JPH03294102A - Rotation dividing device and boring tool using it - Google Patents

Abstract

PURPOSE:To secure relative rotation amount for position conversion so as to improve machining accuracy of a boring tool and so on by transmitting reverse rotation of an input shaft to an output shaft through a differential gear so as to set up constant relation between the reverse amount of the input and the relative rotation amount of the output shaft. CONSTITUTION:When an input shaft is reversely rotated from the state of step 1, the torque is transmitted to an output shaft through a differential gear 10 and the output shaft is rotated in the + direction at a decelerated speed so as to generate a relative rotation, and in step 2, passing of a drive pin 23 is accepted and the relative rotation advances up to the blade tool dividing angle of 120deg. a drive master 12 compresses a spring 14 and escapes in the axial direction, and engagement between gears 12a and 13a is released. In step 3, the drive pin 23 hits against a dog 18 and the relative rotation is stopped, and a return claw 24 is locked by a side cam 19c and the relative rotation is 180deg. When the input shaft is positively rotated after that, the return claw 24 rotates a change ring 19 in the + direction, and when the return angle reaches 60deg, the locking gears 12a and 13a are engaged with each other in a position where the mesh position is changed by one, and the relative rotation at the time of positive rotation of the input is stopped, that means conversion of the blade tool is completed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention has an output shaft eccentric to the input shaft, and n (≧2) converters provided on the output shaft at a dividing angle of φ. A rotary indexing device that accurately changes the position of an object sequentially through two operations, reverse and forward rotation of the input shaft, and a boring tool that uses this to automatically change the position of n cutting tools. Pause.

Incidentally, since the indexing device of the present invention is particularly suitable for use in a boring tool, the following description will be made using this as an example.

[Conventional technology]

Some well-known boring tools use relative rotation between an input shaft and an output shaft to change the position of the cutting tool. This tool holds the output shaft eccentrically within the input shaft, and the head connected to the tip of the output shaft has n cutting tools at an equal dividing angle φ (-3
60''/n). Also, an axial clutch for transmitting normal rotation force is provided between the input shaft and the output shaft, the meshing position of which changes when the relative rotation angle becomes equal to φ.

Note that this type of tool requires relative rotation between the output shaft, which is rotated by hand to change the cutting tool position, and the output shaft, which attempts to maintain a stationary state by inertia by reversing the input shaft. There are 52 main ways that cause this.

FIG. 6 shows the principle of adjusting the machining diameter when changing the cutting tool. In the figure, 0 is the axis center of the input shaft, O' is the axis center of the output shaft, T1 ~
T, there are n pieces on the outer periphery of the head of the output shaft with an angle φ (the figure shows φ-12
0', n=3) The provided cutting tools, r, ~r, are the distances from 0' to the cutting edge of each cutting tool, and e is the eccentricity of 0' with respect to O.

Now, assuming that T is at the position shown in the figure, at this time, “rt
, T, if the cutting edge of T is located inside the locus circle of the cutting edge of T1 centered on 0.

is subjected to machining and the machining diameter is n = 2 (rt + e). The 0th order T, is the rotational coordinate O where T was previously located.
-X, T, ,'rs are Tt centered at O
The machining diameter is kept inside the rotation locus of 2 (r, -r,
) and similarly move T to the coordinates 0-X, the machining diameter changes to D+2 (rs rt). In this case, the difference between the minimum machining diameter and the maximum machining diameter can be increased by increasing e.

Furthermore, if the distance r from 0' to the cutting edge of each cutting tool is kept constant, the damaged cutting tool can be replaced with a new cutting tool.

In this way, by making the output shaft eccentric and rotating this shaft relative to the input shaft, it is possible to change the cutting tool without using a complicated and expensive mechanism, and the number of tools to be prepared and replaced is reduced. The advantages of mold tools are further increased.

[Problem to be solved by the invention]

Automation of the cutting work cannot be expected with tools that manually rotate the eccentric output shaft to change the cutting tool.

On the other hand, those that use the reverse rotation of the input shaft and the static inertia of the output shaft to generate relative rotation for conversion change the engagement point of the clutch by moving the output shaft forward and backward in the axial direction during relative rotation. There is an unavoidable sliding gap in the holding portion of the output shaft, which results in poor reproducibility of the machining diameter after conversion, and also limits the holding force of the output shaft, which tends to lead to insufficient rigidity.

