JPS61244436A - Spindle unit - Google Patents

Abstract

PURPOSE:To secure the superior precision by relaxing the springy force of a spring acting onto a spindle member and averting the strain and heat genera tion of a bearing by installing the spring for clamping a tool holder in a spindle unit, outside the spindle member. CONSTITUTION:A spindle unit consists of a spindle member 54 which revolves under the action of a servomotor 180, tool holder 56 for holding a twist drill 178, rod part 138 fitted into the hole on the spindle member 54, and a clamp mechanism 52 which presses the tool holder 56 onto one edge part of the spindle member 54 by pulling the rod member 138 on revolution and releases the pressing force when a tool is replaced. Said clamping mechanism 52 consists of a cylinder apparatus 50 for pressing the rod part 138, spring member 80, and a ball which is fitted into the hole part of the spindle member 54 and whose one part contacts with the tapered surface foomed onto the rod part 138 on unclamping and contacts with the peripheral surface contiguously formed onto the tapered surface on clamping.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spindle unit, and more particularly, in a spindle unit configured such that a tool is detachably attached to a rotating spindle member via a drive mechanism, the tool is fixed to the spindle member. By avoiding as much as possible the influence of the clamping force, for example, the pressing force on the spindle member due to the elastic force of the spring member, the machining process can be accomplished extremely smoothly and it can be used with high precision over a long period of time. Regarding the spindle unit that made this possible.

In recent years, highly automated line production systems have been adopted when processing and molding products in factories. This is because it allows for efficient mass production of various products. Such line production involves arranging various machine tools in parallel, transporting the workpiece to a predetermined position on each machine tool using a transport device, sequentially performing predetermined processing, and finally producing the desired material. A product having the shape of is obtained.

By the way, depending on the workpiece, there are cases in which a small number of types are produced in large quantities, or a large number of types are produced in small quantities. However, in this case, it is actually not economical to arrange various machine tools according to the type of workpiece, and it is not suitable for the request to effectively utilize the limited space in the factory. It's not something that can be answered at all. Conventionally, in order to solve these drawbacks and perform various types of machining with a single machine tool, a so-called spindle unit, which is a device in which various types of tools are removably attached to a spindle member and used selectively, has been developed. is used. Each tool is also exchanged using a tool exchanger, resulting in extremely automated machining operations.

Therefore, a spindle unit according to such a conventional technique is schematically shown in FIG.

In the figure, reference numeral 2 indicates a unit main body, and inside the main body 2 are bearings 4a, 4b and 6a, 6.
A spindle member 8 is rotatably fitted via b. Further, a tool holder 12 having a predetermined tapered portion 10 is fitted onto one end of the spindle member 8, and a rod portion 14 extending from one end of the tapered portion 10 is inserted into the spindle member 8. It is loosely fitted through the holes 15 to 16 of. On the other hand, a tool such as a drill 17 is fixed to the other end of the tool holder 12.

By the way, the rod member 1 is located at the center of the spindle member 8.
8 is fitted, and this rod member 1 is disposed coaxially with the rod portion 14 of the tool holder 12, and the retaining member 19
The rod member 18 and the loft portion 14 are connected by the rod member 18 and the loft portion 14. In this case, one end of the engaging member 19 is fixed to the rod member 18, and the other end of the engaging member 19 is configured to be swingable in the radial direction.

Further, a sliding member 20 is screwed onto one end of the rod member 18, and one end of this sliding member 20 is in contact with a spring member 22 interposed within the spindle member 8. Further, a guide member 26 is attached to the sliding member 20 via a thrust bearing 24, and a piston rod 30 extending from a cylinder 28 is fitted into the center of the guide member 26. In addition, the spindle member 8
A gear 32 is fixed to the holder, and a drive mechanism 34 is meshed with the gear 32.

In such a configuration, if the drive mechanism 34 is driven to rotate the gear 32 that meshes with the drive mechanism 34, the spindle member 8
rotates integrally with the gear 32, and furthermore, the tool holder 12 fitted and mounted on the spindle member 8 and the drill 17 engaged with this tool holder 12 rotate.

