MACHINE TOOL AND PROTECTIVE ELEMENT

Abstract

In the present invention, a plate-shaped mounting cover (30) is attached to a lower part of a spindle head (6). The mounting cover (30) protects a movement mechanism within a stand (5) from chips and the like. When the spindle head (6) is positioned at the upper end of a range of motion, a movable cover (40) covers and protects a portion of the stand (5) that is not completely covered by the mounting cover (30) and is therefore exposed. As the spindle head (6) moves to the lower end of the range of motion, the movable cover (40) contacts engagement projections (55A, 55B) and is prevented from moving downwards. As the spindle head (6) moves downwards, the movable cover (40) moves upwards relative to the mounting cover (30) and is housed on the rear side of the mounting cover (30).

Description

Technical field

[0001] The disclosure relates to a machine tool and a protective element. State of the art

[0002] The machine tool described in patent document 1 has a Z-axis cover attached to the lower part of the main shaft head. A column with a head movement mechanism, which moves the main shaft head, is mounted on a bed. The Z-axis cover moves the front surface of the column in the Z-axis direction along with the movement of the main shaft head. The Z-axis cover protects the head movement mechanism from chips. Bibliography Patent document

[0003] [Patent literature 1] Japanese published patent application no. 2006-123045. BRIEF SUMMARY OF THE INVENTION

[0004] If the range of motion of the main shaft head is extended, the Z-axis cover must be lengthened in the Z-axis direction. In this case, when the main shaft head is moved to its lowest position in the Z-axis direction, the Z-axis cover may interfere with other structures on the bed. Using a bellows-shaped or nested cover for the Z-axis increases the number of parts, leading to a problem that increases the cost of the machine tool.

[0005] The purpose of the disclosure is to provide a machine tool and a protective element that cover the exposed section of a motion mechanism provided on a stand and are cost-effective.

[0006] According to the first embodiment of the disclosure, a machine tool is provided, the machine tool comprising: a base; a stand provided on the base; a main shaft configured for the removable attachment of a tool; a support body provided on a side face of the stand and supporting the main shaft; a movement mechanism provided on the stand and configured to move the support body in an axial direction of the main shaft; and a protective element covering a section of one side face of the stand where the movement mechanism is exposed when the support body moves.The protective element comprises: a first protective part which is attached to the carrier body and is moved in the axial direction together with the carrier body by the movement mechanism; and a second protective part which moves relative to the first protective part on one side opposite the carrier body of the first protective part.

[0007] The first guard covers a section of the movement mechanism that is exposed on a side face of the stator when the support body moves axially along the main shaft. As the support body moves downward, the first guard moves closer to the base. As the support body moves upward and the guard moves away from the base, the first guard does not completely cover one side face, and the movement mechanism is exposed. The second guard moves relative to the first guard. The second guard covers the section of the movement mechanism that the first guard does not completely cover and that remains exposed. In this way, the first and second guards prevent chips produced by the tool during machining from adhering to the movement mechanism.Furthermore, the protective element is a structure in which the first protective part is attached to the carrier body and the second protective part moves in relation to the first protective part, and can therefore be manufactured cost-effectively.

[0008] In the first aspect, one of the first and second protective parts can have an opening extending in the axial direction, and the other of the first and second protective parts can have a projection extending into the opening and movable in the axial direction relative to the opening. As the support body moves upwards and the protective part moves away from the base, the second protective part moves downwards relative to the first protective part due to its own weight. In this case, the projection is guided towards the opening, allowing the second protective part to move reliably relative to the first protective part.

[0009] The second guard of the first version can have an opening and be positioned closer to the side of the movement mechanism than the first guard. This means the first guard is located closer to the side of the table where the material is being processed than the second guard. Therefore, the first guard prevents chips produced by the tool during material processing from entering the opening of the second guard.

[0010] The first protective element of the first design can have a guide element that directs the movement of the second protective element in the axial direction. The second protective element, guided by the guide element, can move more reliably in the axial direction of the main shaft relative to the first protective element.

[0011] The protective element of the first design includes an elastic element elastically positioned within the projection or opening. As the support body moves upwards and the protective element moves away from the base, the second protective element moves downwards relative to the first due to its own weight. The opening of the second protective element moves downwards relative to the projection of the first protective element. As the projection approaches the end of the opening in the axial direction, the elastic element positioned within the projection or opening becomes wedged between the projection and the end of the opening. The elastic element deforms, and the contact area with the projection and the end of the opening increases.Consequently, the elastic element can reduce the stress exerted on the first protective part due to the movement of the second protective part under its own weight, and the durability of the second protective part can be increased. Furthermore, the elastic element can dampen the impact that would occur if the protruding part and the end part of the opening collided when the elastic element was not present.

[0012] The elastic element of the first impact is ring-shaped and surrounds the circumference of the protruding part. When the ring-shaped elastic element is sandwiched between the protruding part and the end of the opening, it can reliably make contact with the end and undergo elastic deformation, regardless of the relative positional deviation between the opening and the protruding part or the shape of the opening's end. In this way, the elastic element can more reliably dampen the impact during the collision between the first and second protective parts.

[0013] The protective element of the first embodiment can have a spacer provided between the projecting part and the elastic element, and the elastic element can be rotatable in a circumferential direction with respect to the projecting part. By providing the spacer between the elastic element and the projecting part, the elastic element can be rotated with respect to the projecting part. When the elastic element is located between the projecting part and the end part of the opening, the impact exerted on the elastic element is not concentrated in a specific area, but rather distributed over the entire circumferential direction as the elastic element rotates. This results in a longer service life for the elastic element and allows it to mitigate the effects of a collision between the first and second protective parts over an extended period.

[0014] In the first embodiment, a third protective element may be provided, attached to the stand closer to the base than the second protective element; and engagement elements provided on the third protective element that engage with the second protective element when the support body moves axially in a direction approaching the third protective element. The engagement elements may be elastic. The third protective element is attached to the stand closer to the base than the protective element and contains the engagement elements. As the support body lowers, the second protective element approaches the base. The second protective element engages with the engagement elements without touching any other structure. The engagement elements come into contact with the second protective element and are elastically deformed, thereby mitigating the effects of an impact.

