JPH0215334B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tailing device used to appropriately change the attitude of a workpiece when processing the workpiece.

[Prior art]

Generally, a machine tool that processes a workpiece by changing its posture is equipped with a tailing device to change the angle of the table.

In conventional tailing devices, a heavy workpiece is placed on the table, so in order to compensate for the weight of the workpiece, a constant compensating fluid pressure is applied in the opposite direction to the direction in which this weight acts. A weight compensating means such as a hydraulic cylinder is provided to act on the weight.

However, in such a tailing device, the rotational moment acting on the table due to the weight of the workpiece varies greatly depending on the swing angle of the table, so a constant fluid pressure is applied by the weight compensation means. In some cases, the rotational moment acting on the table is not well balanced, causing excessive force to be applied to the drive system for tilting the table, or causing backlash in the drive system, making it impossible to accurately position the table at an angle. Firstly, this had the disadvantage of poor machining accuracy for the workpiece.

[Purpose of the invention]

In view of the above-mentioned conventional drawbacks, the present invention provides weight compensating means in order to counteract the rotational moment generated by the weight of the workpiece on the table when the swing table is tilted, and the compensating means comprises three pieces. By configuring the oscillating table to have three pivot points, and configuring the three pivot points to be located in a straight line when the oscillating angle of the oscillating table is zero, highly accurate angular positioning can be achieved. The purpose of this invention is to provide a tailing device that can

〔Example〕

Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a front view showing an embodiment of the present invention, and FIG. 2 is a side view seen from the direction of FIG. Two supports 2 and 3 are fixed, and a pivot shaft 4 is bridged so as to pass through both supports 2 and 3 (see FIG. 2). A swing table 5 is mounted between the supports 2 and 3, and is swingable around the axis of the pivot shaft 4 integrally with the pivot shaft 4. (Fig. 2) A rotary table 6 is installed so as to be freely rotatable. A workpiece W to be machined is placed on the rotary table 6.
can be installed.

The oscillating movement of the oscillating table 5 is achieved by a worm wheel 7 fixed to the pivot 4 within the support 3.
This is accomplished by rotating the swing motor 8a and the worm 8. Further, the rotary movement of the rotary table 6 is achieved by rotating a worm wheel 10 fixed to the shaft body 9 within the rotary table 5 with a worm 11. In addition, as shown in FIG.
is fixed.

Links 13, 13' are fixed to both ends of the pivot shaft 4, and the ends of piston rods 14, 15 are fixed to the extending ends 13a, 13b of the link 13, respectively.
17, respectively. The piston rods 14 and 15 are each integral with a piston (not shown) that can reciprocate within weight compensation cylinders 18 and 19 as balancing force applying devices, and the cylinders 18 and 19 are connected to rotating brackets 20 and 19 respectively. Since the link 13 is pivotally connected to the support brackets 24 and 25 by pins 22 and 23 through the link 21, the link 13 is integrally connected to the pivot 4, the swing table 5, and the workpiece W, for example, as shown in the arrow a (see FIG. 1). can be swung in any direction. Then, the link 13, the pivot 4, the swing table 5, and the rotation table 6 are in the position shown by the two-dot chain line, for example.

The same piston rods 14, 15, cylinders 18, 19, rotation bracket 20, support brackets 24, 25, etc. shown in FIG. 1 are also provided on the other end of the pivot shaft 4 (see FIG. 2). , cylinder 18' same as cylinder 18, brackets 20,2
Brackets 20', 22', 24' same as 2, 24
only shown).

A swing table clamp device K is installed on the lower surface of the swing table 5, and is configured as follows. That is, the lower surface of the swing table 5 has a second
As shown in the figure, two hanging parts 5a and 5b are provided,
As shown in FIG. 3, arc-shaped elongated holes 501 and 502 (502 is shown in the fourth figure) are formed below these hanging portions 5a and 5b, respectively. These long holes 501,
Shafts 31 and 32 are fitted into the shafts 502, respectively, and one ends of the shafts 31 and 32 are connected to support brackets 33a and 33, respectively.
3b, 34a, 34b, it is supported by the bed 1 in a movable and non-rotatable manner, and male threads 31a, 32a are formed at the other end, and a flange is provided at the central portion slightly closer to the support brackets 33, 34. Portions 31b and 32b are formed. One side of the flange portions 31b, 32b corresponds to the hanging portions 5a, 5.
It is in contact with the outer surfaces 503 and 504 of b.

