Machine tool

Abstract

To provide a machine tool capable of reducing the number of grinding units and grinding the surfaces of workpieces of various shapes.SOLUTION: A machine tool 1 includes a grinding device 30 for grinding a surface of a workpiece 2. The grinding device 30 includes a second moving device 31 movable with respect to the workpiece 2, a robot arm 32 supported by the second moving device 31, and a grinding unit 50 attached to a tip end portion of the robot arm 32.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a machine tool having a grinding device. [Background technology]

[0002] When constructing the framework of a building, one method of joining H-shaped steel beams together is to drill multiple holes in the ends of the H-shaped steel beams, overlap a joining plate with similarly drilled holes over the ends of adjacent H-shaped steel beams, and then fasten both H-shaped steel beams and the joining plate with bolts to join the H-shaped steel beams together. In this type of joining method, multiple holes are drilled in the end of the H-beam before it is delivered to the site.The surface of the end of the H-beam is then ground to remove the oxide film (black scale), intentionally creating rust on the surface of the H-beam, which increases the coefficient of friction between the H-beam and the joining plate.

[0003] BACKGROUND ART Grinding devices for grinding the surface of H-section steel include those equipped with a plurality of grinding units fixed to a base (see, for example, Patent Document 1). In the grinding device, multiple rollers are arranged on the top surface of a base, and a drive mechanism is used to push the H-shaped steel, causing it to slide over each roller and move between each grinding unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-79739 Summary of the Invention [Problem to be solved by the invention]

[0005] The grinding device described above requires the installation of a plurality of grinding units in accordance with the grinding portions of the H-beam, which poses a problem of a large number of grinding units. In addition, when an H-shaped steel beam in which the width of the flange in the vertical direction varies in parts and the lower edge of the flange is curved in the vertical direction is placed on each roller of the grinding device, the H-shaped steel beam tends to tilt on each roller, which creates the problem that it is not possible to move the irregular H-shaped steel beam.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a machine tool that can reduce the number of grinding units and can grind the surfaces of workpieces of various shapes. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides a machine tool including a grinding device for grinding the surface of a workpiece. The grinding device includes a moving device movable relative to the workpiece, a robot arm supported by the moving device, and a grinding unit attached to the tip of the robot arm. The grinding unit includes a drive device and a grinding wheel attached to the drive shaft of the drive device.

[0008] In the machine tool of the present invention, the workpiece is fixed, and the grinding units are moved relative to the workpiece to grind various portions of the workpiece, so the number of grinding units can be reduced. The machine tool of the present invention can grind the surface of workpieces of various shapes without moving the workpiece. For example, the machine tool of the present invention can grind the surface of an irregular H-beam whose flange width varies partially in the vertical direction.

[0009] In the machine tool, it is preferable that the grinding device is provided with two grinding units, and that both grinding units are attached to the tip of the robot arm with the grinding wheels facing each other. In this configuration, by sandwiching the workpiece between both grinding units, both sides of the workpiece can be ground simultaneously, thereby improving work efficiency.

[0010] In the above-described machine tool, when the grinding unit is attached to the tip of the robot arm via a cylinder device, it is preferable that the drive device and the grinding wheel are arranged in a straight line along the axial direction of the extendable rod of the cylinder device. This configuration allows the grinding unit to be compact, so that when a wall portion is erected on the edge of the surface to be ground, the grinding unit can be moved close to the wall portion and grind the surface to the edge.

[0011] The machine tool may be provided with a dust collecting device including a pump supported by the moving device, a cover for covering the grinding wheel, and a connecting hose having one end connected to the pump and the other end connected to the cover. The cover has an opening facing the surface of the workpiece, and air inside the cover is sucked in through the connecting hose by the suction action of the pump.

[0012] In this configuration, dust generated when grinding a workpiece is collected by a dust collector, preventing the dust from scattering. Furthermore, in the dust collector described above, the pump moves together with the grinding machine, so the distance between the pump and the grinding unit does not change as the grinding machine moves. This allows the connecting hose between the pump and the cover to be shortened, making it easier to handle.

