JP7816488B2 - Grinding machine - Google Patents

Description

The present disclosure relates to a grinding machine.

As described in Patent Documents 1 and 2, fluid bearings using circulating fluid have been adopted as bearings for supporting grinding wheels in grinding machines to achieve high-precision grinding. Patent Document 2 also describes a grinding machine equipped with rolling bearings using circulating fluid.

Japanese Patent Application Laid-Open No. 2006-150485 Japanese Patent Application Laid-Open No. 2006-068847

As described in Patent Documents 1 and 2, when using a fluid bearing that uses a circulating fluid, the power of a pump unit is required to supply the circulating fluid, and furthermore, when the circulating fluid is replaced, the used circulating fluid must be disposed of as waste oil. Similar problems arise with rolling bearings that use a circulating fluid.

In recent years, research has focused on bearings that do not use circulating fluids, making it possible to achieve high precision while employing rolling bearings that do not use circulating fluids. However, there will continue to be a need for fluid bearings that use circulating fluids, and they will coexist alongside rolling bearings that do not use circulating fluids.

In these circumstances, separately designing a grinding machine that uses a fluid bearing that uses a circulating fluid and a grinding machine that uses a rolling bearing that does not use a circulating fluid would result in higher grinding machine costs. Furthermore, when making capital investments with future prospects in mind, it is not easy for users to decide which grinding machine to use.

This disclosure has been made in consideration of such problems and aims to provide a grinding machine that can achieve low costs regardless of whether it uses a fluid bearing that uses a circulating fluid or a rolling bearing that does not use a circulating fluid.

One aspect of the present disclosure is a grinding wheel head comprising:
a grinding wheel spindle unit that is detachably attached to the wheel head body and supports a grinding wheel;
Equipped with
the grinding wheel spindle unit is configured to be selectable between a first grinding wheel spindle unit and a second grinding wheel spindle unit,
The first grinding wheel spindle unit is
a first grinding wheel spindle supporting the grinding wheel;
a first unit housing configured to be detachably attached to the wheel head body, rotatably supporting the first grinding wheel spindle by a fluid bearing using a circulating fluid, and having a supply flow path for supplying the circulating fluid to the fluid bearing and a discharge flow path for discharging the circulating fluid from the fluid bearing;
Equipped with
The second grinding wheel spindle unit is
a second grinding wheel spindle supporting the grinding wheel;
a second unit housing configured to be detachably attached to the wheel head body and rotatably supporting the second wheel spindle by a rolling bearing that does not use a circulating fluid;
Equipped with
the wheel head body has a connecting flow path configured to allow the circulating fluid to flow between the supply flow path or the discharge flow path of the first unit housing when the first wheel spindle unit is attached,
The connection flow passage is in a grinding machine and is configured to be closed by the second unit housing of the second grinding spindle unit when the second grinding spindle unit is attached to the grinding wheel head body.

In the above-described embodiment, the grinding machine has a wheel head separated into a wheel head body and a wheel spindle unit. The wheel spindle unit is configured to be selectable between a first wheel spindle unit having a fluid bearing that uses a circulating fluid and a second wheel spindle unit having a rolling bearing that does not use a circulating fluid. In other words, when the first wheel spindle unit is attached to the wheel head body, the grinding machine is configured to have a fluid bearing that uses a circulating fluid. On the other hand, when the second wheel spindle unit is attached to the wheel head body, the grinding machine is configured to have a rolling bearing that does not use a circulating fluid. In this way, by using a common wheel head body and configuring the wheel spindle unit to be interchangeable in the wheel head, low costs can be achieved as a grinding machine regardless of which specification is adopted.

In addition, after a user has received a grinding machine with a first grinding wheel spindle unit equipped with a fluid bearing, they can purchase a second grinding wheel spindle unit separately to replace the grinding machine with a rolling bearing that does not use a circulating fluid. This gives users greater freedom of choice.

The wheel head body also has a connecting flow path that allows circulating fluid to flow between the first grinding spindle unit and the fluid bearing of the first grinding spindle unit when the first grinding spindle unit is attached. When the second grinding spindle unit is attached to the wheel head body, the connecting flow path is not used. At this time, the connecting flow path is configured to be blocked by the second unit housing of the second grinding spindle unit. Therefore, when the connecting flow path is not in use, the second grinding spindle unit can prevent dust and other particles from entering the connecting flow path, maintaining the connecting flow path in good condition.

As described above, according to the above aspect, it is possible to provide a grinding machine that can achieve low costs regardless of whether a fluid bearing using a circulating fluid or a rolling bearing not using a circulating fluid is used.

Note that the symbols in parentheses in the claims indicate their correspondence with the specific means described in the embodiments below, and do not limit the technical scope of the present invention.

