Horizontal feed gear and milling machine using the same

Abstract

To provide a horizontal feed gear and a milling device using the same which can prevent a processing table from tilting to a machine tool body on receiving torque of a feed screw.SOLUTION: A horizontal feed device 2 provided between a support part 11 on the side of a machine tool body 1 and a processing table 12 for fixing a workpiece 8, comprises: a drive unit 3 provided in the support part 11; and a follower unit 6 provided in the processing table 12. The drive unit 3 has: two or more horizontal feed screw parts 4 rotatably supported by the support part 11; and a rotary drive source 5 for feeding and driving each feed screw part 4. The two or more feed screw parts 4 are arranged by the same number on line symmetry from a boundary of a horizontal line HL1 passing through a gravity center 12a of the processing table 12, making either one side of the horizontal line HL1 a right screw, and the other side a left screw. The follower unit 6 is integrated with the processing table 12 to be made the follower female screw part 6 of the right screw or the left screw screwing with each feed screw part 4 at least one by one.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a horizontal feed device that moves a processing table such as a table or saddle of a machine tool such as a machine tool or a mother machine relative to a spindle on which a cutting tool is attached, and in particular to a milling machine utilizing the same. [Background technology]

[0002] Conventionally, when a horizontal feed screw installed between a support part on the machine tool body, such as a knee or saddle, and a machining table, such as a saddle or table, rotates, the machining table, which receives the rotational force of the horizontal feed screw, tilts slightly, deteriorating the machining accuracy.

[0003] As shown in Figures 6(A) and (B), for example, the horizontal feed device 7 provided between the saddle 11b (support part 11) and the table 12b (the processing table 12) has a pair of horizontal feed screws 70 on the left and right so that the amount of movement in the front-rear direction (direction of the two-dot chain line arrow) relative to the feed amount is equal at the left and right ends. For example, as shown in Figure 6(B), if the left and right horizontal feed screws 70 are rotated clockwise as viewed from the front at the same rotation direction and speed, the rotation torque of each horizontal feed screw 70 tilts the table 12b in the rotation direction (direction of the solid line arrow), deteriorating the processing accuracy of the workpiece 8. In Figure 6(B), HL indicates a horizontal line and VL indicates a vertical line.

[0004] For example, Patent Document 1 (JP Patent Publication 7-40163 A) discloses a table transport device and a control method thereof in which a table is supported on a base via a linear guide section so that it can be freely moved, and a pair of drive mechanisms are provided on the left and right sides of the table between the table and the base for driving the table relative to the base, and by driving this pair of drive mechanisms independently to provide a difference in the feed amount on the left and right sides of the table, it is possible to adjust the left and right inclination with respect to the direction of movement of the table and correct any misalignment on the left and right sides of the table.

[0005] Furthermore, Patent Document 2 (JP Patent Publication No. 10-180593) discloses a machine tool configured to drive a movable body arranged on a fixed part such as a column in the directions of a first axis and a second axis, in which two first-axis driving means are arranged parallel to each other on the fixed part, a movable base driven in the first axis direction by the first-axis driving means is provided on the fixed part, a second-axis driving means is arranged on the movable base, the movable body is driven in the second axis direction by the second-axis driving means, a control device is provided for controlling each driving means, and the control device is configured to correct the zero setting of the driving means to correct the angular error of the first and second axes and the attitude of the movable body, thereby easily correcting the angular error of the two driving systems and the attitude of the movable body.

[0006] Patent Document 3 (JP Patent Publication No. 06-055587) shows a movable body drive mechanism in which a movable body is mounted via ball nuts on an even number of ball screws supported in parallel, and a drive device for the ball nuts or ball screws is provided, in which half of the ball screws are configured as right-handed threads and the other half are left-handed threads, and the direction of rotation of the ball nuts or ball screws by the drive device is opposite on the right-handed thread side and the left-handed thread side. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 7-40163 [Patent Document 2] Japanese Patent Application Publication No. 10-180593 [Patent Document 3] Japanese Patent Application Publication No. 06-055587 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the table transfer device of Patent Document 1, in order to provide a difference in the feed amount between the left and right, it is necessary to drive the pair of left and right drive mechanisms independently, and a sensor for detecting the left and right positions of the table and a control device for individually controlling the left and right drive mechanisms are required. As shown in Fig. 6(B), the drawback that the table 12b tilts due to the torque of the feed screw 70 cannot be eliminated.