In addition, since the cutting tool change is not directly driven,
It is difficult to quantitatively specify the amount of input shaft reversal until the conversion is completed, and the conversion lacks certainty.

In addition, due to the axial movement of the output shaft, there is an exposed portion at the end of the shaft, and there is a risk that foreign matter and dust may enter the interior through this portion.

The main object of the present invention is to provide a rotation indexing device that can firmly hold an output shaft in a fixed position and reliably generate relative rotation for changing the position when the input shaft is reversed beyond a certain amount. Our objective is to provide a boring tool with improved machining accuracy and reliability of operation.

[11! Means for Solving the Problem] In order to achieve the above-mentioned requirements, the rotary indexing device of the present invention rotates the output shaft, which is indexed at an angle of 360 @/n, that is, φ, at a fixed position within the eccentric hole of the input shaft. hold possible. In addition, a differential gear mechanism is provided, which consists of a sun gear attached to the output shaft, an internal gear concentrically provided in the fixed housing, and a planetary gear supported by the input shaft and interposed between the two gears. The rotation of the input shaft is transmitted to the output shaft. Furthermore, when the input shaft is reversed, the teeth on the input shaft side escape and the meshing position shifts. There are n locking teeth at the 360°/n dividing point, and the input shaft outputs forward rotation at the meshing position of the teeth. A one-way dog clutch is provided that transmits transmission to the shaft to position the output shaft in the switching position.

This rotary indexing device makes one drive pin provided on the input shaft side come into contact with n dogs provided on the output shaft side at equal pitches, so that the relative rotation angle of the input shaft and output shaft during reversal can be adjusted by φ or more. 1
．． A means to limit the angle to a constant angle α of 5φ or less, and a change ring with a rotatable dog position on the output shaft, when the input shaft rotates forward (
A dog that rotates in the normal rotation direction within the range of α-φ) to make the renumbered bottle receiving dog wait on the drive pin movement path, and evacuates the dog that stopped the drive pin in this conversion from the drive pin movement path. The reliability of the conversion can be improved by using a configuration that includes a means for regulating the amount of relative rotation consisting of a position switching means, or a configuration that further includes a sleeve, a brake, and a one-way clutch between the sleeve and the internal gear described in the embodiment. It will increase further.

A tool head is provided at the tip of the output shaft of the rotary indexing device configured in this way, and the conversion target n (≧2
) cutting tools are attached at a dividing angle of φ to form a boring tool of the present invention.

[Effect]

When the input shaft is reversed, this rotational motion is transmitted to the output shaft via the differential gear mechanism, so that the relative rotation for conversion is 10
0% is guaranteed, and the relationship between the amount of reverse rotation of the input shaft and the amount of relative rotation of the output shaft is always constant.

Further, since the output shaft is rotatably supported at a fixed position and there is no sliding space, the support rigidity of the output shaft and the radial position accuracy after conversion are sufficiently increased.

Note that the effects of other additional configurations will be described in detail later.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 to 4.

This embodiment is an example of application to a boring tool.

As shown in the figure, the input shaft 1 has a structure in which a cylindrical body having an eccentric hole 2 at the tip of a Taber shank is connected to prevent rotation. Reference numeral 3 denotes an output shaft having a large diameter tool head 3a at the tip. This shaft is inserted concentrically into the eccentric hole 2, and both ends are supported by tapered roller bearings 4 to increase support rigidity in both radial and axial directions. ing. Note that the tool head 3a has n
The cutting tools T are provided at equal dividing points.

Reference numeral 5 denotes a stationary housing rotatably attached concentrically to the intermediate outer periphery of the input shaft through a bearing, and includes a rotation preventing means 6 of a known structure that includes a locking shaft 6a that can be freely engaged with and detached from the fixed part. have.

7 is a sun gear fixed to the output shaft, 8 is an internal gear installed concentrically in a fixed housing, and 9 is an internal gear rotatably supported by the input shaft 1 and assembled into a window hole provided in the input shaft. This is a planetary gear interposed between the sun gear 8 and the sun gear 7, and these three constitute a differential gear mechanism 10. The illustrated tool combines two planetary gears S to transmit the rotation of the input shaft 1 to the output shaft 3 in the opposite direction.

