JP7403872B2 - Machine Tools - Google Patents

Description

The present invention relates to a machine tool.

A general machine tool has a so-called four-point support system in which the bed is supported at four locations at its four corners relative to an installation surface such as a floor surface. With such four-point support, it is difficult to support all four points with equal force against the installation surface, and it takes time and effort to adjust the height.

In order to deal with this problem, a configuration has been proposed as a machine tool disclosed in Patent Document 1, in which a bed can be supported at three points on an installation surface such as a floor surface. The machine tool of Patent Document 1 has support points for the installation surface provided at three locations on the bottom surface of a simple box-shaped bed.

Japanese Patent Application Publication No. 2005-131768

An object of the present invention is to provide a machine tool that can adjust the degree of curvature of a bed.

In order to achieve the above object, in the present invention , a table running section extending in one direction, through which a table capable of supporting a workpiece runs, is provided at the front part of the bed, and the table is provided at the front lower part of the bed. Adjustment means is provided for adjusting the degree of curvature of the bed along the length direction of the running section.

Therefore, according to the present invention, the degree of curvature of the bed can be adjusted. Therefore, the degree of deformation and the inclination angle of the table traveling portion with respect to the horizontal plane can be easily finely adjusted using the adjusting member.

According to the present invention, the degree of curvature of the bed can be adjusted.

FIG. 1 is a perspective view of the machine tool of the first embodiment seen from above. FIG. 2 is an exploded perspective view of the machine tool shown in FIG. 1; FIG. 2 is a perspective view of the machine tool shown in FIG. 1 viewed from below. FIG. 2 is a front view of the machine tool shown in FIG. 1; FIG. 2 is a side view of the machine tool in FIG. 1; 5 is a sectional view taken along line 6-6 in FIG. 4. FIG. FIG. 6 is a sectional view taken along line 7-7 in FIG. 5; FIG. 3 is a partial cross-sectional view of a machine tool according to a second embodiment. A partial cross-sectional view similarly shown in a different section.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described based on the drawings.
As shown in FIGS. 1 and 2, the machine tool of the first embodiment includes a bed body 11 of a bed 10, and a table 12 supported movably in the X-axis direction (horizontal direction) at the front of the bed body 11. It is equipped with The machine tool also includes a pair of support members 14 fixed to both sides of the upper surface of the bed body 11, and a processing unit 15 supported movably in the Z-axis direction (back and forth direction) on the support members 14. There is. The support member 14 constitutes a part of the bed 10. The processing unit 15 includes a rotary grindstone 16 that is movable in the Y-axis direction (vertical direction). Then, the workpiece is supported on the table 12, the table 12 is moved in the X-axis direction, and the rotary grindstone 16 is moved in the Z-axis direction and the X-axis direction. Processing is performed.

Therefore, the configuration of each part will be explained in detail below.
First, the bed body 11 and its related configuration will be explained.
As shown in FIGS. 1 to 3, the bed body 11 is integrally formed as a whole by casting, and includes a bottom plate portion 20 having a substantially triangular shape, a lower side plate portion 21 as a pair of hypotenuse portions having a substantially triangular shape, and a substantially triangular side plate portion 21. A pair of upper side plate parts 22, a front plate part 23, and a rear plate part 24 are provided. A horizontal upper plate part 25 is formed at the upper ends of both upper side plate parts 22, and an upright plate part 26 is formed at the front surface of both upper side plate parts 22. As shown in FIG. 6, an inner plate part 27 is formed on the rear side of the front plate part 23. As shown in FIG. 1, an open portion 28 is formed on the upper surface of the bed body 11 between the upper plate portions 25. As shown in FIG.

