JP3526745B2 - Disc spring and spindle device using the disc spring - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc spring and a spindle device incorporating the disc spring.

[0002]

2. Description of the Related Art FIG. 5 shows the shape of a general disc spring 100 in a free state. The disc spring 100 is deformed into a flat shape by receiving a compressive load in the axial direction, and generates an elastic biasing force in the axial direction to return to the original shape of the free state. Disc spring 100
Is deformed by receiving a compressive load in the direction of the central axis O,
In FIG. 5, a compressive stress acts on the area near the upper surface 101 of the disc spring 100, and a tensile stress acts near the lower surface 103. For this reason, the disc spring 100 as a whole has an upper surface 101.
The neighboring region is deformed so as to bulge inward in the radial direction and the region near the lower surface 103 bulges outward in the radial direction. as a result,
A region of the inner peripheral surface 105 in the vicinity of the upper surface 101 is deformed so as to project inward in the radial direction and has its diameter reduced, and a region of the outer peripheral surface 107 in the vicinity of the lower surface 103 is deformed so as to be protruded in the radial direction and enlarged.

As described above, the disc spring changes its shape and dimensions not only in the axial direction but also in the radial direction by receiving the compressive load in the axial direction. Therefore, the disc spring must determine the inner diameter or the outer diameter dimension in consideration of the change in the radial dimension, which inevitably causes a large clearance between the inner diameter or the outer diameter and the fitting component. is there.

In order to solve this problem, for example, a disc spring for pulling up a tool incorporated in a rotary spindle of a machine tool such as a machining center disclosed in Japanese Utility Model Laid-Open No. 6-17807 has a support portion fitted with the rotary spindle. A groove is formed on the side surface in the vicinity to provide a thin portion to absorb a change in diameter due to expansion and contraction of the disc spring. Furthermore, the disc spring disclosed in Japanese Utility Model Laid-Open No. 7-28246 has an axial cross section of the disc spring formed into an arc surface with a radius centered on the rotation axis thereof.

[0005]

However, the actual flat 6-
The disc spring of Japanese Patent No. 17807 has a thin portion by forming a groove in the vicinity of a support portion of the disc spring that fits with the rotating main shaft, and therefore has a problem of brittle fracture at this portion when subjected to repeated compression load, which is high. It is difficult to apply it to machine tools and other products that require reliability.

Further, in the disc spring of Japanese Utility Model Laid-Open No. 7-28246, the change in inner and outer diameters in the free state and the compressed state is reduced, but an extra clearance of about 0.05 mm due to the change in inner and outer diameters is still taken. Must be secured.

Further, as illustrated in both of the above publications,
Normally, a plurality of disc springs are used by stacking them in different directions such as a convex surface, a concave surface, a convex surface, and a concave surface. In particular, when the concave surfaces are stacked facing each other, the outer peripheral portion and the outer peripheral portion of the disc spring are substantially in line contact with each other under the influence of the pressing force. When the disc spring is deformed by an axial load acting on the disc spring, the contacted portion tends to move a small amount outward in the radial direction with respect to the axis. Then, the contact positions of the outer peripheral portions of the adjacent disc springs are slightly deviated in the radial direction, and eventually the inner diameter portion of the disc spring rubs against the mating member. If this phenomenon occurs repeatedly many times, the friction between the inner diameter of the disc spring and the counterpart member increases, and the elastic biasing force of the disc spring may not be fully utilized, or the disc spring and the counterpart member may be destroyed.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a disc spring in which at least one of the inner diameter and the outer diameter does not change in the free state and the compressed state of the disc spring. It is intended to be provided. A further object of the present invention is to provide a spindle device for machine tools incorporating such a disc spring.

[0009]

According to the present invention, an inner diameter,
In a disc spring having an outer diameter and a wall thickness, a disc spring (11)
When an axial load is applied to the plate, the inner diameter of the position (41) on the boundary surface (39) between the part that expands and the part that reduces the diameter in the thick section does not change. A disc spring having a minimum inner diameter (d) of the spring (11) so as not to bulge inward from the minimum inner diameter (d) of the disc spring (11) when an axial load is applied to the disc spring (11). Will be provided.

Further, according to the present invention, in a disc spring having an inner diameter, an outer diameter and a wall thickness, when an axial load is applied to the disc spring (11), a portion that expands in diameter in a thick section and a contraction. The outer diameter dimension of the position (43) on the boundary surface (39) with the diametrical portion where the radial dimension does not change is defined as the maximum outer diameter (D) of the disc spring (11). There is provided a disc spring formed so as not to bulge outward beyond a maximum outer diameter (D) of the disc spring (11) when an axial load is applied to the disc spring.