Reference numeral 12 denotes a drive master that loosely fits around the outer circumference of the output shaft 3 and engages with the center adapter 11 fixed to the input shaft 1 to prevent rotation. This drive master is movable in the axial direction since there is play in the axial direction at the meshing portion with 11. 13 is a locating block integrated with the sun gear 7, and this and the drive master 12 have unidirectional locking teeth 12a, 13a on their abutting surfaces (see Figure 2).
There are n pieces of each tool, which are equal to the number of cutting tools n. The dividing angle of that tooth is of course equal to φ or 360'/n, 14
is a spring that returns the drive master 12 to the locating block 13 side, and 12.1 including this
A one-way dog clutch 15 is configured in which the three-way force shafts 3 of 3.14 are sequentially positioned at the switching position to transmit the forward rotation of the input shaft to the output shaft.

16 is a relative rotation angle regulating means. This regulatory measure is
a positioning ring 17 fixed to the outer periphery of the output shaft 3;
N dogs 18 that can be slid in the axial direction are provided in a groove provided in the ring at a constant pitch φ in the circumferential direction, a spring tea that pushes the dogs downward, and a positive thinning ring 1
A change ring 19 is rotatably fitted to the outer periphery of the output shaft in contact with the change ring 7.

A spring 21 that pushes the change ring 19 toward the position ring 17 via the needle roller 20, a set load adjustment nut 22 for the spring, and a spring 21 that is fixed to the input shaft 1 and inserted into the groove 17a on the outer periphery of the position ring 17. It is composed of a drive pin 23 that is inserted into the input shaft, and a return pawl 24 that is provided inside the input shaft and is caused to protrude into the eccentric hole 2 by a spring force.

The change ring 19 has a dog 18 on the end face on the receiving ring side.
Each side cam 19b has (n-1) side cams 19b for locking the return claws 24 at equal positions on the outer periphery. When the dog 18 falls into the cam groove 19g, it retreats from the movement path of the drive pin 23, that is, from inside the circumferential groove 17a, and when it is pushed by the slope of the cam groove 1Sa and comes out of the groove 19a, it is placed on the waiting path L7. to prevent movement of the drive pin 23.

In FIGS. 1 and 3, 25 is a sleeve rotatably provided within the fixed housing 5, and 26 is a brake that is elastically pressed against the sleeve 25 for the purpose of providing rotational resistance. Both act as a safety device to protect the differential gear mechanism. This device can change the rotational resistance applied to the sleeve 25 by the brake by changing the screwing amount of the pressure adjusting screw 26a.

Reference numeral 27 in FIG. 3 is a one-way clutch provided between the sleeve 25 and the internal tooth 1t8. This clutch is a well-known clutch in which a roller (or a pole may be used) is inserted into a ramp groove, and the clutch can be engaged or disengaged at any position within the sleeve.

28 in FIG. 1 is a disc spring that applies a retracting force to the output shaft 3;
A lock ring (fixed to the manual shaft) that locks the lock pin 6b provided on the locking shaft 6a into the groove 29a (see Figure 4) on the outer periphery to keep the tool at a constant stop position when the tool stops rotating. , 30 is a seal ring that closes the gap at the entrance of the eccentric hole 2, and 31 is a key for preventing rotation.

In the exemplary tool made of quantum metal, assuming that the number n of cutting tools is 3, the locking teeth 12a, 13a and the dog 18 are arranged so that the dividing angle of the cutting tool ≠ (-1
Two cam grooves 19a and two side cams 19b are provided at angles equal to 180 degrees.
It is provided at equally divided positions of 0. In addition, the three cutting tools T were installed at different distances from the output shaft axis, but as mentioned earlier, if there is no need to change the machining diameter, they should be placed at positions equidistant from the output shaft axis. may be provided.

The operation of the boring tool will be explained below with reference to FIG.

The figure shows the expanded positional relationship of each element, and the horizontal axis indicates the relative rotation angle between the input shaft 1 and the output shaft 3.
Relative rotation starts from the 0° position.

Also, in the figure, the forward direction is indicated by a (+) arrow, and the reverse direction is indicated by a (-) arrow.
It is indicated by the arrow. The vertical axis represents the order of operation, and in Figure 0, the cutting tool change is completed in steps ■ to ■, the locking teeth 12a,
T3a, dog 18, cam groove 19a, and side cam 19b are each labeled with a code indicating their ranking.