FIG. 2 is a plan view of the grinding machine with a first grinding wheel spindle unit having a fluid bearing attached thereto. FIG. 2 is a right side view of the grinding machine with a first grinding wheel spindle unit having a fluid bearing attached thereto. FIG. 3 is an exploded perspective view showing a first wheel head that constitutes the grinding machine shown in FIGS. 1 and 2 and includes a wheel head main body and a first wheel spindle unit having a fluid bearing. 4 is a cross-sectional view taken along the line IV-IV in FIG. 5, showing a first wheel head including a wheel head body and a first wheel spindle unit having a fluid bearing. 5 is a cross-sectional view taken along the line VV in FIG. 4. 10 is a side view of the grinding machine when the first wheel head is positioned at the retracted position (rear) on the wheel head base. FIG. FIG. 2 is a plan view of the grinding machine with a second grinding wheel spindle unit having a rolling bearing attached thereto. FIG. 2 is a right side view of the grinding machine with a second grinding wheel spindle unit having a rolling bearing attached thereto. FIG. 9 is an exploded perspective view showing a second wheel head that is included in the grinding machine shown in FIGS. 7 and 8 and includes a wheel head body and a second wheel spindle unit having a rolling bearing. 10 is a cross-sectional view of a second wheel head including a wheel head body and a second wheel spindle unit having a rolling bearing, taken along a direction perpendicular to the axis, and corresponds to the XX cross-sectional view of FIG. 9. 11 is a cross-sectional view taken along the line XI-XI of FIG.

(Embodiment)
1. Overview of the Grinding Machine An overview of the grinding machine 1 of this embodiment will be described with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the grinding machine 1 rotates the workpiece W and also rotates the grinding wheel T, thereby moving the workpiece W and the grinding wheel T relative to each other, thereby grinding the workpiece W with the grinding wheel T. FIGS. 1 and 2 show a state in which the grinding wheel T is in contact with the workpiece W. In this embodiment, a cylindrical grinding machine is used as the grinding machine 1, but various configurations such as a cam grinding machine and a surface grinding machine are applicable. In addition, in this embodiment, a wheelhead traverse grinding machine is used as the grinding machine 1, but a table traverse grinding machine can also be used.

In addition, the grinding machine 1 in this embodiment is configured so that the following two specifications can be selected alternatively by replacing some units. The first specification is a specification in which the grinding spindle supporting the grinding wheel T is configured with a fluid bearing using a circulating fluid. The second specification is a specification in which the grinding spindle supporting the grinding wheel T is configured with a rolling bearing that does not use a circulating fluid.

In the following, we will first explain the specifications configured with a fluid bearing that uses a circulating fluid, and then we will explain the specifications configured with a rolling bearing that does not use a circulating fluid. Furthermore, components that are common to both specifications will be given the same reference numerals.

2. Fluid bearing grinder 1
The configuration of a grinding machine 1 equipped with a fluid bearing 32b using a circulating fluid will be described with reference to Figures 1 and 2. The grinding machine 1 includes a bed 11, a headstock 12, a tailstock 13, a wheel head base 14, a first wheel head 15, a drain unit 16, and a pump unit 17. Although not shown, the grinding machine 1 may also include a sizing device, a rest device, a grinding wheel dressing device, etc.

The bed 11 is placed on the installation surface. A Z-axis guide 11a extending in the Z-axis direction is formed on the top surface of the bed 11. In this embodiment, the Z-axis guide 11a is formed on the rear side of the machine in the X-axis direction (upper side in Figure 1).

The headstock 12 is located on the top surface of the bed 11, at the front side of the machine in the X-axis direction (lower side in Figure 1), and at one end side of the machine in the Z-axis direction (left side in Figure 1). The headstock 12 supports one axial end of the workpiece W, and supports the workpiece W rotatably around the Z-axis.

The headstock 12 comprises a headstock body 12a, a spindle 12b, a motor 12c, and a center member 12d. The headstock body 12a is fixed to the upper surface of the bed 11. The spindle 12b is supported by the headstock body 12a so that it can rotate around the Z axis. The motor 12c is provided on the headstock body 12a and drives the spindle 12b to rotate. The center member 12d is attached to the tip of the spindle 12b and supports one end of the workpiece W. In other words, by driving the motor 12c to rotate, the workpiece W is driven to rotate around the central axis of the workpiece W. Note that while Figure 1 shows the headstock 12 supporting one end of the workpiece W by the center member 12d, a chuck can also be used in place of the center member 12d.

The tailstock 13 is positioned on the top surface of the bed 11, facing the headstock 12 in the Z-axis direction. That is, the tailstock 13 is positioned on the near side in the X-axis direction (lower side in Figure 1), which is the front of the machine, and on the other end side in the Z-axis direction, which is the right side of the machine (right side in Figure 1). The tailstock 13 supports the other axial end of the workpiece W, and supports the workpiece W rotatably around the Z-axis.

