JP7501404B2 - Tool magazines and machine tools - Google Patents

Description

The present invention relates to a tool magazine and a machine tool.

Conventionally, machine tools are equipped with a spindle head that can move up and down, and a tool magazine (see, for example, Patent Document 1). The tool magazine has multiple movable bodies connected in an endless manner. Each movable body holds multiple gripping arms that hold tools. The tool magazine moves the multiple movable bodies along a circular rail that surrounds the spindle head, and positions a predetermined gripping arm below the spindle head. The spindle head descends, and the tool held by the gripping arm is attached to the spindle.

Machine tools hold a workpiece on a table and perform various processes such as milling and tapping by rotating the spindle head, which has tools attached, driven by a motor. The tools attached to the spindle head need to be changed depending on the type of machining being performed on the workpiece.

JP 2013-154436 A

As machining parts become more modular and machining processes become more consolidated, the number of tools used for one workpiece increases, and the number of gripping arms that hold the tools also increases. This causes the total number of moving bodies that hold the gripping arms to increase, or the overall length of the moving bodies to increase, resulting in larger tool magazines.

The objective of this disclosure is to provide a tool magazine and a machine tool equipped with a tool magazine that can increase the number of gripping arms while preventing the tool magazine from becoming too large.

A tool magazine according to one aspect of the present disclosure is a tool magazine in which multiple moving bodies connected endlessly via linear links move along a rail, and the moving bodies have multiple gripping arms for gripping tools arranged in a row at a predetermined interval, the predetermined interval being shorter than the length of the links.

In one embodiment of the present disclosure, the predetermined distance between the gripping arms held by each moving body of the tool magazine is shorter than the length of the link connecting the moving bodies in the arrangement direction of the gripping arms. This makes it possible to reduce the distance between the gripping arms within the moving body and prevent interference between the gripping arms of adjacent moving bodies on the movement path. This makes it possible to suppress an increase in the dimension of the gripping arms of the moving body in the arrangement direction and to increase the number of gripping arms provided in the tool magazine.

In one embodiment of the tool magazine disclosed herein, the rail has two first straight sections that face each other, two second straight sections that face each other in a direction perpendicular to the first straight sections, and a curved section that connects the ends of the first and second straight sections.

In one embodiment of the present disclosure, the rail is shaped like a rounded rectangle with curved corners, which makes the circumference of the rail (travel path distance) longer than an oval or elliptical shape with the same overall length and width. This prevents the tool magazine from becoming too large, and allows for a greater number of moving bodies that move along the rail and a greater number of gripping arms for the moving bodies. Because the distance between the gripping arms is shorter than the length of the link, even when the moving bodies are closest to each other near the connection between the first straight section or the second straight section and the curved section, the adjacent gripping arms can circulate smoothly without interfering with each other.

In one embodiment of the tool magazine disclosed herein, the gripping arm includes a pair of support rods having gripping portions at one end for gripping a tool, and a biasing member provided between the other ends of the support rods, and the biasing member biases each support rod in a direction in which the gripping portions of each support rod approach each other.

In one embodiment of the present disclosure, a gripping arm consisting of a pair of support rods has a biasing member between the other ends of the support rods, and grips a tool by the biasing force of the biasing member. Therefore, the length of the gripping section can be made shorter in a direction perpendicular to the longitudinal direction of the support rods than if a biasing member were provided inside the gripping section. As a result, the width of the gripping arm can be made shorter, and therefore a greater number of gripping arms can be arranged on the rail.

A machine tool according to one aspect of the present disclosure includes a tool magazine as described above and a spindle on which tools are attached, and the rail surrounds the spindle.

In one embodiment of the present disclosure, the same effect as the tool magazine described above is achieved.

In the tool magazine and machine tool according to one aspect of the present disclosure, the number of gripping arms can be increased while preventing the tool magazine from becoming too large.