Now, when the input shaft 1 is reversed from the state of step (2), rotational force is transmitted to the output shaft 3 via the differential gear mechanism 10, and the shaft 3 rotates in the (+) direction at a reduced speed. As a result, relative rotation occurs between 1 and 3, and each member on the input shaft side moves in the (+) direction, and each member on the output shaft side moves in the (-) direction, but the figure shows the relative rotation angle. Therefore, the members on the input shaft side are not moving.

In step ■, the retraction of the dog 18-1 allows the drive pin to pass through, and the relative rotation changes to the cutting tool division angle φ(
120°), the drive master 12 compresses the spring 14 and escapes in the axial direction, indicating that the teeth 12a and 13a are disengaged.

In this step (2), the movement of the drive pin 23 is not yet restricted by the dog, and the relative rotation continues thereafter.

Next, in the state of step ■, the drive pin 23 is in the circumferential groove 1? It hits the dog 184 that has entered inside a, and the relative rotation stops at this position. Further, the return pawl 24 that moves together with the bin 23 is engaged with the side cam 19b-. The relative rotation angle α between 1 and 3 at this point is 1806.

Thereafter, when the input shaft 1 is rotated in the normal direction from the state of step (2), the return pawl 24 rotates the change ring 19 in the (+) direction. When the return angle δ of the relative rotation angle due to normal rotation of the input shaft reaches 60@, the locking teeth 12a and 13a engage at a position where the meshing position has been changed by one, and the relative rotation during normal rotation of the input shaft stops. This means that the cutting tool conversion at the angle φ has been completed, and the cutting torque is then transmitted through the dog clutch 15, making it possible to perform boring with the converted cutting tool.

Also, due to the stoppage of relative rotation, the rotation of the change ring 19 also stops here (the ring 19 generates friction with the block 13 due to the force of the spring 21, so there is no positional shift due to inertial rotation), α - Due to the displacement of the cam groove 19a due to the change ring rotation of φ, that is, δ, the dog 18-8 that stopped the bin 23 in step ■ is retracted from the movement path of the drive pin, and the dog 18-5 with the new number is placed on the movement path of the bottle. stand by.

In other words, you will be ready for the next conversion.

The positional relationship of each element in the state of step (2) is the same as in the state of step (2), so subsequent conversion operations are also performed based on the same steps.

The following is the operation of other elements during steps ① to ②.

The one-way clutch 27 becomes "engaged" at the same time as the input shaft is reversed at the step, and stops the rotation of the internal gear 8. Since the balls and rollers in the ramp groove are in a semi-locked state when "entered", the input shaft remains in the "entered" state even when the input shaft rotates forward in steps ■ to ■ unless unexpected rotational resistance is applied to the output shaft 3. However, even if the "off" state were to occur between steps (2) and (2), there would only be a slight time lag in the conversion, and the conversion operation would not be hindered in any way.

This one-way clutch 27 is connected to the shaft 1.
When the return relative rotation of step 3 stops, R-cutting occurs instantly, which prevents the cutting torque from being transmitted via the differential gear mechanism.

Furthermore, if the internal gear 8 is fixed to the fixed housing 5, when the input shaft 1 attempts to further reverse rotation due to inertia after reaching the state of step (2), an unreasonable load will be applied to the differential gear mechanism 10. However, if there is a sleeve 25 and a brake 26, they act as a safety device at this time, causing the internal gear 8 to slip rotation together with the sleeve 25 and allowing the input shaft to rotate by inertia. , differential gear mechanism 10
Further, when the input shaft 1 rotates by inertia in the (-) direction with the slip rotation of the sleeve 25, the other elements except the fixed housing 5 and the rotation prevention means 6 rotate together. Therefore, the positional relationship between each element does not change, and therefore the subsequent conversion operation is not affected in any way.

In this way, each of 25, 26, and 27 protects the differential gear mechanism, and is therefore very preferable in terms of ensuring durability and reliability.

The seal ring 30 can be installed by eliminating the axial movement of the output shaft 3, and is effective in preventing foreign matter from entering the eccentric hole 2.

