JPH0754845A - Direct acting guide device - Google Patents

Abstract

PURPOSE:To improve the efficiency of controlling the damping property and rigidity of a direct acting guide device of a machine tool. CONSTITUTION:A direct acting guide device is composed of a plurality of blocks having a rolling body guided by a rail 400 and a damping block 200 disposed between the blocks to generate a damping force. The damping block 200 has a brake shoe support parts 300 provided to sandwich the rail 400 from the direction of arrow. A rectangular parallelopiped-shaped slide groove 310 is provided along the rail 400 on the brake shoe support part 300. Also, a plurality of cylindrical grooves 320 are provided at a predetermined interval along the slide groove 310, extending to be connected to the slide groove 310. Further, a brake oil pressure supply pipe 330 is provided, extending to afford communication between the cylindrical groove 320 and a main oil pressure supply pipe 260. The main oil pressure supply pipe 260 distributes oil pressure supplied from an oil pressure port 270 provided on the upper surface of the damping block 200 to a plurality of brake oil pressure supply pipes 330.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motion guide device suitable for application to a machine tool.

[0002]

2. Description of the Related Art FIG. 8 is a side view showing a machine tool using a linear motion guide device for moving a column, and FIG. 9 is a sectional view showing a linear motion guide device according to the prior art. The machine tool 20 includes a bed 30 and a column 40, and the column 40 is movably supported on the bed 30 via a linear motion guide device 10. The linear motion guide device 10 includes a rail 400 and a block 100 movably supported along the rail. On the side surface of the rail 400, a rolling guide surface 410 having two gauges on one side and a total of four gauges is provided. Further, the rail 400 is provided with a bolt hole 490, and the rail 400 is fixed to the bed 3 by a bolt 492 inserted in the bolt hole.
0 is extended and fixed. The bolt hole 490 is drilled so that the head 493 of the bolt 492 is mounted on the rail 40.
It is configured not to project from the upper surface of 0.

A rolling element support portion 110 is provided on the block 100 so as to sandwich the rail 400. A preload variable body 120 is movably provided on each rolling element support portion 110, and the preload variable body is connected to a hydraulic actuator 130. The preload variable body 120 is provided with an annular path 122, and a plurality of rolling elements 124 are enclosed in the annular path. A part of the annular path 122 is open so as to face the side surface of the rail 400, and the rolling element 124 has the rolling guide surface 41 provided on the rail 400 through the opening.
Block 100 against rail 400 while in contact with 0
Support.

With the above structure, the hydraulic actuator 130
By controlling the hydraulic pressure of, the preload applied to the rolling elements 124 via the preload varying body 120 can be changed, and the rigidity of the linear motion guide device 10 can be controlled. For example, when the column 40 is fast-forwarded, rigidity is not required, so the hydraulic pressure of the hydraulic actuator 130 is lowered, the preload applied to the preload variable body 120 is lowered, and the rolling resistance of the rolling elements 124 is reduced. By doing so, the responsiveness of the linear motion guide device 10 is maintained well, and the column 40 is fed at high speed.

Further, when the column 40 is cut and fed, the hydraulic pressure of the hydraulic actuator 130 is increased to increase the preload applied to the preload variable body 120 and the rolling element 124.
Is strongly pressed against the rolling guide surface 410 of the rail 400.
When the rolling element 124 is strongly pressed against the rail 400 in this way, the rolling resistance of the rolling element 124 increases, the responsiveness of the linear motion guide device 10 decreases, and the rigidity increases. Therefore, the column 4 supported by the linear motion guide device 10
0 is less likely to vibrate, and chattering does not occur even when heavy cutting is performed. As described above, a linear motion guide device that appropriately changes the responsiveness and the rigidity by controlling the preload of the rolling elements is disclosed in, for example, JP-A-63-150129 and JP-A-63-162133. ing.

10 and 11 are explanatory views showing a linear motion guide device according to another conventional technique. In FIG. 10, a rail 400 having a polygonal cross section is provided with a rolling guide surface 41.
0 and a sliding guide surface 450, the block 100 includes an annular path 122, a rolling element 124 enclosed in the annular path, a brake shoe 170, and a brake actuator 180 connected to the brake shoe. I have it. The linear motion guide device 10 shown in FIG. 10 controls the brake actuator 180 to control the brake shoe 170 and the rail 4.
The braking force is generated by adjusting the contact pressure with the sliding guide surface 450 of No. 00, and the responsiveness and the rigidity are changed.
Such a linear motion guide device is disclosed in Japanese Patent Laid-Open No. 4-151017. Further, as shown in FIG. 11, there is also a linear motion guide device 10 in which the upper surface of the rail 400 is a sliding guide surface 450 and the brake shoe 170 is provided on the lower surface of the block 100.