Further, according to the present invention, the housing, the main shaft rotatably supported by the housing, the drawbar inserted into the main shaft so as to be movable back and forth in the axial direction, and the elastic urging force applied to the drawbar. In a spindle device including a disc spring, the disc spring (11) is present on a boundary surface (39) between a portion that expands in diameter and a portion that reduces diameter in a thick section when an axial load is applied. The inner diameter of the position (41) where the radial dimension does not change is the minimum inner diameter (d) of the disc spring (11), and the portion that contracts when an axial load is applied to the disc spring (11) is the disc spring ( 11) Minimum inner diameter (d)
The disc spring (1
There is provided a spindle device in which 1) is incorporated in the outer peripheral surface of the draw bar so that the inner diameter of the disc spring (11) is fitted and guided.

Further, according to the present invention, the housing, the main shaft rotatably supported by the housing, the draw bar inserted into the main shaft so as to be movable back and forth in the axial direction, and the elastic urging force applied to the draw bar. In a spindle device including a disc spring, the disc spring (11) is present on a boundary surface (39) between a portion that expands in diameter and a portion that reduces diameter in a thick section when an axial load is applied. The outer diameter dimension at the position (43) where the radial dimension does not change is the maximum outer diameter (D) of the disc spring (11), and the portion that expands in diameter when an axial load is applied to the disc spring (11) is a disc. Maximum outer diameter (D) of spring (11)
The disc spring (1
There is provided a spindle device in which 1) is incorporated into the inner peripheral surface of the central hole of the spindle so that the outer diameter of the disc spring (11) is fitted and guided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The inventor of the present application optimizes the shape of the disc spring by
The shape and stress of the Belleville spring in the free state and the compressed state were numerically analyzed by the finite element method. Referring to FIG.
FIG. 2 shows a perspective view of a typical disc spring cut in half in a plane containing the central axis and the diameter of the disc spring, and FIG. 2 shows two wall thickness sections A of FIG. 3 obtained by finite element analysis. , B
The change in shape of the thick section B is shown. In FIG. 2, the free state of the disc spring is shown by a one-dot chain line, and the compressed state is shown by a solid line. It should be understood that FIG. 2 is shown with the free state and the compressed state of the disc spring superimposed.

As can be seen from FIG. 2, when a compressive load is applied to the disc spring, the upper portion of the radial inner periphery of the disc spring bulges to enter the radial inner side as indicated by the shaded portion 31, and The lower portion of the peripheral portion recedes outward in the radial direction as indicated by the shaded portion 33. At the same time, the lower portion of the radial outer periphery of the disc spring bulges outward in the radial direction as indicated by the shaded portion 35, and the upper portion of the radial outer periphery retracts inward in the radial direction as indicated by the shaded portion 37. At this time,
A compressive stress is mainly generated in the upper region of the disc spring, and a tensile stress is applied in the lower region. Between the two stress regions, a boundary surface 39 where internal stress indicated by a chain double-dashed line does not act
In the disc spring, the portion of the intersection line 41 where the boundary surface 39 and the inner peripheral surface 105 of the disc spring intersect with each other has a diameter of the inner peripheral side where the radial position does not move in the free state and the compressed state of the disc spring. It is a fixed point. Similarly, for disc springs,
Line 4 of intersection between the boundary surface 39 and the outer peripheral surface 107 of the disc spring
The portion 3 is an outer peripheral side radial fixed point where the radial position does not move in the free state and the compressed state of the disc spring.

FIG. 1 is a disc spring 1 according to an embodiment of the present invention.
2 is a sectional view of FIG. The disc spring 11 passes through the inner circumferential side radial fixed point 41 in the general disc spring, and the disc spring 1
On the central axis O of the disc spring 11 passing through the first inner peripheral surface 13 notched by a cylindrical plane parallel to the central axis O of the first inner peripheral surface 13 and the inner peripheral side radial fixed point 41. Cut with a conical surface that converges downward
And a second inner peripheral surface 15 that is lacking . The second inner peripheral surface 15 has the disc spring 1 in a compressed state.
The upper part of the inner circumference of the first member 1 is formed so as not to bulge inward in the radial direction with respect to the fixed point 41. As a result, in the disc spring 11 according to the present embodiment, the radially inner fixed point 41 is the smallest radius portion in the inner circumferential portion of the disc spring 11 that is not displaced radially in the free state and in the compressed state. . Therefore, if the disc spring 11 is fitted and guided to the drawbar of the machine tool at the radially inner fixed point 41 in the free state, the clearance between the disc spring 11 and the drawbar is determined without considering the deformation of the disc spring 11. It becomes possible.

