JPH07266169A - Guide mechanism of movable body - Google Patents

Abstract

PURPOSE:To secure a guide mechanism of a movable body, capable of clamping this body to a specified position accurately. CONSTITUTION:At the time of movements in the rotative indexing of a movable body 8, a keep plate 19 pressing and clamping this movable body 8 and its guide (base 7) is deformed to some extent by means of making hydraulic pressure act on a hydraulic pocket 22, and the clamp is released so as to get a gap produced in space between two sliding guide ways of both these elements, and inversely the hydraulic pressure is released and the deformation of the keep plate 19 is eliminated, whereby the movable body 8 and the guide (base 7) both are pressed and clamped tight by dint of elastic force of the keep plate 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide mechanism for a moving body which rotates or linearly moves along a guide surface of a machine tool, a coordinate measuring machine or the like.

[0002]

2. Description of the Related Art In a conventional device of this type, the amount of tightness (gap) of a sliding surface of a moving body with respect to a reference guide surface of a base is optimal so that the moving body does not meander during movement and the sliding friction force is not too large. Depending on the value, it is clamped by a mechanical brake or a servo for driving the moving body when stopping.

For example, in a conventional linear table mechanism shown in FIG. 3 as a partial sectional view (one side of the sliding portion is shown), the linear table 1 has its sliding guide surface 1a. The sliding reference guide surface 2a of the base 2 guides the paper in a direction perpendicular to the paper surface. The clamp shoe 5 provided on the holding plate 4 fixed to the linear motion table 1 with the set screw 3 is guided by the hydraulic device 6 to the linear motion table 1 against the lower surface 2b of the partial back surface of the reference guide surface 2a. By moving and pressing toward the surface 1a, the pressing plate 4 and the guide surface 1 of the linear motion table 1
It is configured such that the reference guide surface 2a of the base 2 is sandwiched between it and a to clamp the linear motion table 1. In addition, when no hydraulic pressure is applied, there is a gap between the holding plate 4 and the lower surface 2a of the back portion of the base 2, and the sliding direction is the same as the vertical guide surface 1b of the linear motion table 1 and this. It is regulated by the sliding engagement with the vertical guide surface 2c of the base 2 that slides face-to-face.

Further, as disclosed in Japanese Utility Model Laid-Open No. 4-111930, a brake device for a rotary shaft, a thin disk having low rigidity in the axial direction and high rigidity in the circumferential direction is used as a friction plate. There is also known a mechanism in which the other end of this friction plate, one end of which is fixed to the frame, is pressed against a rotating shaft (moving body) using hydraulic pressure and clamped.

[0005]

However, in the mechanism as described above, the hydraulic pressure is used to clamp the moving body when clamping, and the hydraulic pressure is released to unclamp the moving body when unclamping. This action of restraining the moving body gives some distortion to the moving body, and the reaction force also acts on the base side to give some distortion to the base,
The position accuracy of the moving body is adversely affected.

In contrast, when unclamping, the hydraulic pressure is released, neither the moving body nor the base is distorted, and the positional accuracy of the moving body is not adversely affected. .

Therefore, this is sufficient for a machine that processes or measures a moving body while moving it, but for a machine that clamps the moving body after positioning and processes or measures in that state, Due to the clamp, the positional accuracy of the moving body is incorrect.

Therefore, in the past, in order to improve the positional accuracy during clamping, it was general to use a toothed joint (for example, a Carbic coupling) for the rotary indexing table. In this case, at the time of rotation, the table is raised to disengage the teeth, and at the time of positioning, the table is lowered to engage the tooth portions of the joint to obtain the positional accuracy. However, the structure must be complicated by using an expensive toothed joint or requiring a table lifting mechanism.

An object of the present invention is to provide a guide mechanism for a moving body that does not adversely affect the positional accuracy of the moving body even when the moving body is clamped, and the reproducibility of the positional accuracy of the moving body is also improved. It is an object of the present invention to provide a guide mechanism for a moving body which has a good structure and has a simple structure in which the positional accuracy is maintained for a long time.