[0015] In the first embodiment, a notched portion, notched on a side facing away from the base and having inclined edges that are inclined with respect to the axial direction in the section where it is notched, can be formed on an end part of the second protective part on the base side in the axial direction. The engagement parts can abut against the inclined edges of the notched portion when the support body moves in the axial direction in a direction approaching the third protective part. As the support body moves downwards, the engagement parts abut the inclined edges of the notched portion formed on the second protective part. The inclined edges are inclined with respect to the axial direction. Thus, the tensile force exerted on the second protective part is distributed due to contact with the engagement parts in the axial direction and in a direction perpendicular to the axial direction.This means that the tensile force exerted on the second protective element in the axial direction when it abuts the engagement elements is reduced. Thus, the engagement elements can further dampen the impact acting on the second protective element in the axial direction. In this way, the second protective element can suppress the rebound motion in the axial direction caused by the tensile force when the angled edges abut the engagement elements.

[0016] In the first embodiment, the first protective part or the second protective part can have protrusions on a first surface where the first protective part faces the second protective part, or on a second surface where the second protective part faces the second protective part. These protrusions project towards the other surface and have projecting tips that contact the other surface. The protrusion, whether on the first or second surface, comes into contact with the other surface, forming a gap between the first and second surfaces. That is, the opposing surfaces of the first and second protective parts do not come into direct contact with each other due to the gap formed by the protrusion.Therefore, it is unlikely that the second protective part will adhere to the first protective part, and the relative movement of the second protective part with respect to the first protective part will not be hindered.

[0017] In the second embodiment of the disclosure, there is a protective element for a machine tool, wherein the machine tool comprises: a base; a stand provided on the base; a main shaft configured for the removable attachment of a tool; a support body provided on a side face of the stand and supporting the main shaft; and a movement mechanism provided on the stand and configured to move the support body in an axial direction of the main shaft.The protective element covers and protects a section of one side face of the machine tool stand where the movement mechanism is exposed when the support body moves. The protective element comprises: a first protective part that is attached to the support body and moves axially with the support body through the movement mechanism; and a second protective part that moves relative to the first protective part. One of the first and second protective parts may have an opening extending axially, and the other of the first and second protective parts may have a projecting part that extends into the opening and is movable axially relative to the opening.

[0018] The first guard covers a section of the movement mechanism that is exposed on a side face of the stator when the support body moves axially along the main shaft. As the support body moves downward, the first guard moves closer to the base. As the support body moves upward and the guard moves away from the base, the first guard does not fully cover one side face, and the movement mechanism is exposed. The second guard moves relative to the first guard. The second guard covers the section of the movement mechanism that the first guard does not fully cover and that remains exposed. In this way, the first and second guards protect the movement mechanism, preventing chips produced by the tool during machining from adhering to the movement mechanism.Furthermore, the protective element is a structure in which the first protective part is attached to the support body and the second protective part moves relative to the first, and can therefore be manufactured cost-effectively. When the second protective part moves downwards relative to the first due to its own weight, the protruding part is guided to the opening, allowing the second protective part to move reliably in the axial direction relative to the first.

[0019] In the second embodiment, an elastic element can be provided in the projection or the opening. When the second protective part moves below the first protective part due to its own weight, the elastic element is sandwiched between the projection and the end of the opening. The elastic element deforms elastically, increasing the contact area with the projection and the end of the opening. As a result, the elastic element can reduce the stress exerted on the first protective part due to the movement of the second protective part under its own weight, thus increasing the durability of the second protective part. Furthermore, the elastic element can mitigate the impact that would occur if the projection and the end of the opening were to collide without it. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view of machine tool 1. Fig. Figure 2 is a front view of the main shaft head 6 and the stand 5 with the protective cover 25 removed. Fig. Figure 3 is a perspective exploded view of the main shaft head 6, the protective cover 25 and the lower cover 50 before attachment to the stand 5. Fig. Figure 4 is a front view of the protective cover 25 and the lower cover 50 when the main shaft head 6 is positioned at the top end of the range of motion. Fig. Figure 5 is a perspective rear view of the protective cover 25 and the lower cover 50. Fig. Figure 6 is a perspective exploded view of the protective cover 25 and the lower cover 50. Fig. Figure 7 is a front view of the protective cover 25 and the lower cover 50 when the main shaft head 6 is on its way down. Fig. Figure 8 is a front view of the protective cover 25 and the lower cover 50 when the main shaft head 6 is positioned at the lowest end of the range of motion. Fig. Figure 9 is a perspective rear view of the protective cover 125. Fig. Figure 10 is a perspective exploded view of the protective cover 225. Fig. Figure 11 is a front view of the stand when the main shaft head 306 is at the top end in the direction of the Z-axis. Fig. Figure 12 is a front view of the stand when the main shaft head 306 is at the bottom end in the direction of the Z-axis. Fig. Figure 13 is a front view of the fixed cover 330, to which the movable cover 340 is attached with the rubber feet 345. Fig. Figure 14 is a front view of the fixed cover 430 to which the rotatable, movable covers 440 are attached. DESCRIPTION OF THE EXECUTION FORMS

[0020] The following describes machine tool 1 according to an embodiment of the disclosure. In the following description, the directions left and right, front and back, and up and down are indicated by arrows in the drawings. The directions "left" and "right", "front" and "back", and "up" and "down" are the directions of the X-axis, the Y-axis, and the Z-axis, respectively, of machine tool 1.

