JP2798812B2 - Sliding 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 sliding device in which a sliding body slides along a rail.

[0002]

2. Description of the Related Art Generally, a machine tool or the like used for processing a work is provided with a table which allows the machine tool or the like to be movable in a linear direction. A rail extends along the moving direction of the table, and the table includes a sliding device that is guided by the rail and slides. As this type of sliding device, a sliding device as disclosed in Japanese Patent Application Laid-Open No. 58-81215 is conventionally known.

[0003] As shown in FIG.
It is composed of a rail 51 and a sliding body 52 that is laid on the rail 51 and slides along the longitudinal direction. On the upper surface 53 and both side surfaces 54, 55 of the rail 51, groove-shaped track surfaces 56, 57, 58, 5 are formed in the longitudinal direction.
9 are formed. A first bearing plate 62 having track surfaces 60, 61 facing the respective track surfaces 56, 57 of the upper surface 53 of the rail 51 is provided with a fixing screw on the straddling inner surface of the sliding member 52 straddling the rail 51. A pair of second bearing plates 67, 68, which are fixed by 63, 64 and have track surfaces 65, 66 facing the respective track surfaces 58, 59 of both side surfaces 54, 55 of the rail 51, are fixed to the fixing screws 6.
9, 70 fixed.

[0004] In addition, each track surface 60, 61,
65, 66 and each track surface 56, 57, 5 of the rail 51
A bearing area 72 having a plurality of ball-shaped rolling elements 71 that rolls when the sliding element 52 slides is provided in a load region between the bearings 8 and 59. Further, return holes 73, 74, 75, and 76 are formed in the sliding member 52 to allow the rolling element 71 that has moved in the load area to circulate infinitely.

[0005] A sliding device 50 of this type includes a sliding member 5.
When the rail 2 moves along the rail 51, the raceway surfaces 56, 57, 58, 59 of the rail 51 and the rolling element 71 may be worn. When the workpiece is machined by a machine tool or the like on the sliding body 52, the sliding body 52 may vibrate, thereby impairing the machining accuracy. Therefore, the track surfaces 56, 5 of the rail 51
The rolling elements 71 are brought into pressure contact with 7, 58, 59. Specifically, one second bearing plate 6
8 is provided with a preloading device 77 which presses the rolling element 71 against the raceway surfaces 56, 57, 58, 59 of the rail 51 by pressing the rolling element 71 in the horizontal direction to apply a so-called preload to the rolling element 71. The preloading device 77 is connected to the second bearing plate 68.
A preload bolt 78 threaded to reach the outer surface of
And a fixing nut 79 for fixing the preload bolt 78.

[0006] The preloading device 77 causes the bearing portion 72
When the preload is adjusted, first, the fixing screw 70 of the second bearing plate 68 is loosened so that the second bearing plate 68 can be moved. Next, the fixing nut 79 is loosened and the preload bolt 78 is rotated to move the second bearing plate 68 forward and backward. Thus, the width of the load area is adjusted via the second bearing plate 68, and the preload on the rolling elements 71 in the load area can be easily increased or decreased. Thus, for example, when the raceway surfaces 56, 57, 58, 59 of the rails 51 and the rolling elements 71 are worn, the preload is increased by the preloading device 77 and the rails 5 are increased.
The rolling element 71 is pressed into contact with the first raceway surfaces 56, 57, 58, 59 to prevent vibration and the like when the sliding element 52 slides.

Normally, a relatively large load is applied to this type of sliding device 50 at a position where a workpiece is machined by a machine tool or the like provided on the sliding device 50. Therefore,
In this working position, particularly high precision is required for the sliding of the sliding body 52.