[0013] In the above-mentioned machine tool, it is preferable that a drilling device for drilling holes in the workpiece is provided, and that the drilling device is movable relative to the workpiece. With this configuration, after the drilling device is placed at a predetermined position and drills holes in the workpiece, the drilling device can be moved from the predetermined position and the grinding device can be moved to a predetermined position to grind the surface of the workpiece. Then, while the grinding device is grinding the surface of the workpiece at the predetermined position, the drilling device can drill holes in the workpiece at another position. In this way, the drilling and grinding processes of the workpiece can be performed efficiently. [Effects of the Invention]

[0014] The machine tool of the present invention can grind various parts of the workpiece by moving the grinding units relative to the workpiece, which reduces the number of grinding units and ultimately reduces manufacturing costs. Furthermore, since the machine tool of the present invention does not require moving the workpiece, it can grind the surfaces of workpieces of various shapes. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a plan view showing a machine tool according to an embodiment of the present invention; [Figure 2] 1 is a side view showing a machine tool according to an embodiment of the present invention. [Figure 3] FIG. 2 is a side view showing the grinding unit according to the embodiment of the present invention. [Figure 4] 1 is a side view showing a state in which a drilling device is arranged at the front end of a workpiece in a machine tool according to an embodiment of the present invention. FIG. [Figure 5] 1 is a side view showing a state in which a drilling device is arranged at the rear end of a workpiece and a grinding device is arranged at the front end of the workpiece in a machine tool according to an embodiment of the present invention. FIG. [Figure 6] 1 is a side view showing a state in which a grinding device is disposed at the rear end of a workpiece in a machine tool according to an embodiment of the present invention. FIG. [Figure 7] FIG. 10 is a plan view showing a machine tool according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. 1, a machine tool 1 of this embodiment performs drilling and grinding on a workpiece 2. In the following description, the terms "front-rear" and "left-right" are used for the convenience of explaining the machine tool 1 of this embodiment, and do not limit the configuration or usage state of the machine tool 1. However, in this embodiment, the longitudinal direction of the workpiece 2 is defined as the front-rear direction, and the width direction of the workpiece 2 is defined as the left-right direction.

[0017] The workpiece 2 in this embodiment is an H-section steel having flanges 2b, 2b formed on both edge portions of a web 2a. 2, the vertical width of the flange 2b of the workpiece 2 of this embodiment is smaller at the middle portion than at both longitudinal ends. Thus, the workpiece 2 of this embodiment is an irregular H-shaped steel, and the upper and lower edge portions of the flange 2b are recessed at the middle portion in the longitudinal direction.

[0018] The machine tool 1 of this embodiment drills multiple holes in the front and rear ends of the web 2a of the workpiece 2, and grinds the surface of the front and rear ends of the workpiece 2 to remove the oxide coating (black scale).

[0019] As shown in FIG. 1, the machine tool 1 includes left and right rails 10, 10, a drilling device 20, and a grinding device 30. The rails 10 are laid on the base surface and extend in the front-rear direction. The left and right rails 10, 10 are arranged parallel to each other with a gap in the left-right direction. The base surface between the left and right rails 10, 10 is the area where the workpiece 2 is placed. The workpiece 2 is placed on the base surface with its longitudinal direction aligned in the front-to-rear direction. As shown in FIG. 2, the workpiece 2 is placed on the top surface of a receiving stand 2c placed on the base surface. Therefore, the workpiece 2 is placed at a predetermined height from the base surface.

[0020] The perforation device 20 is for making a plurality of holes at the front and rear ends of the web 2 a of the workpiece 2 . The drilling device 20 includes a first moving device 21 supported by left and right rails 10, 10, and a drilling unit 22 supported by the first moving device 21.

[0021] The first moving device 21 has left and right ends engaged with both rails 10, 10 and is movable in the front-rear direction along both rails 10, 10. The punching unit 22 is attached to a movement mechanism (not shown) provided on the top surface of the first moving device 21, and is movable in the left-right direction on the top surface of the first moving device 21. In this way, the drilling unit 22 is movable in the front-rear and left-right directions relative to the workpiece 2 fixed to the base surface. The drive mechanism for moving the drilling unit 22 is not limited.

[0022] In the drilling device 20, the drilling unit 22 is moved in the front-to-back and left-to-right directions relative to the workpiece 2 fixed to the base surface, so that the drill (not shown) of the drilling unit 22 can form multiple holes lined up front-to-back and left-to-right at the end of the web 2a of the workpiece 2.

[0023] The grinding device 30 grinds the surface of the front end and rear end of the web 2a of the workpiece 2. The grinding device 30 is disposed forward of the drilling device 20. The grinding device 30 includes a second moving device 31 supported on left and right rails 10, 10, a robot arm 32 supported on the second moving device 31, two grinding units 50, 50 (see Figure 2) attached to the tip of the robot arm 32, and a dust collection device 60.

[0024] The second moving device 31 has left and right ends connected to both rails 10, 10 and is movable in the front-rear direction along both rails 10, 10. The robot arm 32 is attached to a movement mechanism (not shown) provided on the upper surface of the second movement device 31, and is movable in the left-right direction on the upper surface of the second movement device 31. In this way, the robot arm 32 is movable in the front-rear and left-right directions relative to the workpiece 2 fixed to the base surface. Note that the drive mechanism for moving the robot arm 32 is not limited.

