Industrial Machinery

Abstract

The present invention is an industrial machine (1) comprising a shaft (3) and a machine component (2) that has a processing surface (A). The following are provided to the processing surface (A): a fitting hole (6) that is orthogonal to the processing surface (A) and into which the shaft (3) is fitted; a plurality of screw holes formed at the periphery of the fitting hole (6) with gaps therebetween in the peripheral direction; and a recess disposed between any screw holes that are adjacent in the peripheral direction. A flange (11), which tightly adheres to the processing surface (A) in a state where the shaft (3) has been fitted into the fitting hole (6), is provided to the shaft (3). The following are provided to the flange (11): a plurality of through-holes into which can penetrate bolts (23) that fasten to the screw holes; and a drawing tap hole that can be disposed at a position corresponding to the recess in the state in which the shaft (3) has been fitted into the fitting hole (6). The recess is formed in a region that does not overlap a region equivalent to the outer diameter of a head section (24) of the bolt (23) at the periphery of the screw holes disposed on both sides of the recess in the peripheral direction.

Description

[Technical Field]

[0001] The present invention relates to industrial machinery. [Background technology]

[0002] Conventionally, in a structure in which a shaft part is fitted into a hole, it is known to use a tapped hole provided in the flange of the shaft part when removing the shaft part from the hole for maintenance or the like (see, for example, Patent Document 1). If burrs occur on the machined surface against which the tip of a draw bolt fastened to a draw tap hole is pressed, the burrs get in the way when reassembling the shaft component, and the burr removal process is also troublesome.By providing a relief recess in the machined surface where the tip of the draw bolt abuts, it is possible to prevent the burrs from interfering with the close contact of the flange of the shaft component with the machined surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 59-83105 Summary of the Invention [Problem to be solved by the invention]

[0004] If a recess is provided on the machined surface with which the flange of the shaft part comes into close contact, the contact area between the flange and the machined surface will be reduced, making it difficult to obtain sufficient friction between them. Therefore, it is desirable to ensure sufficient friction between the flange and the machined surface while preventing deterioration in assembly due to burrs. [Means for solving the problem]

[0005] One aspect of the present invention is a machine part having a machined surface, and a shaft, wherein the machined surface is provided with a fitting hole that is perpendicular to the machined surface and into which the shaft is fitted, a plurality of screw holes formed circumferentially spaced around the fitting hole, and a recessed portion disposed between any of the screw holes that are adjacent in the circumferential direction, and the shaft is provided with a flange that is brought into close contact with the machined surface when the shaft is fitted into the fitting hole, and the flange is provided with a plurality of through holes that can pass bolts that are fastened to the screw holes, and a tapped hole that can be disposed at a position corresponding to the recessed portion when the shaft is fitted into the fitting hole, The recessed portion The screw holes are arranged on both sides of the recess in the circumferential direction. Around the head of the bolt and the recess has a circular shape with a diameter equal to the dimension obtained by adding the diameter of the tip of a pull-out bolt fastened to the pull-out tap hole to the radial gap between the through hole and the bolt. It is an industrial machine. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a vertical cross-sectional view partially illustrating an industrial machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing a part of the industrial machine of FIG. [Figure 3] 3 is a perspective view showing a processed surface of a housing of the industrial machine of FIG. 2. [Figure 4] 3 is a partial front view illustrating a recess formed on the processing surface of FIG. 2. FIG. [Figure 5] 3 is a partial front view showing the relationship between the recesses formed on the machined surface of FIG. 2 and the fixing bolts that fix the flange. FIG. [Figure 6] 3 is a perspective view showing a state in which a draw bolt is fastened to a draw tap hole formed in the flange of FIG. 2. FIG. [Figure 7] FIG. 7 is a vertical cross-sectional view showing the relationship between the extraction bolt and the recessed portion in FIG. 6. [Figure 8] 4 is a diagram showing a modified example of the recess in FIG. 3. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0007] An industrial machine 1 according to one embodiment of the present invention will be described below with reference to the drawings. The industrial machine 1 according to this embodiment is, for example, a robot, and as shown in FIG. 1, includes a housing (mechanical component) 2 and a shaft 3 that connects a link member 15 to the housing 2 so that the link member 15 can rotate around a horizontal axis.

[0008] The housing 2 includes a first plate-shaped portion 4 and a second plate-shaped portion 5 formed in the shape of parallel flat plates. When the industrial machine 1 is installed on an installation surface such as a horizontal floor, the first plate-shaped portion 4 and the second plate-shaped portion 5 are arranged to extend in the vertical direction.