As shown in FIG. 3, the bottom plate portion 20 is formed into a triangular shape by forming a lower side plate portion 21 as the oblique side portion. Therefore, in the bottom plate part 20, two triangular apexes are formed on the front side, one triangular apex is formed on the rear side, and the two apexes on the front side serve as legs. A front leg 31 is provided, and a rear leg 32 as a leg is provided at the apex of the rear side. The pair of front legs 31 are located on one line in the X-axis direction, and the rear legs 32 are located on a line in the Z-axis direction passing through the center between both front legs 31. As shown in FIG. 5, the front leg 31 includes a fixed cam body 34 having a slope 33 and a leg member 35 that is movable up and down. A movable cam body 37 is provided. The leg member 35 is prevented from coming off the fixed cam body 34 by regulating portions 39 at the front and rear thereof. The leg members 35 are installed on an installation surface such as a floor surface. Then, due to the screw action based on the rotation of the adjustment screw 38, the slope 36 of the movable cam body 37 slides against the slope 33 of the fixed cam body 34, and the leg member 35 is moved up and down by the cam action. As a result, the height of the front leg 31 is adjusted. The height of the rear leg 32 is fixed.

As shown in FIGS. 3, 5, and 6, the rear plate portion 24 is inclined such that the lower side recedes toward the front. A rear end corner portion of the bottom plate portion 20 projects rearward from the rear plate portion 24, and the rear legs 32 are disposed at the projecting portion. A pair of reinforcing ribs 41 are integrally formed between the rear end corner portion of the bottom plate portion 20 and the outer surface of the rear plate portion 24 as a reinforcing portion. Both reinforcing ribs 41 are formed in a triangular shape on the side, are inclined downward so as to approach each other and converge, and are integrated at the rear leg 32 portion. The rear end portion 29 of the lower side plate portion 21 extends to the lower end portion of the reinforcing rib 41.

As shown in FIGS. 1, 2, and 5, in front of the upright plate section 26, between the front ends of both upper side plate sections 22 is a gutter-shaped table extending in the X-axis direction with its upper surface and both end surfaces open. A running section 43 is formed, and both front legs 31 are located below the widthwise center of both ends of the table running section 43. Both ends of the table traveling section 43 are closed by end members 44. A first guide rail 45 is fixed to the front and rear openings of the table traveling section 43 between the both end members 44, and the table 12 is supported so as to be slidable in the X-axis direction while being guided by the first guide rail 45. There is. The table 12 is moved in the X-axis direction by a linear motor (not shown).

As shown in FIGS. 1, 2, and 5, support members 14 located on both sides of the open portion 28 are fixed to the upper surface of both upper plate portions 25 by a plurality of bolts 13, respectively. An overhang portion 51 that protrudes forward is formed at the upper front end of both support members 14 . Second guide rails 52 extending in the Z-axis direction are attached to the upper surfaces of the support members 14, respectively. The second guide rail 52 extends over the entire length of the support member 14 in the Z-axis direction, including the overhang portion 51.

As shown in FIGS. 1 and 2, a unit frame 61 serving as a support means for the processing unit 15 located in the open portion 28 is disposed between the second guide rails 52 so as to be movable in the Z-axis direction. has been done. This unit frame 61 includes a pair of sliders 62 supported by both the second guide rails 52 and a square frame-shaped support frame 63 installed and fixed between the sliders 62, and an inner surface of the support frame 63. A third guide rail 65 is attached to the. The support frame 63 is reciprocated along the second guide rail 52 along the second guide rail 52 in the Z-axis direction together with the slider 62 by driving the linear motor 66 . A side bulging portion 67 that bulges outward in an arc shape is integrally formed on the outer surface of the slider 62 as a curved portion. A plurality of reinforcing ribs 68 are integrally formed on the inner surface of the support frame 63, and a pair of rear bulges 69 that bulge out in an arc shape are integrally formed on the rear surface.