[0021] The construction of machine tool 1 is described with reference to the Fig. 1 to Fig. The machine tool 1 comprises a base 2, a machine body 3, a table 10, a tool changing device 17, etc. The base 2 is essentially a rectangular, parallelepiped iron sleeper. The machine body 3 is attached to the upper rear of the base 2. The machine body 3 cuts a material (not shown) that is held on the upper surface of the table 10. The base 2 has a feed mechanism in its upper center. The feed mechanism moves the table 10 in the direction of the X-axis and in the direction of the Y-axis. The feed mechanism is described later. The tool changing device 17 is attached to a frame 18 provided on the upper part of the column 5 of the machine body 3. The tool changing device 17 exchanges a tool (not shown) attached to the main shaft 4 of the machine body 3 for another tool.

[0022] The machine body 3 includes a stand 5, a main shaft head 6, a motion mechanism, a protective cover 25, a lower cover 50, a main shaft 4, a control box 19, etc. The stand 5 is a stand-shaped element made of iron, located at the upper rear of the base 2. The main shaft head 6 moves up and down along the front surface of the stand 5 in the direction of the Z-axis. The motion mechanism is attached to the front of the stand 5. The motion mechanism moves the main shaft head 6 in the direction of the Z-axis. The motion mechanism includes a pair of Z-axis rails 21, a Z-axis ball screw 22, and a Z-axis motor 23. The Z-axis rails 21 and the Z-axis ball screw 22 extend in the Z-direction. The main shaft head 6 moves along the Z-axis rails 21. The main shaft head 6 has a nut (not shown) on the back.The nut is screwed into the ball screw 22 of the Z-axis. The Z-axis motor 23 is attached to the upper part of the Z-axis ball screw 22. The Z-axis motor 23 rotates the Z-axis ball screw 22 and moves the nut in the direction of the Z-axis. In this way, the main shaft head 6 moves along with the nut in the direction of the Z-axis. The protective cover 25 is attached to the main shaft head 6 and mounted on the front of the stand 5. The protective cover 25 includes a fixed cover 30 and a movable cover 40. The protective cover 25 is described later. The lower cover 50 is a metal plate. The lower cover 50 is attached to the front of the stand 5 closer to the side of the base 2 than the protective cover 25. The lower cover 50 protects the stand 5 below the rails of the Z-axis 21.A rear cover device (described later) for the Y-axis feed mechanism 8 is provided on the lower part of the lower cover 50. The rear cover device moves in the direction of the Y-axis.

[0023] The main shaft head 6 rotatably supports the main shaft 4. The main shaft 4 is mounted with a tool and driven by the main shaft motor 11. The main shaft motor 11 is attached to the upper part of the main shaft head 6. The control box 19 is mounted on the rear of the stator 5. Various devices are housed in the control box 19. These devices include, for example, an NC control board, a DC switching power supply, a circuit breaker, an inverter for the tool changing device 17, a wiring duct, a servo amplifier, etc.

[0024] The feed mechanism comprises a Y-axis feed mechanism 8, a carrier 7, and an X-axis feed mechanism 9. The Y-axis feed mechanism 8 is attached to the upper surface of the base 2. The Y-axis feed mechanism 8 moves the carrier 7 along the Y-axis. The Y-axis feed mechanism 8 includes a pair of Y-axis rails (not shown), a Y-axis ball screw (not shown), and a Y-axis motor (not shown). The Y-axis rails and the Y-axis ball screw extend along the Y-axis. The Y-axis ball screw is positioned between the two pairs of Y-axis rails. The carrier 7 moves along the Y-axis rails. The carrier 7 has a rectangular parallelepiped shape and is provided with a nut (not shown) on its underside. The nut is screwed into the ball screw of the Y-axis.The Y-axis motor rotates the Y-axis ball screw and moves the nut in the direction of the Y-axis. This causes the carrier 7 to move along with the nut in the direction of the Y-axis.

[0025] The X-axis feed mechanism 9 is attached to the upper surface of the support 7. The X-axis feed mechanism 9 moves the table 10 along the X-axis. The X-axis feed mechanism 9 includes a pair of X-axis rails (not shown), an X-axis ball screw (not shown), an X-axis motor (not shown), etc. The X-axis rails and the X-axis ball screw extend along the X-axis. The ball screw for the X-axis is mounted between the two X-axis rails. The table 10 moves along the X-axis rails. The table 10 has a nut (not shown) on its lower surface. The nut is screwed into the X-axis ball screw. The X-axis motor rotates the X-axis ball screw and moves the nut along the X-axis. This causes table 10 to move along with the nut in the direction of the X-axis.Furthermore, the table 10 moves along the support 7 in the direction of the Y-axis. This means that the table 10 moves in both the X-axis and Y-axis directions via the X-axis feed mechanism 9, the Y-axis feed mechanism 8, and the support 7. As a result, the workpiece on the table 10 moves relative to the tool. The machine tool 1 cuts the workpiece, which moves relative to the tool.

[0026] The table 10 includes a right cover 12 on its right side and a left cover 13 on its left side. The X-axis feed mechanism 9 is visible externally on both the right and left sides of the table 10. The right cover 12 and the left cover 13 each cover a section of the X-axis feed mechanism 9 that is open to the outside. The right cover 12 and the left cover 13 each have a structure in which a plurality of covers, each with a mountain-shaped cross-section, are nested and overlapping. The right cover 12 and the left cover 13 each extend and retract in the left and right directions, i.e., in the direction of the X-axis, in accordance with the movement of the table 10.

[0027] The support 7 includes a front cover 14 at the front and a rear cover (not shown) at the rear. The Y-axis feed mechanism 8 is visible externally at the front and rear of the table 10. The front cover 14 and the rear cover each cover the externally open portion of the Y-axis feed mechanism 8. The front cover 14 has a structure in which multiple covers, each with a mountain-shaped cross-section, are nested and overlapping. The front cover 14 expands and contracts in the front and rear directions, i.e., along the Y-axis, corresponding to the movement of the support 7 along the Y-axis. The rear cover is a metal plate with a mountain-shaped cross-section.The rear cover device moves along with the carrier 7 in the direction of the Y-axis. As the carrier 7 moves towards the side of the stand 5, the stand 5 receives the rear cover device inside its lower section.