Therefore, by fixing a workpiece (not shown) at a predetermined position and moving the main body 2 close to the workpiece (not shown), the rotating drill 17 performs a predetermined processing on the workpiece. In this way, by repeating the above-described steps, it is possible to continuously perform predetermined processing on the same type of workpiece.

By the way, when the types of workpieces to be machined are different,
The tool holder 12 corresponding to a new workpiece is attached to the main body 2 by the procedure shown below.

That is, after stopping the rotation of the spindle member 8, when the cylinder 28 is driven to displace the piston rod 30 extending from it in the direction of arrow B, the tip of the piston rod 30 moves the rod member 18 in the direction of arrow B. to press. Therefore, the rod member 18 is displaced in the direction of arrow B against the elastic force of the spring member 22, and the tip of the rod member 18 presses the rod portion 14. When the distal end of the engagement member 19 enters the hole 15, the distal end of the retaining member 19 swings outward in the radial direction to release the engagement with the rod portion 14. Then, the tool holder 12 is separated from the spindle member 8. In this case, if an arm portion of a tool changer (not shown) is engaged with the tool holder 12 in advance, the tool holder 12 can be automatically removed.

Next, after fitting a new tool holder 12 into the piston member 8, the cylinder 28 is driven to remove the piston rod 30.
When the rod member 18 is displaced in the direction of the arrow A, the rod member 18 is displaced in the direction of the arrow A by the elastic force of the spring member 22. As a result, the retaining member 19 attached to this rod member 18 engages with the rod portion 14 of the new tool holder 12, and said tool holder 12 is attached to the spindle member 8. Here, a predetermined machining operation is performed on a new workpiece using a new tool through the steps described above.

However, in the conventional technique described above, an extremely large external force acts on the spindle member 8 when the tool holder 12 is replaced. That is, when the rod member 18 is displaced in the direction of arrow B under the driving action of the cylinder 28, the spring member 22 is pressed by the sliding member 20.
An extremely large elastic force acts in the direction of arrow B on the spindle member 8 that comes into contact with one end of the spindle member 8 . Therefore, the bearing 4 supported by the spindle member 8 and the main body 2
a, 4b and 6a, 6b may be distorted or deformed. In this way, the bearing 4a
, 4b and 68.6b if distortion, deformation, etc. occur,
This effect appears during machining and reduces the machining accuracy of the spindle unit, so each bearing 4a,
4b and 68.6b will need to be replaced immediately. However, the bearings 4a and 4b
In addition, in order to replace 6a and 6b, work on the spindle unit must be stopped. In addition, such temporary stoppage of work reduces production efficiency and makes tool replacement work extremely complicated. Moreover, in order to ensure smooth rotation of the spindle member, the bearings are usually of high precision and therefore relatively expensive, resulting in the disadvantage that frequent replacement would be extremely uneconomical.

Furthermore, in the conventional spindle unit mentioned above,
Even when the spindle member 8 rotates, the elastic force of the spring member 22 acts on the spindle member 8. Therefore, an external force always acts on each of the bearings 4a, 4b and 6a, 6b in the direction of arrow B, and when the spindle member 8 rotates, friction is generated in these bearings, and, for example, the main body 2 may be deformed by heating.

Furthermore, in the conventional spindle unit, since the spring member 22 is interposed inside the spindle member 8, the outer diameter of the spindle member 8 becomes extremely large. Therefore, for example, by arranging multiple spindle units in parallel,
When processing a large number of workpieces at the same time, the spacing between the cutting edges of the tools attached to the respective spindle members 8 is large, resulting in the inconvenience that the area occupied by the apparatus in the factory becomes extremely large.

The present invention has been made to overcome the above-mentioned disadvantages, and includes providing a spring member for tool holder clamping on the outside of the spindle member, and suitably alleviating the elastic force of the spring member acting on the spindle member. By doing so,
It is an object of the present invention to provide a spindle unit which can be used for a long period of time by avoiding distortion, heat generation, etc. caused by bearings, and which can ensure accuracy in an extremely favorable manner.