As shown in FIGS. 1, 2, and 6, within the support frame 63, an elevating frame 71 is supported by the third guide rail 65 so as to be movable up and down. A ball screw 73 rotated by the drive of a motor 72 is supported on the unit frame 61 in the Y-axis direction, and the elevating frame 71 is raised and lowered by the forward and reverse rotation of the ball screw 73. A grindstone shaft unit 74 as a machining shaft unit is supported on the elevating frame 71, and a grindstone shaft 76 rotated by a motor 75 is supported on this grindstone shaft unit 74. The rotating grindstone 16 located in front of the overhang portion 51 is supported at the front end of the grindstone shaft 76 .

In this embodiment, the processing unit 15 is constituted by a unit frame 61 supported by the third guide rail 65, an elevating frame 71, a grindstone shaft unit 74, and the like. As shown in FIG. 6, in a state where the processing unit 15 is supported by the second guide rail 52, the center of gravity α of the processing unit 15 is located within the internal space of the bed body 11. Furthermore, the center of gravity β of the machine tool of the embodiment is located lower than the center of gravity α of the processing unit 15.

As shown in FIGS. 3, 4, and 7, an arc-shaped recess 81 is formed on the lower surface of the bed body 11 directly below the central portion of the table running section 43 in the length direction and width direction, and an arcuate recess 81 is formed on both sides of the lower surface of the bed body 11. A pair of protrusions 82 are formed in the portion. A receiving member 83 is fixed to the lower surface of both convex portions 82, a female thread 84 is formed in this receiving member 83, and threaded portions at both ends of a male threaded member 85 are screwed into both female threads 84. Therefore, the female thread 84 and the male thread member 85 constitute a turnbuckle. A lock nut 87, which is a double nut for preventing loosening, is screwed into the threaded portion of the male threaded member 85. Therefore, by rotating the male threaded member 85, force acts on both receiving members 83 in the direction of approaching or separating them, and as a result, the bed main body 11 is deformed and the straightness of the first guide rail 45 is adjusted. .

The upper side plate part 22, the front plate part 23, the rear plate part 24, the inner plate part 27, and the table running part 43 are each provided with thinning plates of various shapes and sizes, such as a square, a circle, a triangle, a trapezoid, and a deformed square. A through hole 91 is provided as a part. A plurality of recesses 90 are formed on the lower surface of the bottom plate section 20.

As shown in FIGS. 6 and 7, between the front plate part 23 and the inner plate part 27, there is a plate-shaped first reinforcing frame 92 as a reinforcing part having a symmetrical shape in the X-axis direction of each pair. A second reinforcing frame 93 is integrally formed. The first reinforcing frame 92 and the second reinforcing frame 93 are intersected and integrated. A rectangular through hole 91 serving as a thinning portion is provided in the middle portion of the first reinforcing frame 92 and the second reinforcing frame 93 in the vertical direction. The first reinforcing frame 92 is interposed between the center portion of the lower surface of the table running portion 43 and the lower end of the intersection of the upper side plate portion 22 and the bottom plate portion 20 . Therefore, the front leg 31 and its surrounding area are reinforced by this intersection, and the first reinforcing frame 92 including this intersection and the second reinforcing frame 93 constitute a reinforcing portion. The second reinforcing frame 93 is interposed between the center portion of the lower surface of the table traveling portion 43 and the inner surface of the bottom plate portion 20 in the recessed portion 81 . The through holes 91 of the front plate portion 23 and the inner plate portion 27 are formed in a portion excluding the first reinforcing frame 92 and the second reinforcing frame 93.

Next, the operation of the machine tool configured as above will be explained.
In the machine tool of this embodiment, a workpiece is supported on a table 12. Then, while the rotary whetstone 16 is being rotated, the elevating frame 71 is moved together with the rotary whetstone 16 in the Y-axis direction along the third guide rail 65, and the height is adjusted. Further, the table 12 is reciprocated in the X-axis direction along the first guide rail 45, and the grindstone shaft unit 74 is moved together with the rotary grindstone 16 in the Z-axis direction along the second guide rail 52. Therefore, the rotary grindstone 16 performs grinding on the workpiece.