[0028] The protective cover 25 and the lower cover 50 are described with reference to Fig. 2 and Fig. 4 to Fig. 6 described. The protective cover 25 and the lower cover 50 are protective elements that prevent chips generated during machining from adhering to the Z-axis movement mechanism. The protective cover 25 comprises a fixed cover 30 and a movable cover 40.

[0029] The fixed cover 30 is a metal plate with curved edges and has an essentially rectangular shape when viewed from the front. The upper end 31 of the fixed cover 30 is bent forward. The upper end 31 has a screw hole for fastening it to the lower part of the main shaft head 6 with a screw. The side end 32 on both the left and right sides of the fixed cover 30 are bent backward. The side end 32 position the movable cover 40 in the left and right directions and guide the upward and downward movement of the movable cover 40. The center of the lower end 33 of the fixed cover 30 is positioned higher than both ends in the left and right directions. Therefore, when the main shaft head 6 lowers, the fixed cover 30 avoids collision with the mountain-shaped rear cover device on the lower end 33.Furthermore, the lower end part 33 has a notched part 34, which is located essentially in the middle in the left and right directions. The notched part 34 is trapezoidally notched upwards.

[0030] The fixed cover 30 has a pair of mounting holes 36 located closer to the lower end part 33 than to the center in both the upward and downward directions. The mounting holes 36 are spaced apart from each other in the left and right directions. A pair of guide screws 35 is attached to each pair of mounting holes 36. The guide screws 35 attached to the mounting holes 36 project rearward from the fixed cover 30. The guide screws 35 are each provided in a pair of guide holes 41 of the movable cover 40.

[0031] A metal spacer 27 has a cylindrical shape and is fitted into each of the two guide screws 35. The spacers 27 can rotate in the circumferential direction of the guide screws 35. The elastic elements 28 are ring-shaped and arranged around the outer circumference of the spacers 27. The elastic elements 28 are made of plastic and are elastic. Examples of elastic elements 28 are urethane, nitrile rubber, and fluororubber. The elastic elements 28 can have a lower modulus of elasticity than the movable cover 40 described below and a higher elasticity than the movable cover 40. The elastic elements 28 are positioned so that they surround the guide screws 35 via the spacers 27. By positioning the spacers 27 between the elastic elements 28 and the guide screws 35, the elastic elements 28 can rotate in the circumferential direction of the guide screws 35.The elastic elements 28 are provided in the guide holes 41. The outer circumferential surfaces of the elastic elements 28 are therefore opposite the inner circumferential surfaces of the guide holes 41 of the movable cover 40.

[0032] The fixed cover 30 has a plurality of projections 37 on its rear surface 30A. The rear surface 30A is the surface facing the movable cover 40. The projections 37 are provided in an area of ​​the rear surface 30A of the fixed cover 30 that overlaps the movable cover 40 in the front and rear directions when the movable cover 40 is positioned in the lowest position of its range of motion (see Figure 3). Fig. 4) The projecting parts 37 are arranged at a distance from each other. The projecting parts 37 form a section that is dowelled to the rear surface 30A by pressing the fixed cover 30 (see cross-section along line II in Fig. The projecting parts 37 form a gap D between the rear surface 30A of the fixed cover 30 and the front surface 40A of the movable cover 40. This prevents the rear surface 30A from adhering to the front surface 40A. The end of the projecting part 37 has a hemispherical shape. Therefore, the contact area between the projecting parts 37 and the front surface 40A is small.

[0033] The movable cover 40 is a plastic sheet. An example of a material used for the movable cover 40 is polyvinyl chloride (PVC). The movable cover 40 has a substantially rectangular shape, extending to the left and right when viewed from the front. The length of the movable cover 40 in the left and right directions is slightly shorter than that of the fixed cover 30. The length of the movable cover 40 in the upward and downward directions is 1 / 2 to 1 / 3 the length of the fixed cover 30. The movable cover 40 has a pair of guide holes 41. The guide holes 41 are elongated openings in the upward and downward directions that penetrate the movable cover 40 in the front and backward directions. The positions of the guide holes 41 in the left and right directions correspond to the positions of the mounting holes 36 in the fixed cover 30. The upper and lower ends of the guide holes 41 are circular.The radius of curvature of the upper and lower end sections of the guide hole 41 is larger than the radius of the outer circumference of the elastic element 28. Thus, the length of the guide hole 41 is greater than the diameter of the elastic element 28 in both the left and right directions. This allows the movable cover 40 to move left and right relative to the fixed cover 30. The lateral end sections 32 of the fixed cover 30 position the lateral end sections 42 on both the left and right sides of the movable cover 40. A slight gap exists between the lateral end sections 32 and lateral end sections 42 in both the left and right directions. Therefore, the movable cover 40 can move left and right relative to the fixed cover 30 within this gap.

[0034] The lower end portion 43 of the movable cover 40 has a notched portion 44. The notched portion 44 has a shape in which a substantially central notch is notched upwards in both the left and right directions. When the main shaft head 6 lowers, the notched portion 44 engages the engagement projections 55A and 55B of the lower cover 50. Inclined portions 44A and 44B are provided within the notched portion 44. The inclined portions 44A and 44B are side portions that connect the upper end portion of the notched portion 44 to the lower portion of the notched portion 44 on both the left and right sides. The inclined portions 44A and 44B are each inclined in a direction that widens the notched portion 44 downwards. The engagement projections 55A and 55B each engage with the inclined parts 44A and 44B.

[0035] The movable cover 40 is attached to the rear surface of the fixed cover 30. A pressure plate 26 is attached to the rear surface of the movable cover 40. The pressure plate 26 extends to the left and right. The pressure plate 26 has through holes at two ends. The guide screws 35 are inserted from the rear of the movable cover 40 through the through holes in the pressure plate 26 into the guide holes 41. The guide screws 35 are fastened to the mounting holes 36 with the spacers 27 and the elastic elements 28 arranged in the guide holes 41. A gap is provided between the pressure plate 26 and the movable cover 40. A gap is also provided between the fixed cover 30 and the movable cover 40 due to the projecting parts 37. This allows the movable cover 40 to move up and down relative to the fixed cover 30.

