JPH069836U - Low thermal displacement spindle head - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the thermal displacement of the spindle head. A spherical member 2 is provided on a horizontal line passing through a spindle rotation center of a spindle case main body 3 that pivotally supports a spindle 18, and the spindle case main body 3 is mounted on a support base 4 on the fixed side of the machine via the spherical member 2. Place it. [Effect] The thermal displacement, particularly the thermal displacement in the Y-axis direction is reduced, and high-precision machining is performed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a spindle head that pivotally supports a spindle, and more particularly to a low thermal displacement type spindle head with a small thermal displacement.

[0002]

[Prior art]

 FIG. 4 shows a schematic structure of a conventional general spindle head 1a. The spindle head 1a has a portion that pivotally supports the spindle 18 and a portion that is slidably supported by a fixed type of machine. In FIG. 4, a bracket 19 that pivotally supports the spindle 18 and a support that is supported on the fixed side. The base 20 is formed of a separated structure. The bracket 19 surrounds and holds the entire circumference of the spindle 18, and is fixed on the support 20 by bolts 21. The support 20 is slidably supported on a slide rail 17 arranged on the fixed side of the machine, and a female screw portion 16 is formed along the slide direction. The support base 20 moves on the slide rail 17 by the rotation of a lead screw (not shown) screwed onto the female screw portion 16. The heat generated by the rotation of the spindle 18 is transmitted from the entire circumference of the spindle 18 to the bracket 19 side and the support base 20 side.

[0003]

[Problems to be solved by the device]

 In the case of the conventional spindle head 1a, as described above, the bracket 19 supporting the entire circumference of the spindle 18 is placed on the support base 20 with its entire lower surface in contact. Therefore, the heat generated by the rotation of the spindle 18 raises the temperature of the bracket 19 and the support base 20 and causes a large thermal displacement. In particular, thermal displacement is large in the vertical direction (Y-axis direction) in the figure. Therefore, the center position of the spindle 18 is deviated, which causes a problem that high-precision positioning processing cannot be performed. As a result, it was necessary to process while constantly performing thermal displacement correction.

The present invention solves the above problems, and an object of the present invention is to provide a low thermal displacement type spindle head that reduces the thermal displacement amount of the spindle head and enables high-precision machining.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is a spindle head comprising a support base supported on a fixed side of a machine and a spindle case body for pivotally supporting a spindle, the spindle case body being the center of rotation thereof. The low thermal displacement spindle head is configured to be supported on the support base through a spherical member on a horizontal line passing through the points.

[0006]

[Action]

 Since the spindle case body that pivotally supports the spindle is placed on the support base via the spherical member, the heat of the spindle case body is transferred to the support base side only from the contact point of the spherical member. Therefore, the temperature rise of the support base is reduced and the thermal displacement is reduced. Also, since the spherical member is arranged on the horizontal line passing through the center of rotation of the spindle case body, the spherical member is arranged at the position farthest from the center of rotation, and part of the heat of the spindle is dissipated by the time it reaches the spherical member. As a result, the effect of reducing the amount of heat transfer to the spherical member side is also enhanced.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 is a front view showing the entire structure of the present embodiment, FIG. 2 is a top view of FIG. 1, and FIG. 3 is an enlarged partial sectional view showing a detailed structure around a spherical member. As shown in FIG. 1, the spindle head 1 of this embodiment includes a spindle case main body 3 that surrounds and supports a spindle 18, and a support base 4 that supports the spindle case main body 3. The support base 4 is an upper support base 5 The upper support 5 is fixed to the lower support 6 with bolts 7. A spherical member 2, which is a main element of this embodiment, is provided between the spindle case body 3 and the upper support 5.

The spindle case body 3 is composed of a cylindrical portion 3a surrounding the spindle 18 and a flange portion 3b protruding to the left and right of the cylindrical portion. As shown in FIG. 2, ball receivers 8 having a spherical surface with which the spherical member 2 abuts are fitted in front of and behind the left and right flange portions 3b, 3b (in the axial direction of the spindle 18). As shown in FIG. 3, an oil hole 9 is formed in the ball receiving member 8 so as to open to the spherical surface side. Further, the flange portion 3b is formed with a through hole 10 communicating with the oil hole 9.

As shown in FIG. 1, the upper support base 5 is formed at a position opposed to the recess 5 a into which the lower side of the cylindrical portion 3 a of the spindle case body 3 is inserted and the flange portion 3 b of the spindle case body 3. And a mounting seat 5c for connecting the upper support 5 to the lower support 6 are integrally formed. As shown in FIG. 3, a sphere receiver 11 having a spherical surface that abuts the spherical member 2 is fitted to the flange portion 5b via a spacer 12. An oil hole 13 that opens toward the spherical member 2 is formed through the ball receiver 11. As described above, the spindle case body 3 is supported on the upper support base 5 via the four spherical members 2 as shown in FIG. The spindle case body 3 is fixed to the upper support 5 by bolts 14.

