JP4658798B2 - Machine tool thermal deformation prevention structure - Google Patents

Description

  The present invention relates to a thermal deformation prevention structure for preventing warping and tilting due to thermal deformation in a column or the like in a machine tool such as a portal machining center.

  For example, when a machine tool such as a portal machining center is installed in a factory, the temperature changes in the factory cause thermal deformation such as warping or tilting of the column, etc., and the spindle head tilts from the Z axis (vertical axis). Caused problems such as lowering Thus, conventionally, attempts have been made to prevent thermal deformation of machine tools with a configuration disclosed in, for example, Patent Document 1 and Patent Document 2.

Japanese Utility Model Publication No. 1-97840 JP 2001-54839 A

Here, the thermal deformation prevention structure disclosed in Patent Document 1 and Patent Document 2 will be described.
The thermal deformation prevention structure described in Patent Document 1 is intended to prevent thermal deformation of the column by sticking or filling a heat insulating material over the entire area of the column surface and the inner surface. In addition, the thermal deformation prevention structure described in Patent Document 2 is a method in which a temperature-controlled fluid (for example, a cooling liquid) is filled into a space inside the column or is caused to flow through a pipe disposed on the column surface. It is intended to prevent thermal deformation of.

  However, since a machine tool such as a portal machining center is generally a very large machine, there is a problem that even if the structure described in Patent Document 1 is used, the equipment cost becomes high. In addition, when the structure described in Patent Document 2 is applied, additional equipment costs are required, such as installation of piping and a device for managing the temperature of the liquid, and the machine tool operates. Meanwhile, the temperature of a large amount of fluid must be constantly controlled (heating and cooling), and the running cost is very high.

  Therefore, the present invention has been made in view of the above problems, and can be installed at a low cost even for large machine tools such as a portal machining center, and in particular, thermal deformation for preventing thermal deformation such as warping and sag. It is intended to provide a prevention structure.

In order to achieve the above object, the invention according to claim 1 of the present invention is characterized in that a guide is provided on one surface of a structure, and a thermal deformation of a machine tool provided with a moving body is movable along the guide. a structure, a cover member for covering a surface of the guide in the structure is not provided, Rutotomoni movable in synchronism with the moving body, the width in the moving direction of the movable body of the cover member The width of the surface of the structure that is not covered by the moving body at the arbitrary moving position of the moving body in the same moving direction as the moving body. It is characterized by covering over .
The invention according to claim 2 is characterized in that, in the invention of claim 1, the cover member is provided with heat insulation.

According to the present invention, the cover member whose width in the moving direction of the moving body is the same as that of the moving body covers the surface of the structure that is not covered by the moving body over the width in the same moving direction as the moving body. Therefore, when the temperature of the outside air changes, for example, to reduce the difference between the temperature change on the front surface (guide installation surface) of the structure and the temperature change on the rear surface or side surface (surface where the guide is not installed) Can do. Therefore, it is possible to prevent the occurrence of thermal deformation such as warping or sag in the structure, and this also leads to the effect of realizing highly accurate and efficient processing. In addition, the equipment cost can be reduced as compared with the case where the entire structure is covered with a heat insulating material or the like. Furthermore, since the cover member can be moved in synchronization with the moving body, it is not necessary for the operator to move the cover member in accordance with the movement of the moving body, which is easy to use.
Furthermore, since it can be configured simply by attaching a cover member at a predetermined position, installation work etc. is very easy, and it can be retrofitted to a machine tool already installed in a factory. Rich. In addition, when a machine tool is provided as in the prior art, there is no need for a separate device or the like for temperature management, so that the equipment cost can be kept extremely low and the running cost is not required.
Further, as in the invention of claim 2, by providing the cover member with a heat insulating property, thermal deformation generated in the structure can be further reduced.

  Hereinafter, a thermal deformation prevention structure according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the machine tool will be described as a portal machining center as an example.

FIG. 1 is an explanatory view showing the appearance of the portal machining center 1, and FIG. 2 is an explanatory view showing a horizontal section of the cover portion of the column 4. In the following description, it is assumed that the X-axis direction in FIG.
The portal machining center 1 is provided with a bed 3 in which a table 2 is slidable in the front-rear direction, and a pair of columns (structures) 4 and 4 are erected on both sides of the bed 3. Has been. A guide 8 parallel to the Z-axis direction is provided on the front surface of each column 4, and a cross rail (moving body) that can slide up and down along the guides 8, 8 is provided between the columns 4, 4. 5 is erected. A spindle head 7 having a spindle (not shown) is installed on the front surface of the cross race 5 so as to be slidable in the left-right direction. Further, covers (cover members) 6 and 6 formed of a heat insulating member are attached to both left and right ends of the cross rail 5 so as to cover a part of the surface of the column 4.

  The cover 6 is a belt-like body having a vertical width substantially the same as the vertical width of the cross rail 5, and both the side surfaces and the rear surface (the outer periphery of the moving body installation portion) of each column 4 are substantially the same as the cross rail 5 It is attached to the cross rail 5 so as to cover the width. Therefore, each cover 6 can be moved up and down along the column 4 together with the cross rail 5 (that is, not bonded or adhered to the column 4). Note that one end of the cover 6 is adhered to the outer end surface of the cross rail 5 as shown in FIG. 2 so that outside air does not enter as much as possible between the cover 6 and the surface of the column 4.