[0036] The lower cover 50 is plate-shaped and longer in the left and right directions than the protective cover 25. The upper end portion 51 of the lower cover 50 has an extension portion 51A that extends upwards. The extension portion 51A is wider in the front view than the notched portion 44 of the movable cover 40. When the main shaft head 6 rises, the extension portion 51A prevents the Z-axis rails 21 and the stator 5 from protruding from the notched portion 44 of the movable cover 40. A lower end portion 53 of the lower cover 50 has a notched portion 54. The notched portion 54 has a shape in which the center is notched in a mountain-like fashion on the upper surface in the left and right directions. The rear cover device of the Y-axis feed mechanism 8 is provided in the notched portion 54. The lower cover 50 has a pair of engagement projections 55A and 55B above the notched part 54.The engagement projections 55A and 55B are made of plastic, are elastic, and cylindrical. Examples of materials used for engagement projections 55A and 55B are urethane, nitrile rubber, and fluororubber. The engagement projections 55A and 55B can have a lower modulus of elasticity than the movable cover 40 and a higher elasticity than the movable cover 40. The engagement projections 55A and 55B are fastened to the front surface of the lower cover 50 by screws 56. The engagement projections 55A and 55B are positioned against the inclined portions 44A and 44B of the notched portion 44 of the movable cover 40 when the main shaft head 6 lowers.

[0037] The operation of the fixed cover 30 and the movable cover 40 is described with reference to Fig. 2, Fig. 4, Fig. 7 and Fig. 8 described. As in Fig. As shown in Figure 2, the upper end part 31 of the fixed cover 30 is attached to the lower part of the main shaft head 6 by a screw. Due to its own weight, the movable cover 40 moves downwards relative to the fixed cover 30. The movable cover 40 moves downwards to a position where the upper end parts of the guide holes 41 abut the elastic elements 28 provided around the guide screws 35. The side end parts 42 of the movable cover 40 are positioned against the side end parts 32 of the fixed cover 30 in the left and right directions. Thus, the movable cover 40 moves while allowing positional deviation within the range of the gap between the side end parts 32 and the side end parts 42 in the left and right directions.The protective cover 25 has a gap D defined by the projections 37 between the rear surface 30A of the fixed cover 30 and the front surface 40A of the movable cover 40. This prevents the movable cover 40 from sticking to the fixed cover 30 and allows it to move smoothly.

[0038] As in Fig. As shown in Figure 4, the elastic elements 28, which are positioned around the guide screws 35, abut the upper end portions of the guide holes 41 and limit the downward movement of the movable cover 40. The elastic elements 28 are elastically deformed to mitigate the impact of the collision between the upper end portions of the guide holes 41 and the guide screws 35. The radius of the elastic elements 28 is smaller than the radius of curvature of the upper end portions of the guide holes 41. Thus, during their elastic deformation, the elastic elements 28 make contact with the upper end portions of the guide holes 41 over a large area. This allows the fixed cover 30 to more securely hold the movable cover 40 at the lowest point of its range of motion. The elastic elements 28 are arranged around the guide screws 35 via the spacers 27 and are freely rotatable.This changes the contact positions of the elastic elements 28 with the upper end parts of the guide holes 41 in a circumferential direction. Since the impacts acting on the elastic elements 28 can be distributed in the entire circumferential direction, the service life of the elastic elements 28 can be extended. A substantially lower half-section of the movable cover 40 in the upward and downward directions is exposed by the lower end part 43 of the fixed cover 30.

[0039] When the main shaft head 6 moves to its uppermost position within its range of motion, the fixed cover 30 covers the front face of the stand 5. If the range of motion of the main shaft head 6 is greater than in the conventional case, when the main shaft head 6 is positioned at its uppermost end, portions of the stand 5 and the Z-axis rails 21 are exposed by the lower end portion 33 of the fixed cover 30. A substantially lower half-section of the movable cover 40 is positioned below the lower end portion 33 of the fixed cover 30. The movable cover 40 covers a portion of the stand 5 and the Z-axis rails 21 that are exposed by the fixed cover 30. Thus, the protective cover 40 protects the movement mechanism on the stand 5 from chips and the like during machining. The movable cover 40 is positioned behind the fixed cover 30.Therefore, the guide holes 41 are located behind the fixed cover 30 and are not visible from the front. Thus, the fixed cover 30 prevents chips and the like from entering the guide holes 41 during machining.

[0040] When the main shaft head 6 moves downwards in the direction of the Z-axis, the movable cover 40, by its own weight, maintains a state in which it is in its lowest movable position relative to the fixed cover 30. As shown in Fig. As shown in Figure 7, during the lowering process of the main shaft head 6, the inclined parts 44A and 44B of the notched part 44 of the movable cover 40 abut the engagement projections 55A and 55B of the lower cover 50. The inclined parts 44A and 44B abut the engagement projections 55A and 55B on the inclined surfaces, which are inclined with respect to the upward and downward directions. The inclined surface of the inclined part 44A is inclined at an angle θ to the horizontal direction. The direction perpendicular to the inclined surface of the inclined part 44A points downward to the right. The inclined surface of the inclined part 44B is inclined at an angle θ to the horizontal direction. The direction perpendicular to the inclined surface of the inclined part 44B points downward to the left.When the inclined parts 44A and 44B bear against the engagement projections 55A and 55B, they receive a tensile force N from these projections in the direction perpendicular to the inclined surfaces. Inclined part 44A receives a force of N sin θ in the left direction as the horizontal component of the tensile force N. Inclined part 44B receives a force of N sin θ in the right direction as the horizontal component of the tensile force N. Thus, the horizontal component of the tensile force N received by the movable cover 40 is canceled out. The inclined parts 44A and 44B receive a force of N cos θ in the upward direction as the vertical component of the tensile force N. θ is less than 90 degrees.In contrast to the case where the inclined surfaces are not inclined and are horizontal planes, the inclined parts 44A and 44B can therefore reduce the tensile force N experienced by the movable cover 40 when it collides with the engagement projections 55A and 55B, thus mitigating the impact. The engagement projections 55A and 55B are elastic. Due to the elastic deformation of the engagement projections 55A and 55B at the moment of impact, the movable cover 40 can further mitigate the impact at that moment. In this way, the movable cover 40 is prevented from rebounding upwards.