The tailstock 13 comprises a tailstock body 13a, a ram 13b, and a center member 13c. The tailstock body 13a is fixed to the upper surface of the bed 11. The ram 13b is mounted on the tailstock body 13a so that it can move in the Z-axis direction. In other words, the ram 13b is mounted so that its protrusion amount relative to the tailstock body 13a can be changed. The center member 13c is attached to the tip of the ram 13b and supports the other end of the workpiece W. In this way, the workpiece W is rotatably supported at both ends by the headstock 12 and tailstock 13. Note that the workpiece W may also be cantilevered by the headstock 12 alone. The tailstock 13 may also be configured so that the tailstock body 13a can move in the Z-axis direction relative to the bed 11. In this case, the ram 13b is not required.

The wheel head base 14 (wheel head support member) is arranged on the upper surface of the bed 11 so that it can move in the Z-axis direction while being guided by the Z-axis guide 11a of the bed 11. The wheel head base 14 is configured to be movable via a ball screw device by driving a motor 14a provided on the bed 11. The wheel head base 14 may also be driven by a linear motor instead of the motor 14a and ball screw device. An X-axis guide 14b extending in the X-axis direction is formed on the upper surface of the wheel head base 14.

The first grinding wheel head 15 is arranged on the upper surface of the grinding wheel head base 14, movable in the X-axis direction while being guided by the X-axis guide 14b of the grinding wheel head base 14. The first grinding wheel head 15 is configured to be movable via a ball screw device by driving a motor 15a provided on the grinding wheel head base 14. The first grinding wheel head 15 may be driven by a linear motor instead of the motor 15a and ball screw device. The first grinding wheel head 15 is equipped with a rotatable grinding wheel T. The grinding wheel T rotates via a belt 15c by driving a motor 15b provided on the first grinding wheel head 15. The grinding wheel T is composed of multiple abrasive grains fixed together with a binder.

The first grinding wheel head 15 comprises a grinding wheel head main body 20 and a first grinding wheel spindle unit 30. The grinding wheel head main body 20 and the first grinding wheel spindle unit 30 are formed separately and fixed together, for example, by bolts (not shown). The grinding wheel head main body 20 is supported on the grinding wheel head base 14 so that it can move in the X-axis direction. The grinding wheel head main body 20 is a component that is common to both fluid bearing specifications and rolling bearing specifications.

The first grinding spindle unit 30 is configured to be detachable from the grinding head body 20 and rotatably supports the grinding wheel T. The first grinding spindle unit 30 constitutes a replacement unit exclusively for fluid bearing specifications. The first grinding spindle unit 30 comprises a first grinding spindle 31 and a first unit housing 32. The first grinding spindle 31 supports the grinding wheel T. The first unit housing 32 is configured to be detachable from the grinding head body 20 and rotatably supports the first grinding spindle 31. In this embodiment, the first unit housing 32 rotatably supports the first grinding spindle 31 by a fluid bearing using a circulating fluid.

The drain unit 16 is one of the units used in the grinding machine 1 with fluid bearing specifications. The drain unit 16 is detachably attached to the wheel head body 20 and the wheel head base 14, and is a component that receives the circulating fluid discharged from the first wheel spindle unit 30 via the wheel head body 20.

Like the drain unit 16, the pump unit 17 is one of the units used in the grinding machine 1 with a fluid bearing. The pump unit 17 recovers the circulating fluid from the drain unit 16 via the recovery pipe 17a and sends the recovered circulating fluid back to the first grinding spindle unit 30 via the delivery pipe 17b. In other words, the drain unit 16 and the pump unit 17 function to circulate the circulating fluid in the fluid bearing of the first grinding spindle unit 30. The recovery pipe 17a and the delivery pipe 17b are configured to be able to follow the movement of the first grinding wheel head 15. The pump unit 17 may be installed adjacent to the bed 11 or on the top surface of the bed 11.

3. Detailed Configuration of First Wheel Head 15 The detailed configuration of the first wheel head 15 will be described with reference to Figures 3 to 5. As described above, the first wheel head 15 comprises the wheel head main body 20 and the first wheel spindle unit 30. The wheel head main body 20 comprises a base portion 21 and an upright portion 22. The base portion 21 and the upright portion 22 are integrally formed. For example, the base portion 21 and the upright portion 22 are integrally molded by casting. However, the base portion 21 and the upright portion 22 may also be molded separately and then fixed together.

The base portion 21 has a seat surface 21a on its upper surface. The base portion 21 is supported on the grinding wheel head base 14 so that it can move in the X-axis direction. In this embodiment, the base portion 21 is formed in the shape of a rectangular flat plate. However, the base portion 21 can be formed in any shape as long as it has a seat surface 21a at least on the front side in the X-axis direction. When the base portion 21 and the standing portion 22 are integrally molded, the seat surface 21a of the base portion 21 is a surface on the extension of an area on the upper surface of the base portion 21 where the standing portion 22 is not present, and is a virtual surface that forms the boundary between the base portion 21 and the standing portion 22.