The machine tool of this embodiment has the following effects.
(1) Front legs 31 and rear legs 32 are provided at a total of three locations on the bottom surface of the bottom plate portion 20 of the bed 10 of the machine tool. Therefore, the machine tool of this embodiment can be supported by three-point support on an installation surface such as a factory floor. In other words, the machine tool can be stably supported regardless of the flatness of the installation surface. In this case, the height of the leg member 35 of the front leg 31 can be adjusted by the cam action of the slopes 33 and 36 by operating the adjustment screw 38 of the front leg 31, and the levelness and height of the machine tool can be maintained appropriately. can. On the other hand, in the case of a bed with a four-point support configuration, it is troublesome to adjust the height of the legs, and if the adjustment is insufficient, the center of gravity may shift and the processing accuracy of the workpiece may deteriorate. In a three-point support configuration, such a fear does not occur.

(2) Since the bottom plate portion 20 of the bed body 11 is triangular, the bed body 11 can be made smaller compared to a conventional quadrangular machine tool supported at four points. Therefore, it is possible to reduce the weight of the machine tool. Therefore, in the embodiment, the bottom plate part 20 is formed into a substantially triangular shape, the lower side plate part 21 and the upper side plate part 22 are formed into a triangular shape, and the rear plate part 24 is inclined so as to recede forward toward the lower side. As a result, the volume of the bed body 11 is reduced, and the bed body 11 is further reduced in size and weight. In this way, since the bed body 11 can be downsized, the rigidity of the bed body 11 as a whole can be improved, and high machining accuracy for the workpiece can be obtained. In addition, since recesses 90 and through holes 91 are formed in various parts of the bed body 11 while satisfying the required strength, it is possible to further reduce the weight. Therefore, restrictions on the installation location of the machine tool are reduced, and movement and transportation become easier.

(3) The size of the bed body 11 is reduced to reduce the volume of the bed body 11, and the concave portions 90 and through holes 91 are formed in each part, so that the constituent materials of the bed body 11 can be reduced and the weight can be reduced. . Therefore, the natural frequency of the bed body 11 can be increased. Therefore, the resonant frequency of the bed body 11 becomes high, and the machining accuracy improves.

(4) A portion of the bed main body 11 excluding the table running portion 43 is formed narrower than the table running portion 43. Furthermore, the width of the bed main body 11 is narrowed so as to converge toward the rear due to the formation of the triangular lower side plate portion 21. Therefore, as described above, the bed body 11 can be made smaller and lighter, allowing high-precision machining, and since a space is formed below the lower side plate portion 21 of the bed body 11, this space can be Can be used for installing hydraulic piping and electrical wires.

(5) Since the front legs 31 are provided corresponding to both ends of the table running part 43, even if the bed main body 11 on the rear side of the table running part 43 is narrower than the table running part 43, the table Deformation of the running portion 43 can be suppressed, and high-precision machining becomes possible.

(6) Since the lower sides of the table running section 43 intersect together and are reinforced by the inclined first and second reinforcing frames 92 and 93, deformation of the table running section 43 can be suppressed as described above. , high-precision machining becomes possible. Further, the first and second reinforcing frames 92 and 93 are inclined, and the lower end of the first reinforcing frame 92 and the lower end position of the upper side plate portion 22 of the bed main body 11 are combined, and the front legs are attached to the combined part. 31 is located. Further, the second reinforcing frame 93 is converged and integrated at the lower center of the bed body 11. Therefore, the processing pressure acting on the table running section 43 acts on the first and second reinforcing frames 92 and 93 as a force in the direction of compression thereof, so that deformation of the table running section 43 can be effectively prevented.

(7) The rear legs 32 are located on a line in the Z-axis direction extending rearward from the longitudinal center of the table travel section 43. Therefore, since the rear leg 32 is located directly below the movement range of the unit frame 61 having the grindstone shaft unit 74, the movement of the unit frame 61 is stabilized, contributing to high precision machining of the workpiece.

