallet 13 fixed above has a workpiece mounting surface 13a on which a workpiece is mounted, and a T-shaped engagement groove 13b is provided at the lower part of the pallet 13 in the figure. It is formed by engaging blocks 13c, 13c provided in an L-shape facing each other.

Since the tilt table 1 etc. have the above configuration, when clamping the pallet 13 carrying the workpiece onto the tilt table 1, first the tilt table 1 is moved so that the clamp plate 6 is fixed as shown in FIG. Drive and position via the tilt shaft 3 so that it is horizontal. When the clamp plate 6 is positioned horizontally, the detection bar 15a of the inclination detection pulp 15 provided below the frame 2 is aligned with the floor surface 16.
As a result, the detection bar 15a moves in the F direction against the elasticity of the coil spring 15b. Then, the actuator 15d of the control pulp 15c
is disengaged from the notch 15e of the detection bar 15a and is pressed in the G direction, and the switching valve 1
7 and the hydraulic circuit 10 communicate with each other via a control valve 15c. Therefore, the switching valve 17 is switched to the unclamp side, and the pressure oil from the hydraulic pump 19 is passed through the tilt detection pulp 15 and the hydraulic circuit 10.
It is supplied to the main cylinder 7, cylinder 7b and sub cylinder 9. Then, the lock pin 7c locks into the cylinder 7.
bb in the D direction against the elasticity of the coil spring 7c, and the clamp plate 6 as a whole is moved in the C direction by the pressure oil supplied to the main cylinder 7 and the four sub cylinders 9. Rise. Then, as shown in FIG. 5a, the distance L1 between the lower surface 6b of the clamp plate and the seating block 12 becomes larger than the thickness T of the engagement block 13c of the pallet 13, and the pallet 13 can be set. becomes.

Therefore, the pallet 13 is inserted from a direction perpendicular to the plane of FIG. 5 with the clamp plate 6 fitted into the engagement groove 13b, and the pallet 13 is transferred to a predetermined position on the clamp plate 6. The operation of transferring the pallet 13 onto the clamp plate 6 is smoothly performed by a guide roller 6a provided on the clamp plate 6. Palette 13
When is transferred onto the clamp plate 6,
Switch the switching valve 17 to the clamp side,
The hydraulic circuit 10 is switched to the drain tank 20 side, and pressure oil is supplied to the main cylinder 7, cylinder 7b, and sub cylinder 9 via the hydraulic circuit 11, as shown in FIG. Then, lock pin 7
As shown in FIG. 4, e is driven to protrude in the direction C through the cylinder 7b with the elasticity of the coil spring 7c, and locks into the lock hole 13 provided in the pallet 13.
d to restrain movement of the pallet 13 in a direction perpendicular to the plane of FIG. 4. Further, the clamp plate 6 is moved and lowered in the direction D by the pressure oil supplied to the main cylinder 7 and the sub cylinder 9, and as shown in FIG.
As shown in FIG. 2, the engagement block 13c of the pallet 13 is held between the lower surface 6b of the clamp plate 6 and the seating block 12.
3 is firmly held on the frame 2. Since the pallet 13 is clamped to the frame 2 by one main cylinder 7 and four sub cylinders 9 arranged around it, a stronger clamping force is exerted compared to clamping by a single cylinder. Ru.
Furthermore, since the main cylinder 7 and the sub-cylinder 9 are arranged so as to sandwich the seating block 12, the clamping force transmitted to the clamp plate 6 by the main cylinder 7 and the sub-cylinder 9 is applied to each seating block 12. It works effectively.

In this state, the tilt table 1 rotates around the tilt axis 3.
From the horizontal state shown in Figure 3, frame 2
is rotated 90 degrees around the tilt axis 3 in the A direction, and the predetermined machining is performed on the workpiece on the pallet 13. When the table 1 rotates in the direction A with respect to the floor surface 16, the abutment and engagement relationship between the detection bar 15a and the floor surface 16 is released, and the detection bar 15a is released.
a protrudes and moves in the E direction due to the elasticity of the coil spring 15b. Then, the actuator 15d and the notch 1
5e is engaged, the control valve 15c moves in the H direction, and the circuit from the switching valve 17 side to the hydraulic circuit 10 side is cut off. In this state, the detection bar 15a
This will continue as long as there is no contact with the floor surface 16, that is, as long as the tilt table 1 is tilted.
If the tilt table 1 is tilted due to an incorrect operation,
When the switching valve 17 is switched from the clamp side to the unclamp side, the hydraulic pump 20
Since the pressure oil from the cylinder is blocked by the inclination detection pulp 15, the cylinders 7, 7b, and 9 are not driven to the unclamping side. Further, in this case, the hydraulic circuit 11 is communicated with the drain tank 20 side, but the lock pin 7e is pressed in the direction C by the elasticity of the coil spring 7c, so that the pallet 13
Since the engagement relationship with the lock hole 13d is maintained, even if the oil pressure in the hydraulic circuit 11 drops, the pallet 13
will not fall from the top of the tilt table 1. This is true even if a situation such as a power outage occurs while the switching valve 17 is operated to the normal clamp side, and even if the oil pressure in the hydraulic circuit 11 drops, the lock pin 7e is C due to the elasticity of the coil spring 7c.
Since the pallet 13 is pressed in the direction and the engagement relationship with the lock hole 13d of the pallet 13 is maintained, the pallet 13 will not fall from the top of the tilt table 1 and is safe.