[0007]

In the conventional linear motion guide device shown in FIG. 9, the damping property (rigidity) is improved by adjusting the preload applied to the rolling elements. Since the life of the moving body is shortened, the preload cannot be increased above a certain level, and therefore the damping property and the rigidity cannot be significantly improved.
Since the conventional linear motion guide device shown in FIG. 11 presses the brake shoes only from above the rail, the rigidity in the rail longitudinal direction (arrow AB direction) is improved, but the rigidity in other directions is not so improved. When the brake shoe is pressed against the sliding surface of the rail upper surface, the reaction force causes the block to be pushed upward, adversely affecting accuracy. Since the bolt holes are drilled on the top surface of the rail, the frictional force varies depending on whether the brake shoe is engaged with the bolt hole or not. There is a drawback in that cutting chips and the like flying on the rail top surface affect the frictional force between the brake shoe and the rail.

Further, in the conventional linear motion guide device shown in FIGS. 9, 10, and 11, even if the rigidity between the rail and the preload variable body (or brake shoe) is increased, the preload variable body (or brake) is increased. Since vibration occurs between the shoe) and the block, the rigidity between the preload variable body (or the brake shoe) and the block becomes a bottleneck, so that higher rigidity cannot be obtained.

[0009]

A linear motion guide device of the present invention comprises a rail, a block supported by the rail, and a damping block. The rail has a convex portion having a trapezoidal cross section on its side surface, and the convex portion has a two-rail rolling guide surface. The block has an annular path and a rolling element enclosed in the annular path and supporting the block by contacting the rolling guide surface. The damping block slides on the rolling guide surface to change the damping property and the rigidity of the linear motion guide device, a first piston and a cylinder for driving the brake shoe, and the first piston. Oil pressure is supplied to an oil chamber formed between the cylinders, an oil passage connected to the oil chamber, a second piston provided at the end of the oil passage and abutting a side surface of the first piston, and the oil chamber. It has a hydraulic supply pipe, a hydraulic port, and a spring that urges the brake shoe to separate from the rail.

[0010]

When the hydraulic pressure is not supplied, the restoring force of the spring holds the brake shoe in a position where it does not contact the rail. Therefore, the damping, rigidity, and responsiveness of the linear motion guide device in this state are the same as those of the conventional linear motion guide device. When hydraulic pressure is supplied to the hydraulic port, the hydraulic pressure is transmitted to the oil chamber via the hydraulic pressure supply pipe. When the oil pressure in the oil chamber rises, the piston pushes the brake shoe, and the brake shoe is pressed against the rolling guide surface of the rail. In this state, a frictional force is generated between the brake shoe and the rail, and the damping property and rigidity of the linear motion guide device are improved. Further, the second piston contacts the side surface of the first piston by the hydraulic pressure supplied to the oil chamber, and prevents the first piston from vibrating. Also,
The damping property and rigidity of the linear motion guide device can be controlled by adjusting the hydraulic pressure supplied to the hydraulic port.

[0011]

1 is a perspective view showing a linear motion guide device according to a first embodiment of the present invention. FIG. 2 is a perspective view showing the damping block 200, in which a part of the front side of the drawing is omitted so that the inside can be seen. 3 is a sectional view taken along line HH of FIG. 2, and FIG. 4 is a sectional view taken along line I-I of FIG. FIG. 5 is a view on arrow J of FIG. The linear motion guide device 10 is a rail 400.
And a block 100 and a damping block 200 which are supported by the rail so as to be movable in the directions of arrows AB. Two blocks 100 shown in FIG. 1 and one damping block 200 arranged between the blocks.
Is the minimum configuration of the linear motion guide device 10 according to the present invention, and the number of blocks 100 and damping blocks 200 can be changed depending on the load supported by the linear motion guide device 10. The rail 400 has a polygonal cross section, and a trapezoidal depression 420 provided on the side surface of the rail 400.
The upper slope 422 and the lower slope 424 are rolling guide surfaces. The block 100 is based on the prior art, and includes two sets on one side, and a total of four sets of ring roads (not shown),
A rolling element that is enclosed in the annular path and rolls on any of the rolling surfaces 422 and 424 is provided.