However, the moving distance of the machine tool or the like at the machine position is smaller than the distance of moving the machine tool or the like to the machine position or the distance of moving the machine tool or the like after the machine is completed. That is, in order to secure particularly high precision for the sliding of the sliding body 52, the track surfaces 56, 5 of the rail 51 are used.
Although it is necessary only to press the rolling element 71 to 7, 58, 59 at the work position of the work,
According to the sliding device 50, the rolling elements 71 are provided on the raceway surfaces 56, 57, 58, 59 of the rail 51 even at positions other than the working position.
Is brought into a pressed state. Thereby, when moving the machine tool or the like to the machine position or when moving the machine tool or the like from the machine position, even when it is desired to move the machine tool or the like at high speed in order to improve work efficiency. , Rail 5
Since the preload is applied between the raceway surfaces 56, 57, 58, 59 and the rolling elements 71, the resistance at the time of sliding increases, which hinders high-speed movement. The surfaces 56, 57, 58, 59 and the rolling elements 71 are severely worn,
The life of the sliding device 50 may be reduced.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a sliding device which can ensure high sliding accuracy and can prevent the life of rails and rolling elements from being shortened. With the goal.

[0010]

According to the present invention, there is provided a machine tool for machining a workpiece.
A rectangular table and groove-shaped track surfaces are provided in the longitudinal direction of both side surfaces, and extend in parallel along the moving direction of the table.
A pair of rails provided and provided at the four corners of the table
Is, four sliding body slidable along the respective rails are in pairs to each of the rails saddled, the saddled inner surface of each slider, the supported by the raceway surface of each of said rails sliding and the rolling elements that roll along the raceway surface during the sliding of the moving object, the rails each slide the sliding body to press the upper surface of the provided rail and decorated in a substantially central position of facing the upper surface of the rail An actuator that moves in a direction away from the actuator and presses the rolling element against the raceway surface, and an actuator that is provided between the actuator and the upper surface of the rail and slides along the upper surface of the rail together with the sliding body to move the actuator. sliding instrumentation with a sliding plate which is pressed against the upper surface of the rail when activated
The actuator, the
The pressure for pressing the sliding plate against the upper surface of the rail according to the amount
The contact force is variable and slides by releasing electric charge
Piezoelectric actuator for releasing the pressure contact of the plate with the upper surface of the rail
The machine tool, which is an eta and moves along the rail
Position sensor that detects whether the machine is
And a load sensor that detects the load on each sliding body separately.
And the respective piezoelectric actuators of each sliding body are driven
A driving circuit, wherein the driving circuit includes a piezoelectric actuator.
Injection circuit for injecting electric charge into the piezoelectric actuator
Discharge circuit that discharges electric charge from the piezoelectric actuator
Charge detection circuit for detecting the amount of charge that the
Based on the detection signals of the position sensor and the load sensor.
The charge injection circuit and the charge
And an arithmetic circuit for operating the load discharging circuit .

[0011]

[0012]

Further, in the present invention, at least two or more groove-shaped track surfaces are provided on each of both side surfaces of the rail, and each rolling element in contact with each track surface of the rail is an inner surface of the straddle of the sliding member. It is characterized by being provided on the side.

[0014]

According to the present invention, when the actuator is operated, the actuator presses the upper surface of the rail via the sliding plate. The sliding body is pushed upward by the reaction force of the pressing away from the rail, and the rolling element is pressed against the raceway surface of the rail. At this time, since the actuator is pressed into contact with the upper surface of the rail via the sliding plate, the sliding plate smoothly slides on the upper surface of the rail, thereby preventing the operation of the actuator from affecting the sliding of the sliding body. Is done. Thereby, the accuracy of sliding of the sliding body along the rail is improved. Also, when the operation of the actuator is released, the pressure of the rolling element against the raceway surface of the rail is loosened, and the pressure contact amount is reduced. This makes it possible to reduce the resistance at the time of sliding of the sliding body along the rail and to slide the sliding body at high speed. Further, in the present invention,
The actuator is a piezoelectric actuator and four sliders
The piezoelectric actuators provided on the moving body are individually controlled. Immediately
That is, each piezoelectric actuator of the four sliding bodies is individually loaded.
The drive circuit of the heavy sensor and the piezoelectric actuator is connected
And the position sensor detects that the machine tool is in the machine position.
Is detected, the load sensor of each sliding body
The load is detected. At this time, the load sensor signal
Each drive circuit operates based on the
Load applied to the sliding body by injecting electric charge into the actuator
Rolling element so that the rolling element contacts the raceway surface
To the preload. At this time, an injection charge detection circuit is provided.
That the piezoelectric actuator has
An arithmetic circuit determines whether or not the amount of the load is appropriate,
The preload of the rolling elements is appropriately adjusted. Thus, the piezoelectric actuator
The drive of the heaters is performed separately for each of the four sliding bodies.
Even if a different load is applied to each sliding body,
The pressure contact of the rolling element to the raceway surface is maintained at an appropriate level.