Female threaded portions at one ends of the swing arms 35, 36 are screwed into the male threaded portions 31a, 32a,
Pins 37, 3 are provided at the other ends of the pivot arms 35, 36.
One ends of the connecting members 39 and 40 are pivotally connected via 8.

A piston rod 41 is connected to the connecting member 39 as shown in FIG. 3, and the rod 41 is capable of reciprocating in its axial direction by a clamping cylinder 42. Although not shown, the same piston rod 41 and cylinder 42 are naturally provided for the connecting member 40 as well.

Note that the reference numeral 43 in FIG. 3 is a support bracket.

In this configuration, when processing the workpiece W, if the workpiece W is tilted by θ to the position shown by the two-dot chain line in FIG. 1 by swinging the swing table 5, the center of gravity G of the workpiece W is moves to G ₁ (see Figure 5). In this case, since the link 13 also rotates together with the swing table 5, the link 13 also rotates by θ as shown in FIG. In this case, the respective axes O ₄ and O ₂₂ of the pivot 4 and the pin 22 are always stationary, but the sliding of the piston rod 14 causes the pin 1 to move.
6's axis O ₁₆ moves to O ₁₆ '.

Here, when the workpiece W rotates by θ as shown in FIGS. 5 and 6, the respective moments due to the force _W1 due to the weight of the workpiece W and the force F acting on the piston rod 14 due to the hydraulic pressure in the weight compensation cylinder 18 are calculated. Considering the balance, first, the moment M around O ₄ due to W ₁ is as follows, where ₄ is R, M=W ₁ × _{1 4} = W ₁ ·Rsinθ (1). Also, the moment m around _O4 due to F is,
Let O ₄ O ₁₆ and _{4 22} be r and a, respectively, and the angle
If O ₄ O ₂₂ O ₁₆ is α, then m=F× _{2 4} =F・a sinα (2) Here, tanα= ₃ ′ ₁₆ / _{3 22} = ₃ ′ ₁₆ / (a− _{3 4} ). , _{3 4} = ₄ ′ ₁₆ ×cosθ=r・cosθ ₃ ′ ₁₆ =′ _{4 16} ×sinθ=r・sinθ Therefore, tanα=r sinθ/(a−r cosθ) = sinθ/(a/r−cosθ ) ∴α=tan ^-1 sinθ/a/r-cosθ (3) Substituting (3) into (2), m=F・a sin{tan ^-1 sinθ/a/r-cosθ} (4) These From the formula, in order to make the moment m due to F almost equal to the moment M due to W ₁ , considering the formula (1) = (4), as long as F is constant, then a and It is only necessary to appropriately select the ratio with r. However, in this case, the other weight compensation cylinder 19 also acts as a moment in the direction opposing M, and the link 13' in FIG.
Since two similar weight compensating cylinders are also provided at the position, the moment (4×m) due to a total of four cylinders opposes the above M.
If the ratio of a and r is determined with this in mind, a countering moment approximately equal to the moment M caused by the workpiece can be obtained.

In this case, as is clear from FIG. 6, ₄₂ increases as θ increases, so as the inclination of _the workpiece W increases, the counter moment m due to the weight compensation cylinder also increases.

Here, as a method of "keeping F constant", for example, as shown in FIG.
8, 19 is a ready-made counterbalance valve 5
1 and 52, and by sending the oil in the oil tank T by the pump P, a constant force can be applied to the piston rod 14.