The damping block 200 is a rail 40.
The brake shoe support portion 300 is provided so as to sandwich 0 from the direction of arrow CD. A sliding groove 310 having a rectangular parallelepiped shape is provided along the rail 400 on the brake shoe support portion. In addition, a plurality of cylindrical cylinder grooves 320 that are connected to the sliding grooves and extend in the direction of arrow CD are formed along the sliding grooves 310 at predetermined intervals. Further, the brake hydraulic pressure supply pipe 330 connects the cylinder groove 320 with the main hydraulic pressure supply pipe 260 so that the brake hydraulic pressure supply pipe 330 communicates with the arrow E.
It is provided by extending in the −F direction. Main hydraulic pressure supply pipe 26
0 distributes the hydraulic pressure supplied from the hydraulic port 270 provided on the upper surface of the damping block 200 to the brake hydraulic pressure supply pipe 330 provided with a plurality.

A brake shoe 340 is fitted in the sliding groove 310 so as to be slidable in the direction of arrow CD. The brake shoe is provided with a plurality of pistons 344 corresponding to the positions of the cylinder grooves 320, and the pistons are slidably fitted in the cylinder grooves 320 in the directions of arrows CD. A lid 210 is fixed to the opening of the cylinder groove 320 on the outer surface of the damping block 200 by a bolt 212, and an oil chamber 220 is formed between the lid and the piston 344. The O-ring 2 is attached to the piston 344 and the lid 210 so that the hydraulic oil in the oil chamber 220 does not leak out.
14 is attached. A sub-hydraulic pressure supply pipe 230 is bent from the oil chamber 220 and extends in a U-shape, and its tip is opened to the side surface of the piston 344 of the cylinder groove 320. A sub piston 232 is slidably fitted into the opening end of the side surface of the piston 344 of the sub hydraulic pressure supply pipe.
A rectangular parallelepiped retaining groove 345 is provided at a position on the side surface of the piston 344 facing the opening of the sub-hydraulic supply pipe 230 so as to extend in the sliding direction of the piston 344 (arrow C-D direction). The tip of the sub-piston 232 is
It is loosely fitted in the retaining groove 345.

In the brake shoe 340, the rail 40
A sliding member 342 is provided on the surface facing the 0 rolling surface 410. Further, hooks 348 are attached to both ends of the brake shoe 340 along the rail, and springs 250 are attached between the hook 240 and the hook 348 provided on the brake shoe support portion 300. The spring 250 biases the brake shoe 340 via the hook 348 in the direction of separating from the rail 400. A cover 280 for protecting the spring 250 and the like is attached to both ends of the damping block 200 along the rail 400, and a skirt 282 for removing chips and the like adhering to the rail 400 is provided on the cover 280. There is.

Damping block 200 according to the present invention
The hydraulic pressure is supplied from a hydraulic control device (not shown) via a hydraulic transmission pipe (not shown) connected to a hydraulic port 270 provided on the upper surface of the damping block 200. FIG. 6 is a circuit diagram showing a hydraulic circuit used in the hydraulic control device. The hydraulic pump 610 is connected to the inputs of the first pressure reducing valve 620 and the second pressure reducing valve 630 by an oil passage 690, and the outputs of the first pressure reducing valve and the second pressure reducing valve are oil passages 692 and Hydraulic pressure selection valve 640 via oil passage 694
It is connected to the. The hydraulic pressure selection valve 640 is further connected to the oil passage 69.
6 is connected to a hydraulically operated valve 650, and the hydraulically operated valve is connected via a hydraulic transmission pipe to the damping block 20.
0 hydraulic port 270. Here, the pressure reducing valve 620 and the pressure reducing valve 630 also serve as return valves, are provided with an oil passage 698 for returning oil to the tank 660, and further the hydraulic operation valve 650 is also provided with the damping block 200.
An oil passage 699 is provided for returning the hydraulic oil supplied to the oil chamber 220 to the tank 660. Also, the hydraulic oil passage 6
An oil pressure gauge 670 for measuring oil pressure is attached to 96.