[0015]

[0016]

Furthermore, since the rolling elements corresponding to at least two or more raceways are pressed against each of both side surfaces of the rail, the loads applied to the raceways and the rolling elements are dispersed to reduce their wear. Small.

[0018]

An embodiment of the present invention will be described with reference to the drawings.

[0019] Figure 1 is an explanatory view showing a basic configuration of a sliding body, FIG. 2 is a sectional view, of the illustration of the II-II line of FIG. 1, FIG. 3 is explanatory diagram shows the sliding device of the present embodiment, FIG. 4 is a piezoelectric actuator of the present embodiment.
It is a view to a block diagram of the configuration of a driving circuit of Chueta.

As shown in FIG. 3, the sliding device 1 of this embodiment moves a machine tool 2 used for machining a workpiece (not shown) in a linear direction.
It is provided below.

First, the configuration of the sliding device 1 according to the present embodiment will be described.

As shown in FIGS. 1 and 2, the sliding device 1 is formed by a rail 4 and a sliding member 5 which is laid on the rail 4 and slides along its longitudinal direction. .

To describe each part in detail, on both side surfaces 6 and 7 of the rail 4, track surfaces 8 and 9 each having a substantially V-shaped groove are formed in two rows in the longitudinal direction. On the straddling inner surface of the sliding body 5 straddled on the rail 4, substantially V-shaped groove-shaped track surfaces 10, 11 facing the respective track surfaces 8, 9 of the rail 4 are formed in two rows, respectively. I have.

Each of the raceway surfaces 10 and 11 of the sliding body 5
A plurality of ball-shaped rolling elements 12 that roll when the sliding element 5 slides are provided in a load area a between the rails 4 and the raceway surfaces 8 and 9. Further, passage holes 13 and 14 through which the rolling element 12 is moved without receiving a load are formed in the sliding body 5, and the load area a is provided with a load at each of the start end side and the end end side. Area a and passage hole 13,
Return bracket 16 having an arc-shaped direction change hole 15 for changing the moving direction of rolling element 12 by communicating with
a and 16b are provided continuously. That is, the rolling element 12
When the sliding member 5 slides, the load region a rolls in a direction opposite to the moving direction of the sliding member 5 to promote the sliding of the sliding member 5, and the return bracket 16 at the end of the load region a.
The direction is changed by a direction change hole (not shown) b, and is moved to the passage holes 13 and 14. The rolling elements 12 that have moved in the passage holes 13 and 14 in the traveling direction of the sliding body 5 are changed in direction by the direction changing holes 15 of the return bracket 16a, and are moved to the load area a.

As shown in FIG. 1, an actuator 17 is provided in a substantially central position of the sliding body 5 facing the upper surface of the rail 4 . Further, in between the upper surface of the rail 4 and the actuator 17, sliding plate 21 which slides along the rail 4 with the sliding body 5 is provided.

Next, the sliding device 1 configured as described above
The operation of will be described.

First, the actuator 17 is operated.
Then, the sliding plate 21 is pressed against the upper surface of the rail 4. this
Due to the reaction force at this time , the sliding body 5 is pushed upward in a direction away from the rail 4. Since the raceway surfaces 8 and 9 formed on the rail 4 and the raceway surfaces 10 and 11 formed on the sliding body 5 are both formed in a substantially V-shaped groove shape, the raceway surfaces 8 and 9 of the rail 4 The upper surfaces 8a and 9a and the lower surfaces 10b and 11b of the raceway surfaces 10 and 11 of the sliding member 5 approach each other, and the ball-shaped rolling element 12 is pressed between them. As a result, a preload is applied to the rolling elements 12.