(8) Since the slider 62 that supports the unit frame 61 on the second guide rail 52 is formed with a side bulge portion 67 that bulges out in the lateral direction, the support rigidity of the unit frame 61 is improved and the workpiece It can contribute to high precision machining.

(9) Since reinforcing ribs 68 are formed on the inside of the support frame 63 of the unit frame 61, and a rear bulge portion 69 that bulges rearward is formed on the rear side, the unit frame 61 is The support rigidity is improved, contributing to high-precision machining of workpieces.

(10) Since the unit frame 61 is supported by the second guide rail 52 via the sliders 62 on both sides thereof, the processing unit 15 is moved into the internal space of the bed body 11 through the open portion 28 at the upper end of the bed body 11. It is located in Therefore, the machining unit 15 forming the upper end portion of the machine tool can be placed at a lower position, and the height of the entire machine tool can be lowered. In addition, since the center of gravity α of the machining unit 15 can be located at a low position within the bed body 11, the height of the entire machine tool can be lowered, and the support rigidity of the machining unit 15 is increased. 15 vibration can be suppressed to improve the machining accuracy of the workpiece.

(11) Since the center of gravity β of the machine tool is located lower than the center of gravity α of the processing unit 15, good installation stability as a machine tool can be obtained. Therefore, it is possible to reduce the vibration of the entire machine tool and contribute to improving the machining accuracy of the workpiece.

(12) Since the front end of the support frame 63 protrudes forward to form the overhang portion 51, even when the grindstone shaft unit 74 is moved forward for machining the workpiece, the grindstone shaft 76 remains in a cantilevered state. It almost never happens. Therefore, even if the grindstone shaft 76 is moved forward by a large amount, the workpiece machining accuracy can be prevented from decreasing.

(13) The front plate portion 23 of the bed body 11 is inclined so as to recede rearward toward the lower side. Therefore, the lower limbs such as the toes of the worker located on the front side of the bed main body 11 are less likely to interfere with the front plate part 23, making it easier to work.

(14) Since the frame of the machine tool has a unit configuration including a plurality of members such as the bed body 11, the support member 14, the support frame 63, the slider 62, and the unit frame 61, it is easy to mold them. Further, by adjusting the positional relationship of the assembly of each member, the movement precision of the members moved in the X-axis, Y-axis, and Z-axis can be set to be accurate.

(15) Since the upper part of the rear leg 32 is reinforced by the reinforcing rib 41, the strength and rigidity of the rear leg 32 can be ensured even if the lower part of the rear plate part 24 is inclined forward.
(16) A turnbuckle-shaped adjustment member 86 is provided at the center of the lower part of the front end of the bed body 11. Then, by loosening the lock nut 87 and rotating the adjustment member 86, the degree of curvature around the center of the front lower part of the bed body 11 can be adjusted by the action of the screw. Therefore, the degree of deformation and the inclination angle of the table traveling portion 43 with respect to the horizontal plane can be easily finely adjusted by the adjusting member 86, and the movement accuracy of the table 12 can be improved, which in turn can improve the processing accuracy of the workpiece.

(17) Since the recesses 90 and through holes 91 are formed in each part of the bed body 11, air can smoothly circulate between the inside and outside of the machine tool through the recesses 90 and through holes 91. Therefore, the temperature difference between the inside and outside of the machine tool can be suppressed, the temperature distortion can be reduced, and the machining accuracy of the workpiece can be improved. Furthermore, since it becomes possible to check, inspect, and clean the internal condition of the machine tool through the through hole 91, maintainability can be improved.

