JPH04141337A - Clamp method for cross beam of machining center - Google Patents

Abstract

PURPOSE:To eliminate the deflection of a cross beam with a reaction force being made parallel to the cross beam, by converting a clamp motion force in the horizontal direction along the longitudinal direction of the cross beam by a cylinder mechanism into a pressing force orthogonal with the support shaft of a clamp arm being slid. CONSTITUTION:A cross beam 4 is made liftable along a column 2 between a pair of the right and left columns 2. A cylinder mechanism 5 is fixed in a horizontal posture in the longitudinal direction of the back side face both ends of the cross beam 4, the piston rod 5b thereof is longly projected horizontally in the column 2 direction. On the cross beam 4, a fixed support shaft 7 is provided at the position slid to the horizontal directional outside from on the piston rod 5n extension via a bracket at the column 2 side, and a clamp arm 8 turnable with the support shaft 7 as the fulcrum is provided. The tip of the piston rod 5b is pivotally attached by a pin 8a to the arm 8 one end, and a pressing member 9 is attached onto the abutment face of the arm 8 and column 2. Therefore the motion force in the horizontal direction of the rod 5a becomes the pressing force of a pressing member 9, and the deflection of the beam 4 is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a method for clamping a crossbeam at an appropriate height, which is raised and lowered along columns erected on the left and right sides of a gate-type machining center.

Prior Art As the above-mentioned cross beam clamping method, as shown in Fig. 5,
The cylinder mechanism 5 is attached to the crossbeam 4 in a horizontal position in a direction orthogonal to its longitudinal direction, and the tip of the piston rod 5a of the cylinder mechanism 5 is bolted at the edge of the column 2, and swings about the bolted part as a fulcrum. pressing one end of the possible clamping arm 8', on the side opposite said cylinder mechanism 5 with respect to the bolting point of said clamping arm 8';
The side in contact with the column 2 is used as a pressing surface, and the clamping force of the cylinder mechanism 5 in the horizontal direction perpendicular to the longitudinal direction of the cross beam is used to press the pressing surface of the clamp arm 8' against the column 2 side and clamp it. Are known.

C. Problems to be Solved by the Invention According to the conventional clamping method, the clamping force by the cylinder mechanism is applied as a pressing clamping force that presses the suppression surface of the clamp arm against the column, but on the other hand, it is applied in a direction perpendicular to the longitudinal direction of the crossbeam. 100% of the force acts as a reaction force. Therefore, when installing a cylinder mechanism on a cross beam, a strong bending stress acts between the cylinder mechanism attachment point and the bolt tightening point of the clamp arm, causing distortion, resulting in distortion of the vertical and horizontal movement of the spindle head. There was a drawback that the accuracy deteriorated. Furthermore, if the crossbeam bends and twists, the clearance between the pressing surface of the clamp arm and the column increases accordingly, which has the disadvantage of shortening the effective operating distance of the cylinder mechanism.

2. Means for Solving the Problems The present invention is a clamping method that aims to reduce the reaction force against the crossbeam and reduce the clamping force. To the longitudinal direction of the back of
A clamp arm that fixes the forward/backward drive mechanism in a horizontal position and allows the tip of the operating rod of the forward/backward drive mechanism to rotate horizontally around a fixed support shaft provided at a position horizontally outward from the extension of the rod. A pressing member is pivotally attached to one end of the clamp arm, and is attached to a contact surface with the column on the opposite side of the forward/backward drive mechanism with respect to the fixed support shaft of the clamp arm, so that the longitudinal direction of the crossbeam by the forward/backward drive mechanism is The object is to operate the pressing member in a horizontal direction orthogonal to the clamping force using a parallel horizontal clamping force.

When a clamping force is applied in the horizontal direction (in the direction in which the clamp arm is pulled) by the forward/backward drive mechanism, the clamp arm rotates around the support shaft, and the suppressing member is pressed against the column with a strong force that exceeds the clamping force. and the crossbeams are securely clamped to the columns.

EXAMPLE The method for clamping cross beams of a machining center according to the present invention is as follows.
The explanation will be based on the drawings.

In FIG. 1, reference numeral 1 denotes a base frame configured in a gate shape by installing horizontal beams 3 on the upper ends of a pair of left and right columns 22, and a crossbeam 4 is installed between the columns 2.2. It is installed so that it can be raised and lowered along the A clamping device is provided between the column 2 and the crossbeam 4, and the clamping device is driven by a forward/backward drive mechanism in the longitudinal direction of the rear side end of the crossbeam 4, as shown in FIGS. 2 to 4. A cylinder mechanism 5 having a built-in disc spring 5a is fixed in a horizontal position, and its piston rod 5b projects long toward the column 2. Further, a fixed support shaft 7 is vertically provided on the crossbeam 4 at a position horizontally shifted outward from the extension of the piston rod 5b of the cylinder mechanism 5 via a bracket 6 on the side of the column 2.
A clamp arm 8 is provided which can rotate horizontally about the fixed support shaft 7 as a fulcrum. The tip of the piston rod 5b is pivotally attached to one end of the clamp arm 8 by a pin 8a, and is in contact with the column 2 on the opposite side of the cylinder mechanism 5 with respect to the fixed support shaft 7 of the clamp arm 8. A suppressing member 9 is attached to the contact surface. The fixed support shaft 7 has an eccentric shaft structure, and a flange portion 7a is integrally provided at the upper end, and drill holes 7b, 7b, etc. are bored around the flange portion 7a at a pitch of 15 degrees. ing.