At this time, the actuator 17
Since being pressed against the upper surface of the rail 4 via the sliding plate 21, without the actuator 17 is in direct contact on the upper surface of the rail 4, it is possible to prevent damage to the upper surface of the rail 4. Further, since the sliding plate 21 slides smoothly on the upper surface of the rail, it is possible to prevent the sliding of the sliding body 5 from being hindered when the rolling element 12 is preloaded.

As described above, the actuator 17 is
The preload can be applied to the rolling element 12 simply by operating the sliding element 12, and the accuracy of sliding of the sliding element 5 along the rail 4 is improved.

Further, sliding by the actuator 17
When the pressure contact of the plate 21 is released, as shown in FIG. 2, the upper surfaces 8 a and 9 a of the track surfaces 8 and 9 of the rail 4 and the lower surface 10 b of the track surfaces 10 and 11 of the sliding body 5. , 11b
Are separated from each other, the compression of the rolling element 12 during that time is loosened, and the preload is reduced. At the same time, the lower surfaces 8b, 9b of the track surfaces 8, 9 of the rail 4 and the track surfaces 10, 1 of the sliding body 5
The rolling element 12 is in contact with the upper surfaces 10a and 11a of the rolling element 1 to reduce the resistance when the sliding element 5 slides, and the sliding element 5 can be slid at high speed.

In this way, the actuator 17
Since the rolling elements 12 to apply a preload I, even while the sliding body 5 is slid along the rail 4, the rolling elements 12 by simply controlling the actuator 1 7 by a valve (not shown) or the like Can easily be adjusted.

Next, as shown in FIG. 3, an operation when the sliding device 1 of the present embodiment is provided on the machine tool 2 indicated by a virtual line in the figure, and an example of a control method of the sliding device 1 at that time. Will be described.

The machine tool 2 is fixed on a table 3, and the slide 5 is fixed to each lower part of the four corners of the table 3. A pair of parallel rails 4a, 4b are provided along the moving direction of the machine tool 2,
On each of the rails 4a and 4b, two sliding members 5 at four corners of the table 3 are straddled two by two. In such a case, for example, the load applied to each sliding body 5 may be different due to a partial difference in weight of the machine tool 2. Therefore, as described above, the actuator 17 of each sliding body 5
Thus , a preload is applied to each of the sliding members 5 separately. By doing so, vibrations and the like during sliding of the sliding body 5 are prevented,
The machine tool 2 is moved in a state where the accuracy of the movement position is high.

In the movement of the machine tool 2, the highest position accuracy is required for the processing position of the work by the machine tool 2, and in other positions, it is desirable to move at high speed. In this case, as shown in FIG. 3, at the moving position X to the processing area Y, the sliding device 1 does not operate the actuator 17 of each sliding member 5 and does not apply a preload to the rolling member 12 without applying a preload. The moving body 5 is slid so that the machine tool 2
Can be moved at high speed. And machine tool 2
Is moved into the processing region Y, the actuator 17 of each sliding body 5 is operated as described above. As a result, in the processing area Y, a preload is applied to each of the slides 5, so that an accurate processing operation by the machine tool 2 can be performed. Thereafter, when the machine tool 2 moves out of the processing area Y to the movement position Z, the sliding of each sliding body 5 by the actuator 17 is performed.
The processing machine 2 can be moved at high speed by releasing the pressure contact of the plate 21 and sliding the sliding body 5 without applying a preload to the rolling elements 12. As described above, the sliding device 1 can adjust the preload by the actuator 17 even during the sliding, and moves the machine tool 2 at high speed in the regions X and Z where the preload is not required. As a result, wear of the rails 4a and 4b and the rolling elements 12 is prevented, and work efficiency can be improved.

The actuator 17 of the sliding member 5 includes:
It is preferable to employ a so-called piezoelectric actuator, specifically, a laminated ceramic actuator that operates using a PZT element that expands in proportion to the applied voltage.

By doing so, the actuator 1
7 can be electrically controlled, so that the control can be performed easily and quickly. In FIG. 3, each of
The piezoelectric actuator as signed _{P 1, P 2, P 3} , P 4
Then, the control method will be described in detail.