[0041] As in Fig. As shown in Figure 8, the movable cover 40 maintains the state in which the inclined parts 44A and 44B bear against the engagement projections 55A and 55B, even when the main shaft head 6 is further away from the one shown in Figure 8. Fig. The state shown in Figure 7 is as follows. While the main shaft head 6 lowers, the movable cover 40 does not move up and down. The lower end 43 of the movable cover 40 has a small gap between itself and the rear cover of the Y-axis feed mechanism 8 and does not rest against the rear cover. The fixed cover 30 moves downwards relative to the movable cover 40. On the rear side of the fixed cover 30, the movable cover 40 moves upwards relative to the fixed cover 30. Thus, the movable cover 40 does not impede the downward movement of the fixed cover 30. The position of the lower end of the main shaft head 6 is determined by controlling the drive of the Z-axis motor 23.When the main shaft head 6 is in its lowest position within the moving range, the position of the lower end portion 33 of the fixed cover 30 is controlled to a position with a small gap between it and the rear cover device of the Y-axis feed mechanism 8. Thus, the fixed cover 30 does not abut the rear cover device. The notched portion 34 does not contact the engagement projections 55A and 55B. The lower end portion 43 of the movable cover 40 is located at essentially the same height as the lower end portion 33 of the fixed cover 30. The movable cover 40 moves upward relative to the fixed cover 30 and is located at the rear of the fixed cover 30. Thus, the movable cover 40 does not impede the downward movement of the fixed cover 30.

[0042] As described above, the fixed cover 30 covers the area where the Z-axis rails 21 and the stand 5 are exposed on the front surface of the stand 5 when the main shaft head 6 moves in the axial direction of the main shaft 4. As the main shaft head 6 moves downward, the fixed cover 30 approaches the base 2. As the main shaft head 6 moves upward and the protective cover 25 moves away from the base 2, the fixed cover 30 does not completely cover the front surface, and the Z-axis rails 21 and the stand 5 are exposed. The movable cover 40 moves relative to the fixed cover 30. The movable cover 40 covers the portion of the Z-axis rails 21 and the stand 5 that is not completely covered by the fixed cover 30.Thus, the fixed cover 30 and the movable cover 40 prevent chips produced during machining of the material by the tool from adhering to the Z-axis rails 21 and the stand 5. Furthermore, the protective cover 25 is a design in which the fixed cover 30 is attached to the main shaft head 6 and the movable cover 40 moves relative to the fixed cover 30, and can therefore be manufactured cost-effectively.

[0043] When the main shaft head 6 moves upwards and the protective cover 25 moves away from the base 2, the movable cover 40 moves downwards relative to the fixed cover 30 due to its own weight. In this case, the guide screws 35 are guided in the guide holes 41, so that the movable cover 40 can move reliably relative to the fixed cover 30.

[0044] The fixed cover 30 is located closer to the side of the table 10 where the material is processed than the movable cover 40. Thus, the fixed cover 30 prevents chips produced by the tool during processing the material from entering the guide holes 41 of the movable cover 40.

[0045] The movable cover 40 can move more reliably in the axial direction of the main shaft 4 relative to the fixed cover 30 by means of the guidance of the lateral end parts 32.

[0046] As the main shaft head 6 moves upwards and the protective cover 25 moves away from the base 2, the movable cover 40 moves downwards relative to the fixed cover 30 due to its own weight. The guide holes 41 of the movable cover 40 move downwards relative to the guide screws 35 of the fixed cover 30. As the guide screws 35 approach the upper end portions of the guide holes 41, the elastic elements 28 surrounding the guide screws 35 become sandwiched between the guide screws 35 and the upper end portions of the guide holes 41. The elastic elements 28 deform elastically, and the contact area with the guide screws 35 and the upper end portions of the guide holes 41 increases.As a result, the elastic elements 28 can reduce the load exerted on the fixed cover 30 due to the movement of the movable cover 40 by their own weight, and the durability of the movable cover 40 can be increased. Furthermore, the elastic elements 28 can dampen the impact that would occur if the guide screws 35 and the end parts of the guide holes 41 were to collide, were the elastic elements 28 not present.

[0047] When the ring-shaped elastic elements 28 are sandwiched between the guide screws 35 and the end parts of the guide holes 41, the elastic elements 28 can reliably come into contact with the end parts and deform elastically, regardless of the relative positional deviation between the guide holes 41 and the guide screws 35 or the shape of the end parts of the guide holes 41. In this way, the elastic elements 28 can more reliably dampen the impact during a collision between the fixed cover 30 and the movable cover 40.

[0048] By providing spacers 27 between the elastic elements 28 and the guide screws 35, the elastic elements 28 can rotate relative to the guide screws 35. When the elastic elements 28 are sandwiched between the guide screws 35 and the upper end portions of the guide holes 41, the impact acting on the elastic elements 28 is not concentrated in a specific area, but rather distributed over the entire circumferential direction as the elastic elements 28 rotate. This results in a longer service life for the elastic elements 28 and allows them to mitigate the effects of a collision between the fixed cover 30 and the movable cover 40 over an extended period.

[0049] The lower cover 50 is attached to the stand 5 closer to the base 2 than the protective cover 25 and has engagement projections 55A and 55B. When the main shaft head 6 lowers, the movable cover 40 approaches the base 2. The movable cover 40 engages the engagement projections 55A and 55B without touching any other structures. The engagement projections 55A and 55B come into contact with the movable cover 40 and are elastically deformed, thereby reducing the impact in the event of a collision.