The erected portion 22 extends upward from the seating surface 21a of the base portion 21. Specifically, the erected portion 22 extends from the seating surface 21a of the base portion 21 at the front in the X-axis direction. The erected portion 22 has a mounting surface 22a for mounting the first grinding spindle unit 30 on its vertically extending surface, i.e., on its front surface in the X-axis direction. The erected portion 22 is configured to withstand the horizontal grinding resistance that the first grinding spindle unit 30 experiences when grinding the workpiece W with the grinding wheel T.

In detail, the standing portion 22 includes a plate-like portion 22b extending vertically from the front edge of the seat surface 21a of the base portion 21, and multiple ribs 22c on the back surface of the plate-like portion 22b. The multiple ribs 22c are configured so that their depth increases from the top to the bottom. For example, as shown in Figures 3 and 4, when viewed from the side, the multiple ribs 22c are formed in the shape of a right triangle with its apex located at the top, or a trapezoid with its top side shorter than its bottom side.

Furthermore, the grinding wheel head body 20 is formed with a drain connection channel 23 spanning the base portion 21 and the upright portion 22 for circulating the circulating fluid. The drain connection channel 23 has an inlet 23a1 formed on the mounting surface 22a of the upright portion 22 and an outlet 23c1 formed on the side surface of the base portion 21. In this embodiment, the drain connection channel 23 includes a first channel 23a, a second channel 23b, and a third channel 23c. The first channel 23a is formed in the upright portion 22 and extends from the inlet 23a1 toward the rear in the X-axis direction (horizontal direction). The second channel 23b is connected to the first channel 23a and is formed to extend in the Y-axis direction (vertical direction). The second channel 23b is formed spanning from the upright portion 22 to the base portion 21. From a processing standpoint, the second channel 23b is closed at its upper end by a cover member. The third flow path 23c is formed to extend in the Z-axis direction (horizontal direction) from the lower end of the second flow path 23b to the outlet 23c1 on the side surface of the base portion 21.

Here, the discharge connection flow path 23 is formed so that the flow path cross-sectional area decreases from the inlet 23a1 to the outlet 23c1. This configuration makes it easier for the circulating fluid to flow naturally from the inlet 23a1 to the outlet 23c1. The flow path shape of the discharge connection flow path 23 can be any shape as long as it allows free flow from the inlet 23a1 to the outlet 23c1 due to gravity.

The first grinding wheel spindle unit 30 comprises a first grinding wheel spindle 31 and a first unit housing 32. As described above, the first grinding wheel spindle 31 supports the grinding wheel T. The first unit housing 32 rotatably supports the first grinding wheel spindle 31 via a fluid bearing 32b that uses a circulating fluid.

As shown in Figures 4 and 5, the first unit housing 32 has a first housing main body 32a and multiple fluid bearings 32b. The first housing main body 32a has a through-hole 51 through which the first grinding wheel spindle 31 can be inserted. The first housing main body 32a further has a mounting surface 52 that abuts against the mounting surface 22a of the erect portion 22 of the grinding wheel head main body 20, and a flange 53 that rests on the upper end surface of the erect portion 22. By placing the flange 53 on the upper end surface of the erect portion 22, the first unit housing 32 is positioned in the up-down direction.

In this embodiment, two fluid bearings 32b are arranged at one end and the other end of the through hole 51 of the first housing body 32a. The fluid bearings 32b support the outer surface of the first grinding wheel spindle 31 on their inner circumferential surfaces via circulating fluid.

Furthermore, a supply flow path 54 is formed in the first housing body 32a to supply the circulating fluid to the fluid bearing 32b. The inlet 55 of the supply flow path 54 is formed on the upper surface of the first housing body 32a and is connected to the delivery pipe 17b. Therefore, the circulating fluid is supplied to the supply flow path 54 from the delivery pipe 17b.

The first housing body 32a also has discharge passages 56, 57 formed therein for discharging the circulating fluid from the fluid bearings 32b. The first discharge passage 56 is formed from each of the two fluid bearings 32b toward the center of the first housing body 32a in the Z-axis direction. The second discharge passage 57 is formed near the center of the first housing body 32a in the Z-axis direction and connects the first discharge passage 56 to an outlet 58 formed in the mounting surface 52. The second discharge passage 57 is formed in a range extending from the lower region of the through hole 51 to the outlet 58. The second discharge passage 57 collects the circulating fluid discharged from the two fluid bearings 32b and is formed to have a sufficiently large space to maintain good circulation of the circulating fluid in the fluid bearings 32b.

In particular, the outlet 58 of the second discharge flow passage 57 is shaped like an ellipse with its longitudinal direction extending vertically, allowing for easy formation of a space above it when the circulating fluid flows. The inlet 23a1 of the discharge connection flow passage 23 formed in the wheel head body 20 is also shaped like an ellipse with its longitudinal direction extending vertically. The inlet 23a1 of the discharge connection flow passage 23 of the wheel head body 20 is formed to face the entire outlet 58 of the discharge flow passage 57 of the first housing body 32a and is larger than the outlet 58 of the second discharge flow passage 57. A sealing member (not shown) is disposed around the outlet 58 of the second discharge flow passage 57 and abuts against the mounting surface 22a of the wheel head body 20 and the mounting surface 52 of the first housing body 32a. This sealing member therefore provides a sealing function when the circulating fluid flows from the second discharge flow passage 57 to the discharge connection flow passage 23 of the wheel head body 20.

