JP2592505Y2 - Bearing device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device for a sliding surface of a machine tool.

[0002]

2. Description of the Related Art In a sliding center of a slide table and a rotary table constituting a work table in a machining center or the like, when a moving object becomes heavy, the contact surface pressure applied to the slide increases. When the contact surface pressure increases, stick-slip is likely to occur, and the positioning accuracy and the processing accuracy deteriorate.

[0003] In order to avoid this, some use a hybrid slide bearing in which a sliding slide and a rolling slide are combined. This hybrid slide bearing applies a certain preload to the roller by a disc spring,
A constant weight is always assigned to the rollers.

[0004]

It is very difficult to adjust the preload by the above-mentioned disc spring due to variations in the characteristics of each disc spring, an excessive change in the output value due to a slight change in the deflection of the disc spring, and the like. Further, in the case of the disc spring, since only a constant load of the weight of the moving object (table + work, etc.) can be shared, there is a problem that the slide surface pressure changes due to the fluctuation of the weight, and the optimum control cannot be performed.

An object of the present invention is to provide a bearing device in which a sliding slide surface pressure becomes constant irrespective of weight fluctuations, stabilization of positioning accuracy, and improved followability during high-speed feeding.

[0006]

According to the first aspect of the present invention, a linear movement is provided on a bed through a hybrid slide bearing comprising a sliding slide and a roller slide roller. The slide table,
A plurality of the hybrid slide shafts provided on the lower surface of the
And receiving a roller, a plurality of hydraulic cylinder device for supporting the slide table by driving the plurality of rollers in a vertical direction, a hydraulic source for supplying the same pressure oil to these hydraulic cylinder device, on the slide table a weight detecting device for detecting the weight of the workpiece, before detected by the weight detecting device
A control device for adjusting a hydraulic pressure supplied to the plurality of hydraulic cylinder devices according to the weight of the work .

According to a second aspect of the present invention, the weight detecting device is provided.
Is a path on which the work is placed on the slide table.
The pallet is engaged with the pallet and moved up and down.
Clamp to the slide table, class to unclamp
And a clamp for driving the clamp member in the vertical direction.
A ramp cylinder and the clamp member
The back of the clamp cylinder when descending under the weight
And a pressure detector for detecting pressure.

[0008]

According to the above construction, the change in the load weight of the slide table is detected by the weight detection device, and the hydraulic pressure supplied to the hydraulic cylinder device of the roller portion of the hybrid slide bearing is adjusted according to the load weight. Regardless of
Keep the surface pressure of the slide table properly. In addition,
The load weight is detected by the back pressure of the pump cylinder.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an example of a machine tool using the present invention, wherein 1 is a machining center, a bed 2, a column 3 provided on the bed 2 so as to be able to move forward and backward , and
A spindle head 5 which is provided on the column 3 so as to be vertically movable.
A work table 7 disposed on the bed 2 in front of the column 3; 5a is a spindle rotatably supported by the spindle head 5; 4 is a servomotor for moving the column 3 forward and backward; This is a servomotor for vertically moving the spindle head 5.

The work table 7 includes a slide table 8 guided movably in the left-right direction perpendicular to the direction of movement of the column 3, and a rotary table 10 rotatably guided on the slide table 8. A pallet 11 on which a work is placed is carried in and out of the rotary table 10. 9 is the slide table 8
Is a servo motor for left and right movement. 13 is pallet 11
And is provided on the turntable 10.

Reference numeral 13 denotes a pallet changer arranged in front of the work table 7. The pallet changer 13 has a hook 16 movable in a direction orthogonal to the horizontal direction of the slide table 8 in a plane.
, And pallet supports 14a and 14b arranged at the left and right positions of the exchange drive device 15.

Reference numeral 17 denotes a numerical controller, and an input device 18
A pulse distribution circuit is connected to the numerical controller 17 and the servomotor 4 for moving the column 3 forward and backward, the servomotor 6 for moving the spindle head 5 up and down, and the servomotor 9 for moving the slide table 8 right and left. 20
a, 20b, 20c, drive circuits 21a, 21b, 21c
Connected through. In addition, the numerical controller 17
The pallet 11 and the exchange drive device 15 are connected via a sequence controller 22.