[0009] In addition, the machine tool of Patent Document 2 has two first-axis drive means between the fixed part and the movable base, and two platform two-axis drive means between the movable base and the movable body, and has a control device to control each of them. However, this does not eliminate the drawback that each of the movable base and the movable body tilts due to the torque of the feed screw 70, as shown in Figure 6 (B).

[0010] Furthermore, in the movable body drive mechanism of Patent Document 3, the direction of rotation of the ball nut or ball screw by the drive device is opposite on the right-hand and left-hand screw sides, making it possible to simultaneously move the movable body in the same direction using the ball screw on the right-hand screw side and the ball screw on the left-hand screw side. However, since this mechanism is based on an injection unit in an injection molding device and its only purpose is to prevent the movable body from twisting and deterioration of accuracy, it does not solve the problem of tilt and distortion of the processing table.

[0011] In view of the above-described situation, one of the objectives of the present invention is to provide a horizontal feed device that can prevent the machining table from tilting or warping relative to the spindle (spindle head) of the machine tool body when subjected to the torque of the feed screw, and a horizontal feed device for a milling machine or the like that utilizes the same. Furthermore, adjusting the perpendicularity of the left-right movement direction of the table and the front-back movement direction of the saddle requires skilled parts machining skills and a great deal of work load and time. Another object of the present invention is to provide a horizontal feed device for a milling machine or the like that can solve this problem. Furthermore, in the past, the position of the feed screw for moving the saddle back and forth was offset from the center of the knee from side to side, which resulted in a deterioration in parallelism between the left and right movement direction of the table and the front surface of the column when the saddle moved back and forth. Another objective of the present invention is to provide a horizontal feed device for a milling machine or the like that solves this problem. A further object of the present invention is to provide a horizontal feed device for a milling machine or the like that can solve the problem of deterioration of the perpendicularity between the table top surface and the knee up and down movement direction due to the torsional torque of the saddle forward / backward movement feed screw. [Means for solving the problem]

[0012] The present invention provides a horizontal feed device that enables a work table to be moved and fed while maintaining a horizontal and vertical attitude with high precision relative to a machine tool body. The present invention relates to a horizontal feed device that is provided between a support part on a machine tool body and a processing table for fixing a workpiece mounted on the support part, and drives the processing table in a horizontal direction relative to the support part, the horizontal feed device comprising a drive unit provided on the support part and a driven unit provided on the processing table, the drive unit having two or more parallel feed screw parts rotatably supported on the support part, and a rotary drive source for feeding and driving each of the feed screw parts, the two or more feed screw parts being arranged in equal numbers and symmetrically about a horizontal line passing through the center of gravity of the processing table, one side of the horizontal line being a right-handed thread and the other side being a left-handed thread, and the driven unit being a right-handed or left-handed driven female screw part that is integrated with the processing table and screws into at least one of the feed screw parts.

[0013] The present invention also provides a horizontal feed device for a milling machine or the like in which the number of feed screws in the saddle forward / backward movement drive device is two and the feed screws are supported symmetrically in parallel to the center of the knee.The perpendicularity between the left / right movement direction of the table and the forward / backward movement direction of the saddle can be adjusted by providing a difference in the position of one feed screw nut from the other.The present invention also provides a horizontal feed device for a milling machine or the like in which the number of feed screws in the saddle forward / backward movement drive device is two, one feed screw is a right-handed screw and the other feed screw is a left-handed screw, and they rotate in opposite directions.

[0014] The machine tool is a device equipped with a feeder that mounts a workpiece and moves horizontally, and can be a device having a feeder. The machine tool includes a support provided on the main body and a processing table mounted on the support. The machine tool can be replaced with, for example, an inspection device, a projector, etc. The machine tool can be replaced with, for example, a grinding machine, a shaping machine, a drilling machine, or other machine tools. The machine tool can be replaced with, for example, a milling machine such as a vertical milling machine, a horizontal milling machine, a universal milling machine, a general-purpose milling machine, or an NC milling machine.

[0015] The machine tool may be equipped with, for example, a horizontal track device consisting of a dovetail groove, a dovetail, a shaft, a bush, etc., in addition to the horizontal feed device, which guides the processing table in the driven direction of the driven unit.