On the central axis O of the disc spring 11 passing through the first outer peripheral surface 23, which is a notch in a cylindrical plane parallel to the central axis O of the disc spring 11, and the radial fixed point 43 on the outer peripheral side. Second outer peripheral surface 25 notched by a conical surface that converges below
It has and. The second outer peripheral surface 25 is formed so that the outer peripheral lower portion of the disc spring 11 does not bulge outward in the radial direction from the fixed point 43 when the disc spring 11 is in the compressed state. As a result, the disc spring 11 is fixed at the outer peripheral side radial fixed point 4
In the outer peripheral portion of the disc spring 11, the portion 3 has the largest radius and is not displaced in the radial direction in both the free state and the compressed state. Therefore, if the disc spring 11 is fitted and guided in the radial fixed point 43 on the outer peripheral side in the free state, for example, to the spindle center hole of the machine tool, the clearance with the spindle center hole is not taken into consideration without considering the deformation of the disc spring 11. Can be determined .

In the thick section of FIG. 1, the upper region of the chain double-dashed line 39 is the portion where both the inner diameter and the outer diameter are reduced when an axial load is applied to the disc spring, and the lower area is enlarged. Is.
An intersection line 40 between the boundary surface 39 and the inner peripheral surface is a position where the inner diameter does not change, and one point on the intersection line 40 is represented as an inner peripheral side radial fixed point 41. Similarly, one point on the line of intersection between the boundary surface 39 and the outer peripheral surface is represented as the outer peripheral radial fixed point 43. Inside diameter disc spring design in the inner position of the circumferential side radially fixed point 41, it can I and the inner diameter d of the fabrication. Further, the outer diameter at the position of the outer radial side fixed point 43 may be set as the outer diameter D in designing the disc spring.

When the disc spring is deformed by an axial load, the inner peripheral surface 15 and the outer peripheral surface 25 have a smaller inner diameter than the inner peripheral side radial fixed point 41 or the outer peripheral side radial fixed point. If the outer diameter does not become larger than 43, the original inner and outer peripheral surfaces of the disc spring may be used as they are, instead of being specially formed.

[0019] In the present embodiment has been described disc spring having a beautiful outer diameter D Oyo inner diameter d to one disc spring at the same time, the disc spring may be used in the outer surface riding in inside diameter guide It is a versatile disc spring that can be used. Of course, and disc spring having only inner diameter d of the inner diameter of the guide applications only, also disc spring having only outer diameter D of the-only applications outside surface riding within the scope of the present invention.

Next, the behavior of the disc spring when an axial load acts on the disc spring of FIG. 1 to deform the disc spring will be described. The radially inner fixed point 41 only displaces right below and never displaces radially with respect to the central axis O. And never inside diameter also circumferential surface 13, 15 is not deformed until becomes smaller than the position inner diameter d. Therefore, if this disc spring is inserted into the draw bar of the spindle of a machine tool by inner diameter guide, the clearance between the disc spring and the draw bar is always constant regardless of whether the disc spring is deformed or not. Can be set to.

On the other hand, the radially outer fixed point 43 only displaces right above and never displaces in the radial direction with respect to the central axis O. The Never outer diameter peripheral surface 23, 25
Does not deform to a position larger than the outer diameter D. Therefore, if this disc spring is inserted, for example, in the center hole of the spindle of the machine tool by the outer diameter guide, the clearance between the disc spring and the center hole of the spindle is always constant whether the disc spring is deformed or not.
This clearance can be set to the lowest possible value.

The corners 45, 46, 4 of the disc spring are also
Reference numerals 7 and 48 are chamfered in a rounded shape or an oblique line shape to prevent the concentration of stress when the disc springs are deformed and the concentration of contact surface pressure between adjacent disc springs.