Here, thermal deformation of a column in a general portal machining center not provided with a thermal deformation prevention structure such as the cover 6 will be described.
When the outside air temperature (room temperature) changes, the column surface temperature also changes and the column expands and contracts. At that time, in the portion where the column surface is exposed, the temperature change of the column surface is substantially the same as the temperature change of the outside air. On the other hand, at the place where the cross rail is installed on the front surface of the column, the front surface of the column does not come into contact with outside air as shown in FIG. Therefore, there is a difference between the temperature change at the front of the column and the temperature change at the rear (and side) of the column, so the deformation rate of the column differs between the front and rear (and side), resulting in warping and tapping on the column. Thermal deformation (that is, thermal deformation in which the column tilts) will occur.

  On the other hand, in the portal machining center 1 in which the covers 6 and 6 covering the columns 4 and 4 are provided at both ends of the cross rail 5 as in the present embodiment, the cross rail 5 and the cross rail 5 are installed at the positions where the cross rails 5 of each column 4 are installed. Since the same vertical width is covered by the cover 6, even if the temperature of the outside air changes, the rear surface (and side surface) of the column 4 covered by the cover 6 is the same as the front surface of the column 4 on which the cross rail 5 is installed. Similarly, it is less susceptible to temperature changes. Therefore, there is no difference in temperature change between the front surface and the rear surface (and side surfaces) of the column 4 as described above, and the column 4 is not subject to thermal deformation such as warping or sag. Since not all of the column 4 is covered with the cover 6, the exposed portion of the column 4 undergoes thermal deformation (thermal deformation along the Z-axis direction) that expands and contracts in the vertical direction, but the column 4 is inclined. Since this is not deformation, the thermal deformation is performed by a conventionally known thermal displacement correction method and apparatus (for example, adding a correction value to the amount of movement of the main shaft in the Z-axis direction based on the amount of thermal displacement of the column 4). Correction can be made relatively easily.

  According to the structure for preventing thermal deformation as described above, the cross rail 5 installation position of each column 4 is covered by the cover 6 having substantially the same vertical width as that of the cross rail 5, so that when the temperature of the outside air changes, There is no difference in the temperature change of the column surface temperature between the front surface and the rear surface (and side surface) of the column 4. Therefore, it is possible to prevent the occurrence of thermal deformation such as warping or sag in the column 4, which leads to the effect of realizing highly accurate and efficient machining. In addition, the equipment cost can be reduced compared with a case where the entire column is covered with a heat insulating material or the like.

  Furthermore, since the covers 6 and 6 are attached to the left and right ends of the cross rail 5 so as to cover the column 4, installation work and the like are very easy, and for machine tools already installed in the factory. It can be retrofitted and is versatile. Furthermore, since a separate device for temperature management is not required when preparing a machine tool as in the prior art, the equipment cost can be kept extremely low and the running cost is not required.

Furthermore, by forming the covers 6 and 6 with a heat insulating member, it is possible to further reduce thermal deformation such as warping or tilting that occurs in the column 4.
In addition, since the covers 6 and 6 can be slid together with the cross rail 5, it is not necessary for the operator to move the covers 6 and 6 in accordance with the position of the cross rail 5.

  The thermal deformation prevention structure of the present invention is not limited to the aspect described in the above embodiment, and the configuration of the target machine tool, the installation position, shape, size, material, etc. of the cover Such a configuration can be appropriately changed as necessary without departing from the spirit of the present invention.

  For example, the structure for preventing thermal deformation according to the present invention is naturally applicable to a vertical machining center or the like, and can be configured such that a cover is attached to a spindle head that can slide vertically along the front surface of the column. It is. In general, room temperature has a correlation with indoor height (almost the same temperature at the same height position), so it is more effective to provide a cover on a movable body that is movable in the vertical direction. There is no problem even if a cover is provided on a movable body that is movable in the left-right direction. In addition, it is good also as a structure which provides separately the cover mobile body which moves in synchronization with a mobile body instead of sticking a cover directly to a mobile body.

  Furthermore, in the said embodiment, although the cover is formed with the raw material which has heat insulation, it is good also as a cover consisting of the raw material which does not have heat insulation. Although it is more susceptible to changes in the temperature of the outside air compared to those with heat insulation properties, it has a configuration that prevents the wind blowing inside the factory from directly hitting the column surface, etc. Can be expected.

It is explanatory drawing which showed the external appearance of the portal type machining center provided with the thermal deformation prevention structure. It is explanatory drawing which showed the horizontal cross section of the cover part of a column.

Explanation of symbols

  1 .. Portal machining center 2.. Table 3. Bed 4. Column 5 5 Cross rail 6 Cover 7 Head spindle 8 Guide

Claims (2)

A structure is provided with a guide on one surface of the structure, and a structure for preventing thermal deformation of a machine tool including a moving body movable along the guide,
A cover member covering the surface of said guide in said structure is not provided, Rutotomoni movable in synchronism with the moving body, the width in the moving direction of the movable body of the cover member, the movable body Is the same as
A machine tool characterized in that, at an arbitrary movement position of the moving body, the cover member covers a surface of the structure that is not covered by the moving body over a width in the same moving direction as the moving body . Thermal deformation prevention structure.   The structure for preventing thermal deformation of a machine tool according to claim 1, wherein the cover member is provided with heat insulation.

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