[0016] The support portion supports the processing table so as to be movable and fed in a horizontal direction. The support portion is provided closer to the main body of the machine tool than the processing table. The support portion has a drive unit. The support portion can be, for example, a knee or a saddle of a milling machine.

[0017] The workpiece is mounted or fixed on the processing table, and the processing table is moved horizontally relative to the support. The processing table has a follower unit. The processing table can be, for example, a saddle or a table of a milling machine.

[0018] The horizontal feed device drives and feeds the processing table in the horizontal direction relative to the support part. The horizontal feed device includes a drive unit provided on the support part and a driven unit provided on the processing table. The linear guide of the guide mechanism in the horizontal feed device may be a dovetail groove, a square groove, a linear guide, a slideway, a slide rail, a linear bush, a ball spline, a linear ball bush, a ball retainer for a ball guide, an oil-free bush, a metal bush, or a combination of these. The number of linear guides in the guide mechanism is one or more, and two or more may be provided. The feed screw may be a ball screw, a trapezoidal screw, or a combination of these.

[0019] The drive unit applies a horizontal driving force to the driven unit. The drive unit has two or more parallel feed screw units rotatably supported on the support unit, and a rotary drive source that feeds and drives each feed screw unit. The drive unit can be two or more horizontal feed screw units. The drive unit can be two or more front-rear feed screw units or left-right feed screw units. The two or more front-rear feed screw units are arranged symmetrically on the left and right sides of a horizontal line that passes through the center of gravity of the processing table in the front-rear direction, and one side of the horizontal line can be a right-handed thread and the other side can be a left-handed thread.

[0020] The two or more left and right feed screw units are arranged symmetrically with respect to a horizontal line passing through the center of gravity of the processing table in the left-right direction, with one side of the horizontal line being a right-handed thread and the other side being a left-handed thread. The two or more feed screw units can have, for example, the same diameter (nominal diameter) and pitch. The two or more feed screw units can have, for example, the same diameter (nominal diameter), pitch, outer diameter, and root diameter. The feed screw unit can be, for example, any of a multiple thread thread, a triangular thread, a trapezoidal thread, a square thread, a metric thread, a ball screw, and a sliding screw.

[0021] The rotary drive source drives each feed screw portion and the driven unit to feed forward and backward. The rotary drive source can be, for example, a feed motor (servo motor, stepping motor, induction motor, etc.) and gears that are driven and controlled according to input from a feed handle of the machine tool or a feed control device of an NC machine tool. The rotary drive source is, for example, connected to at least one end of each feed screw portion so as to transmit a driving force. The rotary drive source controls the rotation direction (clockwise or counterclockwise) according to whether the feed screw portion is right-handed or left-handed, so that the feed directions of the processing table and each driven female screw portion (driven unit) coincide with each other.

[0022] The rotary drive source is controlled, for example, so that each feed screw portion feeds the processing table and each driven female screw portion (driven unit) at a uniform speed. Even if the nominal diameter, pitch, etc. of each feed screw portion are different, the rotary drive source is controlled, for example, so that each feed screw portion feeds the processing table and each driven female screw portion (driven unit) at a uniform speed. For example, if the nominal diameter, pitch, etc. of each feed screw portion are different, the backlash between them can be offset to achieve more accurate feeding.

[0023] The driven unit receives a driving force from the drive unit to move the processing table in the horizontal direction. The driven unit can be a right-handed or left-handed driven female thread portion that is integrated with the processing table and is screwed into each feed screw portion at least one at a time. The driven female thread portion can have, for example, a diameter (nominal diameter) and pitch that match each of the feed screw portions. The driven female thread portion can have, for example, a diameter (nominal diameter), pitch, outer diameter, and root diameter that match each of the feed screw portions.

[0024] The driven female thread portion may be arranged at intervals relative to one feed screw portion, and the intervals may be enlarged or reduced by a dimension corresponding to backlash relative to the one feed screw portion. The driven female thread portion may be machined so that the pitch of the roots of the female thread is enlarged or reduced by a dimension corresponding to backlash relative to the pitch of the crests of the feed screw portion.

[0025] The present invention relates to the horizontal feed device, in which the driven female thread portions are arranged in equal numbers on the front-rear and left-right sides and symmetrically with respect to each horizontal line passing through the center of gravity of the processing table from left to right and from front to back.