(Second embodiment)
Next, a second embodiment of the present invention will be described, focusing on the differences from the first embodiment.
As shown in FIGS. 8 and 9, a pair of fixed wedge members 95 each having a slope 96 is fixed to both sides of the recess 81 at the lower center of the bed body 11. An adjustment screw 97 is rotatably supported on the bed body 11 at a fixed position. A movable wedge member 99 having slopes 98 on both sides is screwed into the adjustment screw 97 at its female thread 100. The slopes 98 on both sides of the movable wedge member 99 are in pressure contact with the slopes 96 of the fixed wedge member 95.

Therefore, when the adjustment screw 97 is rotated, the movable wedge member 99 moves in one direction or the other in the Z-axis direction due to the action of the screw, and due to the wedge action, the movable wedge member 99 moves against the fixed wedge member 95. 95 in the expansion direction or the opposite direction. Therefore, the amount of deflection of the bed body 11 is adjusted, and the straightness of the first guide rail 45 is adjusted.

(Example of change)
The present invention is not limited to the first and second embodiments, but can be embodied in the following manner.

- Changing the installation position of the turnbuckle-shaped adjustment member 86 to, for example, the rear side of the bed body 11.
- Changing the number of turnbuckle-shaped adjustment members 86 installed. For example, in addition to the center position in the front lower part of the bed body 11, it may also be provided at the rear position or both sides of the lower part of the bed body 11. Alternatively, it may be provided at an intermediate position in the vertical direction of the bed body 11 or at an upper position.

- In the above embodiment, a rotating grindstone was provided as a tool, but instead of the rotating grindstone, another type of tool such as a drill, a milling cutter, an end mill, a hob, etc. may be provided.
- Omit one of the recess 90 and the through hole 91 as the thinned part.

- The lower side plate part 21 as the oblique side part is omitted, and the upper side plate part 22 is formed into an inclined shape that recedes toward the lower side, similar to the lower side plate part 21 of the embodiment, so as to constitute the oblique side part.
- Integrating the bed body 11 and the support member 14.

- As an adjustment means for adjusting the amount of deformation of the bed body 11, a pair of male screws are provided protruding from the bed body 11 on the same axis, and a nut-shaped female screw is screwed into both the male screws between the two male screws. The female screws should be provided so that the female screws bring the two male screws closer to each other and separate them.

(Other technical ideas)
The technical ideas understood from the embodiment and modified examples are listed below.
(A) At the top of the front part of the bed, there is a table running part on which a table that can support a work is run, and at three places on the bottom of the bed, there are legs for installing the bed. A machine tool in which a pair of legs are arranged at both ends in the length direction of a table running part, and the length of the table running part is longer than the width of the bed on the rear side of the table running part.

With the above configuration, the bed can be made smaller.
(B) The machine tool according to the technical concept (A), wherein the leg portion on the rear side is arranged behind the center in the length direction of the table traveling portion.

With the above configuration, the machine tool can be stably installed on an installation surface such as a floor.
(C) An adjusting means is provided in a part of the bed, and includes a pair of female threaded portions facing each other on the same axis, and an adjusting member in which male screws provided at both ends of the operating portion are screwed into the female threaded portions. Machine tools installed.

With this configuration, the bed can be deformed by the adjustment means to adjust the levelness, straightness, etc. of the movement range of the table. Note that this configuration is also applicable to machine tools with other configurations than the embodiment, such as four-point support for the legs.

(D) A part of the bed is provided with a fixed wedge member and a movable wedge member that engages with the fixed wedge member, and the degree of deformation of the bed is adjusted by the wedge action of both the wedge members. The machine tool described in technical concept (C).

With this configuration, the horizontality, straightness, etc. of the movement range of the table can be adjusted by the wedge action of both wedge members.
(E) A machine tool in which a table running section extending in one direction is provided in the front part of the bed, and the adjusting means is arranged corresponding to the center of the table running section in the length direction.