In order to achieve the above object, the present invention includes a spindle member that rotates under the action of a rotational drive source, a tool holder that abuts one end of the spindle member and holds a rotating tool, and a tool holder that is attached to the spindle member. a rod member that fits into a defined axially extending hole; and a rod member that engages with the rod member and pulls the rod member at least during rotation to press the tool holder against one end of the spindle member. The clamp mechanism includes a cylinder device that presses the rod member, a spring member, and a hole formed in the circumferential direction of the hollow spindle member. The rod member is fitted with a spherical body, and a part of the spherical body abuts a tapered surface formed on the rod member when unclamped, while a spherical body abuts a circumferential surface formed adjacent to the tapered surface when clamped.

Next, preferred embodiments of the spindle unit according to the present invention will be described in detail with reference to the accompanying drawings.

In FIGS. 2 and 3, reference numeral 40 indicates a base. At the upper end of the base 40, a support 42a is erected approximately at the center, and a first holding portion 44a is formed to bulge out in the horizontal direction on the support 42a. On the other hand, in the figure, a support 42b is provided on the left edge of the base 40 and oriented upward, and a second holding portion 44b is similarly formed in a bulging manner on the support 42b.

In this case, holes 46a and 46b are formed coaxially in the horizontal direction in each of the holding parts 44a and 44b. And the first
An outer frame member 48 that bulges out in the horizontal direction is attached to the holding portion 44a, and a cylinder 50 is fixed to one end of the outer frame member 48. A clamp mechanism 52 is provided in the outer frame member 48 in relation to the cylinder 50, and a spindle member 54 that engages with the clamp mechanism 52 is attached to the respective holding portions 44a, 44b.
The tool holder 56 is rotatably supported within the spindle member 54, and a tool holder 56 is detachably attached to the tip of the spindle member 54. At this time, the holding member 58 and the head cover 60 are attached to the tip of the second holding part 44b, and the head cover 60 is attached to the tip of the second holding part 44b.
Cutting oil is supplied to the tool holder 56 through an oil supply port 62 provided in the tool holder 56 . Note that a stopper member 63 is provided on this holding portion 44b. Furthermore, a clamp rod 64 is fitted into the spindle member 54 , one end of the clamp rod 64 is engaged with the tool holder 56 , and the other end of the clamp rod 64 is engaged with the clamp mechanism 52 . Further, a drive mechanism 66 is provided above the clamp mechanism 52, and the spindle member 54 is rotated under the drive action of the drive mechanism 66.

The configuration of the spindle unit according to the present invention has been schematically shown above, and the details thereof will be explained next.

First, the clamp mechanism 52 will be explained. That is,
A bearing 68 is disposed in contact with the inner wall surface 67 of the outer frame member 48, and a spring member set sleeve 70 is brought into contact with the other end of the bearing 68.

As shown in FIG. 5a, a flange portion 72 is formed on the outer peripheral edge of the set sleeve 70.
A protrusion 74 that slightly protrudes from the other end of 2 through the step.
form. One end of this protruding portion 74 has a circular, cylindrical portion 76.
A tapered hole 78 is formed in the cylindrical portion 76 and is oriented inward and inclined radially inward. Therefore, the bearing 68 is brought into contact with the cylindrical portion 76 and the protruding portion 74. Further, a spring member 80 made of a plurality of disc-shaped leaf springs is disposed on the outer circumferential portion of the set sleeve 70, and one end side of the spring member 80 is brought into contact with the flange portion 72, and the other end of the spring member 80 is brought into contact with the flange portion 72. The part side is brought into contact with the pressing member 82.

Holes 84 and 86 are formed in the center of the pressing member 82 at a predetermined depth from both ends thereof, and the set sleeve 70 is loosely fitted into the hole 84. The thrust bearing 90 and guide member 92 are installed. In this case, the guide member 92 fits the piston rod 94 extending from the cylinder 50 and guides it appropriately. In this case, the set sleeve 70 is fitted onto the spindle member 54 and the pressing member 82 is screwed onto the clamp rod 64.

Therefore, next, the spindle member 54 will be explained.

A hole 96 is formed in the center of the spindle member 54 in the axial direction, and one end of the hole 96 communicates with a hole 98 having a smaller diameter via a step.