FIG. 2 shows the detailed structure of the work table 7.
And FIG. The slide table 8 is slidably guided on the bed 2 through a plurality of sliding slide guide surfaces 30 having a flat portion and an upright surface portion. 1
The location is based on the roller slide by the roller 31, and is performed by the slide slide and the roller slide.
Ri constitute a hybrid slide bearing.

The rotary table 10 is rotatably guided by a support shaft 23 erected at the center of the slide table 8, and has a plurality of sliding slide guide surfaces 25 on a flat portion of the slide table 8. Supported through. The slide table 8 is provided with a plurality of rollers 27 and a plurality of clamping hydraulic cylinders 26 for pressing the rollers 27 against the guide surface 25 at the indexing position of the rotary table 10 to restrain the rotary table 10 in the rotation direction of the rotary table 10. I have. The rotary table 10 is indexed for rotation via a worm 28 and a worm wheel 29 by a motor (not shown).

The clamp member 12 of the pallet 11 is provided on a clamp cylinder 24 provided on the rotary table 10.

In view of the above, the present invention has a piston 33 connected to the roller 31 and applies a hydraulic pressure to the piston 33 to support the slide table 8. A hydraulic source for supplying oil, a weight detecting device for detecting a load weight of the slide table 8, and a control device for adjusting an oil pressure supplied to the hydraulic cylinder device 32 according to the weight detected by the weight detecting device. It is provided with. A plurality of the rollers 31 and the hydraulic cylinder device 32 are provided on the lower surface of the slide table 8 in the sliding direction, and the rollers 31 roll on the guide surface 30.

A first embodiment of a weight detecting device for detecting the load applied to the slide table 8 and a control device for adjusting the hydraulic pressure supplied to the hydraulic cylinder device 32 according to the weight detected by the weight detecting device. An example will be described with reference to FIG.

The hydraulic cylinder device 32 includes a hydraulic pump 3
4 and a pipe connection via a pressure reducing valve 35. The clamp cylinder 24 of the pallet 11 provided on the rotary table 10 includes a hydraulic pump 36 and a first switching valve 37,
The piping is connected via a second switching valve 38.

The first switching valve 37 is connected to the clamp port 3
7a and an unclamping port 37b, and the second switching valve 38 has a clamping and unclamping port 38a and a hydraulic block port 38b.

The weight detecting device for detecting the load applied to the slide table 8 is provided with a pressure sensor 39 on the hydraulic pipe of the clamp cylinder 24 of the pallet 11,
The pressure sensor 39 detects a pressure balanced with the weight on the clamp cylinder 24 when the first switching valve 37 is switched to the unclamping port 37b and is switched to the hydraulic block port 38b of the second switching valve 38. Note that a load cell may be used instead of the pressure sensor 39. In this case, a load cell is provided on the rotary table 10, and the pallet is placed on the load cell to detect the weight of the pallet.

The pressure sensor 39 is connected to the control valve 35 via an amplifier 40 and a gate circuit 41, and the gate circuit 41 is connected to the sequence controller 22.

The operation according to the structure of the first embodiment of the present invention will be described with reference to the flowchart of FIG. First, the slide table 8 is positioned on the pallet support 14a side of the pallet changer 13 (step 50). Next, the hook 16 is moved forward (step 51). Then the second
Clamp and unclamping port 38a for switching valve 38
Side, and the first switching valve 37 is switched to the unclamping port 37b side to unclamp the pallet 11 by the clamp cylinder 24 (step 52), and to engage the pallet 11 with the hook 16. The hook 16 is retracted (step 53) to move the pallet 11 to the pallet support 1
The pallet support 14a supporting the pallet 11 is taken out to the side 4a and lowered (step 54). As a result, the engagement between the pallet 11 and the hook 16 is released.

Next, the slide table 8 is positioned toward the pallet support table 14b of the pallet changer 13 (step 55), and the pallet support table 14b supporting the pallet 11 is raised (step 56). And are engaged. Next, the hook 16 is moved forward (step 57) to move the pallet 1 on the pallet support 14b.
1 is carried on the turntable 10.

When the pallet 11 is carried on the rotary table 10, the second switching valve 38 is switched to the hydraulic block port 38b to detect the pallet weight (step 5).
8) Yes. The detection of the pallet weight is the first as described above.
With the switching valve 37 switched to the unclamping port 37b, the pressure sensor 39 detects a pressure that matches the weight on the clamp cylinder 24 when switching to the hydraulic block port 38b of the second switching valve 38.