[0009] The outer surface of the first plate-shaped portion 4 is provided with a processing surface A, which is a flat surface extending in the vertical direction. The first plate-shaped portion 4 is provided with a first fitting hole (fitting hole) 6 extending from the processing surface A in a direction perpendicular to the processing surface A. The second plate-shaped portion 5 is provided with a second fitting hole 7 that is arranged coaxially with the first fitting hole 6 and has an inner diameter smaller than that of the first fitting hole 6.

[0010] The shaft 3 is inserted horizontally into the first fitting hole 6 from the machined surface A side of the first plate-shaped portion 4, thereby comprising a large diameter portion 8 that fits into the first fitting hole 6, a small diameter portion 9 that fits into the second fitting hole 7, an intermediate portion 10 that is disposed between the large diameter portion 8 and the small diameter portion 9, and a flange 11 adjacent to the large diameter portion 8. The intermediate portion 10 is fitted into an inner ring 13 of a bearing 12, and an outer ring 14 of the bearing 12 is fitted into a hole 16 provided in one end of a link member 15. As a result, the shaft 3 is supported in the form of a double-supported beam between the first plate-shaped portion 4 and the second plate-shaped portion 5, and the link member 15 is supported on the shaft 3 so as to be rotatable around the horizontal axis line, which is the central axis O of the shaft 3.

[0011] The flange 11 is formed in a circular plate shape provided in the form of a brim at one end of the large diameter portion 8, and as shown in Figure 2, has a plurality of through holes 17 equally spaced circumferentially around the central axis O of the shaft 3. Furthermore, two tapped holes 18 are provided in the flange 11 at positions spaced 180° apart around the central axis O of the shaft 3. Each tapped hole 18 is disposed between two circumferentially adjacent through holes 17 at the same radial position about the central axis O of the shaft 3.

[0012] 3, a plurality of screw holes 19 are provided on the processing surface A radially outward from the first fitting hole 6 and arranged at intervals in the circumferential direction. Also, two recesses 20 are provided on the processing surface A at positions 180° apart around the central axis of the first fitting hole 6 and positioned above and below the horizontal line, for example, at positions vertically above and below the first fitting hole 6. Each recess 20 has a bottom surface 21a positioned one step lower than the processing surface A.

[0013] The radius of the circle connecting the centers of the screw holes 19 on the machined surface A is the same as the radius of the circle connecting the centers of the through holes 17 in the flange 11. In addition, the distance from the central axis of the first fitting hole 6 to the recess 20 on the machined surface A is the same as the distance from the central axis O of the shaft 3 to the punch tap hole 18.

[0014] In this embodiment, as shown in Fig. 4, each recess 20 is formed in a circular shape with a diameter D larger than the dimension obtained by adding the outer diameter d of the tip of the extraction bolt 22 fastened to the extraction tap hole 18 of the flange 11 and the radial gap δ between the through hole 17 and the fixing bolt (bolt) 23. Specifically, D≧d+2δ The relationship is fulfilled. As shown in Figure 5, each recess 20 is formed in an area surrounding two adjacent screw holes 19 on both sides in the circumferential direction, and does not overlap with a circular area equal to the outer diameter dimension of the head 24 of the fixing bolt 23 fastened to each screw hole 19.

[0015] The operation of the industrial machine 1 according to this embodiment configured as described above will be described below. In the industrial machine 1 according to this embodiment, to assemble the shaft 3 into the housing 2, with the bearing 12 fitted onto the intermediate portion 10 of the shaft 3, the shaft 3 is inserted horizontally into the first fitting hole 6 from the side of the processed surface A of the first plate-shaped portion 4. This causes the small diameter portion 9, the intermediate portion 10, and the bearing 12 assembled to the intermediate portion 10 to pass through the first fitting hole 6. Then, the small diameter portion 9 is fitted into the second fitting hole 7 of the second plate-shaped portion 5, the outer ring 14 of the bearing 12 is fitted into the hole 16 of the link member 15, and the large diameter portion 8 is fitted into the first fitting hole 6 of the first plate-shaped portion 4.

[0016] Then, when the large diameter portion 8 of the shaft 3 is fitted into the first fitting hole 6 and the small diameter portion 9 of the shaft 3 is fitted into the second fitting hole 7 and the flange 11 is brought into close contact with the machining surface A, the mounting phase around the central axis O of the shaft 3 is adjusted. This allows the through holes 17 of the flange 11 to be positioned opposite the screw holes 19 of the machining surface A, and the punch tap holes 18 to be positioned opposite the recesses 20.