When the machining of the workpieces on the pallet 13 is completed in this way, the tilt table 1 is returned to the horizontal state and the pallet 13 on which the machined workpieces are mounted is removed from the tilt table 1, but the clamp plate 6 is positioned horizontally. Then, the detection bar 15a of the inclination detection pulp 15 provided below the frame 2 comes into contact with the floor surface 16, so that the detection bar 15a moves in the F direction against the elasticity of the coil spring 15b. Then, control valve 1
The actuator 15d of 5c is the notch 15 of the detection bar 15a.
The engagement with the portion e is released and it is pressed in the G direction, and the switching valve 17 and the hydraulic circuit 10 communicate with each other via the control valve 15c, and an unclamping operation becomes possible. Therefore, switching valve 1
7 to the unclamp side and hydraulic pump 19
Pressure oil from the tilt detection pulp 15, hydraulic circuit 10
It is supplied to the main cylinder 7, cylinder 7b, and sub cylinder 9 via. Then, the lock pin 7e is moved in the direction D in the cylinder 7b against the elasticity of the coil spring 7c, and the clamp plate 6 is moved by the pressure oil supplied to the main cylinder 7 and the four sub cylinders 9. The entire pallet 13 is raised in the direction C, and the pallet 13 is lifted and moved relative to the seating block 12 by the clamp plate 6. In that state, move palette 13 to the fifth
The work is completed by removing it from the clamp plate 6 and hence from the tilt table 1 by pulling it out in a direction perpendicular to the plane of the drawing.

(g) Effects of the Invention As explained above, according to the present invention, the clamp plate 6 is attached to the frame 2, the main cylinder 7,
The pallet 13 is movably provided so that it can be clamped and unclamped by a hydraulic drive means such as the sub-cylinder 9, and a hydraulic pump 19, a switching valve 17, etc. are connected to the hydraulic drive means via hydraulic circuits 10, 11, etc. A hydraulic drive means is connected, and a locking means for the pallet 13 such as a locking pin 7e is connected.
The pallet 1 is always biased toward the lock side of the pallet 13 by an elastic means such as a coil spring 7c.
An inclination detection pulp 15 or the like is provided so as to be freely engageable and lockable with respect to the hydraulic drive means 3, and detects the inclination of the frame 2 with respect to the floor surface 16, and interrupts the connection between the hydraulic drive means and the hydraulic drive means when the frame 2 is tilted. Since the mechanical detection supply cutoff means is provided in the hydraulic circuit, as long as the tilt table 1 is tilted, the mechanical detection supply cutoff means always cuts off the supply of pressure oil from the hydraulic pressure supply means to the hydraulic drive means. Furthermore, even in the event of a power outage, etc., the elastic means maintains the engagement between the locking means and the pallet 13, so the danger of the pallet 13 falling from the top of the tilt table 1 can be completely eliminated, making it safe and highly reliable. It becomes possible to provide a pallet clamp mechanism on the tilt table.

[Brief explanation of drawings]

FIG. 1 is a hydraulic circuit diagram showing an embodiment of the pallet clamping mechanism according to the present invention, FIG. 2 is a front view showing an example of a tilt table to which an embodiment of the pallet clamping mechanism according to the present invention is applied, and FIG. 3 is a side view of the tilt table shown in FIG. 2, FIG. 4 is an operation diagram showing how the cylinder is driven when clamping a pallet, and FIG. 5 is a diagram showing how the pallet is clamped by the pallet clamping mechanism according to the present invention. It is an operation diagram. 1...Tilt table, 2...Frame, 6...
... Clamp plate, 7 ... Hydraulic drive means (main cylinder), 7e ... Lock means (lock pin), 7
c... Elastic means (coil spring), 9... Hydraulic drive means (sub cylinder), 10, 11... Hydraulic circuit, 13... Pallet, 15... Mechanical detection supply cutoff means (tilt detection valve), 16 ……Floor,
17...Hydraulic supply means (switching valve), 19
...Hydraulic supply means (hydraulic pump).

Claims (1)

[Claims] 1. A clamp plate is movably provided on the frame so that the pallet can be clamped and unclamped by a hydraulic drive means, a hydraulic supply means is connected to the hydraulic drive means via a hydraulic circuit, and a pallet locking means is provided. is provided so that it can freely engage and lock against the pallet in a manner that is always biased toward the locking side of the pallet by elastic means, and detects the inclination of the frame with respect to the floor surface, and when the frame is tilted, the hydraulic supply means and the hydraulic drive A pallet clamping mechanism for a tilt table, comprising a mechanical detection supply cutoff means for cutting off connection with the hydraulic circuit.