FIG. 4 shows a partial cross-sectional view of the tip of a spindle device 51 of a machine tool incorporating a disc spring according to the present invention. The spindle device 51 includes a rotary spindle 59 rotatably supported by the housing 53 via bearings 55 and 57. A taper hole 59a for mounting a tool holder 61 to which a tool T is attached is formed at the tip of the rotary spindle 59. By fitting the tapered shank portion 61a of the tool holder 61 into the tapered hole 59a, the tool holder 61 is attached to the tip of the rotary spindle 59. A pull stud 61b is attached to the rear end of the taper shank portion 61a of the tool holder 61. A central hole 59b is formed in the rotary main shaft 59 along the central axis, and a draw bar 65 is arranged in the central hole 59b so as to be movable forward and backward along the central axis. A collet chuck 63 is attached to the tip of the draw bar 65, and the collet chuck 63 can engage with and separate from the pull stud 61b of the tool holder 61.

Further, in order to elastically urge the draw bar 65 toward the rear end of the rotary main shaft 59, a plurality of disc springs 11 according to the above-described embodiment are arranged, and the disc springs 11 are arranged.
The spring retainer 67 for pressing and compressing the drawbar 6 is
It is connected to 5. The disc spring 11 is arranged so as to be fitted and guided by the inner circumferential side radial fixed point 41 with respect to the outer circumferential surface of the draw bar 65 and positioned in the radial direction.

In the same manner as the conventional spindle device, the spindle device 51 pushes the disc spring 11 with the spring retainer 67 from the state shown in FIG. 51
By moving the collet chuck 6 toward the tip of the collet chuck 6
3 and the pull stud 61b are disengaged, and the tool holder 61 can be removed from the tapered hole 59a of the rotary spindle 59.

When the tool holder 61 is removed from the tapered hole 59a by an automatic tool changer (not shown) and a new tool holder 61 is then mounted in the tapered hole 59a, the pull stud 61b and the collet 63 are engaged with each other. In this state, when the drawbar driving device is released from the drawbar 65, the drawbar 65 is elastically urged by the disc spring 11.
Is urged toward the rear end of the rotary spindle 59, and the pull stud 6
The tool holder 61 is drawn into the tapered hole 59a through the engagement of the collet chuck 63 with the tool holder 6b.
1 is completely mounted on the rotary spindle 59.

As described above, since the radially inner fixed point 41 of the disc spring 11 is the portion with the smallest radius that is not displaced in the radial direction, the disc spring 11 is compressed during the series of tool changing operations described above. Even if the state and the free state released from the compressed state are repeated, the minimum size of the inner peripheral portion of the disc spring 11 does not change. Therefore, by guiding and positioning with respect to the outer peripheral surface of the drawbar 65 at the radial fixed point on the inner peripheral side of the disc spring 11, the clearance between the disc spring 11 and the drawbar 65 should be considered in consideration of the change in the inner diameter of the disc spring 11. It can be set to almost zero without any need. As a result, the positions of the plurality of disc springs 11 do not deviate in the radial direction at the time of high-speed rotation of the rotary main shaft 59 to cause abnormal vibration. Therefore, the rotary main shaft 59 is rotated at a high-speed rotation exceeding 10,000 rpm, for example. Is possible.

Further, in the embodiment of FIG. 4, the disc spring 11 is configured to be fitted and guided with respect to the draw bar 65 at the inner radial side fixed point 41, but the outer radial side fixed point 43. In, the disc spring 11 may be fitted and guided in the central hole 59b of the rotating main shaft 59. In this case, since the radially outer fixed point 43 is the portion with the largest radius that is not displaced in the radial direction, the disc spring 11 is released from the compressed state and the compressed state during the series of tool changing operations described above. Even if the free state is repeated, the disc spring 11
The maximum size of the outer periphery of the is unchanged. Therefore, the disc spring 11
If the disc spring 11 is fitted and guided to the inner surface of the central hole 59b of the rotary spindle 59 at the outer radial side fixed point 43 of
The clearance between the center hole 59b and the central hole 59b can be set to almost zero without considering the change in the outer diameter of the disc spring 11. As a result, the abnormal vibration due to the displacement of the disc spring 11 disappears when the rotating main shaft 59 rotates at high speed, as described in the embodiment of FIG.