[0026] The driven female thread portions are, for example, arranged in an equal number in the front-rear and left-right directions in line symmetry with respect to each horizontal line passing through the center of gravity of the processing table from left to right and from front to back, and the driven female thread portions arranged in symmetrical positions from left to right or from front to back can have the same diameter (nominal diameter) and pitch. The driven female thread portions are, for example, arranged in an equal number in the front-rear and left-right directions in line symmetry with respect to each horizontal line passing through the center of gravity of the processing table from left to right and from front to back, and the driven female thread portions arranged in symmetrical positions from left to right or from front to back can have the same thread length.

[0027] The present invention provides a milling machine utilizing a horizontal feed device that enables the processing table to be moved while maintaining a highly accurate horizontal and vertical attitude relative to the machine tool body. The present invention relates to a milling machine that utilizes the horizontal feed device in which the support portion is a knee, the machining table is a saddle, the feed screw portion is a front-to-rear feed screw portion whose axis faces in the front-to-rear direction, and the two or more front-to-rear feed screw portions are arranged symmetrically on the left and right sides of a horizontal line that passes through the center of gravity of the machining table in the front-to-rear direction, with one side of the horizontal line being a right-handed thread and the other side being a left-handed thread.

[0028] The horizontal feed device feeds and moves the saddle in the front-rear direction relative to the knee. When the saddle is fed in the front-rear direction, the horizontal feed device causes the right-handed and left-handed threads arranged symmetrically on the left and right to cancel each other's rotational moments, preventing the saddle from tilting around the axis in the front-rear direction (left-right direction).

[0029] The present invention relates to a milling machine that utilizes the horizontal feed device in which the support portion is a saddle, the machining table is a table, and the feed screw portion is a left-right feed screw portion whose axis faces in the left-right direction, and the two or more left-right feed screw portions are arranged symmetrically in equal numbers front and back with respect to a horizontal line passing through the center of gravity of the machining table in the left-right direction, and one side of the horizontal line is a right-handed thread and the other side is a left-handed thread.

[0030] The horizontal feed device feeds and moves the table in the left-right direction relative to the saddle. When the table is fed in the left-right direction, the horizontal feed device causes the right-handed and left-handed screws arranged symmetrically in the front and rear to cancel each other's rotational moments, preventing the table from tilting around the left-right axis (in the front-rear direction).

[0031] The present invention can be a horizontal feed device or a milling machine utilizing the same, in which a plurality of the driven female thread portions are arranged at intervals relative to a single feed screw portion, and the arrangement interval is expanded or reduced by a dimension equivalent to backlash relative to the single feed screw portion.

[0032] The plurality of driven female thread portions are arranged at intervals with respect to the one feed screw portion, and the arrangement interval is enlarged or reduced by a dimension corresponding to the backlash with respect to the one feed screw portion, so that the feed amount of each feed screw portion can be controlled with higher precision. The adjustment of the position of the driven female thread portion can be an adjustment of a fixed position of the feed screw portion in the feed direction with respect to the work table.

[0033] The present invention can be a horizontal feed device or a milling machine utilizing the same, in which the driven female thread portion is machined so that the pitch of the valleys of the female thread is increased or decreased by a dimension equivalent to backlash relative to the pitch of the crests of the feed screw portion.

[0034] The driven female thread portion may be machined to a shape in which the pitch of the valleys of the female thread is changed in the thread length direction by a dimension corresponding to the backlash. The driven female thread portion may be machined to a shape in which the pitch of the valleys of a part of the thread length of the female thread matches the pitch of the crests of the feed screw portion, and the pitch of the valleys of the valleys of another part of the thread length of the female thread is changed by a dimension corresponding to the backlash relative to the pitch of the crests of the feed screw portion.

[0035] In order to solve the problems of table distortion, deformation, or tilt, the present invention provides a horizontal feed device using a linear motor for the drive unit. That is, the horizontal feed device is provided between a support part on the machine tool body and a processing table for fixing a workpiece mounted on the support part, and drives the processing table in a horizontal direction relative to the support part, and is characterized in that the horizontal feed device includes a drive unit provided on the support part and a driven unit provided on the processing table, the drive unit being constituted by a linear motor. This horizontal feed device can also solve the problems of table distortion, deformation, or tilt caused by the rotation torque of the feed screw. Effect of the Invention

[0036] According to the present invention, it is possible to provide an excellent effect of providing a horizontal feed device that can prevent the machining table from tilting or distorting relative to the machine tool body due to the torque of the feed screw and support the postures of the machining table and workpiece with higher precision, and a milling machine utilizing the same.