As mentioned above, the workpiece W is tilted by a certain angle θ,
In order to process in this state, it is necessary to fix the workpiece W at this angular position. For this reason, in the device of this embodiment, in order to fix the swing table 5 at the position of the angle θ, the swing table clamp device K described above is provided, and by supplying hydraulic pressure to the clamp cylinder 42, The rod 41 and the connecting member 39 are extended and the pivot arm 35 pivots counterclockwise about the axis 31 in FIG. Therefore, due to the screw connection between the pivot arm 35 and the shaft 31, the shaft 31 is pulled to the right in FIG. 4, and a frictional force is generated between the flange portion 31b and the side surface 503. Similarly, the pivoting of the other pivoting arm 36 creates a frictional force on the other side 504 as well. Due to this frictional force, the swing table 5 is held and fixed in a state tilted by a certain angle θ, and a predetermined part of the workpiece W is machined in this state (in this case, of course, the weight compensation cylinders 18 and 19 are also (acting against the rotational moment M due to the weight of the workpiece W).

In the above description, the workpiece W is tilted counterclockwise in FIG. 1, but
Naturally, it can also be tilted clockwise, and the operation is the same, so the explanation will be omitted.

In the above embodiment, as a weight compensating means for compensating the weight when the workpiece W is tilted,
Four weight compensation cylinders and a piston rod that slides inside the cylinders are provided, but the invention is not limited to this. For example, as shown by the two-dot chain line in FIG. 16
It may be configured such that it is engaged with the pin 22 and suspended from the pin 22, and the weight 62 is suspended from the other end. Although only one weight 62 is shown in the figure, it is preferable to provide four weights 62 as in the case of the weight compensation cylinder.

〔Effect of the invention〕

As described above, the present invention includes a pair of supports fixed on a bed, a swinging table that can swing freely around the axis of a pivot bridged over the supports, and a drive device that swings the swinging table. and a swinging table clamp device for holding and fixing the workpiece in the swinging position, and one or more weight compensating means for counteracting the rotational moment due to the weight of the workpiece on the swinging table, the means comprising: The link has two fixed pivot points, a first pivot point of the link fixed to the pivot point and a second pivot point of the balance force applying device that is a certain distance away from the pivot point, and the link and the second pivot point are provided between these two pivot points. It has a third pivot point that swingably connects to the balance force applying device, and is configured so that the three pivot points are located in a straight line when the swing angle of the swing table is zero, so that the workpiece As the tilt angle increases, the countermoment due to the weight compensating means can be increased, and the drive system for swinging the swing table will not be subjected to excessive force or crash, and the swing table can be raised to a higher height. Accurate angular positioning is possible, improving machining accuracy for workpieces.

[Brief explanation of drawings]

Figure 1 is a front view showing one embodiment of the present invention, Figure 2 is a front view showing one embodiment of the present invention;
The figure is the left side view of Figure 1, and Figure 3 is the - of Figure 2.
4 is a sectional view taken along the - line in FIG.
19 is a hydraulic circuit diagram for operating the 19. 2, 3... Support body, 4... Pivot, 5... Rocking table, 13... Link, 18, 19... Weight compensation cylinder, K... Rocking table clamp device.

Claims (1)

[Claims] 1. A pair of supports fixed on a bed, a rocking table that can swing freely around the axis of a pivot bridged by the supports, and a drive device that swings the rocking table. and a swinging table clamp device for holding and fixing the workpiece in the swinging position, and one or more weight compensating means for counteracting the rotational moment due to the weight of the workpiece on the swinging table, the means comprising: The link has two fixed pivot points, a first pivot point of the link fixed to the pivot point and a second pivot point of the balance force applying device that is a certain distance away from the pivot point, and the link and the second pivot point are provided between these two pivot points. It has a third pivot point that swingably connects to the balance force applying device, and when the swing table has a swing angle of zero, the third pivot point
A tailing device characterized in that the pivot points are arranged in a straight line. 2. The weight compensating means consists of a link fixed to a pivot, a piston rod connected to the end of the link, and a weight compensating cylinder in which the piston rod is slidable and pivotally supported. A tailing device according to claim 1, characterized in that: 3. The weight compensation means includes a link fixed to a pivot, a wire whose one end is connected to the end of the link and whose other end extends downward via the pivot pin, and a weight suspended from the lower end of the wire. 2. The tailing device according to claim 1, further comprising a weight.