[0017] Thereafter, with the flange 11 in close contact with the processing surface A, the fixing bolt 23 passed through the through hole 17 is fastened to the screw hole 19 in the processing surface A. As a result, the shaft 3 is fixed in a state in which it is supported like a double-supported beam between the two plate-like portions 4, 5 of the housing 2, and the link member 15 can be supported rotatably around the central axis O of the shaft 3 relative to the housing 2.

[0018] In this case, the area of ​​the machined surface A with which the flange 11 is in close contact is reduced by the recess 20, so no friction is obtained at that portion between the flange 11 and the machined surface A. The area where the flange 11 and the machined surface A are brought into contact with each other at high pressure by the fixing bolt 23 fastened to the screw hole 19 in the machined surface A is an area around the screw hole 19 that is equal to the outer diameter 24 of the head of the fixing bolt 23.

[0019] In this embodiment, by forming the recess 20 so that it does not overlap with the area where the flange 11 and the processing surface A are brought into close contact with each other under high pressure, it is possible to prevent a significant decrease in the friction force between the flange 11 and the processing surface A. As a result, there is an advantage that the relative movement of the shaft 3 around the central axis O of the shaft 3 due to insufficient friction between the shaft 3 and the housing 2 can be prevented.

[0020] On the other hand, when removing the shaft 3 from the housing 2, all of the fixing bolts 23 are removed, and draw bolts 22 are fastened to the tapped draw holes 18 of the flange 11, as shown in Fig. 6, and the tips of the draw bolts 22 are pressed against the bottom surface 21a of the recess 20, as shown in Fig. 7. This applies a force to the flange 11 in a direction that pulls it away from the machined surface A, making it possible to easily remove the shaft 3 from the first fitting hole 6 and the second fitting hole 7.

[0021] In this case, as described above, the draw bolt 22 contacts the bottom surface 21a of the recess 20 and presses against it while rotating, which can roughen the bottom surface 21a of the recess 20 and cause burrs to form. Because the bottom surface 21a of the recess 20 is located one step lower than the machined surface A, the burrs do not protrude outward from the machined surface A and do not interfere with the close contact between the flange 11 and the machined surface A during the next assembly. In addition, there is no need to remove the burrs that have formed, making reassembly easy.

[0022] Furthermore, even if the fixing bolt 23 is correctly aligned with the screw hole 19 on the machined surface A, there is a gap between the fixing bolt 23 and the through hole 17 through which the fixing bolt 23 passes, so the flange 11 may be positioned circumferentially shifted by the amount of the gap with respect to the machined surface A. Since the recess 20 is formed in a circular shape with a diameter larger than the sum of the tip diameter dimension of the extraction bolt 22 fastened to the extraction tap hole 18 and the radial gap dimension between the through hole 17 and the fixing bolt 23, the tip face of the extraction bolt 22 can be positioned within the recess 20 even if the flange 11 is shifted circumferentially.

[0023] This prevents the machining surface A from being roughened by the tip of the extraction bolt 22 fastened to the extraction tap hole 18, even if the flange 11 is positioned offset by the above-mentioned gap with respect to the housing 2.

[0024] Furthermore, when the removal work of the shaft 3 is performed by gradually tightening the removal bolt 22 into one of the removal tap holes 18, an unbalanced load is applied to the flange 11, causing the large diameter portion 8 of the shaft 3 to tilt with respect to the first fitting hole 6. If this tilt angle becomes large, galling occurs between the large diameter portion 8 and the first fitting hole 6, making it difficult to remove the shaft 3 from the first fitting hole 6.

[0025] In this embodiment, the tapped holes 18 are located on opposite sides of the central axis O of the shaft 3, so that by alternately tightening the two pull-out bolts 22 little by little, the shaft 3 can be pulled out of the first fitting hole 6 without causing galling.

[0026] In particular, when the shaft 3 is arranged horizontally as in this embodiment, a moment around the horizontal axis acts on the shaft 3 due to its own weight when the shaft 3 is pulled out. Even in this case, because recesses 20 are disposed in two locations, one above and one below the first fitting hole 6 in the vertical direction, it is possible to apply moments in opposite directions about the horizontal axis to the shaft 3 by fastening the pull-out bolt 22. Therefore, even if galling occurs due to its own weight, this can be corrected and the shaft 3 can be easily pulled out.

[0027] In this embodiment, when the shaft 3 is pulled out partway and the small diameter portion 9 is no longer fitted into the second fitting hole 7, a load may be applied upward or downward to the intermediate portion 10 due to the weight of the link member 15 or a member connected to the link member 15. In this case, a moment about the horizontal axis is generated in the shaft 3, but there is an advantage in that a moment in the opposite direction is applied by the pull bolts 22 above and below the large diameter portion 8, making it possible to easily pull out the shaft 3 while correcting any galling.