[0037] According to the present invention, the perpendicularity adjustment between the table left-right movement direction and the saddle front-back movement direction can be achieved by providing a difference in the position of the saddle front-back movement feed screw nut, which eliminates the need for skilled part processing skills and a large workload and work time, making it possible to provide a milling machine that is inexpensive and can be delivered in a short time. Furthermore, the number of feed screws in the saddle front-back movement drive device is set to two, and they are supported symmetrically in parallel to the left and right center of the knee, which solves the problem of the parallelism between the table left-right movement direction and the front surface of the column deteriorating, and by making one of the feed screws a right-handed screw and the other a left-handed screw and rotating in opposite directions, the torsional torque can be offset, which solves the problem of the perpendicularity between the table top surface and the knee up-down movement direction deteriorating during the saddle front-back movement feed, thereby improving the processing quality. [Brief description of the drawings]

[0038] [Figure 1] 1A is a plan view showing the horizontal feed device of the present invention, and FIG. [Diagram 2] 1(A) is a side view showing a case where the feed screw unit is rotated in the opposite direction to that shown in FIG. 1(B), (B) is a side view showing the downward deflection of the work table with emphasis, and (C) is a side view showing the upward deflection of the work table with emphasis. [Diagram 3] 1A is a plan view showing a horizontal feed device having a plurality of feed screw portions, and FIG. 1B is a side view showing a horizontal feed device having a plurality of feed screw portions. [Figure 4] 1A is a perspective view showing a milling machine using the horizontal feed device of the present invention, and FIG. 1B is a plan view showing a milling machine using the horizontal feed device of the present invention. [Diagram 5] 1A is a front view of a milling machine using the horizontal feed device of the present invention, FIG. 1B is a right side view of a milling machine using the horizontal feed device of the present invention, and FIG. 1C is a left side view of a milling machine using the horizontal feed device of the present invention. [Figure 6] (A) is a plan view showing a conventional horizontal feed device, (B) is a side view showing the conventional horizontal feed device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Hereinafter, the horizontal feed device according to the present embodiment and the milling machine using the same will be specifically described with reference to the drawings. In particular, this embodiment is a knee-type vertical milling machine 1 using the horizontal feed device 2 of the present invention, but the present invention can also be applied to vertical milling machines, horizontal milling machines, universal milling machines, general-purpose milling machines, NC milling machines, grinding machines, shaping machines, drilling machines, and other machine tools, and horizontal feed devices used therein.

[0040] 4(A), (B) and 5(A)-(C), the knee-type vertical milling machine 1 has a column 10a rising from the rear of a base 10, a knee 11a, a saddle 11b and a table 12b mounted on an elevation device 10b erected on the front of the base 10, and a spindle head 10c extending vertically above the table 12b from the upper end of the column 10a. Between the knee 11a (supporting portion 11) and the saddle 11b (working table 12), and between the saddle 11b (supporting portion 11) and the table 12b (working table 12), there are horizontal feed devices 2 each having a number of feed screw portions 4 corresponding to the driving force.

[0041] An example of the horizontal feed device 2 provided between the saddle 11b (support portion 11) and the table 12b (work table 12) is shown below. 1(A) and (B), the horizontal feed device 2 is provided between a saddle 11b (support part 11) on the main body side of a knee-type vertical milling machine 1 as a machine tool main body 1 and a table 12b (machining table 12) mounted on the saddle 11b, and drives the table 12b in the horizontal left-right direction relative to the saddle 11b. The horizontal feed device 2 includes a drive unit 3 provided on the saddle 11b side and a driven unit 6 provided on the table 12b side.

[0042] The drive unit 3 has two parallel left and right feed screw parts 4 rotatably supported by the saddle 11b, and a rotary drive source 5 provided at one end of each left and right feed screw part 4 to feed and drive each left and right feed screw part 4. Both ends of each left and right feed screw part 4 are rotatably supported by bearing parts 11c provided on the saddle 11b. The two left and right feed screw parts 4 are arranged symmetrically with respect to a horizontal line HL1 passing through the center of gravity 12a of the table 12b in the left-right direction, and one side of the horizontal line HL1 in the left-right direction is a right-handed thread, and the other side is a left-handed thread. The driven unit 6 is integrated with the table 12b and is a driven female screw part 6 with a right-handed thread or a left-handed thread that is screwed into each left and right feed screw part 4, at least one each.

