JPH0719694Y2 - Machine Tools - Google Patents

Description

TECHNICAL FIELD The present invention relates to a machine tool having a structure against thermal displacement.

2. Description of the Related Art Conventional structures of conventional lathes often have a headstock fixed to legs or beds. Recently, with the diversification of needs, there are many demands for machines with a flexible line configuration and layout and a small work transfer distance and a small width. Many employ a vertical structure as a measure to minimize it.

Problem to be Solved by the Invention In the former of those described in the related art, in the former, the width of the machine is large, and further, the headstock causes thermal displacement between the fixed surface and the center of the spindle, resulting in relative displacement with the cutting point. This causes an error in the machining diameter. Although various methods have been implemented as measures against this, there is a problem that the heat radiation of the heat source is not uniform and the effect is not sufficient, and in the latter case, the tool rest is placed on the horizontal headstock. It is the most effective method to reduce the machine width, but there was a problem in machining accuracy that the amount of upward displacement of the spindle directly affects the dimensional error of the machining diameter due to heat. . The present invention has been made in view of the above problems of the conventional technology, and an object of the present invention is to provide a heat countermeasure structure that can meet the needs of high speed and high accuracy with a vertical structure having a small machine width. It aims to provide machine tools.

Means for Solving the Problems In order to achieve the above object, a machine tool according to the present invention has two upper and lower surfaces, which are parallel to a built-in spindle and are opposed to each other, of projections on both side surfaces as horizontal slide guide surfaces. The horizontal slide guide surface of is located on the horizontal plane passing through the center of the spindle or near the center, and at least one of the protrusions on the upper and lower surfaces is opposed to the right and left 2
A cross-shaped headstock having a surface as a vertical slide guide surface, and a guide surface for receiving the lower horizontal slide guide surface of the headstock in a horizontal central spindle direction and receiving a vertical slide guide surface of the headstock. A lower frame having a first vertical guide surface substantially symmetrically with respect to the center of the main shaft, and a second vertical guide surface which is established on the same plane as the guide surface of the lower frame and straddles the headstock and directly above the main shaft. An upper frame, a spindle head movement positioning means provided directly below the spindle center, a tool rest positioned by the moving means directly above the spindle center along the second vertical guide surface, and cutting on the tool rest. It is provided with a left-right symmetric turret provided so that its position is on a vertical plane passing through the center of the main axis, and each part is configured substantially symmetrically with respect to the vertical plane passing through the center of the main axis. .

In addition, the moving stroke of the headstock has both regions of the machining stroke and the work transfer stroke at the forward position.

A rectangular ram type headstock is advanced to the work transfer stroke position near the forward end by NC control along a Z-axis guide surface provided in the horizontal center of the action frame, and a loader or a workpiece is manually attached to the chuck at the tip of the main spindle. Is attached, the headstock is retracted to the cutting start position within the machining stroke, and the spindle is rotated. Then, the turret waiting on the spindle rotates and the tool is indexed, the tool rest moves to the spindle side in the X-axis direction and descends to the cutting start position, and the tool rest is on the vertical plane passing through the spindle center as the cutting point. The cutting process is performed by the movement in the X-axis direction and the movement of the headstock in the Z-axis direction. When the division of machining is completed, the rotation of the spindle is stopped, and the headstock is advanced to the Z-axis direction workpiece transfer stroke position to remove the machined workpiece and mount the material. The temperature of the headstock rises and thermal displacement occurs due to the rotation of the spindle during machining, but since the spindle center is located on the extension line of the horizontal pressure receiving surface of the Z-axis guide surface, the vertical movement of the spindle center does not occur. Further, since the entire machine is configured symmetrically with respect to the vertical plane passing through the center line of the spindle to balance the heat radiation, the horizontal movement of the center of the spindle is unlikely to occur.

Examples Examples will be described with reference to the drawings. 1 to 3
In the figure, the upper frame 2 is fixed on the lower frame 1 installed on the floor, and the sliding guide surface for the square ram type headstock is cut horizontally in the front-rear direction at the center of the joint surfaces 1a, 2a of the frames 1,2. Has been done. The headstock 3 has a spindle 4 rotatably supported by a plurality of bearings (not shown) at the center of a ram having a rectangular cross-section, and the spindle 4 is rotated by a drive device (not shown) incorporated in the headstock, and is attached to the tip of the spindle 4. The chuck 5 is fitted. As shown in FIG. 3, the headstock 3 has a single cross-shaped projection parallel to the main shaft, which is provided on each of the four outer surfaces, and has a cruciform shape. , 3b, and the vertical 2 facing the upper and lower projections
Surfaces are formed on the slide guide surfaces 3c and 3d. The frames 1 and 2 and the headstock 3 are vertical planes aa passing through the centerline of the spindle.
The sliding guide surface 3a is provided on a horizontal plane (bb) passing through the center of the main axis, and the guide surface 1b of the lower frame corresponding to the sliding guide surface 3a is joined to the joint surface 1a. It is provided on the same plane.