The weight detection signal of the pressure sensor 39 is amplified by the amplifier 40 and transmitted to the gate circuit 41. The signal from the amplifier 40 is transmitted to the gate circuit 41 from the sequence controller 22 by the data latch signal. 35 is input. This controls the pressure reducing valve 35 to adjust the hydraulic pressure supplied to the hydraulic cylinder device 32 of the roller 31 (step 59). As a result, the roller 3
The weight supporting the slide table 8 varies depending on the part, and the weight supporting the slide table 8 varies depending on the guide surface 30 for the sliding slide. That is, it is possible to optimally control the surface pressure of the sliding slide guide surface 30 according to the load weight acting on the slide table 8.

Thereafter, the first switching valve 37 is switched to the clamping port 37a and the second switching valve 38 is switched to the clamping and unclamping port 38a to clamp the pallet 11 on the rotary table 10 (step 60). The cycle is completed by retracting the hook 16 (step 61).

FIG. 4 shows a second embodiment of the present invention. In the second embodiment, the structure of the work table 7 and the weight detecting device are the same as those in the first embodiment, and the hydraulic pressure supplied to the hydraulic cylinder device 32 of the roller 31 is adjusted by the adjusting control means. Has changed. That is, the hydraulic pump 34
Pressure P1, P
2, a plurality of pressure reducing valves 42, 43, 44 adjusted for P 3 are arranged, and the sequence controller 22 selects the plurality of pressure reducing valves 42, 43, 44 based on the weight signal detected by the pressure sensor 39. By controlling the hydraulic cylinder device 32 of the roller 31 in the same manner as in the first embodiment.
The surface pressure of the slide slide guide surface 30 can be optimally controlled in accordance with the weight by adjusting the oil pressure supplied to the slide slide.

[0028]

According to the present invention, as described above , claim 1
In the arrangement, according to the weight of the word over click on the slide table
Of the roller slide supporting the slide table
By moving the number of rollers up and down,
Regardless, the surface pressure of the slide table is maintained properly,
Stable positioning accuracy of ride table and high speed feed
Improve.

According to the second aspect of the present invention, a work is placed on the work.
Pallet clamp and unclamping clamp
Clamp when the member descends due to the weight of the pallet
Measure the cylinder back pressure with a pressure detector to determine the weight of the workpiece.
Special equipment for detecting the weight of the workpiece.
It is not necessary to use a device, and the device can be made inexpensive.
Have the advantages that can be.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a machine tool using the device of the present invention.

FIG. 2 is a sectional view showing a first embodiment of the device of the present invention;

FIG. 3 is a flowchart showing the operation of the device of the present invention.

FIG. 4 is a sectional view of a main part of a second embodiment of the present invention;

[Explanation of symbols]

 2 Bed 8 Slide table 10 Rotary table 30 Guide surface for sliding slide 31 Roller 32 Hydraulic cylinder device 34 Hydraulic pump 35 Pressure reducing valve 39 Pressure sensor

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B23Q 1/00-1/76 F16C 29/00

Claims (2)

(57) [Scope of request for utility model registration] 1. A slide table supported on a bed via a hybrid slide bearing composed of a slide slide and a roller slide with rollers so as to be capable of linear movement, a plurality of slide tables being provided on the lower surface of the slide table.
A roller for the hybrid slide bearing;
A plurality of hydraulic cylinder device for supporting the slide table by driving the roller in the vertical direction, a hydraulic source for supplying the same pressure oil to these hydraulic cylinder device, the weight detection to detect the weight of the workpiece on the slide table Equipment and front
Before according to the weight of the workpiece detected by serial weight detecting device
A control device for adjusting a hydraulic pressure supplied to the plurality of hydraulic cylinder devices. 2. The apparatus according to claim 2, wherein the weight detecting device is provided with the slide table.
On a pallet on which the work is placed
The pallet is moved to the slide table by vertical movement
A clamping member for clamping and unclamping,
A clamp cylinder that drives the pump member up and down,
The clamp member descends under the weight of the pallet
Pressure detection to detect the back pressure of the clamp cylinder at the time of
The bearing device according to claim 1, wherein the bearing device comprises:
Place.