[0025] As shown in Fig. 2, the robot arm 32 is a vertically articulated industrial robot. The robot arm 32 of this embodiment has an arm 32a that is movable about six axes, and the base end of the arm 32a is supported by a base member 32b. The base member 32b is attached to the movement mechanism of the second movement device 31. The arm 32a is connected to the base member 32b so as to be rotatable about a vertical axis.

[0026] 3, a support bracket 33 is attached to the tip of the arm 32a of the robot arm 32. The support bracket 33 has upper and lower support portions 33a, 33a protruding laterally from the top and bottom, and is formed in a C-shape when viewed from the side. An upper grinding unit 50 is attached to the tip of the upper support portion 33a that protrudes laterally from the top of the support bracket 33. In addition, a lower grinding unit 50 is attached to the tip of the lower support portion 33a that protrudes laterally from the bottom of the support bracket 33.

[0027] The upper grinding unit 50 includes a drive device 51 connected to the support bracket 33 , a grinding wheel 52 attached to a drive shaft 51 c of the drive device 51 , and a cylinder device 53 .

[0028] The drive unit 51 includes a cylindrical housing 51a that penetrates vertically, a drive motor 51b attached to the upper end of the housing 51a, and a drive shaft 51c that is inserted into the housing 51a. The upper end of the drive shaft 51c is connected to the output portion of the drive motor 51b. The housing 51a is connected to an upper support portion 33a of the support bracket 33 via a slide member 51d. The housing 51a is movable relative to the support bracket 33 in the vertical direction.

[0029] The cylinder device 53 includes a cylinder body 53a and an extension rod 53b that is extendable and contractible in the vertical direction relative to the cylinder body 53a. The cylinder body 53a is attached to the side of the driving device 51. The tip of the extensible rod 53b is attached to the upper support part 33a of the support bracket 33. When the extension rod 53b is extended or retracted relative to the cylinder body 53a, the grinding unit 50 moves up or down relative to the support bracket 33 with the housing 51a guided by the slide member 51d.

[0030] The grinding wheel 52 is attached to the tip of the drive shaft 51c of the drive device 51. The grinding wheel 52 is disposed with its grinding surface facing downward, and rotates in conjunction with the drive shaft 51c. In the grinding unit 50 of this embodiment, the drive device 51 and the grinding wheel 52 are arranged in a straight line along the axial direction of the extendable rod 53b of the cylinder device 53. That is, the central axis of the housing 51a, the drive shaft 51c, and the center of rotation of the grinding wheel 52 are arranged coaxially and parallel to the axial direction of the extendable rod 53b.

[0031] The dust collecting device 60 includes a pump 61 supported by the second moving device 31 shown in FIG. 2, a cover 62 that covers the grinding wheel 52 shown in FIG. 3, and a connecting hose 63 connected to the cover 62. 2, the pump 61 is supported by the base member 32b of the robot arm 32. A dust collection tank is provided in the pump 61. The pump 61, together with the grinding device 30, is movable in the front-rear and left-right directions.

[0032] 3, the cover 62 is a box-shaped member that covers the grinding wheel 52. An opening 62a that faces the surface of the workpiece 2 is formed in the lower surface of the cover 62, and the end of the grinding wheel 52 on the grinding surface side protrudes from the opening 62a to the outside.

[0033] One end of the connecting hose 63 is connected to the suction port of the pump 61 (see FIG. 2), and the other end of the connecting hose 63 is connected to the cover 62 and communicates with the internal space of the cover 62.

[0034] The dust collector 60 is configured to suck air from inside the cover 62 through a connecting hose 63 by the suction action of a pump 61 (see FIG. 2). The outlet of the pump 61 is connected to a dust collection tank. This allows dust generated when the surface of the workpiece 2 is ground by the grinding wheel 52 to be sucked into the dust collection tank through the connecting hose 63 and collected therein without scattering outside the cover 62.

[0035] The lower grinding unit 50 is configured to be vertically symmetrical with respect to the upper grinding unit 50. The lower grinding unit 50 is attached to the lower support part 33a of the support bracket 33 with the grinding wheel 52 disposed at the upper end and the drive unit 51 disposed at the lower end.

[0036] The upper and lower grinding units 50, 50 are attached to the tip of the arm 32a of the robot arm 32 with the grinding surfaces of the grinding wheels 52, 52 facing each other up and down. The cylinder device 53 of the grinding unit 50 is driven to move the grinding wheel 52 in the vertical direction, thereby making it possible to adjust the distance between the upper and lower grinding wheels 52, 52.