[0050] When the main shaft head 6 lowers, the engagement projections 55A and 55B abut the inclined portions 44A and 44B of the notched portion 44 formed on the movable cover 40. The inclined portions 44A and 44B are inclined with respect to the Z-axis direction. Therefore, the tensile force N exerted on the movable cover 40 due to contact with the engagement projections 55A and 55B is distributed in the Z-axis direction and in a direction perpendicular to the Z-axis direction. That is, the tensile force N acting on the movable cover 40 in the Z-axis direction when it is in contact with the engagement projections 55A and 55B is reduced. Thus, the engagement projections 55A and 55B can further attenuate the impact acting on the movable cover 40 in the Z-axis direction.In this way, the movable cover 40 can suppress the vertical movement in the direction of the Z-axis caused by the tensile force N when the inclined parts 44A and 44B are in contact with the engagement projections 55A and 55B.

[0051] The projecting parts 37, which are provided on the rear surface 30A of the fixed cover 30, come into contact with the front surface 40A of the movable cover 40, thereby forming a gap D between the rear surface 30A and the front surface 40A. That is, the opposing surfaces of the fixed cover 30 and the movable cover 40 do not come into direct contact with each other due to the gap D formed by the projecting parts 37. Therefore, it is unlikely that the movable cover 40 will adhere to the fixed cover 30, and the relative movement of the movable cover 40 with respect to the fixed cover 30 is not impeded.

[0052] In the embodiment above, the front surface of the stand 5 corresponds to the "one side surface" of the disclosure. The main shaft head 6 corresponds to the "support body" of the disclosure. The Z-axis ball screw 22 and the Z-axis rails 21 correspond to the "movement mechanism" of the disclosure. The protective cover 25 corresponds to the "protective part" of the disclosure. The fixed cover 30 corresponds to the "first protective part" of the disclosure. The movable cover 40 corresponds to the "second protective part" of the disclosure. The guide holes 41 correspond to the "opening" of the disclosure. The guide screws 35 correspond to the "projecting part" of the disclosure. The side end parts 32 correspond to the "guide part" of the disclosure. The lower cover 50 corresponds to the "third protective part" of the disclosure. The engagement projections 55A and 55B correspond to the "engaging parts" of the disclosure. The inclined parts 44A and 44B correspond to the "inclined edges" of the disclosure.The notched part 44 corresponds to the “notched part” of the disclosure. The rear surface 30A of the fixed cover 30 corresponds to the “first surface” of the disclosure. The front surface 40A of the movable cover 40 corresponds to the “second surface” of the disclosure.

[0053] The disclosure is not limited to the above embodiment, and various modifications can be made. Although a pair of guide holes 41 is provided in the movable cover 40, the number of guide holes 41 can be one, three, or more. If one guide hole 41 is present, the movable cover 40 can move reliably in the up and down direction because it is guided by the lateral end parts 32 of the fixed cover 30. If two or more guide holes 41 are present, the lateral end parts 32 of the fixed cover 30 can be omitted. The pressure plate 26 can be omitted. Washers with an outer diameter larger than the radius of curvature of the guide holes 41 can be attached to the guide screws 35 and used in place of the pressure plate 26. The notched portion 34 of the fixed cover 30 can be omitted.The notched part 44 of the movable cover 40 can be formed into a pair of V-shapes, which include inclined parts 44A and 44B corresponding to the engagement projections 55A and 55B. In this case, the engagement projection 55A and the inclined part 44A are provided in the center in the left and right directions, and the engagement projection 55B and the inclined part 44B can be omitted.

[0054] The projecting parts 37 need not necessarily be formed by doweling, but can also be formed by screwing them to the rear surface 30A of the fixed cover 30 or by inserting a dowel. The pointed end of the projecting part 37 need not be hemispherical. The projecting part 37 is not limited to a stand-like shape, but can also have a tapered shape. The projecting parts 37 can be attached to the front surface 40A of the movable cover 40. The radius of curvature of the end of the guide hole 41 can be the same as the radius of the outer circumferential section of the elastic element 28. The shape of the end of the guide hole 41 is not limited to a semicircular shape, but can be rectangular or trapezoidal with chamfered corners. The spacer 27 can be omitted.

[0055] As in Fig. As shown in Figure 9, the protective cover 125 can have elastic elements 128 formed in an oval ring shape and attached to the inside of the guide holes 141 of the movable cover 140. In this case, the spacers 127 are larger than the spacers 27 of this embodiment. The spacers 127 are arranged around the guide screws 135, which are attached to the fixed cover 130. The radius of the outer circumferential part of the spacer 127 is set smaller than the radius of curvature at the end part of the inner circumferential part of the elastic element 128. In this configuration, the guide screws 135 can contact the guide holes 141 via the elastic elements 128. In this way, the elastic elements 128 can cushion the impact in a collision. In the above case, the spacers 127 can be omitted.The elastic element 128 is not limited to a ring-shaped form and can be provided only at the upper end part of the guide hole 141 or at both the upper and lower end parts.

[0056] As in Fig. As shown in Figure 10, the protective cover 225 can have guide holes 241 on the fixed cover 230 and guide screws 235 on the movable cover 240. The guide screws 235 are inserted from the front of the press plate 226 through the through holes in the two end parts into the guide holes 241. The guide screws 235 are secured to the mounting holes 236 of the movable cover 240 with the spacers 227 and the elastic elements 228 in the guide holes 241. Even in this configuration, the movable cover 240 can move up and down relative to the fixed cover 230. The guide holes 241 open on the front surface of the fixed cover 230. Therefore, a cover that covers the guide holes 241 can be provided on the front of the fixed cover 230 to prevent chips and the like from entering the guide holes 241 during machining.In this case, instead of the pressure plate 226, washers with an outer diameter larger than the radius of curvature of the guide holes 241 can be attached to the guide screws 235.