In this way, when the first grinding wheel spindle unit 30 is attached to the grinding wheel head body 20, the discharge connection flow path 23 of the grinding wheel head body 20 is configured to allow circulating fluid to flow between the discharge flow paths 56, 57 of the first housing body 32a of the first unit housing 32.

4. Detailed Configuration of Drain Unit 16 The detailed configuration of the drain unit 16 will be described with reference to Figures 1, 2, and 6. As described above, the first housing main body 32a of the first unit housing 32 is formed with discharge flow paths 56, 57 for discharging the circulating fluid from the hydrodynamic bearing 32b. The discharge connection flow path 23 of the base portion 21 of the wheel head main body 20 is configured to allow the circulating fluid to flow between the discharge flow paths 56, 57 of the first unit housing 32. Therefore, the circulating fluid discharged from the hydrodynamic bearing 32b flows to the outlet 23c1 on the side surface of the base portion 21 of the wheel head main body 20.

The drain unit 16 is connected to the discharge connection flow path 23 and functions as a component that receives the circulating fluid discharged from the outlet 23c1 of the discharge connection flow path 23. The drain unit 16 then circulates the circulating fluid received from the discharge connection flow path 23 to the recovery pipe 17a connected to the pump unit 17.

Here, as described above, the wheel head body 20 is configured to be movable in the X-axis direction on the top surface of the wheel head base 14. Therefore, as shown in Figures 1 and 2, the drain unit 16 is provided on the side of the wheel head body 20 and the side of the wheel head base 14, and is configured to be detachable from both the wheel head body 20 and the wheel head base 14. Furthermore, as shown in Figures 1 and 6, since the wheel head body 20 moves in the X-axis direction relative to the wheel head base 14, the drain unit 16 has a length adjustment mechanism that corresponds to the movement distance of the wheel head body 20 relative to the wheel head base 14.

In detail, the drain unit 16 comprises a first gutter 41, a second gutter 42, and a length adjustment pipe 43. The first gutter 41 is provided on the side of the wheel head body 20. Therefore, the first gutter 41 moves integrally with the wheel head body 20. The first gutter 41 receives the circulating fluid discharged from the outlet 23c1 of the discharge connection passage 23 of the wheel head body 20. The first gutter 41 is configured to be detachable from the wheel head body 20. The second gutter 42 is provided on the side of the wheel head base 14. Therefore, the second gutter 42 moves integrally with the wheel head base 14. The second gutter 42 is connected to the recovery pipe 17a, which is connected to the pump unit 17. The second gutter 42 is configured to be detachable from the wheel head base 14.

The length adjustment pipe 43 connects the first gutter 41 and the second gutter 42. In this embodiment, the length adjustment pipe 43 is connected to the first gutter 41 and is configured to pass through an opening formed in the second gutter 42. Therefore, the length adjustment pipe 43 moves integrally with the first gutter 41, but moves relative to the second gutter 42. The length adjustment pipe 43 may be, for example, a metal or resin pipe with a fixed shape. In this case, the amount of insertion of the tip of the length adjustment pipe 43 into the second gutter 42 changes as the grinding wheel head body 20 moves. The length adjustment pipe 43 may also be formed in a bellows shape that is expandable and contractible in the longitudinal direction.

5. Rolling bearing grinder 2
The configuration of a grinding machine 2 configured with a rolling bearing 132b that does not use a circulating fluid will be described with reference to Figures 7 and 8. The grinding machine 2 includes a bed 11, a headstock 12, a tailstock 13, a grinding wheel base 14, and a second grinding wheel 115. The bed 11, the headstock 12, the tailstock 13, and the grinding wheel base 14 are similar in configuration to those of the grinding machine 1. Although not shown, the grinding machine 1 may also include a sizing device, a rest device, a grinding wheel dressing device, etc. The grinding machine 2 does not include a drain unit or a pump unit.

The second grinding wheel head 115 is arranged on the upper surface of the grinding wheel head base 14, movable in the X-axis direction while being guided by the X-axis guide 14b of the grinding wheel head base 14. The second grinding wheel head 115 is configured to be movable via a ball screw device by driving a motor 15a provided on the grinding wheel head base 14. The second grinding wheel head 115 may be driven by a linear motor instead of the motor 15a and ball screw device. The second grinding wheel head 115 is equipped with a rotatable grinding wheel T. The grinding wheel T rotates via a belt 15c by driving a motor 15b provided on the second grinding wheel head 115.