Although the preferred embodiment of the present invention has been described above, it is obvious to those skilled in the art that the present invention is not limited to this and various modifications and improvements can be made within the scope. For example, in the embodiment of FIG. 1, the first inner peripheral surface 13 is cut at a cylindrical surface that passes through the inner peripheral side radial fixed point 41 in the inner peripheral portion of the disc spring 11 and is parallel to the central axis O. Although the shape is described as having a missing shape, the present invention is not limited to this. As described above, in the inner peripheral portion of the disc spring 11, the portion below the radially inner fixed point 41 is the disc spring 11.
Is deformed outward in the radial direction when it is in a compressed state, so that in the free state, the inner radial side immovable point 41 becomes a portion having the smallest radius in the inner peripheral portion of the disc spring 11. The peripheral surface 13 may be formed. Therefore, the shape may be a part of the conical surface. Further, it may be a curved surface such that the cross section is not a straight line like a conical surface but a curved line. Similarly, the second inner peripheral surface 15 has been described as a shape that is cut out by a conical surface that converges downward, but it may be formed by a curved surface that has a curved cross section instead of a straight cross section. . The point is that when the disc spring 11 is in a compressed state, the upper portion of the inner circumferential side radial fixed point 41 does not have to bulge radially inward from the inner circumferential radial fixed point 41.

Further, the first outer peripheral surface 23 has been described as a shape which is cut out by a cylindrical surface which passes through the outer peripheral radial fixed point 43 in the outer peripheral portion of the disc spring 11 and which is parallel to the central axis O. However, the present invention is not limited to this. As described above, in the outer peripheral portion of the disc spring 11, the outer peripheral side radial fixed point 4
Since the portion below 3 is deformed radially inward when the disc spring 11 is in a compressed state, the radially outer fixed point 43 in the free state is the portion with the largest radius in the outer peripheral portion of the disc spring 11. The first outer peripheral surface 23 may be formed so that Therefore, the shape may be a part of a conical surface, or may be a curved surface such that the cross section is a curved line instead of a straight line like a conical surface. Similarly, the second outer peripheral surface 25 is cut by a conical surface that converges downward.
Although it has been described that the shape is notched, it may be formed with a curved surface such that the cross section is curved instead of being straight. The point is that, when the disc spring 11 is in a compressed state, the lower part of the outer peripheral side radial fixed point 43 does not have to bulge outward in the radial direction from the outer peripheral radial fixed point 43.

Further, although FIG. 4 shows a spindle device of a machine tool, the disc spring according to the present invention can be applied to a precision indexing table and a valve device of a machine tool in addition to the spindle device of a machine tool. Further, it can be used in various devices such as an outer ring of a bearing and a spring for applying an inner ring preload.

[0032]

According to the disc springs of the first and second aspects, the radial fixed point on the inner peripheral side has the maximum radius which is not displaced radially in the inner peripheral portion of the disc spring in both the free state and the compressed state. It becomes a small part. Therefore, if the disc spring is fitted and guided at the inner circumferential side radial fixed point in the free state, the clearance with the mating member can be determined without considering the change in the inner diameter due to the deformation of the disc spring.

Further, in the Belleville springs according to the third and fourth aspects, the radially outer fixed point is the portion having the largest radius which does not displace radially in the outer periphery of the Belleville spring in both the free state and the compressed state. . Therefore, if the disc spring is fitted and guided at the outer radial side fixed point in the free state, the clearance with the mating member can be determined without considering the outer diameter change due to the deformation of the disc spring.

According to the spindle device of the fifth aspect, in the inner peripheral portion of the disc spring, the radial fixed point on the inner peripheral side is a portion having the smallest radius which is not displaced radially in the free state and the compressed state. Since the disc spring is fitted and guided with respect to the drawbar of the main shaft device, the clearance between the disc spring and the drawbar should be set to almost 0 (zero) without considering the change in the inner diameter due to the deformation of the disc spring. Therefore, even if the rotary spindle of the spindle device is rotated at high speed, radial displacement of the plurality of disc springs does not occur, and therefore abnormal vibration does not occur, and highly accurate machining can be performed.

According to the spindle device of the sixth aspect, in the outer peripheral portion of the disc spring, the disc spring having the largest radius that is not radially displaced in both the free state and the compressed state is formed in the outer peripheral radial direction. At the fixed point, the disc spring is fitted and guided in the center hole of the rotating spindle of the spindle device, so the inner peripheral surface of the center hole of the disc spring and the rotating spindle does not take into account the change in outer diameter due to deformation of the disc spring. It is possible to determine the clearance between them to almost zero, and even if the rotating main shaft of the main shaft device is rotated at high speed, the displacement of the plurality of disc springs in the radial direction does not occur, so abnormal vibration does not occur, and highly accurate. Can be processed.