On the other hand, a groove 99 having a predetermined length is formed at the other end of the hole 96, and the other end of the groove 99 communicates with a large diameter hole 100 via a step. Further, holes 104a to 104c are formed in the outer cylinder portion 102 of the spindle member 54 at equal intervals and oriented in the radial direction.

Further, the outer cylinder portion 102 has holes 104a to 104.
A thread groove 106 is formed adjacent to the thread groove 106.
A keyway 108 is carved on the other end side. A thread groove 110 is further formed on the other end side of the key groove 108.

On the other hand, a thread groove 1 is formed in the outer cylinder part 111 which has a large diameter through the stepped part.
12, and a tapered portion 114 having a predetermined angle is formed at a predetermined distance from the thread groove 112.

The other end of the tapered portion 114 forms an outer cylindrical portion with a larger diameter via a stepped portion.

In the spindle member 54 configured in this way, the key 116 is fitted into the keyway 108 and the gear 11B is attached,
This gear 11 is screwed into the thread groove 106 with the presser member 120.
B is fixed to the spindle member 54. Furthermore, the spindle member 54 is inserted into the holes 4 of the respective holding parts 44a and 44b.
6a, 46b, bearings 122a, 122b are interposed between the spindle member 54 and hole 46a, and the holding member 124 is screwed into the thread groove 110 to support the respective bearings 122a, 122b. do. At this time, each bearing 122a.

A pair of sleeves 126 are installed between 122b. On the other hand, similarly, bearings 128a and 128b are connected to sleeve 130 between spindle member 54 and hole 46b.
A bearing 132 having a corresponding tapered surface is mounted on the tapered portion 114. Further, the holding member 134 is screwed into the thread groove 112 to hold the respective bearings 128a, 128b and 132.

Therefore, the spindle member 54 is attached to the respective holding portions 44a, 4.
4b can be rotated very suitably and precisely.

Therefore, the first coupling 136 is installed in the hole 100 of the spindle member 54. Said first coupling ring 13
Teeth portions 137a to 137f of a predetermined shape are provided at equal intervals on the outer peripheral edge of one end surface of the first camp ring 13.
6 is fixed to the spindle member 54.

By the way, the clamp rod 64 is fitted into the hole 96 of the spindle member 54 so that it can be displaced. That is, a rod portion 138 constituting the clamp rod 64 is loosely fitted into the hole 96, and a large diameter portion 140 that fits into the hole 96 is formed at one end of the rod portion 138. A retaining member 142 is fixed to the outer periphery of this large diameter portion 140, and this engaging member 14
2 is fitted into the groove 99 of the spindle member 54, so that the spindle member 54 and the clamp rod 64 can rotate integrally. Furthermore, a circumferential groove portion 144 having a predetermined width is carved on the other end side of the large diameter portion 140, and a distal end portion 146 is formed by expanding the diameter at the terminal end portion of the circumferential groove portion 144. The distal end portion 146 is largely cut out from its outer circumferential direction to form locking portions 48a to 148c having the same width and equally spaced apart (see FIG. 4).

On the other hand, a cylindrical portion 150 having a smaller diameter is formed at the other end of the rod portion 13B via a step, and a tapered portion 152 having a predetermined slope is formed at one end of the cylindrical portion 150. Further, a thread groove 1 is provided at one end of this rod portion 13B.
54, and a hole 156 is bored at a predetermined depth in the center of the clamp rod 64 so as to extend in the axial direction from the thread groove 154 side. Therefore, the pressing member 8 is inserted into the thread groove 154.
2 and clamp rod 64 via the spring member 80.
Press in the direction of arrow B. Furthermore, balls 158a to 158c are fitted into holes 104a to 104c of spindle member 54. In this case, the balls 158a to 158c are close to the inner wall surface of the tapered hole 78 of the cent sleeve 70.