The operation of the linear motion guide device 10 having the above configuration will be described. When hydraulic pressure is not supplied to the damping block 200, the brake shoe 340 is set to the spring 250.
It is held at a position where it does not contact the rail 400 due to the restoring force. In this state, there is no contact point between the damping block 200 and the rail 400, and the linear motion guide device 10
The working resistance is the rolling element 124 in the block 100.
Therefore, the responsiveness of the linear guide device 10 is kept excellent. When the hydraulic pressure is supplied to the damping block 200 by the hydraulic circuit, the hydraulic pressure is supplied from the hydraulic port 270 to the brake hydraulic pressure supply pipe 330 through the main hydraulic pressure supply pipe 260 and guided to the oil chamber 220. The piston 344 is pushed by the oil pressure of the oil chamber 220 and the cylinder groove 32
The inside of 0 slides toward the rail 400, and the brake shoe 340 is pressed against the rail 400 at that time. In this state, the sliding member 342 of the brake shoe 400 and the rail 40 are
A frictional force is generated between the rolling guide surface 410 and the rolling guide surface 410, and the damping property and the rigidity of the linear guide device are increased. Further, the hydraulic pressure supplied to the oil chamber 220 is also transmitted to the sub-piston 232 through the sub-hydraulic supply pipe 230, the sub-piston 232 moves and abuts the bottom surface of the retaining groove 345 of the piston 344, and the piston 344 causes the arrow C to move. The piston 344 is fixed by friction so as not to vibrate in the -D direction.

The frictional force between the rail 400 and the brake shoe 340 can be controlled by changing the hydraulic pressure supplied to the damping block 200. For example, when the linear motion guide device 10 according to the present invention is applied to a three-axis machining center, when rough machining or heavy cutting is performed, the first axis in the cutting direction, the second axis in the feed direction, and the stopped second axis. Three
The high hydraulic pressure is supplied to all three linear motion guide devices of the above-mentioned shafts to improve damping and rigidity and prevent chattering. Also,
In the case of finishing, similarly, the hydraulic pressure supplied to the straightness guide devices of all three axes is lowered to adjust the frictional force according to the processing conditions and conditions to ensure optimum damping and rigidity.

The hydraulic circuit of the hydraulic control system shown in FIG. 6 can change the hydraulic pressure supplied to the damping block 200 in three stages: high pressure, low pressure, and no pressure. The hydraulic pump 610 supplies hydraulic pressure to the first pressure reducing valve 620 and the second pressure reducing valve 630 via the oil passage 690. Since the first pressure reducing valve 620 has little pressure reducing effect, the oil passage 692 is
The hydraulic pressure supplied to is high. Since the second pressure reducing valve 630 has a large pressure reducing effect, the hydraulic pressure supplied to the oil passage 694 is low.
The oil passage 692 and the oil passage 694 are connected to the oil pressure selection valve 640, and the oil pressure selection valve is either the oil passage 692 (high pressure) or the oil passage 69.
4 (low pressure) is connected to the oil passage 696. Oil passage 6
96 is connected to a hydraulically operated valve 650, which selects whether to supply the hydraulic pressure of the oil passage 696 to the damping block. That is, the hydraulic operation valve 650 selects the supply or non-supply of the hydraulic pressure, and the hydraulic selection valve 640 selects the level of the hydraulic pressure when supplying the hydraulic pressure. Also, the hydraulically operated valve 65
0 indicates the hydraulic port 270 and the oil passage 6 when the hydraulic pressure is not supplied.
Connect with 99. Then, the restoring force of the spring 250 causes the brake shoe 340 and the piston 344 to move to the rail 40.
The hydraulic oil in the oil chamber 220, which is narrowed when being pulled away from zero, passes through the hydraulic port 270 and the oil passage 699 to the tank 66
It is set back to 0. Although an example in which the hydraulic pressure is controlled in three stages has been shown here, it is also possible to control the hydraulic pressure more finely if necessary, or to use only two stages.

FIG. 7 is a sectional view of a damping block 200 of a linear motion guide device 10 according to a second embodiment of the present invention. The elements corresponding to the elements shown in the first embodiment have the same element numbers. The linear motion guide device 10 according to the second embodiment has rails 400 whose side faces project in a trapezoidal shape, and the upper slope 422 and the lower slope 424 of the trapezoidal protrusions are rolling guide faces. On the other hand, the brake shoes 340 provided on the brake shoe support portion 300 of the damping block 200 have the rolling guide surfaces 422, 424.
It has a trapezoidal cross section so that it can engage with it. The operation of the linear motion guide device 10 according to the second embodiment is the first
Is the same as that shown in the embodiment of FIG. As described above, the linear motion guide device 10 according to the present invention includes the block 1 having the rolling elements.
00, a damping block 200 provided with a brake shoe 170 is provided, and the rail 400 is sandwiched between the brake shoes to control the damping property and rigidity of the linear motion guide device 10, and to specify the shape of the rail. Instead, it can be applied to rails with various cross-sectional shapes. Further, the linear motion guide device 10 of the present invention can be easily configured by adding the damping block 200 to the conventional linear motion guide device.