With this configuration, it is possible to accurately adjust the levelness, straightness, etc. of the table traveling section.
The technical field, background art, problem to be solved by the invention, means for solving the problem, and effects at the time of the division are as follows.
The present invention relates to a machine tool in which a bed can be supported at three points on an installation surface such as a floor.
A general machine tool has a so-called four-point support system in which the bed is supported at four locations at its four corners relative to an installation surface such as a floor surface. With such four-point support, it is difficult to support all four points with equal force against the installation surface, and it takes time and effort to adjust the height.
In order to deal with this problem, a configuration has been proposed as a machine tool disclosed in Patent Document 1, in which a bed can be supported at three points on an installation surface such as a floor surface. The machine tool of Patent Document 1 has support points for the installation surface provided at three locations on the bottom surface of a simple box-shaped bed.
In the machine tool described in Patent Document 1, the bed has a simple box shape even if it is supported at three points. Since the bed must be constructed by casting to ensure sufficient strength and stability, it is not only difficult to avoid a large weight, but also the rigidity of the entire bed is reduced. This decrease in rigidity leads to a decrease in machining accuracy for the workpiece. A box-shaped bed like this tends to become unstable if it is supported at three points. Further, since the bed has a large volume and a large weight, the natural frequency becomes low, resulting in a low resonance frequency that adversely affects machining accuracy. As described above, when the resonance frequency decreases, the amplitude of vibration increases, leading to a decrease in processing accuracy.
SUMMARY OF THE INVENTION An object of the present invention is to provide a machine tool in which machining accuracy for a workpiece can be improved by using a bed with a three-point support configuration.
In order to achieve the above object, the present invention includes legs for installing the bed at three locations on the bottom of the bed, and the bed has an oblique side to make the bottom of the bed triangular. It is characterized by the fact that it has been formed.
Therefore, according to the present invention, the machine tool can be supported on an installation surface such as a factory floor by three-point support. Therefore, the machine tool can be stably supported regardless of the flatness of the installation surface. Furthermore, since the bottom surface of the bed is formed in a triangular shape, the bed can be made smaller and lighter than conventional machine tools with four-point support. Since the bed can be made smaller in this way, the rigidity of the bed is improved, making it possible to increase the accuracy of machining the workpiece. Furthermore, since the bed can be made smaller, there are fewer restrictions on where the machine tool can be installed, and the machine tool can be easily moved and transported. By reducing the weight of the bed, the natural frequency of the bed can be increased. Therefore, the resonant frequency of the bed becomes high, and the processing accuracy improves.
According to the present invention, it is possible to improve the machining accuracy of a workpiece by using a bed having a three-point support structure.

DESCRIPTION OF SYMBOLS 10... Bed, 11... Bed main body, 12... Table, 14... Support member, 15... Processing unit, 16... Rotary grindstone, 20... Bottom plate part 20... Lower side plate part, 22... Upper side plate part, 23... Front plate part, 24... Rear plate part, 25... Upper plate part, 26... Standing plate part, 27... Inner plate part, 28... Opening part, 31... Front leg, 32... Rear leg, 43... Table running part, 51... Overhang Part, 61... Unit frame, 67... Side expansion part, 68... Reinforcement rib, 69... Rear expansion part, 73... Ball screw, 74... Grindstone shaft unit, 77... Rotary grindstone, 84... Female thread, 85... Male thread member, 86... Adjustment member, 91... Through hole, 92... First reinforcing frame, 93... Second reinforcing frame.

Claims (2)

A table running part extending in one direction in which a table capable of supporting a workpiece runs is provided at the front part of the bed, and the degree of curvature of the bed is provided at the front lower part of the bed along the length direction of the table running part. provided with an adjustment means for adjusting the
The adjusting means includes a pair of female threaded parts facing each other on the same axis, and an adjusting member in which male threads provided at both ends of the operating part are screwed into the female threaded parts. 2. The machine tool according to claim 1 , wherein the adjusting means is disposed at the center of the lower side of the table traveling section in the length direction.