FIG. FIG. FIG. 2 is a right side view of the machine tool with the chain portion and other parts omitted. FIG. FIG. 4 is a schematic perspective view of a tool magazine that moves along a rail portion. 6 is a cross-sectional view taken along line VI-VI shown in FIG. 5. FIG. 2 is a schematic perspective view of a moving body and a gripping arm. FIG. FIG. FIG. 2 is a simplified partially enlarged plan view of the machine tool; FIG. 4 is an explanatory diagram for explaining a rail shape and a circumferential length.

The present invention will be described below with reference to the drawings showing a machine tool according to an embodiment of the invention. In the following description, the directions up, down, front, back, left and right shown in the drawings will be used.

As shown in FIG. 1, the machine tool 100 includes a base 10, a spindle head 20, a tool magazine 30, etc.

The base 10 is rectangular and extends forward and backward. The workpiece holding unit 11 is provided on the upper front side of the base 10. The workpiece holding unit 11 holds the workpiece to be machined. The workpiece holding unit 11 can rotate around the C-axis extending vertically. The support table 12 is provided on the upper rear side of the base 10. An X-axis direction moving device 14 is provided on the upper surface of the support table 12. The X-axis direction moving device 14 can move left and right (X-axis direction). The Y-axis direction moving device 15 is provided on the upper part of the X-axis direction moving device 14. The Y-axis direction moving device 15 supports the column 13 so that it can move forward and backward (Y-axis direction). The Z-axis direction moving device 16 is provided on the front side of the column 13. The Z-axis direction moving device 16 moves the spindle head 20 up and down (Z-axis direction).

The spindle head 20 is equipped with a spindle 21 that extends vertically. The spindle 21 rotates around its axis. A tool is attached to the lower end of the spindle 21. A spindle motor 22 is provided at the upper end of the spindle head 20. The spindle 21 and the tool rotate with the rotation of the spindle motor 22. The rotating tool machines the workpiece held by the workpiece holding unit 11.

The tool magazine 30 will be described with reference to Figures 4 to 7. The tool magazine 30 includes a rail portion 31, a chain portion 32, and a magazine drive portion 33. The tool magazine 30 moves the chain portion 32 along the rail portion 31 by being driven by the magazine drive portion 33.

The rail section 31 comprises two support beams 311, a rail base 312, and a rail 313. The support beam 311 is a plate-like structural member in the shape of a right triangle. The hypotenuse of the support beam 311 is located on the upper side. The hypotenuse of the support beam 311 slopes downward as it approaches the front. The support beam 311 is fixed to the left and right sides of the column 13 in a cantilever manner. The support beam 311 extends from the parts fixed to the left and right sides of the column 13 to both side parts of the spindle head 20. The upper end surface of the support beam 311 is inclined approximately 30 degrees from the horizontal plane, from the lower front to the upper rear.

The rail base 312 is a rounded rectangular shape in plan view, and extends forward and backward. The rail base 312 is fixed to the hypotenuse of the support beam 311, and surrounds the column 13 and the spindle 21. The rail base 312 is inclined at approximately 30 degrees from the horizontal plane. A positioning mechanism 314 that aligns the positions of the tool and the spindle 21 is provided in the center of the front lower end of the rail base 312. The center of the lower end of the rail base 312 is located at the tool replacement position.

The rail 313 is provided on the top of the rail base 312 and forms an endless track. The rail 313 is a rounded rectangle in a plan view and has a substantially rectangular cross section. The rail 313 has two first straight portions 313a facing each other and two second straight portions 313b facing each other, and the ends of the first straight portions 313a and the second straight portions 313b are connected by a curved portion 313c. The two first straight portions 313a are provided in front of and behind the spindle head 20, respectively, and extend linearly in the left-right direction. The two second straight portions 313b are provided on the left and right sides of the spindle head 20, respectively, and extend linearly in the front-rear direction, i.e., in a direction perpendicular to the left-right direction. The rail base 312 and the rail 313 are arranged so that the first straight portion 313a is parallel to the direction perpendicular to the axial direction of the spindle 21, and the longitudinal center of the first straight portion 313a coincides with the axis of the spindle 21.