As shown in FIG. 4, the position sensor 26 detects which of the moving positions X, Y, and Z of the machine tool 2 the machine tool 2 has moved, and is applied to each sliding member 5. Load sensors 27, 33, 34, 3 for detecting loads individually
5 are provided.

This control method, as shown in FIG. 4, uses the respective piezoelectric actuators P ₁ , P ₂ , P ₃ ,
Performing a projection of the piston portion by a signal from the drive circuit 22, 23, 24 and 25 connected to the P _4. That is, the drive circuits 22, 23, 24, 25 increase or decrease the preload on the rolling elements 12.

[0039] First, an explanation will be made for a driving circuit 22 for performing pre-load acceleration and by the piezoelectric actuator P _1. As shown in FIG. 4, the drive circuit 22 is provided with an arithmetic circuit 28 to which a position sensor 26 and a load sensor 27 are connected and which processes signals from these sensors. The arithmetic circuit 28 is connected to a charge injection circuit 30 connected to a high-voltage power supply 29 to inject electric charges into the piezoelectric actuator P ₁ , and is connected to a ground and connected to a charge discharging circuit 31 that releases electric charges from the piezoelectric actuator P _1. ing. The charge injection circuit 30 and a charge releasing circuit 31 the piezoelectric actuator P ₁ is connected. Further, the piezoelectric actuator P _1, injection charge detection circuit 32 for detecting the charge injected into the piezoelectric actuator P ₁ is connected, the injected charge detection circuit 32 calculation circuit 2
8 is connected.

Next, the operation of the drive circuit 22 will be described.
First, a signal of the moving position of the machine tool 2 detected by the position sensor 26 is sent to the arithmetic circuit 28. At this time,
When the machine tool 2 enters the machining area Y, the arithmetic circuit 28
Is sent to the charge injection circuit 30. Further, the arithmetic circuit 28 detects the rolling element 12 based on a signal from the load sensor 27.
The amount of the electric charge for giving a desired preload is calculated and a command is sent to the electric charge injection circuit 30. Charge injection circuit 30 injects charge into the piezoelectric actuator P ₁ based on the instruction of the arithmetic circuit 28, thereby, the preload is applied to the rolling elements 12.

When the machine tool 2 moves out of the processing area Y and moves to another moving position Z, the arithmetic circuit 28 sends a command to the charge discharging circuit 31. Charge emission circuit 31 emits charge from the piezoelectric actuator P ₁ based on the instruction of the arithmetic circuit 28, thereby, is reduced preload was given to the rolling elements 12, smoothly subjected to sliding of the sliding body 5 At high speed.

Further, the injected charge detection circuit 32 detects the amount of charge of the piezoelectric actuator P ₁ , and sends the signal to the arithmetic circuit 28. Arithmetic circuit 28, it is determined whether the amount of charge that the piezoelectric actuator P ₁ has is appropriate, if not properly sends a command to the charge injection circuit 30 or the charge discharge circuit 31. Thereby, the rolling element 1
2 can be given the desired preload.

As described above, the drive circuit 22 for the piezoelectric actuator P ₁ has been described. However, the other piezoelectric actuators P ₂ , P ₃ , and P ₄ have the same configuration and each drive circuit 2
3, 24, 25.

Thus, it is possible to easily and quickly increase or decrease the preload on the rolling elements 12 for each of the piezoelectric actuators P ₁ , P ₂ , P ₃ , and P _{4 of} each sliding body 5. It is also possible to automate the adjustment of the preload.

[0045]

As is clear from the above description, the rolling element can be pressed against the track surface of the rail only by operating the actuator. In addition, since the actuated actuator smoothly slides on the upper surface of the rail by the sliding plate, even if the rolling element is pressed against the track surface of the rail, the sliding of the sliding body can be smooth. by this,
Accuracy at the time of sliding of the sliding body along the rail can be improved.

Also, the pressure contact of the rolling element on the track surface of the rail is loosened only by releasing the operation of the actuator, so that when the sliding element is slid at high speed, the sliding element along the rail is not slid. The resistance can be easily reduced, and the sliding body can slide at high speed.