The lower support base 6 is composed of a base portion 6a having a seat surface to which the mounting seat 5c of the upper support base 5 is adhered, and a protrusion 6b extending downward from the base portion 6a. A slide rail receiver 15 is fixed to the lower surface side of the pedestal portion 6a, and a female screw portion 16 to which a lead screw (not shown) is screwed is formed on the protruding portion 6b. Further, the slide rail receiver 15 is supported by a slide rail 17 arranged on the fixed side of the machine. With the above structure, the support base 4 is slidably supported in the laying direction of the slide rail 17 (axial direction of the spindle 18), and reciprocates the spindle 6 in the axial direction.

Next, the operation of this embodiment will be described. As the spindle 18 rotates, it becomes hot. The generated heat is transferred to the cylindrical portion 3a of the spindle case body 3 that surrounds the outer periphery of the spindle 18. Since the cylindrical portion 3a is composed of a relatively thin cylindrical body, a part of the heat generated above is radiated from around the cylindrical portion 3a. Since the flange portion 3b is formed at a position farthest from the center of the spindle 18, the remaining heat that has not radiated from the cylindrical portion 3b is transferred. The transferred heat is transferred to the spherical member 2 side via the ball receiver 8. However, since the ball receiving member 8 and the spherical member 2 are in spherical contact, and in extreme cases point contact, the heat of the flange portion 3b is difficult to be transferred to the spherical member 2 side. As a result, high heat of the spherical member 2 is prevented. The heat of the spherical member 2 is transferred to the upper support base 5 via the ball support 11 and further to the lower support base 6. Since the spherical member 2 and the ball receiver 11 are in spherical contact or point contact, it is difficult to transfer heat from the spherical member 2 to the ball receiver 11 side. Therefore, the temperature rise of the support base 4 is reduced. As a result, the thermal displacement of the spindle head 1, especially the thermal displacement in the Y-axis direction is greatly reduced.

The spindle case body 3 is supported on the support base 4 only by the four spherical members 2. However, by appropriately setting the size and strength of the spherical member 2, the spindle case body 3 can withstand its own weight. You can Further, by supplying the lubricating oil from the passage hole 10, the spherical member 2 is lubricated through the oil holes 9 and 13, and it is possible to prevent galling and the like.

Although the material of the spherical member 2 is not particularly limited in the above-described embodiment, the spherical member 2 having a low thermal conductivity, for example, a material such as ceramics is used to further reduce the heat conduction to the support base 4 side. The thermal displacement can be further reduced.

In the above embodiment, the spherical members 2 are arranged at four places, but of course the invention is not limited to this.

[0015]

[Effect of device]

 According to the present invention, the following effects can be obtained. (1) By adopting a structure in which the spindle case body that pivotally supports the spindle is mounted on the support base via a spherical member, the heat transfer of the spindle heat to the support base side can be greatly reduced. . This reduces the thermal displacement of the spindle head. (2) Since the spherical member is placed on the horizontal line passing through the spindle center of the spindle case body and is located away from the spindle center, the heat of the spindle is dissipated by the time it reaches the spherical member. The heat transfer to is reduced. (3) Since the thermal displacement is reduced, the frequency of thermal displacement correction is reduced and the work efficiency is improved. (4) The thermal displacement can be further reduced by using a spherical member having a low thermal conductivity.

[Brief description of drawings]

FIG. 1 is a front view showing the overall structure of an embodiment of the present invention.

FIG. 2 is a top view of FIG.

FIG. 3 is an enlarged partial sectional view showing a detailed structure around the spherical member of FIG.

FIG. 4 is a front view showing a conventional spindle head structure.

[Explanation of symbols]

 1 Spindle Head 2 Spherical Member 3 Spindle Case Main Body 3a Cylindrical Part 3b Flange Part 4 Support Stand 5 Upper Support Stand 5a Recess 5b Flange Part 5c Mounting Seat 6 Lower Support Stand 6a Pedestal 6b Projection 7 Bolt 8 Ball Receiver 9 Oil Hole 10 Through Hole 11 Ball Receiver 12 Spacer 13 Oil Hole 14 Bolt 15 Slide Rail Receiver 16 Female Threaded Part 17 Slide Rail

Claims (2)

[Scope of utility model registration request] 1. A spindle head comprising a support base supported on a fixed side of a machine and a spindle case main body for pivotally supporting a spindle, the spindle case main body having a spherical shape on a horizontal line passing through a rotation center point thereof. A low thermal displacement type spindle head, which is supported on the support base via a member. 2. The low thermal displacement spindle head according to claim 1, wherein the spherical member is a hard member having a low thermal conductivity.