The mounting base 315 is provided on the inside rear of the rail base 312. The magazine drive unit 33 is attached to the upper side of the mounting base 315. The magazine drive unit 33 includes a motor 331 and a gear 332. The axis of the gear 332 is approximately perpendicular to the oblique side of the support beam 311. The gear 332 meshes with the chain portion 32. When the motor 331 rotates, the chain portion 32 and the multiple gripping arms 36 rotate.

A chain section 32 is provided along the rail 313. The chain section 32 includes a plurality of moving bodies 34, a plurality of links 35, and a plurality of gripping arms 36. The links 35 are elongated, approximately rectangular plates. In other words, the links 35 extend linearly. The links 35 connect adjacent moving bodies 34. The multiple moving bodies 34 and the links 35 form an endless chain.

6 and 7, the moving body 34 includes a base plate 341, two inner rollers 342, two outer rollers 343, two bearings 344, and two connecting shafts 345. The base plate 341 is a generally rectangular plate extending in the left-right direction when viewed from above. The two inner rollers 342 are provided on the rear long side of the lower surface of the base plate 341. The two inner rollers 342 are aligned in a row along the longitudinal direction, i.e., the left-right direction. The two outer rollers 343 are provided on the front long side of the lower surface of the base plate 341. The two outer rollers 343 are aligned in a row along the longitudinal direction. The rotation axes of the inner rollers 342 and the outer rollers 343 are perpendicular to the base plate 341.

Two connecting shafts 345 are provided at both ends of the upper surface of the base plate 341. The two connecting shafts 345 are aligned in a row in the left-right direction. The axis of the connecting shafts 345 is perpendicular to the upper surface of the base plate 341. As shown in FIG. 5, both ends of the link 35 in the longitudinal direction are rotatably connected to the adjacent moving body 34 via the connecting shafts 345. A bearing 344 is rotatably provided around the connecting shaft 345. The rotation axis of the bearing 344 is perpendicular to the upper surface of the base plate 341. Two gripping arms 36 are attached to both ends of the lower surface of the base plate 341. The two gripping arms 36 are aligned in a row at a predetermined interval in the left-right direction of the base plate 341.

As shown in FIG. 8, point A indicates the axis of the inner roller 342, point B indicates the axis of the outer roller 343, and point C indicates the axis of the connecting shaft body 345. The positions of the two points A in the front-to-rear direction coincide. The positions of the two points B in the front-to-rear direction coincide. The positions of the two points C in the front-to-rear direction coincide. The distance L1 between the axis centers of the inner rollers 342 is shorter than the distance L2 between the axis centers of the outer rollers 343.

As described below, the gripping arm 36 changes tools by pivoting the lower tip that grips the tool holder about the axis of the arm pivot 368. In one moving body 34, the axis direction of the arm pivot 368, the linear direction connecting the axes of the inner rollers 342, the linear direction connecting the axes of the outer rollers 343, and the linear direction connecting the axes of the connecting shaft bodies 345 are all parallel.

The lower surface of the substrate 341 is placed on the upper side of the rail 313. The inner roller 342 rotatably contacts the inner peripheral side surface of the rail 313. The outer roller 343 rotatably contacts the outer peripheral side surface of the rail 313. The bearing 344 of the substrate 341 meshes with the gear 332, and the moving body 34 moves along the rail 313 in conjunction with the rotation of the gear 332. The bearing 344 reduces friction and wear by meshing with the gear 332 and rotating. Since the bearing 344 is used as a meshing part with the gear 332, the diameter can be made larger than when a pin is used, and a larger load can be received. When a pin with a small diameter is used, many pins are required, but by using the bearing 344, the number of parts can be reduced, leading to a reduction in manufacturing costs. In addition, the distance L1 between the axis centers of the inner rollers 342 is shorter than the distance L2 between the axis centers of the outer rollers 343, so that rattling between each roller and the rail 313 that occurs in the straight and curved parts of the rail 313 is suppressed.

In the following explanation, the gripping arm 36 located at the front first straight portion 313a is used as an example, and the up, down, front, back, left and right directions shown in the figure are used. As shown in Figures 7 and 9, the gripping arm 36 has a mounting plate 361 that is attached to the aforementioned base plate 341. An extension portion 362 is provided at the bottom of the mounting plate 361. The extension portion 362 extends in the vertical direction, and the lower end portion is bent backward. A positioning pin 363 is provided midway up and down on the extension portion 362 to align the positions of the gripping arm 36 and the spindle head 20.