[0037] Next, a description will be given of drilling and grinding of a workpiece 2 using the machine tool 1 of this embodiment. The operation of each part of the machine tool 1 is controlled by a control device (not shown).

[0038] First, as shown in Figure 1, the workpiece 2 is placed on the base surface between the left and right rails 10, 10. At this time, the longitudinal direction of the workpiece 2 is arranged in the front-to-rear direction, and both surfaces of the web 2a are arranged vertically. In other words, both flanges 2b, 2b of the workpiece 2 are arranged perpendicular to the base surface, and the lower edges of both flanges 2b, 2b are abutting the base surface (see Figure 2). When the workpiece 2 is placed between the left and right rails 10, 10, the drilling device 20 and the grinding device 30 are disposed in front of the workpiece 2.

[0039] After the workpiece 2 is placed between the left and right rails 10, 10, the drilling device 20 is moved rearward and positioned at the front end of the workpiece 2, as shown in FIG. Then, a plurality of holes are drilled in the front end portion of the web 2 a of the workpiece 2 by a drill (not shown) of the drilling unit 22 .

[0040] Next, as shown in FIG. 5, the drilling device 20 is moved rearward and positioned at the rear end of the workpiece 2. Then, a plurality of holes are drilled in the rear end portion of the web 2 a of the workpiece 2 by a drill (not shown) of the drilling unit 22 . Furthermore, the drilling device 20 is moved rearward, and the grinding device 30 is also moved rearward, so that the grinding device 30 is positioned at the front end of the workpiece 2 . Then, the arm 32a of the robot arm 32 is driven to sandwich the web 2a between the upper and lower grinding wheels 52, 52, as shown in Fig. 3. In this state, the grinding wheels 52, 52 are rotated, and both surfaces of the front end portion of the web 2a are ground by the grinding wheels 52, 52, thereby removing the oxide coatings (black scales) on both surfaces of the web 2a. When the surface of the web 2a is ground by the grinding wheel 52 of the grinding unit 50, the dust collector 60 is driven to suck air from within the cover 62, thereby preventing dust from scattering. In this way, drilling of the rear end portion of the workpiece 2 and grinding of both surfaces of the front end portion of the workpiece 2 are carried out simultaneously.

[0041] Next, as shown in FIG. 6, the drilling device 20 is moved rearward and positioned behind the workpiece 2. The grinding device 30 is then moved backward to be positioned at the rear end of the workpiece 2, and the arm 32a of the robot arm 32 is rotated about an axis in the vertical direction relative to the base member 32b. Then, similarly to the grinding of the front end portion of the workpiece 2, both surfaces of the rear end portion of the web 2a are ground by the upper and lower grinding units 50, 50 to remove the oxide film (black scale).

[0042] 5, in the machine tool 1 as described above, while the grinding device 30 is grinding a predetermined portion of the surface of the workpiece 2, the drilling device 20 can drill holes in other portions of the workpiece 2. In this way, drilling and grinding can be efficiently performed on the workpiece 2 fixed to the base surface.

[0043] The machine tool 1 of this embodiment can perform drilling and grinding on the workpiece 2 without moving the workpiece 2. Therefore, the machine tool 1 of this embodiment can also grind the surface of the workpiece 2, which is an irregular H-section steel in which the width of the flange 2b in the vertical direction varies partially, as shown in Figure 2, and which is difficult to move on a roller conveyor.

[0044] 5 and 6, in the machine tool 1 of this embodiment, the workpiece 2 is fixed to the base surface, and the drilling device 20 and grinding device 30 are moved relative to the workpiece 2 to drill and grind various portions of the workpiece 2. In this way, there is no need to install a drilling unit 22 and a grinding unit 50 for each machining portion of the workpiece 2, so the number of drilling units 22 and grinding units 50 can be reduced. This in turn reduces the manufacturing cost of the machine tool 1.

[0045] In the machine tool 1 of this embodiment, as shown in FIG. 3, the web 2a of the workpiece 2 is sandwiched between upper and lower grinding units 50, 50, so that both sides of the web 2a can be ground simultaneously, thereby improving work efficiency.

[0046] In the grinding unit 50 of the machine tool 1 of this embodiment, the drive unit 51 and the grinding wheel 52 are arranged in a straight line along the axial direction of the extendable rod 53b of the cylinder device 53. Because the grinding unit 50 is configured compactly in this way, the grinding unit 50 can be brought close to the flange 2b (see FIG. 1) and grinding can be performed up to the edge of the web 2a.