[0043] 1(A), the two left and right feed screw units 4 have the same distance 4a from the horizontal line HL1. A horizontal track device (not shown) that is made of a dovetail groove, a dovetail, a shaft, and a bush and guides the feed screw units 4 in the front-rear direction is provided between the saddle 11b and the table 12b in addition to the horizontal feed device 2.

[0044] As shown in Figures 1(B) and 2(A), the left and right feed screw units 4, which are driven in reverse directions in front of and behind the left and right horizontal line HL1 by the rotary drive source 5, cancel out the rotational moments in the front and rear directions of the table 12b, prevent the table 12b from tilting in the front and rear directions, support the workpiece 8 on the table 12b in a vertical position, and achieve higher precision machining than ever before.

[0045] As shown in Fig. 2(B), even when the rotation of both the left and right feed screw units 4 generates a rotation moment that deforms the vicinity of the center of gravity 12a of the table 12b downward, the workpiece 8 does not tilt forward or backward but maintains a vertical posture, thereby achieving machining with higher accuracy than conventional methods. As shown in Fig. 2(C), even when the rotation of both the left and right feed screw units 4 generates a rotation moment that deforms the vicinity of the center of gravity 12a of the table 12b upward, the workpiece 8 does not tilt forward or backward but maintains a vertical posture, thereby achieving machining with higher accuracy than conventional methods.

[0046] Another example of the horizontal feed device 2 provided between the saddle 11b (support portion 11) and the table 12b (work table 12) will be described below. 3(A) and (B), the drive unit 3 of the horizontal feed device 2 has four parallel left and right feed screw sections 4 rotatably supported on a saddle 11b, and a rotary drive source 5 provided at one end of each left and right feed screw section 4 for feeding and driving each left and right feed screw section 4. Both ends of each left and right feed screw section 4 are rotatably supported by bearing sections 11c provided on the saddle 11b.

[0047] The four left and right feed screw sections 4 are arranged in a line symmetrical manner, two at a time, in front and two at a time, with respect to a horizontal line HL1 passing through the center of gravity 12a of the table 12b in the left-right direction, and one side of the horizontal line HL1 in the left-right direction is a right-handed thread, and the other side is a left-handed thread. The driven unit 6 is integrated with the table 12b and is a right-handed or left-handed driven female screw section 6 that is screwed into each of the left and right feed screw sections 4, at least one each.

[0048] 3(B), all the four left and right feed screw units 4 may be arranged on the same horizontal plane, or, for example, two pairs of left and right feed screw units 4 arranged symmetrically with respect to the horizontal line HL1 may be arranged on different horizontal planes located above and below each other. For example, the two left and right feed screw units 4 closer to the center of gravity 12a may be arranged on the lower horizontal plane, and the two left and right feed screw units 4 farther from the center of gravity 12a may be arranged on the upper horizontal plane.

[0049] The driven female screw portions 6 are provided, for example, at positions corresponding to the center of gravity 12a in the direction of the horizontal line HL1 of the left and right feed screw portions 4, one at the front and one at the rear, which are disposed near the center of gravity 12a of the table 12b. For example, the left and right feed screw portions 4, one at the front and one at the rear, which are disposed near the front and rear ends of the table 12b, are provided with two driven female screw portions 6 in total, one at each of the left and right ends of the table 12b of the left and right feed screw portions 4.

[0050] For example, the thread length 61 of one driven female thread portion 6 arranged near the center of gravity 12a of the table 12b, which is screwed into each left and right feed screw portion 4, is set to the same dimension as the sum of the thread lengths 60 of two driven female thread portions 6 arranged near the front and rear ends of the table 12b, respectively, thereby making the frictional resistance of each left and right feed screw portion 4 equal.

[0051] The driven female screw portion 6 is, for example, arranged symmetrically with respect to a horizontal line HL1 in the left-right direction passing through the center of gravity 12a of the table 12b, and is further arranged symmetrically with respect to a horizontal line HL2 in the front-rear direction passing through the center of gravity 12a, so that a uniform feed force is applied to the entire table 12b. As described above, a horizontal track device (not shown) is provided between the saddle 11b and the table 12b.