A tool holder 56 is removably attached to the spindle member 54 and clamp loft 64 configured in this way. That is, the first coupling 13 is attached to the tool holder 56.
A second coupling 160 that meshes with 6 is attached. In this case, as shown in FIG.
A pair of teeth 162a to 162f are provided on one end surface of the first coupling ring 60, each defining a gap in which the teeth 137a to 137f of the first coupling ring 136 fit into the outer peripheral edge thereof. Therefore, the second coupling 160 is fixed to the tool holder 56 via bolts 164a to 164f, and an opening 166 is defined in the center of the tool holder 56, and one end side of the opening 166 has a step. It communicates with a hole 168 which expands through a hole 167. In this case, the shape of the opening 166 corresponds to the tip end 146 of the clamp rod 64, and defines openings 170a to 170c having a slightly larger shape than the respective locking parts 148a to 148c. On the other hand, a groove 172 having a predetermined width is formed on the outer peripheral edge of the tool holder 5G, and one end of the groove 172 communicates with the oil supply port 62 of the navel cover 60. Further, the other end of the groove 172 is provided with a tool holder 56.
The tool holder 56 communicates with a passageway 174 bent therein, and finally communicates with the outside from the tip of the tool holder 56. Also,
Grooves 1 are formed at predetermined intervals on the outer periphery of the tool holder 56.
75a and 175b are carved to form a grip portion 176.

Note that a predetermined tool, for example, a drill 178, is attached to the tip extending from the gripping portion 176.

Next, the drive mechanism 66 will be explained. A rotary drive shaft 1 is connected to a servo motor 180 constituting the drive mechanism 66.
82 extends. A first gear 184 is provided on the rotary drive shaft 182, and the other end of the first gear 184 is supported by a bearing 186. Furthermore, the first
The gear 184 meshes with the second gear 18B, and the second gear 188 has both ends thereof bearings 190a and 19, respectively.
It is pivotally supported by 0b. Therefore, the second gear 188 is meshed with the gear 118 attached to the spindle member 54,
On the other hand, this gear 118 is meshed with the third gear 192, and both ends of the third gear 192 are connected to the bearings 19, respectively.
4a and 194b.

The spindle unit according to the present invention is basically constructed as described above, and its operation and effects will be explained next.

First, when the servo motor 180 is driven to rotate the rotary drive shaft 182 extending from it, this rotary drive shaft 182
A first gear 184 fixed to the
The second gear 188 meshing with the gear 184 also begins to rotate.

The rotation of the second gear 188 is transmitted to the spindle member 54 via the gear 118 meshing with the second gear 188. In this case, the gear 118 is further meshed with and supported by the third gear 192 on the other end side. each gear 184
．． 188 and 192 are bearings 186 and 190 respectively
a, 190b and 194a, 194b, the spindle member 54 rotates smoothly. Moreover, the spindle member 54 is connected to each holding portion 44.
Bearings 122a, 122b in a, 44b
, 128a.

The spindle member 54 is rotatably supported via the spindle member 128b and 132, and the spindle member 54 is sufficiently supported in its longitudinal direction, so that rotation of the spindle member 54 is performed smoothly and accurately. To this end, the tool holder 5 engages the spindle member 54 via the respective coupling 136,160.
6 also rotates well.

Therefore, when the base 4o is transported in the direction of arrow A by a transport device (not shown), drilling is performed on the workpiece (not shown) by the drill 178.

At this time, in the present invention, the stopper member 63 is provided to prevent the drill 178 from being displaced into the workpiece more than necessary. During cutting, head cover 60
When cutting oil is supplied from the oil supply port 62 of the tool holder 56, the cutting oil passes through a passage 174 in the tool holder 56 and is then led out to the tip of the drill 178.

In this way, after drilling a predetermined hole in a workpiece (not shown) using the drill 178, the spindle unit is transferred in the direction of arrow B.Then, the workpiece after machining is removed, and a new workpiece is inserted into the predetermined hole. It is fixed in position and a predetermined processing operation is performed in the same way.

By the way, when processing different types of workpieces, the tool holder 56 corresponding to the different workpieces may be attached to the spindle member 54 by the procedure shown below.

That is, the drive of the servo motor 180 is stopped and the tool holder 56 is stopped at a predetermined angular position.

Therefore, when the cylinder 50 is driven to displace the piston rod 94 in the direction of arrow A in the figure while holding the gripping part 176 by a tool changer (not shown), the tip of the piston rod 94 is moved to the clamp rod 64. hole 1
56 and press.