[0020]

As described above, the linear motion guide device according to the present invention comprises the block mounted on the rail so as to be movable along the rail and the damping block, and the brake shoe provided on the damping block is hydraulically operated. Damping and rigidity are controlled by pressing it against the rail. Therefore, it is possible to obtain higher damping and rigidity as compared with the conventional linear motion guide device in which the rolling element is pressed against the rail. Also, by controlling the hydraulic pressure, the frictional force between the brake shoe and the rail can be changed to obtain optimum damping and rigidity. When the hydraulic pressure is not applied, the brake shoe is separated from the rail by the spring. For,
Not only the responsiveness of the linear motion guide device is not impaired, but also wear of the brake shoes can be prevented. By arranging the brake shoes at the positions sandwiching the rail, the force when the brake shoes are pressed against the rail is balanced, so that the block does not move even if the brake shoes are pressed against the rail. Since the sliding member of the brake shoe is pressed against the rolling guide surface of the rail, uniform frictional force can be obtained without being affected by the holes of the bolts and the like. Since the brake shoe is pressed against the side surface of the rail, a stable frictional force can be obtained without disturbing substances such as chips entering between the brake shoe and the rail.

[Brief description of drawings]

FIG. 1 is a perspective view showing a linear motion guide device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a damping block.

3 is a sectional view taken along line HH of the damping block in FIG.

4 is a cross-sectional view taken along the line II of the damping block in FIG.

5 is a view of the damping block in FIG. 2 as viewed in the direction of arrow J. FIG.

FIG. 6 is a circuit diagram showing a hydraulic circuit of a hydraulic control device for a linear motion guide device.

FIG. 7 is a sectional view showing a damping block of a linear motion guide device according to a second embodiment of the present invention.

FIG. 8 is an explanatory diagram showing an example in which the linear motion guide device of the present invention is applied to a machine tool.

FIG. 9 is a sectional view showing a linear motion guide device according to a conventional technique.

FIG. 10 is a sectional view showing a linear motion guide device according to a conventional technique.

FIG. 11 is a perspective view showing a linear motion guide device according to a conventional technique.

[Explanation of symbols]

 10 linear motion guide device 20 machine tool 30 bed 40 column 400 rail 410 rolling guide surface 420 trapezoidal depression 450 sliding guide surface 100 block 110 rolling element support 120 preload variable body 130 hydraulic actuator 170 brake shoe 180 brake actuator 200 damping / Block 220 Oil chamber 260 Main hydraulic supply pipe 270 Hydraulic port 232 Sub piston 300 Brake shoe support 310 Sliding groove 320 Cylinder groove 340 Brake shoe 344 Piston 342 Sliding member 610 Hydraulic pump 620 First pressure reducing valve 630 Second pressure reducing Valve 640 Hydraulic selection valve 650 Hydraulic operation valve

Claims (4)

[Claims] 1. A linear motion guide device having a rail having a rolling guide surface on its side surface and a block movably supported along the rail via rolling elements, wherein a plurality of blocks provided on the rail are provided. A linear motion guide device characterized in that a damping block for generating a damping force is provided therebetween. 2. The damping block includes a brake shoe and an actuator for driving the brake shoe, and the rail is sandwiched from both sides at a position facing the rolling guide surface provided on the rail side surface. The linear motion guide device according to claim 1, wherein the linear motion guide device is arranged so as to be open. 3. The linear actuator is a hydraulic actuator, wherein the hydraulic pressure supplied to the hydraulic actuator is controlled in multiple stages to adjust the frictional force between the brake shoe and the rolling guide surface of the rail. The linear motion guide device according to claim 2, wherein damping characteristics and rigidity are controlled. 4. The hydraulic actuator is inserted into a cylinder, a piston fitted into the cylinder, and a hole formed in a side surface of the cylinder to abut against a side wall of the cylinder, and the hydraulic actuator is operated at the same hydraulic pressure. The linear motion guide device according to claim 3, further comprising a driven sub-piston, wherein the sub-piston is pressed against a side wall of the piston when the actuator is actuated to prevent vibration of the piston.