[0052] As shown in FIG. 3(A), the left and right feed screw units 4, which are driven in reverse relative to each other in front of and behind the left and right horizontal line HL1 by the rotary drive source 5, cancel out the rotational moments in the front and back directions of the table 12b, and as shown in FIG. 3(B), prevent the table 12b from tilting in the front and back direction (left and right direction in the figure), support the workpiece 8 on the table 12b in a vertical position, and achieve higher precision machining than ever before.

[0053] In the above embodiment, the left and right feed screw unit 4 is used, but a linear motor can be used instead of the feed screw. When a linear motor is used, it is possible to eliminate distortion or deformation of the table caused by the rotation torque of the feed screw. A horizontal feed device using such a linear motor is provided between a support part on the machine tool body and a processing table for fixing a workpiece mounted on the support part, and drives the processing table in a horizontal direction relative to the support part. The horizontal feed device includes a drive unit provided on the support part and a driven unit provided on the processing table, and the drive unit can be a horizontal feed device constituted by a linear motor. [Industrial Applicability]

[0054] The horizontal feed device of the present invention and the milling machine utilizing it can be a vertical milling machine, a horizontal milling machine, a universal milling machine, a general-purpose milling machine, an NC milling machine, a grinding machine, a shaping machine, a drilling machine, or other machine tools, or a feed device utilized in such machine tools. The horizontal feed device of the present invention can be used in measuring instruments, inspection machines, support devices, microscopes, projectors, exhibition devices, other stages, and the like. [Explanation of symbols]

[0055] 1 Milling Machine (machine tool book) 10 Same base 10a Same Column 10b Same lifting device 10c Same spindle head 11 Support part 11a Same knee 11b same saddle 11c Same bearing part 12 Same processing table 12a Center of gravity of the processing table 12 12b Same table HL1 Same Horizontal line in left and right direction HL2 Same Horizontal line in the front-back direction 2 Horizontal feed device 3 Drive unit 4 Feed screw section (front and rear feed screw section, left and right feed screw section, right screw, left screw) 4a Distance from horizontal line HL1 to feed screw 5 Rotational drive source 6 Follower female thread 60 The short thread length of the driven female thread portion 6 61 The long thread length of the driven female thread portion 6 7. Conventional horizontal feed device 70 Horizontal feed screw 8 Work VL same vertical line HL same horizontal line

Claims

1. A horizontal feed device is provided between a support part on a machine tool body side and a processing table for fixing a workpiece mounted on the support part, and drives the processing table in a horizontal direction relative to the support part, A drive unit provided on the support portion; A driven unit provided on the processing table; Equipped with The drive unit includes: The feed screw mechanism includes two or more parallel feed screw units rotatably supported on the support unit, and a rotation drive source that drives each of the feed screw units, The two or more feed screw units are arranged in equal numbers and symmetrically with respect to a horizontal line passing through the center of gravity of the processing table, and one side of the horizontal line is a right-handed thread and the other side is a left-handed thread, The horizontal feed device according to the present invention, wherein the driven unit is integrated with the processing table and is a driven female screw portion having a right-handed or left-handed screw that screws into at least one of the feed screw portions.

2. 2. The horizontal feed device according to claim 1, wherein the driven female thread portions are arranged symmetrically on each of horizontal lines passing through the center of gravity of the processing table from left to right and from front to back, with an equal number of driven female thread portions on both the front and rear sides.

3. The support part is knee-shaped. The processing table is a saddle, The feed screw portion is a front-rear feed screw portion having an axis oriented in the front-rear direction, The two or more front-rear feed screw units are arranged symmetrically on the left and right sides of a horizontal line passing through the center of gravity of the processing table in the front-rear direction, with one side of the horizontal line being a right-handed screw and the other side being a left-handed screw. A milling machine utilizing the horizontal feed device according to claim 1 or 2.

4. The support portion is a saddle, The processing table is a table, The feed screw portion is a left-right feed screw portion having an axis oriented in the left-right direction, The two or more left and right feed screw units are arranged symmetrically with respect to a horizontal line passing through the center of gravity of the processing table in the left-right direction, with one side of the horizontal line being a right-handed screw and the other side being a left-handed screw. A milling machine utilizing the horizontal feed device according to claim 1 or 2.

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