The second wheel head 115 comprises a wheel head main body 20 and a second wheel spindle unit 130. The wheel head main body 20 and the second wheel spindle unit 130 are formed separately and are fixed together, for example, by bolts (not shown). The wheel head main body 20 is a component shared with the wheel head main body 20 that constitutes the hydrodynamic bearing-equipped grinding machine 1.

The second grinding spindle unit 130 is configured to be detachable from the grinding head body 20 and rotatably supports the grinding wheel T. The second grinding spindle unit 130 constitutes a replacement unit exclusively for rolling bearing specifications. The second grinding spindle unit 130 comprises a second grinding spindle 131 and a second unit housing 132. The second grinding spindle 131 supports the grinding wheel T. The second unit housing 132 is configured to be detachable from the grinding head body 20 and rotatably supports the second grinding spindle 131. In this embodiment, the second unit housing 132 rotatably supports the second grinding spindle 131 by a rolling bearing that does not use a circulating fluid.

6. Detailed Configuration of Second Wheel Head 115 The detailed configuration of the second wheel head 115 will be described with reference to Figures 9 to 11. As described above, the second wheel head 115 comprises the wheel head main body 20 and the second wheel spindle unit 130. The wheel head main body 20 is a common component with the wheel head main body 20 constituting the first wheel head 15, and therefore comprises a base portion 21 and an upright portion 22. The base portion 21 and the upright portion 22 are integrally formed. However, the base portion 21 and the upright portion 22 may be molded separately and then fixed together. The detailed configuration of the base portion 21 and the upright portion 22 is as described above.

The second grinding wheel spindle unit 130 comprises a second grinding wheel spindle 131 and a second unit housing 132. As described above, the second grinding wheel spindle 131 supports the grinding wheel T. The second unit housing 132 rotatably supports the second grinding wheel spindle 131 by a rolling bearing 132b that does not use a circulating fluid.

The second unit housing 132 has a second housing body 132a and multiple rolling bearings 132b. The second housing body 132a has a through hole 151 through which the second grinding wheel spindle 131 can be inserted. The outer shape of the second housing body 132a is formed substantially the same as that of the first housing body 32a described above. Therefore, the second housing body 132a has a mounting surface 152 that abuts against the mounting surface 22a of the standing portion 22 of the grinding wheel head body 20, and a flange portion 153 that rests on the upper end surface of the standing portion 22. By placing the flange portion 153 on the upper end surface of the standing portion 22, the second unit housing 132 is positioned in the vertical direction.

In this embodiment, multiple rolling bearings 132b are arranged at one end and the other end of the through hole 151 of the second housing body 132a. The rolling bearings 132b are configured not to use a circulating fluid. For example, grease is pre-filled inside the rolling bearings 132b to ensure lubrication.

Because the rolling bearing 132b is configured not to use a circulating fluid, the second housing body 132a of the second unit housing 132 does not have supply or discharge flow paths for the circulating fluid formed in the rolling bearing 132b. Therefore, in the second housing body 132a, the areas of the supply flow path 54 and discharge flow paths 56, 57 in the first housing body 32a are filled with the material (e.g., cast iron) that forms the second housing body 132a. Therefore, the second housing body 132a does not have an inlet 55 or an outlet 58.

Therefore, when the second grinding wheel spindle unit 130 is attached to the wheel head body 20, the discharge connection passage 23 of the wheel head body 20 is configured to be blocked by the second housing body 132a of the second unit housing 132. In other words, the inlet 23a1 of the discharge connection passage 23 formed in the wheel head body 20 is blocked by the mounting surface 152 of the second housing body 132a. Meanwhile, the outlet 23c1 of the discharge connection passage 23 is blocked by the cover 121, which is a separate member. In this way, by blocking both openings of the discharge connection passage 23 in the shared wheel head body 20, it is possible to prevent dust from entering the discharge connection passage 23.

7. Effects and Effects The grinding machines 1 and 2 have wheel heads 15 and 115 separated into a wheel head main body 20 and a wheel spindle unit 30 or 130. The wheel spindle unit 30 or 130 is configured to be selectable between a first wheel spindle unit 30 having a fluid bearing 32b that uses a circulating fluid and a second wheel spindle unit 130 having a rolling bearing 132b that does not use a circulating fluid. That is, when the first wheel spindle unit 30 is attached to the wheel head main body 20 as shown in FIG. 1, the grinding machine 1 is configured to have a fluid bearing 32b that uses a circulating fluid. On the other hand, when the second wheel spindle unit 130 is attached to the wheel head main body 20 as shown in FIG. 7, the grinding machine 2 is configured to have a rolling bearing 132b that does not use a circulating fluid. In this way, by using a common grinding wheel head body 20 in the grinding wheel heads 15 and 115 and configuring the grinding wheel spindle units 30 and 130 to be interchangeable, it is possible to achieve low costs for the grinding machines 1 and 2 regardless of which specifications are adopted.

Furthermore, after receiving a grinding machine 1 with specifications that employ a first grinding wheel spindle unit 30 having a fluid bearing 32b, the user can purchase a second grinding wheel spindle unit 130 separately to replace the grinding machine 2 with a rolling bearing 132b that does not use a circulating fluid. This gives the user greater freedom of choice.