The side bracket 6 has screw holes 6a, 6a at 20 degree intervals in the portions corresponding to the drilled holes 7b, 7b, etc.
... is formed, and can be adjusted at a pitch of 5 degrees by selecting a combination of the drilled hole 5b and screw hole 6a. Thereby, the pushing distance by the pressing member 9 can be changed. Further, the pressing member 9 has a structure in which a pressing plate 10 is adhered to the surface, the back surface is brought into contact with a vertical shaft 11 in the clamp arm 8, and the front surface is pressed and fixed by a plate spring 12.

Therefore, the pressing surface of the pressing plate 10 is always kept parallel to the column 2 regardless of the attitude of the clamp arm 8, and is drawn toward the clamp arm 8 by the leaf spring 12, so that the clamp arm 8 can rotate. When it moves, it will not rub against column 2.

In a machining center equipped with such a ramp device, when a clamp operating force (force in the direction in which the piston rod is pulled in) is applied to the clamp arm by the cylinder mechanism, the clamp arm rotates about the fixed support shaft, and the suppression member is pressed against the column and the crossbeam is clamped to the column. In this way, the clamping force in the horizontal direction parallel to the longitudinal direction of the crossbeam causes the suppression member to actuate in the horizontal direction perpendicular to the clamping force, and the reaction force acts in the longitudinal direction of the crossbeam. Deflection and twisting of the girder can be reduced. In the embodiment, by effectively arranging the pivot position (force point) of the piston rod in the clamp arm, the support shaft position (fulcrum), and the pressing surface (point of action) of the suppressing member, the clamping force, which is the clamping force, can be reduced by 10%. We succeeded in reducing it to less than one-fold.

To confirm whether the clamp is clamped or unclamped, a limit switch 13 is attached to the cylinder mechanism 5, and a plate-shaped dog 14 is provided at the rear end of the piston rod 5b.
This is possible by hitting a.

In the embodiment described above, a cylinder mechanism is used as the forward/backward drive mechanism, but the forward/backward drive mechanism may also be a mechanism that is screw-fed by a motor, for example.

G. Effect According to the present invention, the clamping force in the horizontal direction along the longitudinal direction of the crossbeam by the cylinder mechanism is converted into a horizontal direction perpendicular to that direction and acts as a pressing force, so that the reaction force is applied to the crossbeam. It acts parallel to the crossbeam, and there is almost no deflection or twist of the crossbeam.

Furthermore, by effectively arranging the fulcrum, force point, and application point, the clamping force can be kept low.

[Brief explanation of the drawing]

Fig. 1 is an external view of a machining center that implements the cross beam clamping method according to the present invention, Fig. 2 is a front view of the clamping device section, Fig. 3 is a plan view thereof, and Fig. 4 is a cross section taken along line A-A. FIG. 5 is an explanatory diagram of a conventional example. 1. Base frame, 2. Column, 3. Horizontal beam, 4. Cross beam, 5. Cylinder mechanism, 5a. Belleville spring, 5b. Piston rod, 6. Bracket, 6a. Screw. Hole,
7...Fixed support shaft 7a...flange part, 7b...drill hole,
8.8'...Clamp arm, 8a...Bin, 9...Suppressing member, 10...Press plate, 11...Vertical shaft, 12
...Plate spring, 13..Limit switch, 13a..Contactor, 14..Dog, patent applicant Okuma Iron Works Co., Ltd.

Claims (1)

[Claims] The forward/backward drive mechanism is fixed in a horizontal position in the longitudinal direction of the back of a crossbeam that moves up and down along an erected column, and the tip of the operating rod of the forward/backward drive mechanism is shifted horizontally outward from the extension of the rod. A clamp arm is pivotally connected to one end of a clamp arm that is horizontally rotatable using a fixed support shaft provided at a certain position as a fulcrum, and a contact surface with the column is located on the opposite side of the forward/backward drive mechanism with respect to the fixed support shaft of the clamp arm. A method for clamping a cross beam of a machining center, in which a pressing member is attached to the horizontal beam, and the pressing member is actuated in a horizontal direction perpendicular to the clamping force by the clamping force in a horizontal direction parallel to the longitudinal direction of the cross beam by the advance/retreat drive mechanism.