JPH0524236U - Turntable fixing device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a fixing device for a turntable that can obtain a large clamping force with a small device. [Structure] Spindle 1 that rotatably supports the turntable
A clamp cylinder 4 having a ring-shaped pressure chamber 4b is provided above and below a disk 3 fixed to the disk 3, and a ring piston 4 is provided in each pressure chamber 4b of the clamp cylinder 4.
In addition to accommodating c, a plurality of rods 4d for clamping the disc 3 are provided on the disc surface of each of the ring pistons 4c so as to protrude from the vertical direction, and a large pressure receiving area can be obtained by the ring piston. A larger clamping force can be obtained with a fixing device that can be installed in a small space.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a turntable fixing device provided in a machine tool or the like.

[0002]

[Prior Art]

 Conventionally, there is a multi-task machine tool equipped with a turntable that enables machining such as turning, cutting and drilling with a single device. With the above machine tools, when turning, the turn table with the work is rotated to process the work, but when cutting or drilling, the turntable with the work is rotated with a fixing device. Is fixed and processed. Further, if the turntable moves during processing, it is difficult to perform highly accurate processing. Therefore, conventionally, the rotation of the turntable is fixed by a fixing device as shown in FIGS. 1 and 2. That is, a disc b is provided at the lower end of a support shaft a for rotatably supporting a turntable, and a clamp cylinder having a large number of pressure chambers f at equal intervals on the same circumference above and below the disc b. c is installed. The pressure chambers f of the clamp cylinders c accommodate pistons e each having a rod d protruding toward the disc b. The discs b are clamped between the rods d of the pistons e in the vertical direction. It is configured to fix the rotation of the turntable.

[0003]

[Means for solving the problem]

In the above-mentioned conventional fixing device, in order to fix the rotation of the turntable, the torque T is as follows: piston diameter d = 6.3 cm, number of pistons N = 24, disc friction coefficient μ = 0.1, cylinder pressure P = 70 kg / cm ² , and the diameter D of the circle in which the cylinders are arranged is D = 32 cm.

[0004]

[Equation 1]

It is represented by That is, since the pressure receiving area of the piston e is small despite the large installation space, a large clamping force cannot be obtained, and if an attempt is made to increase the clamping force, the entire device becomes large and a lot of space is required for installation. There was a bug I needed. The present invention has been made for the purpose of improving the above-mentioned conventional problems, and an object thereof is to provide a turntable fixing device capable of obtaining a larger clamping force without increasing the installation space.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a clamp cylinder having ring-shaped pressure chambers above and below a disk fixed to a support shaft for rotatably supporting a turntable, and the pressures of the clamp cylinders. A ring piston is housed in the chamber, and a plurality of rods for clamping the disc are vertically provided on the disc surface of each of the ring pistons from above and below.

[0007]

[Work]

 With the above configuration, the pressure receiving area of the piston that obtains the clamping force can be increased, so that a larger clamping force can be obtained without increasing the size of the entire device.

[0008]

【Example】

 An embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. FIG. 3 is a plan view of the fixing device, and FIG. 4 is a sectional view thereof. In these drawings, reference numeral 1 shows a spindle provided at the center of a turntable (not shown). The support shaft 1 is rotatably supported on a bed (not shown) of a machine tool by a bearing (not shown), and a disc 3 is fixed to the lower end of the support shaft 1 by a fastener 2. Reference numeral 4 denotes a ring-shaped clamp cylinder having the spindle 1 as a center, and a slit 4a is formed on the inner peripheral surface in the horizontal direction. The slit 3a accommodates the disk 3 and the slit 4a. A ring-shaped pressure chamber 4b is formed above and below 4a, and a ring piston 4c is housed in these pressure chambers 4b slidably in the vertical direction.

[0009] On the inner and outer peripheral surfaces of the ring piston 4c, there are provided 0-rings 5 which are in sliding contact with the inner and outer peripheral surfaces of the pressure chamber 4b, and the disks 3 of the respective ring pistons 4c are provided. Eight rods 4d, for example, are provided at equal intervals on the surface so as to face each other. These rods 4d have a columnar shape, and as shown in FIG. 5, the disc 3 of each ring piston 4c is fixed to the groove surface by a fixing tool 6, and a small hole is formed in a hole 4e formed in the clamp cylinder 4. It is vertically slidably inserted with a gap, and its movement in the radial direction is restricted. Then, the disk 3 is clamped in the vertical direction by the surfaces of the rods 4d that face each other to fix the rotation of the turntable.

The operation of the fixing device configured as described above will be described. When cutting or boring a work mounted on the turntable, the rotation is fixed by the fixing device after indexing the turntable. In this case, the hydraulic pressure P 1 is supplied to each pressure chamber 4b of the clamp cylinder 4. As a result, the ring piston 4c housed in the pressure chamber 4a moves to the disc 3 side, and the plurality of rods 4d fixed to each ring piston 4c clamp the disc 3 from above and below to rotate the turntable. Fix it. The torque for fixing the turntable at this time is such that the outer diameter D ₁ = 38 cm, the inner diameter D ₂ = 26 cm of the ring piston 4 c, the friction coefficient μ = 0.1 of the disc 3, the hydraulic pressure P = 70 kg / cm ² , and the rod 4 d are arranged. If the diameter of the circle is D = 32 cm,

[0011]

[Equation 2]

[0012] Therefore, the torque of the conventional fixing device is 8.37 × 10 ⁴ kg · cm, and the tortuosity torque of 1.61 times can be obtained. Further, the ratio of the pressure receiving area is S _{1 where} the pressure receiving area of the conventional fixing device is

[0013]

[Equation 3]

On the other hand, if the pressure receiving area of the above embodiment is S ₂ ,

[0015]

[Equation 4]

[0016]

[0017]

[Equation 5]

It becomes Actually, n may not be an integer, and a gap needs to be provided between the cylinders, so that the pressure receiving area ratio is further increased.

[0019]

[Effect of the device]

 As described in detail above, this invention provides a larger clamping force than when the fixing device is formed in a size that can be installed in the same space as the conventional fixing device, so that the turntable can be fixed more reliably. However, if the clamping force is the same as the conventional one, the size can be made smaller and it can be installed easily in a small space.

[Brief description of drawings]

FIG. 1 is a plan view showing a conventional turntable fixing device.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a plan view showing a turntable fixing device according to an embodiment of the present invention.

4 is a cross-sectional view taken along the line BB of FIG.

FIG. 5 is an enlarged sectional view of a link piston.

[Explanation of symbols]

1 spindle, 3 discs, 4 clamp cylinders, 4b
Pressure chamber, 4c ring piston, 4d rod.

Claims (1)

[Scope of utility model registration request] 1. A clamp cylinder 4 having ring-shaped pressure chambers 4b is provided above and below a disc 3 fixed to a support shaft 1 for rotatably supporting a turntable, and each pressure chamber of the clamp cylinder 4 is provided. A turntable fixing device in which a ring piston 4c is housed in 4b, and a plurality of rods 4d for clamping the disc 3 from the up and down direction are projected from the disk 3 of each ring piston 4c.