The wheel head body 20 also has a drain connection passage 23 to allow circulating fluid to flow between the first grinding spindle unit 30 and the fluid bearing 32b of the first grinding spindle unit 30 when the first grinding spindle unit 30 is attached. When the second grinding spindle unit 130 is attached to the wheel head body 20, the drain connection passage 23 is not used. In this case, the drain connection passage 23 is configured to be blocked by the second unit housing 132 of the second grinding spindle unit 130. Therefore, when the drain connection passage 23 is not in use, the second grinding spindle unit 130 can prevent dust and other particles from entering the drain connection passage 23, maintaining the drain connection passage 23 in good condition. Therefore, whether a fluid bearing 32b using a circulating fluid or a rolling bearing 132b not using a circulating fluid is employed, the cost of the grinding machines 1 and 2 can be reduced.

As described above, the wheel head body 20 is formed with a drain connection flow path 23 that allows the circulating fluid to flow between the wheel head body 20 and the drain flow paths 56, 57 of the first grinding spindle unit 30. It is not easy to form a drain path for the circulating fluid using piping. Therefore, by forming the drain connection flow path 23 in the wheel head body 20, it is possible to easily form a drain path for the circulating fluid. Even if the wheel head body 20 has the drain connection flow path 23, the wheel head body 20 can be made compatible with rolling bearings 132b that do not use circulating fluid, thereby making the replacement unit smaller.

Furthermore, the grinding machine 1 is equipped with a drain unit 16 that is detachably attached to the wheel head body 20, connected to the discharge connection flow path 23, and receives the circulating fluid discharged from the discharge connection flow path 23. By making the drain unit 16 detachable, it is possible to reduce the size and cost of the grinding machine 2 that is equipped with a rolling bearing 132b that does not use a circulating fluid.

Furthermore, the grinding machines 1 and 2 are equipped with a wheel head base 14 that movably supports the wheel head body 20. The drain unit 16 is configured to be detachable from the wheel head body 20 and the wheel head base 14, and has a length adjustment mechanism 43 that corresponds to the movement distance of the wheel head body 20 relative to the wheel head base 14. Therefore, even if the wheel head body 20 is configured to move relative to the wheel head base 14, the length adjustment mechanism 43 of the drain unit 16 allows a portion of the drain unit 16 to be attached to the wheel head base 14. As a result, the circulating fluid can be drained up to the position of the wheel head base 14.

More specifically, the drain unit 16 comprises a first gutter 41 that is detachably attached to the wheel head body 20 and receives the circulating fluid discharged from the discharge connection flow path 23 of the wheel head body 20, a second gutter 42 that is detachably attached to the wheel head base 14 and connected to the pump unit 17, and a length adjustment pipe 43 that connects the first gutter 41 and the second gutter 42 and constitutes a length adjustment mechanism. This configuration makes it possible to easily and reliably realize the length adjustment mechanism.

In addition, the inlet 23a1 of the discharge connection passage 23 of the wheel head body 20 is formed to face the entire outlet 58 of the discharge passages 56, 57 of the first unit housing 32, and is formed larger than the outlet 58 of the discharge passages 56, 57. This prevents the flow of circulating fluid in the discharge passages 56, 57 of the first grinding spindle unit 30 from being obstructed. In other words, the fluid bearing 32b can continue to exert the desired supporting force.

In addition, the discharge connection flow path 23 of the wheel head body 20 is formed so that the flow path area decreases from the inlet 23a1 to the outlet 23c1. This configuration allows a free flow of circulating fluid to be formed in the discharge connection flow path 23 of the wheel head body 20 from the inlet 23a1 to the outlet 23c1.

The wheel head body 20 also comprises a base portion 21 having a seat surface 21a on its upper surface, and an upright portion 22 extending upward from the seat surface 21a of the base portion 21, having a mounting surface 22a for mounting the grinding spindle unit 30, 130 on its vertically extending surface, and configured to withstand the horizontal grinding resistance experienced by the grinding spindle unit 30, 130 when grinding the workpiece W with the grinding wheel T. The inlet 23a1 of the discharge connection flow path 23 is formed on the mounting surface 22a of the upright portion 22, and the outlet 23c1 of the discharge connection flow path 23 is formed on the side surface of the base portion 21, with the discharge connection flow path 23 spanning the upright portion 22 and the base portion 21.

By configuring the wheel head body 20 from a base portion 21 and an upright portion 22, the wheel head body 20 can be made lighter. Furthermore, by forming the discharge connection flow path 23 across the base portion 21 and the upright portion 22, the upstream position of the discharge connection flow path 23 can be positioned upward, and the downstream position can be positioned downward. As a result, the circulating fluid can flow freely through the discharge connection flow path 23.