When the disc springs are overlapped with each other, the disc springs try to escape in the radial direction with respect to the axial line, especially when the axial load is repeatedly applied in a state where the concave surfaces face each other and are in contact with each other at the outer peripheral portion. Since the disc spring is fitted on the circumferential surface or outer peripheral surface of the mating member with almost no clearance, there is no radial displacement of the disc spring, and the disc spring and the mating member are twisted together. It doesn't fit. Therefore, phenomena such as reduction of elastic biasing force and destruction of the disc spring or the counterpart member do not occur.

[Brief description of drawings]

FIG. 1 is a half sectional view of a disc spring according to an embodiment of the present invention.

FIG. 2 is a diagram showing a finite element analysis showing a change in cross-sectional shape of a disc spring.

FIG. 3 is a perspective view showing a cross section of a disc spring.

FIG. 4 is a partial cross-sectional view of a spindle device tip portion of a machine tool incorporating a disc spring according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a general shape of a disc spring.

[Explanation of symbols]

11 ... Disc spring 13 ... 1st inner peripheral surface 15 ... Second inner peripheral surface 23 ... First outer peripheral surface 25 ... Second outer peripheral surface 41 ... Inner radial side fixed point 43 ... Fixed point in the radial direction on the outer peripheral side

Claims (6)

(57) [Claims] 1. In a disc spring having an inner diameter, an outer diameter and a wall thickness, when an axial load is applied to the disc spring (11), a boundary between a portion that expands and a portion that contracts in a thick section the minimum and the inner diameter (d) of the surface of the inner diameter disc spring (39) does not change the radial dimension present on position (41) (11), if pan
The part that contracts when the axial load is applied to the knee (11) does not bulge inward beyond the minimum inner diameter (d) of the disc spring (11).
A disc spring characterized by being formed as described above . 2. The inner circumference of the disc spring (11) has a portion whose diameter increases at a position (41) where the radial dimension does not change when an axial load is applied to the disc spring (11). It is formed in a cylindrical shape and reduced diameter portions are disc spring as claimed in claim 1, which is made form a conical surface shape. 3. A disc spring having an inner diameter, an outer diameter and a wall thickness, when an axial load is applied to the disc spring (11), a boundary between a portion that expands in diameter and a portion that decreases in diameter in a thick section. The outer diameter of the position (43) on the surface (39) where the radial dimension does not change is the maximum outer diameter (D) of the disc spring (11), and the disc
When the axial load is applied to the knee (11), the part that expands in diameter does not bulge outward beyond the maximum outer diameter (D) of the disc spring (11).
A disc spring characterized by being formed as described above . 4. The outer periphery of the disc spring (11) has a cylindrical portion where the diameter is reduced at a position (43) where the radial dimension does not change when an axial load is applied to the disc spring (11). is formed in a shape, and the disc spring as claimed in claim 3 portions whose diameter increases is being made form a conical surface shape. 5. A main shaft comprising a housing, a main shaft rotatably supported by the housing, a draw bar inserted in the main shaft so as to be movable back and forth in the axial direction, and a disc spring for giving an elastic biasing force to the draw bar. In the device, the disc spring (11) has a boundary surface (3) between a portion that expands in diameter and a portion that reduces diameter in a thick section when an axial load is applied.
9) The position (4) where the radial dimension above does not change
The inner diameter dimension of 1) is set to the minimum inner diameter (d) of the disc spring (11), and the portion that reduces in diameter when an axial load is applied to the disc spring (11) is the minimum inner diameter (d) of the disc spring (11). Swell more inward
A spindle device which is formed so as not to come out, and which is assembled so that the inner diameter of the disc spring (11) is fitted and guided to the outer peripheral surface of the draw bar. 6. A spindle comprising a housing, a spindle supported by the housing for rotation, a drawbar inserted in the spindle so as to be movable back and forth in an axial direction, and a disc spring for giving an elastic biasing force to the drawbar. In the device, the disc spring (11) has a boundary surface (3) between a portion that expands in diameter and a portion that reduces diameter in a thick section when an axial load is applied.
9) The position (4) where the radial dimension above does not change
The outer diameter of 3) is the maximum outer diameter (D) of the disc spring (11), and the portion that expands when an axial load is applied to the disc spring (11) is the maximum outer diameter of the disc spring (11). (D) Swells outward
A spindle device which is formed so as not to come out, and in which the disc spring (11) is incorporated into the inner peripheral surface of the central hole of the spindle so that the outer diameter of the disc spring (11) is fitted and guided.