Z on the upper rear side of the leg 1c of the lower frame 1 via the bracket 7.
The shaft servo motor 8 is fixed, and the headstock 3 is mounted on the headstock 3 via a ball screw 9 provided directly below the main shaft.
By the NC control, the movable stroke is positioned in both the machining stroke C and the workpiece conveying stroke d near the forward end.

A lower tool post 11 having a vertical X-axis guide surface 11a is fixed to the front end surface 2b of the upper frame 2, and a tool post 12 is provided on the guide surface 11a.
Is movably provided, and the turret is moved and positioned by NC control by an X-axis servomotor 13 provided right above the center of the spindle. A turret 14 for detachably mounting a plurality of tools is provided on the tool rest 12 so as to be rotatable and indexable. The tool post 11, the tool post 12, and the turret 14 described above are all formed symmetrically with respect to a vertical plane aa passing through the center line of the spindle, and cutting is performed on the vertical plane aa. There is.

The headstock is not limited to the ram type, but may be a saddle type.

Further, the sliding guide surfaces projectingly provided on the outer peripheral four surfaces of the ram type headstock are symmetrical with respect to the vertical surface aa, and the sliding guide surface 3a is limited to be necessarily on the horizontal surface bb. If the horizontal slide guide surfaces 3a, 3b are arranged near the horizontal plane bb and the vertical slide guide surfaces 3c, 3c are arranged near the vertical plane aa, it is obvious that the purpose can be achieved. Is.

The heat-stable structure of the present invention is not limited to the horizontal spindle, but can be applied to a vertical spindle, for example, and is not limited by the direction of the spindle.

Effects Since the present invention is configured as described above, it has the following effects.

Since the tool rest is placed vertically above the ram type headstock and the horizontal guide surface for Z-axis movement of the headstock is provided on the horizontal plane passing through the centerline of the headstock, the headstock expands and contracts due to heat. However, the vertical position of the center of the spindle does not change. In addition, since the heat balance type mechanical structure is symmetrical with respect to the vertical plane passing through the center line of the spindle, it is not affected by the forward or reverse rotation of the spindle, and the change in the horizontal position of the spindle center is minimized. Further, since the opposing width of the guide surface of the protrusion of the headstock is reduced, the position of thermal change is small and the clearance of the guide surface can be kept constant, so that the machining accuracy can be improved.

Further, since the configuration width is small due to the vertical configuration, there is a high degree of freedom in the line configuration and layout along with a substantial space, and since the cutting point is on the upper side, the flow of chips is good and the work efficiency is improved.

[Brief description of drawings]

FIG. 1 is a front view of a heat stable structure machine tool, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a sectional view showing a slide guide surface of a ram type headstock. 1 …… Upper frame, 2 …… Lower frame 3 …… Spindle head, 4 …… Spindle 12 …… Turret, 14 …… Turret

Continuation of the front page (56) References JP-A-60-263634 (JP, A) Actually opened 63-100127 (JP, U) Actually opened 50-132788 (JP, U)

Claims (2)

[Scope of utility model registration request] 1. A horizontal slide guide surface is defined by two upper and lower surfaces, which are parallel to the built-in spindle and are opposed to each other on both side projections, and the horizontal slide guide surface below the horizontal slide guide surface is located on a horizontal plane passing through or near the center of the spindle. A cross-shaped headstock having at least two opposing left and right surfaces of the upper and lower projections, which are vertical slide guide surfaces, and a guide surface for receiving the lower horizontal slide guide surface of the headstock are provided in the horizontal central spindle direction. And a lower frame having a first vertical guide surface that receives the vertical slide guide surface of the headstock and is substantially bilaterally symmetrical with respect to the center of the main shaft, and the headstock on the same plane as the guide surface of the lower frame. , An upper frame having a second vertical guide surface directly above the spindle, a headstock moving positioning means provided directly below the center of the spindle, and a moving means directly above the center of the spindle along the second vertical guide surface. Positioned by Turret and a turret that is symmetrical to the left and right so that the cutting position is on a vertical plane that passes through the center of the spindle. A machine tool characterized by being configured symmetrically. 2. The machine tool according to claim 1, wherein the moving stroke of the headstock has both regions of a machining stroke and a work conveying stroke at a position advanced from the machining stroke.