The first unit housing 32 also has an inlet 55 for the supply flow path 54 formed on its top surface, and outlets 58 for the discharge flow paths 56, 57 formed on the mounting surface 52 that abuts against the wheel head body 20. With this configuration, the discharge connection flow path 23 of the wheel head body 20 is connected only to the discharge flow paths 56, 57 in the first unit housing 32. The supply flow path 54 is connected to the pump unit 17, for example, by separate piping.

8. Others In the above embodiment, the wheel head body 20 is formed with the drain connection passage 23, allowing circulation of the fluid between the drain passages 56, 57 of the first unit housing 32. Alternatively, the wheel head body 20 may be further formed with a supply connection passage, allowing circulation of the fluid between the supply passage 54 of the first unit housing 32. Furthermore, the wheel head body 20 may not be provided with the drain connection passage 23, but may instead be provided with a supply connection passage.

In the above embodiment, the grinding machines 1 and 2 are exemplified as being of the wheel head traverse type. In this case, the wheel head base 14 functions as a wheel head support member that supports the wheel head 15, 115. As mentioned above, the grinding machines 1 and 2 can also be of the table traverse type. In this case, the wheel head support member that supports the wheel head 15, 115 is the bed 11.

Claims (9)

A grinding wheel head body (20),
a grinding wheel spindle unit (30, 130) configured to be detachable from the grinding wheel head body and supporting a grinding wheel (T);
Equipped with
The grinding wheel spindle unit is configured to be selectively selectable between a first grinding wheel spindle unit (30) and a second grinding wheel spindle unit (130),
The first grinding wheel spindle unit is
a first grinding wheel spindle (31) supporting the grinding wheel;
a first unit housing (32) configured to be detachable from the wheel head body, rotatably supporting the first wheel spindle by a fluid bearing (32b) using a circulating fluid, and having a supply flow path (54) for supplying the circulating fluid to the fluid bearing and discharge flow paths (56, 57) for discharging the circulating fluid from the fluid bearing;
Equipped with
The second grinding wheel spindle unit is
a second grinding wheel spindle (131) supporting the grinding wheel;
a second unit housing (132) configured to be detachable from the wheel head body and rotatably supporting the second wheel spindle by a rolling bearing (132b) that does not use a circulating fluid;
Equipped with
the wheel head body has a connection flow path (23) configured to allow the circulating fluid to flow between the supply flow path or the discharge flow path of the first unit housing when the first wheel spindle unit is attached,
The grinding machine (1, 2) is configured so that the connecting flow passage is closed by the second unit housing of the second grinding spindle unit when the second grinding spindle unit is attached to the grinding wheel head body. A grinding machine as described in claim 1, wherein the connecting flow path is a discharge connecting flow path (23) configured to allow the circulating fluid to flow between the connecting flow path and the discharge flow path of the first grinding wheel spindle unit. The grinding machine described in claim 2 further comprises a drain unit (16) that is detachably attached to the grinding wheel head body, connected to the discharge connection flow path, and receives the circulating fluid discharged from the discharge connection flow path. Further, a wheel head support member (14) is provided for movably supporting the wheel head body,
4. The grinding machine according to claim 3, wherein the drain unit is configured to be detachable from the wheel head body and the wheel head support member, and has a length adjustment mechanism (43) that corresponds to a movement distance of the wheel head body relative to the wheel head support member. The drain unit is
a first trough (41) configured to be detachable from the wheel head body and for receiving the circulating fluid discharged from the discharge connection flow path of the wheel head body;
a second trough (42) configured to be detachable from the wheel head support member and connected to a pump unit;
a length adjusting pipe (43) that connects the first gutter and the second gutter and constitutes the length adjusting mechanism;
The grinding machine of claim 4 , comprising: A grinding machine as described in any one of claims 2 to 5, wherein the inlet (23a1) of the discharge connection passage of the grinding wheel head body is formed to face the entirety of the outlet (58) of the discharge passage of the first unit housing, and is formed larger than the outlet (58) of the discharge passage. A grinding machine as described in claim 6, wherein the discharge connection flow path of the grinding wheel head body is formed so that the flow path area decreases from the inlet (23a1) to the outlet (23c1). The wheel head body is
a base portion (21) having a seat surface (21a) on its upper surface;
an upright portion (22) that stands upward from the seating surface of the base portion, has a mounting surface (22a) for mounting the grinding spindle unit on a surface extending in a vertical direction, and is configured to resist horizontal grinding resistance that the grinding spindle unit receives when grinding a workpiece with the grinding wheel;
Equipped with
an inlet of the discharge connection flow path is formed on the mounting surface of the erected portion;
an outlet of the discharge connection channel is formed on a side surface of the base portion;
The grinding machine according to any one of claims 2 to 7, wherein the discharge connection flow path is formed across the upright portion and the base portion. A grinding machine as described in any one of claims 2 to 8, wherein the first unit housing has an inlet (55) for the supply flow path formed on its upper surface and an outlet for the discharge flow path formed on its surface abutting the grinding wheel head body.