[0010]

In order to solve the above-mentioned problems, the device according to the present invention deforms the holding plate when the moving body is moved to provide a gap in the guide surface, and removes the deformation of the holding plate during clamping to remove the gap. The moving body is clamped instead of the above, and the following structure is provided. That is, in a guide mechanism of a moving body that guides a moving body that rotates or linearly moves along a guide surface, a base having a reference guide surface, and a holding plate that holds the moving body on the reference guide surface of the base, A guide for a moving body including a pressing plate deforming means that deforms the pressing plate during movement to provide a gap between the pressing plate and a reference guide surface, and eliminates deformation of the pressing plate during clamping to eliminate the gap. The pressing plate deforming means is composed of a hydraulic pocket provided on the pressing plate and a hydraulic device for supplying pressure oil to the hydraulic pocket.

[0011]

In the present invention, when the pressing plate is deformed, the base is also deformed by the reaction force, so that a gap is created between the guide surface and the movable body and the movable body can be moved. Then, when the deformation of the holding plate is removed, the gap disappears, and the holding plate presses the moving body against the reference guide surface and clamps it. At this time,
No distortion occurs in the holding plate or base.

[0012]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a sectional view of an embodiment in which the present invention is applied to a rotary indexing table. A shaft 9 serving as a rotation center of a rotary table (moving body) 8 is screwed in the center of an annular bottom recess formed in three stages of a base 7. It is fixed by 10, and the rotary table 8 is rotatably supported by a bearing 11. In addition,
Reference numeral 12 is a bearing fixing nut.

On the back surface of the rotary table 8, the back surface is a sliding surface.
The gear 13 which is 13a is integrated by a fixing screw 14 and is configured to be slidably engaged with a reference guide surface 15 formed on the surface of the second step annular recess of the base 7. This gear 13 transmits a driving force from the outside to the rotary table 8 and rotates the pallet 17 supported by the cones 16 (4 places) provided on the rotary table 8 to perform an indexing operation for machining. To do.

Further, in the third step annular recess 18 of the base 7, an annular holding plate 19 is fixed to the base 7 at the outer edge portion thereof with a fixing screw 20, and the inner tip lower surface portion 19a thereof is provided on the rear surface of the rotary table 8. In the normal state, the fixed gear 13 has an upper surface protruding peripheral edge 13b which is pressed and sandwiched between the fixed gear 13 and the reference guide surface 15 of the base 7 so that the rotary table 8 is held in a clamped state. The upper surface of the annular pressing plate 19 and the rotary table 8
A gap 21 is provided between the lower surface and the lower surface.

A ring-shaped hydraulic pocket 22 is provided on the surface of the base 7 of the annular pressing plate 19 corresponding to the third annular recess 18, and the annular pressing ring 23 is provided with a hydraulic pressure from the hydraulic device 6 to the base. It is configured to be pressed to the 7 side. Reference numeral 24 is an O-ring.

Therefore, when hydraulic pressure is applied to the ring-shaped hydraulic pocket 22 from the hydraulic device 6, the annular pressing ring 23 is pressed against the base 7, and the reaction force thereof causes the inner tip lower surface portion 19a of the annular pressing plate 19 to move to the gear 13 The pressing engagement with the projecting peripheral surface 13b is released, and the rotary table 8 integrated with the gear 13 and thus the pallet 17 held on the rotary table 8 can also be rotationally driven.

With the above-described structure, when the rotary table 8 is moved, the annular pressing plate 19 is deformed by the hydraulic pressure, and the pressure on the gear 13 integrated with the rotary table 8 is released. Although the relative sliding relationship with 7 changes, the hydraulic pressure does not work at the time of machining with the pallet 17 fixed, and for example, there is a possibility that deformation that adversely affects the indexing work of the rotary table 8 may occur. Absent.

FIG. 2 is a similar sectional view showing an embodiment in which the present invention is applied to a linear motion table similar to the conventional example shown in FIG. 3, and similar members are shown by using the same names and reference numerals. There is. That is, the linear motion table 1 has its sliding guide surface 1a slidably guided by the reference guide surface 2a of the base 2 in a direction perpendicular to the plane of the drawing, and the sliding direction is the vertical guide surface 1b of the linear motion table 1 and the facing surface thereof. Vertical guide surface 2c of sliding base 2
It is regulated by sliding with.