Further, since the actuator can be controlled even while the sliding body is sliding along the rail, the increase or decrease in the amount of pressure contact of the rolling element to the track surface of the rail can be controlled. It can be easily performed during sliding.

[0048]

Also, the actuator may be a piezoelectric actuator.
Actuated by its drive circuit
For example, when moving a machine tool, etc.,
Optimal preload is applied to each sliding body even when different loads are applied.
Can be given.

Further, at least two or more track surfaces are provided on each of both side surfaces of the rail, and the rolling elements are pressed against the respective track surfaces, so that the load applied to each of the track surfaces and the rolling elements is dispersed. Thus, their wear can be prevented.

Therefore, according to the present invention, it is possible to provide a sliding device capable of securing high sliding accuracy and preventing a reduction in the life of rails and rolling elements.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a basic configuration of a sliding body .

FIG. 2 is an explanatory view showing a cross section taken along line II-II of FIG. 1;

[Figure 3] shows describes diagram sliding device of the present embodiment.

FIG. 4 is a diagram illustrating a configuration of a driving circuit of the piezoelectric actuator according to the embodiment .
Shown to block diagram of the formation.

FIG. 5 is a sectional view showing a conventional sliding device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sliding device, 2 ... Machine tool, 3 ... Table, 4, 4
a, 4b: rail, 5: sliding body, 8, 9: track surface, 12
... rolling _{element, 17, P 1, P 2} , P 3, P 4 ... actuator, 21 ... slide plate, 26 ... position sensors, 27 and 33,
34, 35 ... load sensors, 22, 23, 24, 25 ... drive circuits, 28 ... arithmetic circuits, 30 ... charge injection circuits, 31 ...
Charge discharge circuit, 32 ... Injection charge detection circuit.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-129406 (JP, A) JP-A-5-123932 (JP, A) JP-A-2-229913 (JP, A) 9324 (JP, U) JP-A-2-61537 (JP, U) JP-A 62-78233 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16C 29/00-29 / 06 B23Q 1/26-1/28

Claims (2)

(57) [Claims] 1. A rectangle on which a machine tool for processing a workpiece is mounted.
Table, and a groove-shaped track surface provided in the longitudinal direction of both side surfaces, and extend in parallel along the moving direction of the table.
And a pair of rails provided at the four corners of the table.
Is, four sliding body slidable along the respective rails are in pairs to each of the rails saddled, the saddled inner surface of each slider, the supported by the raceway surface of each of said rails sliding and the rolling elements that roll along the raceway surface during the sliding of the moving object, the rails each slide the sliding body to press the upper surface of the provided rail and decorated in a substantially central position of facing the upper surface of the rail An actuator that moves in a direction away from the actuator and presses the rolling element against the raceway surface, and an actuator that is provided between the actuator and the upper surface of the rail and slides along the upper surface of the rail together with the sliding body to move the actuator. sliding instrumentation with a sliding plate which is pressed against the upper surface of the rail when activated
The actuator, the
The pressure for pressing the sliding plate against the upper surface of the rail according to the amount
The contact force is variable and slides by releasing electric charge
Piezoelectric actuator for releasing the pressure contact of the plate with the upper surface of the rail
The machine tool, which is an eta and moves along the rail
Position sensor that detects whether the machine is
And a load sensor that detects the load on each sliding body separately.
And the respective piezoelectric actuators of each sliding body are driven
A driving circuit, wherein the driving circuit includes a piezoelectric actuator.
Injection circuit for injecting electric charge into the piezoelectric actuator
Discharge circuit that discharges electric charge from the piezoelectric actuator
Charge detection circuit for detecting the amount of charge that the
Based on the detection signals of the position sensor and the load sensor.
The charge injection circuit and the charge
A sliding circuit comprising: an arithmetic circuit for operating the load discharging circuit . Wherein at least two to each of both side surfaces of the rail
The sliding device according to claim 1, wherein the groove-shaped track surface is provided, and each rolling element that is in contact with each track surface of the rail is provided on the straddle inner surface side of the slide member. .