Therefore, this clamp rod 64 is displaced in the direction of arrow A against the elastic force of the spring member 80. Therefore, the tip end 146 of the clamp rod 64 is separated from the step 167 of the tool holder 56 and loosely fits into the hole 168. Then,
The tool holder 56 is displaced by a predetermined amount in the direction of arrow A to release the engagement between the respective couplings 136 and 160. Further, by driving the servo motor 180, the spindle member 54
When rotated by 60 degrees, the opening 170a of the tool holder 56
170c and the locking portions 148a to 148c of the clamp rod 64 are in phase with each other in the horizontal direction. Therefore, by displacing the tool holder 56 in the direction of arrow A using a tool exchange device (not shown), the tool holder 56 can be taken out from the device.

Next, a tool holder 56 corresponding to a new work is transferred using a tool changer (not shown), and the tip 146 of the clamp loft 64 is loosely fitted into the hole 168 by a predetermined amount.

Then, the servo motor 180 is driven to rotate the spindle member 54 and the clamp rod 64 by 60 degrees, and the tool holder 56 is further displaced in the direction of arrow B so that the respective couplings 136 and 160 are engaged. After that, the cylinder 50 is driven and the piston rod 94 is moved to the arrow B
When the clock is moved in the direction, the pressing force of the cylinder 50 acting on the clamp rod 64 is released. Therefore, the spring member 8 is connected to the clamp rod 64 via the pressing member 82.
An elastic force of 0 acts, and the clamp rod 64 moves in the direction of arrow B.
The distal end portion 146 is displaced in the direction of the new tool holder 5.
6 and presses it in the direction of arrow B. Therefore, the tool holder 56 and the spindle member 54 are firmly engaged. Next, after removing the tool changer (not shown) from the tool holder 56, the servo motor 180
A new tool holder 56 is rotated under the driving action of , and a different workpiece (not shown) is machined according to the procedure described above.

By the way, in the spindle unit according to the present invention, the elastic force of the spring member 80 does not act on the spindle member 54 during the above-described attachment and detachment work of the tool holder 56, and therefore, in particular, the bearings 122a, 122b and 128a, It does not cause friction, deformation, etc. to 128b.

That is, when the tool holder 56 is detached from the spindle member 54, the pressing member 82 is displaced in the direction of the arrow A together with the crank blond 64 under the driving action of the cylinder 50.

Therefore, the spring member 80 is further compressed and its elastic force acts on the cent sleeve 7°. Therefore, the set sleeve 70 is displaced in the direction of arrow A, and the protrusion 7
4 is pressed against one end of the pair link 68. On the other hand, when the clamp rod 64 is displaced in the direction of arrow A, the contact portion between the clamp rod 64 and the balls 158a to 158c that fit into the holes 104a to 104c of the spindle member 54 shifts from the cylindrical portion 150 to the tapered portion 152. do. As a result, each of the balls 158a to 158c is displaced in the radial direction of the spindle member 54 along the inclination of the tapered portion 152, and the respective balls 158a to 158c are displaced in the radial direction of the spindle member 54.
A gap H1 is defined between the set sleeve 70 and the inner wall surface of the tapered hole 78 of the set sleeve 70 (see FIG. 5a). As a result, the elastic force of the spring member 80 is absorbed by the outer frame member 48 via the set sleeve 70 and the bearing 68, so that the elastic force of the spring member 80 does not act on the spindle member 54. Therefore, in particular, the bearings 122a, 122b and 128a, 128b for rotating the spindle are not deformed by the elastic force of the spring member 8o.

On the other hand, when the tool holder 56 is engaged with the spindle member 54, the elastic force of the spring member 80 can be suitably relaxed. That is, when the clamp rod 64 is displaced in the direction of arrow B by the elastic force of the spring member 8°, the ball 1
The contact portion between the clamp rod 64 and the tapered portion 152 transitions from the tapered portion 152 to the cylindrical portion 150. Therefore, each of the balls 158a to 158c is connected to the tapered portion 1.
The spindle member 54 is displaced radially outward along the slope 52, and one end of each is brought into contact with the inner wall surface of the tapered hole 78 of the cent sleeve 70. Therefore, the set sleeve 70 is pressed by the balls 158a to 158c and slightly displaced in the direction of arrow B, and a gap H2 is defined between the protrusion 74 and the bearing 68 (see FIG. 5). .