[0028] In this embodiment, recess 20 is formed in a circular shape with a diameter larger than the outer diameter of the tip of pull bolt 22 plus the radial gap between through hole 17 and fixing bolt 23, but this is not limited to this. In other words, even if flange 11 is misaligned by the radial gap between through hole 17 and fixing bolt 23, as long as the tip of pull bolt 22 is positioned within recess 20, recess 20 may be formed in an oval shape extending in the circumferential direction, as shown in Fig. 8. In this case, the radial width dimension relative to the center of the first fitting hole 6 may be slightly larger than the tip diameter of the pull bolt 22. This reduces the reduction in the contact area between the flange 11 and the machined surface A caused by the recess 20, allowing a greater frictional force to be generated between the flange 11 and the machined surface A.

[0029] In addition, in this embodiment, the recesses 20 are provided in two locations, one vertically above and one vertically below the first fitting hole 6, but this is not limited to this. As long as they are located above and below a horizontal line that passes through the central axis of the first fitting hole 6 and is located on the processing surface A, they may be positioned away from the vertically above or below.

[0030] Furthermore, the housing 2 may be provided with an identification mark that allows the position of the recess 20 to be identified when the flange 11 is in close contact with the processing surface A. Examples of the identification mark provided on the processed surface A include providing a mark on the bottom surface 21a of the recess 20, or coloring only the bottom surface 21a of the recess 20, etc.

[0031] This allows the identification mark to be confirmed through the tapped draw hole 18 even when the flange 11 is in close contact with the machined surface A, preventing the draw bolt 22 from pressing against the machined surface A other than the recess 20. The identification mark may also be a mark such as an arrow that is arranged radially outward of the flange 11 that is in close contact with the machined surface A and indicates the position of the recess 20.

[0032] Furthermore, in this embodiment, the mechanical components are exemplified as the housing 2 and the shaft 3, with the link member 15 rotatably attached to the housing 2, but the present invention is not limited to this and may be applied to any other mechanical components of the industrial machine 1. Furthermore, the present invention is exemplified as the industrial machine 1 as a robot, but instead, the present invention may be applied to any other industrial machine. [Explanation of symbols]

[0033] 1. Industrial machinery 2 Housing (mechanical parts) 3 shafts 6 First fitting hole (fitting hole) 11 flange 17 Through hole 18 tapped holes 19 screw holes 20 recess 22 Extraction bolt 23 Fixing bolt (bolt) 24 Head A Machining surface

Claims

1. a machine part having a machined surface; a shaft; The machined surface is provided with a fitting hole that is perpendicular to the machined surface and into which the shaft is fitted, a plurality of screw holes that are formed around the fitting hole at intervals in the circumferential direction, and a recess that is arranged between any of the screw holes that are adjacent in the circumferential direction, a flange is provided on the shaft, the flange being brought into close contact with the processing surface when the shaft is fitted into the fitting hole; The flange is provided with a plurality of through holes through which bolts to be fastened to the respective screw holes can pass, and a tapped hole that can be arranged at a position corresponding to the recess when the shaft is fitted into the fitting hole, the recess is formed in an area that does not overlap with an area around the screw hole that is located on both sides of the recess in the circumferential direction and that is equal to the outer diameter of the head of the bolt, the recess has a circular shape with a diameter equal to the dimension obtained by adding the tip diameter of the extraction bolt to be fastened to the extraction tap hole and the radial gap between the through hole and the bolt.

2. a machine part having a machined surface; a shaft; The machined surface is provided with a fitting hole that is perpendicular to the machined surface and into which the shaft is fitted, a plurality of screw holes that are formed around the fitting hole at intervals in the circumferential direction, and a recess that is arranged between any of the screw holes that are adjacent in the circumferential direction, a flange is provided on the shaft, the flange being brought into close contact with the processing surface when the shaft is fitted into the fitting hole; The flange is provided with a plurality of through holes through which bolts to be fastened to the respective screw holes can pass, and a tapped hole that can be arranged at a position corresponding to the recess when the shaft is fitted into the fitting hole, the recess is formed in an area that does not overlap with an area around the screw hole that is located on both sides of the recess in the circumferential direction and that is equal to the outer diameter of the head of the bolt, the recess has an oval shape with a length dimension equal to the sum of the tip diameter of a pull bolt fastened to the pull tap hole and the radial gap between the through hole and the bolt, and a width dimension slightly larger than the tip diameter.

3. 3. The industrial machine according to claim 1, wherein the recesses are provided on opposite sides of the central axis of the fitting hole.

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