[0047] The grinding unit 50 of the machine tool 1 of this embodiment is provided with a dust collection device 60, which can prevent the scattering of dust generated when the workpiece 2 is ground. Furthermore, in the dust collection device 60, as shown in Figure 2, a pump 61 is attached to the second moving device 31, and the pump 61 moves together with the grinding device 30, so the distance between the pump 61 and the grinding unit 50 does not change as the grinding device 30 moves. This allows the connecting hose 63 between the pump 61 and the cover 62 shown in Figure 3 to be shortened, which allows for efficient collection of dust and makes it easier to handle the connecting hose 63.

[0048] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate within the scope of the invention. In the machine tool 1 of this embodiment, as shown in Figure 1, one workpiece 2 is arranged between the left and right rails 10, 10, but multiple workpieces 2 may also be arranged between the two rails 10, 10. For example, as shown in FIG. 7 , four workpieces 2 may be arranged between the rails 10, 10, front to back, left to right. In this case, after the drilling device 20 drills the front ends of the two front workpieces 2, 2, the drilling device 20 also drills the rear ends of the two rear workpieces 2, 2. While the drilling device 20 is drilling the rear ends of the two front workpieces 2, 2, the grinding device 30 can grind the front ends of the two front workpieces 2, 2. While the drilling device 20 is drilling the front ends of the two rear workpieces 2, 2, the grinding device 30 can grind the rear ends of the two front workpieces 2, 2. While the drilling device 20 is drilling the rear ends of the two rear workpieces 2, 2, the grinding device 30 can grind the front ends of the two rear workpieces 2, 2. In this way, by moving the drilling device 20 and the grinding device 30, drilling and grinding of a plurality of workpieces 2 can be performed efficiently.

[0049] In the grinding device 30 of this embodiment, as shown in FIG. 3, two grinding units 50, 50 are attached to the tip of the arm 32a of the robot arm 32, one above the other, but it is also possible to attach one grinding unit 50 to the tip of the arm 32a.

[0050] In the grinding device 30 of this embodiment, as shown in Figure 2, both sides of the web 2a of the workpiece 2 are ground by upper and lower grinding units 50, 50, but by driving the arm 32a of the robot arm 32, both sides of the flange 2b can also be ground by both grinding units 50, 50.

[0051] The robot arm 32 of the grinding device 30 of this embodiment has an arm 32a that is movable on six axes, but the configuration of the robot arm is not limited thereto.

[0052] In this embodiment, the workpiece 2 is an H-shaped steel beam with recesses at the upper and lower edges of the flange 2b, but the workpieces that can be drilled and ground using the machine tool of the present invention are not limited to these.

[0053] The machine tool 1 of this embodiment is equipped with the drilling device 20 and the grinding device 30, but may be configured to be provided with only the grinding device 30 and to perform grinding of the workpiece 2. [Explanation of symbols]

[0054] 1 Machine tools 2 Work material 2a Web 2b flange 2c Cradle 10 Rail 20 Drilling device 21 First moving device 22 Drilling unit 30 Grinding equipment 31 Second moving device 32 Robot Arm 32a Arm 32b Base member 33 Support bracket 33a Support part 50 Grinding Unit 51 Drive unit 51a Housing 51b Drive motor 51c drive shaft 51d Slide member 52 Grinding Wheel 53 Cylinder device 53a Cylinder body 53b Telescopic rod 60 Dust collector 61 Pump 62 Cover 62a opening 63 Connecting hose

Claims

1. A grinding device is provided for grinding the surface of the workpiece, The grinding device is a moving device that is movable relative to the workpiece; a robot arm supported by the moving device; a grinding unit attached to the tip of the robot arm, The grinding unit comprises: A drive unit; a grinding wheel attached to the drive shaft of the drive device.

2. 2. The machine tool according to claim 1, The grinding device includes two grinding units, The machine tool is characterized in that both grinding units are attached to the tip of the robot arm with the grinding wheels facing each other.

3. 2. The machine tool according to claim 1, The grinding unit comprises: attached to the tip of the robot arm via a cylinder device, The machine tool is characterized in that the drive device and the grinding wheel are arranged in a straight line along the axial direction of the extendable rod of the cylinder device.

4. 2. The machine tool according to claim 1, a pump supported by the moving device; a cover for covering the grinding wheel; a connecting hose having one end connected to the pump and the other end connected to the cover, The cover has an opening formed therein facing the surface of the workpiece, A machine tool characterized in that air inside the cover is sucked in through the connecting hose by the suction action of the pump.

5. 2. The machine tool according to claim 1, a drilling device for drilling holes in the workpiece; The machine tool is characterized in that the drilling device is movable relative to the workpiece.

Images