In the conventional apparatus shown in FIG. 3, the pressing plate 4 fixed to the linear motion table 1 by the set screw 3 is
By pressing the partial lower surface 2b of the reference guide surface 2a facing the sliding guide surface 1a of the linear motion table 1 of the base 2 with the clamp shoe 5 by the hydraulic pressure from the hydraulic device 6,
While both are fixed, in the embodiment according to the present invention shown in FIG. 2, when the linear motion table 1 is stopped, the tip of the presser plate 4 partially reverses the reference guide surface 2a. With the lower surface 2b of the section pressed down, the linear motion table 1
At the time of the movement, the hydraulic device 6 is attached to the pressing shoe 25 in the cylinder 4a formed on the pressing plate 4 itself against the lower surface 1c of the pressing plate 4 of the linear motion table 1 to which the pressing plate 4 is fixed by the hydraulic device 6. By applying more hydraulic pressure, the presser plate 4 is curved as shown by the alternate long and short dash line, and the engagement between the linear motion table 1 and the base 2 is released.

When the linear motion table 1 is stopped and clamped, the presser plate 4 is not deformed if the hydraulic pressure is released, and the elastic force of the presser plate 4 causes the base 2 to slide between the sliding guide surface 1a. Therefore, the linear motion table 1 can be positioned without any distortion of each part.

[0021]

As described above, according to the present invention,
At the time of clamping, even if the pressing plate is deformed by the hydraulic pressure from the hydraulic device, the base and moving body are not distorted, so
The displacement in the reference plane does not occur, and the movable body can be clamped under the necessary condition that maintains the most accuracy with the set pressing force of the pressing plate in a state where no hydraulic pressure is applied. That is, the moving body can be accurately clamped at a predetermined position. Also, there is little secular change in clamping force, and it is possible to clamp with the same pressure at all times.

Conventionally, it was general to use a toothed joint (for example, a Carbic coupling) for the rotary indexing table, but in this case, the rotary indexing operation always required lift and down operations. . However, according to the present apparatus, an expensive toothed joint is not required, and a mechanism for performing lifting and down operations is also unnecessary, so that it is possible to provide a rotary indexing table having a simple structure and inexpensive.

Further, when the base and the table are stopped, processing and measurement can be performed while maintaining high precision and rigidity, and when the base is moved, the pressing plate can be loosened to speed up the movement. Furthermore, since the moving time is originally much shorter than the stop time, the presser plate is deformed by the hydraulic system only when the base and the table move to each other, which reduces the operating time of the hydraulic system and reduces operating costs. It is also possible to save money.

In the above embodiment, the pressing plate is deformed by the hydraulic device, but an appropriate actuator other than hydraulic pressure may be used.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a rotary indexing table using a device of the present invention.

FIG. 2 is a partial cross-sectional view showing the structure of a linear motion table using the device of the present invention.

FIG. 3 is a partial cross-sectional view showing the structure of a linear motion table of a conventional device.

[Explanation of symbols]

 1 Linear motion table (moving body) 1a Sliding guide surface 1b Vertical guide surface 1c Presser plate mounting surface 2 Base 2a Reference guide surface 2b Back surface 2c Vertical guide surface 3 Set screw 4 Presser plate 4a Cylinder (hydraulic pocket) 5 Clamp Shoe 6 Hydraulic device 7 Base of rotating body 8 Rotary table (moving body) 9 Shaft 11 Bearing 13 Gear 13a Gear lower surface sliding surface 13b Top protruding peripheral surface 14 Fixing screw 15 Reference guide surface 17 Pallet 18 Third stage annular recess 19 Ring Holding plate 20 Fixing screw 21 Clearance 22 Hydraulic pocket 23 Pressing ring 25 Pressing shoe

Claims (2)

[Claims] 1. A guide mechanism for a moving body for guiding a moving body that rotates or linearly moves along a guide surface, a base having a reference guide surface, and a presser for pressing the movable body on the reference guide surface of the base. A plate and a pressing plate deforming means that deforms the pressing plate when moving to provide a gap between the pressing plate and the reference guide surface, and eliminates the deformation of the pressing plate when clamping to eliminate the gap. A guide mechanism for a moving body, which is characterized in that 2. The guide mechanism for a moving body according to claim 1, wherein the pressing plate deforming means includes a hydraulic pocket provided in the pressing plate and a hydraulic device that supplies pressure oil to the hydraulic pocket.