Two guide plates 365 that guide the swinging of a support rod 369 (described later) are fixed to the left and right sides of the lower end of the extension section 362. The two guide plates 365 face each other. In a side view, the guide plate 365 has a roughly triangular shape that widens downward from the upper end. The upper end of the guide plate 365 has an arm shaft hole 366 into which an arm shaft 368 (described later) is inserted.

Between the two guide plates 365, a support plate 367 is provided, which extends in a generally vertical direction. Two cam followers 364 are provided on the left and right rear sides of the upper part of the support plate 367. The lower end of the support plate 367 is curved so as to protrude rearward. The rear edge portion of the lower end is in a circular arc shape in plan view, recessed toward the front. An arm pivot 368 is fixed to the upper end of the support plate 367. Both ends of the arm pivot 368 are inserted into the arm shaft holes 366 of each guide plate 365 so that they can swing. The gripping arm 36 is attached to the moving body 34 so that the arm pivot 368 follows the track of the rail 313.

A groove X is formed on each of the left and right side surfaces of the lower end of the support plate 367. The groove X extends in the front-rear direction. A first support rod 369a and a second support rod 369b are inserted into each groove X. The first support rod 369a and the second support rod 369b form a pair of support rods 369. The first support rod 369a and the second support rod 369b extend in the front-rear direction. The front parts of the first support rod 369a and the second support rod 369b protrude forward from the groove X. The rear parts of the first support rod 369a and the second support rod 369b protrude rearward from the groove X. The mid-front-rear part of the first support rod 369a is connected to the rear of the support plate 367 via a pivot 369c whose axial direction is the up-down direction. The midpoint of the second support rod 369b in the front-to-rear direction is connected to the rear of the support plate 367 via a pivot 369d whose axial direction is in the up-down direction.

The portion of the first support rod 369a rearward of the pivot 369c curves so as to protrude to the left along the arc of the support plate 367. The portion of the second support rod 369b rearward of the pivot 369d curves so as to protrude to the right along the arc of the support plate 367. A cylindrical grip 369e is provided at each tip (one end) of the rear end of the first support rod 369a and the second support rod 369b. The axial direction of each grip 369e is the left-right direction, i.e., the same direction as the arm pivot 368.

A gripping pin 369f protrudes in the axial direction from each gripping portion 369e. The tip surfaces of both gripping pins 369f face each other. The tip surfaces of the gripping pins 369f are curved and protrude outward. The gripping pins 369f grip the tool holder. The tool holder is cylindrical with the axial direction being the up-down direction, and the tool is fitted into the tool holder. A groove is formed on the outer periphery of the tool holder. When the tool holder is inserted between both gripping pins 369f, the gripping pin 369f engages with the groove and grips the tool holder and tool.

A spring seat 369g is provided at the front end (other end) of each of the first support rod 369a and the second support rod 369b. The two spring seats 369g are disk-shaped and face each other in the left-right direction. A compression spring 369h is provided between the two spring seats 369g. The compression spring 369h biases the two spring seats 369g so that the two spring seats 369g move away from each other in the left-right direction, and biases both gripping pins 369f in a direction in which the tip surfaces of both gripping pins 369f approach each other. The compression spring 369h is an example of a biasing member, and rubber may be used instead of the compression spring 369h.

As described above, the first support rod 369a and the second support rod 369b have a gripping pin 369f at their rear end and a compression spring 369h at their front end. The length of the gripping portion 369e can be made shorter than when the compression spring 369h is provided inside the gripping portion 369e and the compression spring 369h biases the gripping pin 369f. The dimension in the movement direction of the gripping arm 36 can be made smaller without reducing the dimension between the tip faces of both gripping pins 369f.