In this way, the elastic force of the spring member 80 acts on the set sleeve 70 and then connects the spindle member 54 and the clamp rod 64 via the respective balls 158a to 158c, as shown by the dashed arrow in the figure. divided into In the end, a reduced pressing force is applied to the spindle member 54, so
In particular, bearings 122a, 12 for spindle rotation
2b and 128a, 128b are not subjected to any significant external force. Therefore, when the spindle member 54 is rotated under the driving action of the drive mechanism 66, the respective bearings 12
2a, 122b and 128a, 128b do not generate heat or deform due to friction. Also, the bearing 68 is connected to the spring member 8 during attachment and detachment work of the tool holder 56.
However, when this tool holder 56 is mounted on the spindle member 54, a gap H2 is created between the bearing 68 and the set sleeve 70, as can be understood from FIG. defined. Therefore, when the spindle member 54 rotates, the bearing 68 can rotate extremely smoothly.

As described above, according to the present invention, the spring member for clamping the tool holder is disposed outside the spindle member, and the elastic force of the spring member acts on the spindle member when the tool holder is replaced. effectively avoid. Moreover, when the spindle member rotates, external forces applied to the spindle member are suitably distributed and alleviated.

Therefore, it is possible to obtain a spindle unit that can be used for a long period of time without causing distortion or heat generation, especially in the bearings that support the rotation of the spindle member with high precision. Furthermore, since the spindle member can be made even smaller in diameter, for example,
When the devices are installed in parallel, it becomes possible to reduce the area occupied by the devices, and the device becomes extremely suitable for use in a factory.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design can be made without departing from the gist of the present invention. Of course.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a spindle unit according to the prior art, FIG. 2 is a partially omitted front longitudinal cross-sectional view of a spindle unit according to the present invention, and FIG. 3 is a perspective view of the main parts of the spindle unit according to the present invention. FIG. 4 is a sectional view taken along the line IV--IV in FIG. 2, and FIGS. 5a and 5a are explanatory views during tool holder work. 40... Base 44a, 44b... Holding part 4
8..Outer frame member 50..Cylinder 52..Clamp mechanism 54..Spindle member 56..Tool holder 64..Clamp rod 66..Drive mechanism
68...Bearing 70...Sent sleeve 80
... Spring member 82 ... Pressing member 92 ... Guide members 104a to 104c ... Holes 122a, 122b, 128a, 12Bb --
Bearing 136... Coupling 13B...
Rod part 140...Large diameter part 150...Cylindrical part 152...Tapered part 158a to 158c
−・Ball 160 ・・Coupling 176 ・・
Gripping part 178... Drill 180... Servo motor patent applicant Honda Motor Co., Ltd. Fig, 5a A-B Fig, 5b A-Ichika B

Claims (2)

[Claims] (1) a spindle member that rotates under the action of a rotational drive source; a tool holder that abuts one end of the spindle member to hold a rotating tool; and a tool holder extending in an axial direction defined by the spindle member; a rod member that fits into a hole to be replaced; and a rod member that engages with the rod member and pulls the rod member at least during rotation to press and engage the tool holder to one end of the spindle member; The clamp mechanism is composed of a cylinder device that presses the rod member, a spring member, and a hole formed in the circumferential direction of the hollow spindle member, and the clamp mechanism is fitted into a hole formed in the circumferential direction of the spindle member in the form of a hollow hole, and when unclamped. 1. A spindle unit comprising a spherical body, a part of which abuts against a tapered surface formed on a rod member, and which, on the other hand, abuts against a circumferential surface formed adjacent to the tapered surface during clamping. (2) In the unit according to claim 1,
A spindle unit in which a sphere is held by a surface formed on a sleeve member that fits onto the spindle member, abuts against a spring member, and is displaced in the axial direction of the spindle.