[0057] As in Fig. As shown in Figure 11, the lower cover 350 of the machine tool 301 must not have an engagement projection. As shown in Fig. As shown in Figure 12, when the main shaft head 306 is in its lowest position within the moving range, the position of the lower end portion 333 of the fixed cover 330 is controlled to a position with a small gap between it and the cover device of the Y-axis feed mechanism. Thus, the fixed cover 330 does not abut the cover device. The lower end portion 343 of the movable cover 340 is located below the lower end portion 333 of the fixed cover 330 and abuts the cover device. In this way, the movable cover 340 moves upward relative to the fixed cover 330 and is located behind the fixed cover 330. Thus, the movable cover 340 does not impede the downward movement of the fixed cover 330.Furthermore, the movable plastic cover 340 suppresses the impact noise and the impact generated by the collision with the cover device, compared to the case where the fixed metal cover 330 collides with the cover device.

[0058] Furthermore, the movable cover can be 340, as shown in Fig. Figure 13 shows a lower end part 343, which is provided with an elastic buffer material such as rubber feet 345. In this case, the movable cover 340 can be made of metal. When the main shaft head 306 moves near the lower end of the range of motion, the rubber feet 345 of the movable cover 340 abut the cover device on the base 2. The rubber feet 345 can dampen noise and impact caused by contact through elastic deformation.

[0059] Furthermore, the guide screws 335 of the fixed cover 330 do not need to be provided with an elastic element or a spacer surrounding the outer circumference. In this case, the width of the guide holes 341 in the left and right directions is slightly larger than the outer diameter of the guide screws 335, and it is desirable to have a slight gap between the guide holes 341 and the guide screws 335 in the left and right directions so that the guide holes 341 and the guide screws 335 can move smoothly. Additionally, the lateral end pieces 332 on both the left and right sides of the fixed cover 330 guide the lateral end pieces 342 on both the left and right sides of the movable cover 340. This allows the movable cover 340 to move more smoothly downwards and upwards.

[0060] As in Fig.As shown in Figure 14, the movable cover 440 does not need to move up and down relative to the fixed cover 430. For example, the movable cover 440 can be provided so that it can rotate left and right about a pivot shaft 441 located near the center of the fixed cover 430. Two movable covers 440 are provided, which rotate by their own weight between a position where they are housed on the back of the fixed cover 430 and a position where they are free of the fixed cover 430. When the main shaft head lowers, the pair of movable covers 440 collide with the cover device and rotate in a direction in which both the left and right end parts move upward and are thus housed on the back of the fixed cover 430.As the main shaft head rises, the pair of movable covers 440 rotate under their own weight in a direction in which both the left and right ends move downwards and are exposed by the fixed cover 430. The pair of movable covers 440 can be positioned in a shape that protects the inside of the stand by butting against each other in the center in the left and right directions. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2006-123045

[0003]

Claims

[1] Machine tool, comprising: a base; a stand provided on the base; a main shaft configured for removably mounting a tool; a support body provided on a side surface of the stator and supporting the main shaft; a moving mechanism provided on the stator and configured to move the support body in an axial direction of the main shaft; and a protective member covering a portion of one side surface of the stand where the moving mechanism is exposed during movement of the support body; wherein the protective element comprises: a first protective member which is fixed to the support body and is moved in the axial direction together with the support body by the moving mechanism; and a second protective part which moves relative to the first protective part on a side opposite the support body of the first protective part. [2] Machine tool according to claim 1, wherein one of the first protective part and the second protective part has an opening extending in the axial direction, and the other of the first protection part and the second protection part has a projection part that projects into the opening and is movable in the axial direction relative to the opening. [3] The machine tool according to claim 2, wherein the second protection member has the opening and is arranged closer to the side of the moving mechanism than the first protection member. [4] A machine tool according to claim 3, wherein the first protection member has a guide member that guides a movement of the second protection member in the axial direction. [5] A machine tool according to claim 4, wherein the protective member comprises an elastic member elastically provided in the projecting part or the opening. [6] A machine tool according to claim 5, wherein the elastic member is formed in a ring shape surrounding a periphery of the projection part. [7] Machine tool according to claim 6, wherein the protective member has a spacer provided between the projection part and the elastic member, and the elastic member is rotatable in a circumferential direction with respect to the projection part. [8] Machine tool according to claim 7, comprising: a third protective part attached to the stand closer to the base side than the protective part; and engagement parts provided on the third protection part and engaging with the second protection part when the carrier body moves in the axial direction in a direction approaching the third protection part, and the engaging parts are elastic. [9] Machine tool according to claim 8, wherein: a notched part, which is notched on a side facing away from the base and has inclined edges inclined with respect to the axial direction in a portion in which it is notched, is formed at an end part of the second protective part on the base side in the axial direction, and the engaging parts abut against the inclined edges of the notched part when the carrier body moves in the axial direction in a direction approaching the third protective part. [10] A machine tool according to any one of claims 1 to 9, wherein the first protection member or the second protection member has projection parts on one of a first surface on which the first protection member faces the second protection member and a second surface on which the second protection member faces the second protection member, and the projection parts project toward the other surface and have projecting tips contacting the other surface. [11] Protective element for a machine tool, the machine tool comprising: a base; a stator provided on the base; a main shaft configured to detachably mount a tool; a support body provided on a side surface of the stator and supporting the main shaft; and a moving mechanism provided on the stator and configured to move the support body in an axial direction of the main shaft, wherein the protective member covers a portion of the one side surface of the stator of the machine tool, and protects where the movement mechanism is exposed when the carrier body moves, wherein the protective element comprises: a first protective member which is fixed to the support body and is moved in the axial direction together with the support body by the moving mechanism; and a second protective part which moves relative to the first protective part, one of the first protective part and the second protective part has an opening extending in the axial direction, and the other of the first protection part and the second protection part has a projection part that projects into the opening and is movable in the axial direction relative to the opening. [12] A protective member according to claim 11, comprising an elastic member elastically provided in the projection part or the opening.

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