The length of the first straight portion 313a, the predetermined distance between the gripping arms 36, and the length of the link 35 will be explained using Figures 10 and 4. The distance L3 between the two gripping arms 36 arranged side by side on the moving body 34 is shorter than the length L4 of the link 35. The distance L3 is the distance between the centers of the adjacent gripping arms 36 in the moving direction. The length L4 of the link 35 is the length between the axis centers of the connecting shaft body 345 at both ends of the link 35.

Consider a case where the interval L3 and the length L4 of the link 35 are the same. If the interval L3 is made smaller in order to connect more gripping arms 36, the adjacent gripping arms 36 will interfere with each other when adjacent moving bodies 34 approach each other closest to each other near the connection between the first straight portion 313a or the second straight portion 313b and the curved portion 313c. In this embodiment, the interval L3 is made shorter than the length L4 of the link 35, preventing the tool magazine 30 from becoming larger and preventing interference between the gripping arms 36, thereby allowing the number of gripping arms held by the chain portion 32 to be increased.

In addition, the length L5 of the first straight portion 313a of the rail 313 is at least twice the distance L6 between the gripping arms 36 at both ends of the movable body 34. In FIG. 10, the movable body 34 has two gripping arms 36, and the distance L3 = distance L6. The gripping arms 36 move along the rail 313 while aligned in the moving direction, and index the tool to the replacement position below the spindle 21. The replacement position is located at the center of the front first straight portion 313a extending in a direction perpendicular to the axial direction of the spindle 21, that is, the center in the left-right direction of the front first straight portion 313a. When the spindle 21 descends, the spindle 21 mounts the tool holder and tool located at the replacement position. If L5 ≧ L6 × 2, no matter which gripping arm 36 of the movable body 34 is located at the replacement position, a part of the movable body 34 does not overlap the curved portion 313c, and the posture of the movable body 34 can be maintained straight with respect to the spindle 21. Therefore, the gripping arm 36 that grips the tool to be attached faces the spindle 21 directly, allowing the tool to be attached smoothly.

The number of gripping arms 36 in one moving body 34 may be three or more. In this case, since the dimension of the moving body 34 in the left-right direction becomes large, three or more bearings 344 may be provided to match the pitch of the gear 332.

The upper side of FIG. 11 shows the rail of this embodiment, which has a rounded rectangular shape. The lower side of FIG. 11 shows the rail of the comparative example, which has an oval shape. When the overall length and overall width of the rail are the same, the circumference (travel path distance) of the rail in the embodiment is longer than that of the comparative example. An example calculated by applying specific numerical values will be described. The overall length of the rail is 1055 mm, and the overall width is 612 mm. According to the calculation, the circumference of the comparative example is 2807 mm, while the circumference of the embodiment is 2950 mm. By using a rail with rounded rectangular corners rather than an oval shape, etc., it is possible to prevent the rail from becoming large, increase the circumference, and increase the number of gripping arms 36 provided in the tool magazine 30.

The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The technical features described in each embodiment can be combined with each other, and the scope of the present invention is intended to include all modifications within the scope of the claims and equivalents to the scope of the claims.

100 Machine tool 21 Spindle 30 Tool magazine 313 Rail 313a First straight section 313b Second straight section 313c Curved section 34 Moving body 35 Link 36 Grip arm 369 Support rod 369e Grip section 369h Compression spring (biasing member)

Claims (4)

In a tool magazine, a plurality of movable bodies are connected endlessly via linear links and move along a rail,
The movable body has a plurality of gripping arms arranged in a line for gripping tools,
A tool magazine , wherein a distance between centers of adjacent gripping arms in the moving direction of the same moving body is shorter than a length of the link. 2. The tool magazine according to claim 1, wherein the rail has two first straight portions opposed to each other, two second straight portions opposed to each other in a direction perpendicular to the first straight portions, and a curved portion connecting ends of the first straight portions and the second straight portions. The gripping arm includes a pair of support rods each having a gripping portion at one end for gripping a tool, and a biasing member provided between the other ends of the support rods,
The tool magazine according to claim 1 or 2, wherein the biasing member biases each of the support rods in a direction in which the gripping portions of the support rods approach each other. A tool magazine according to any one of claims 1 to 3;
A spindle on which tools are attached;
Equipped with
The rail surrounds the spindle of the machine tool.

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