Next, the differential gear mechanism 10 used is one that transmits the rotation of the input shaft to the output shaft 3 in the opposite direction in order to eliminate loss of relative motion. However, the purpose of conversion can also be achieved by using something that transmits the rotation of the input shaft in the same direction to the output shaft. That is, since the output shaft 3 rotates at a reduced speed, even if the output shafts 3 rotate in the same direction, the relative rotation for conversion can be performed using the difference in rotational speed.

In addition, the input shaft rotation speed when changing the cutting tool can be controlled on the machine tool side, and on the other hand, the relative rotation amount of the output shaft is accurately determined by the rotation amount of the input shaft. The configured relative rotation angle regulating means 16 is not necessarily required.

However, with this means 16, even if the input shaft reverses more than necessary, the relative rotation angle α at the time of reverse rotation is regulated to φ〈α〈1゜5φ, so it is difficult to control the rotation speed during reverse rotation, which increases costs. Accurate conversion is guaranteed even without this, making it possible to realize a boring tool that is extremely advantageous from a practical point of view.

Although the embodiment has been described with respect to a tool in which the number n of cutting tools is three, the boring tool of the present invention can also be manufactured with an increased or decreased number of cutting tools even if it is equipped with means for regulating the relative rotation angle. .

Now 2. The relative rotation angle when the input shaft is reversed shown in Fig. 5 is α, the return angle of the relative rotation angle due to normal rotation of the input shaft is δ, the division angle according to the number of cutting tools n is φ, and the number of installed cam grooves 19a and side cams 19b is respectively If i, these values have the following relationship.

φ=360°/n −i・δ, δ≦φ/2α−φ+6 (However, if i is an even value, it becomes an odd number except 1 and n
is the smallest integer that is even if is odd).

Therefore, using this relationship, n-4 (locking teeth 12a, 1
3a and the number of dogs 18 is equal to n). In this case, φ=90", and if i is the smallest odd number other than 1, 3, then δ=306α=120, and each time the change ring 19 rotates to 30 degrees, it will drive at this time. The dog position is sequentially changed so that the dog 18 that has stopped the pin 23 is retracted and the dog with the new number is on standby in the movement path of the bottle 23, and the position of the side cam 19b is also moved to a position having an angle of α from the return claw 24. Therefore, accurate cutting tool change is performed at φ=90°.

In the case of n=2, the angle is φ-180°, and when i is set to 3, the angles are δ-60° and α-240°, and the cutting tool is changed at φ=180'' in the same manner as in the illustrated embodiment. will be held.

The case of n-5 is also φ-72°, i=4, δ=18, α
-909 Similarly, in the case of n=6, φ=60°, i-5, δ=1
2. Conversion by each φ is carried out at α=72°.

In this way, the present invention can accommodate a number of blades other than n=3. Further, as can be seen from the above explanation, when n is a highly practical number such as 2 and 4, the change ring 1S can be shared by setting the quantity to 3, which is economically advantageous.

In addition, although the above explanation was based on the case where the cutting tools change one by one in one switching operation, the switching angle can also be the angle obtained by dividing the n cutting tool division angle by an integer of 2 or more. It is possible. However, this causes play in the conversion operation, so
Although this is not particularly desirable, and although the embodiments have been described using a boring tool as an example, the rotary indexing device of the present invention can also be applied to tools for other purposes.

〔effect〕

As described above, the rotary indexing device of the present invention and the boring tool using the same use a differential gear mechanism to interlock the output shaft with the input shaft, thereby increasing the reliability of conversion.

It is also possible to quantify the rotation amount of the input shaft.
Makes conversion work easier.

Furthermore, since there is no sliding gap around the output shaft, the support rigidity of the shaft and the radial position accuracy after conversion are greatly improved. The machining accuracy is greatly improved.

In addition, if there is a means for regulating the relative rotation angle, even if there is excessive rotation of the input shaft, no extra relative rotation will occur, and the reliability of conversion will be absolute.

Furthermore, those equipped with a safety device do not impose an unreasonable load on the differential gear mechanism, and the reliability and durability are sufficiently increased.

As described above, according to the present invention, it is possible to dramatically improve the reliability, conversion accuracy, stability during use, etc. of indexing devices and boring tools that perform conversion by reversing or forward rotation of the input shaft. This can greatly contribute to improving the efficiency, accuracy, and machining accuracy of automatic machining.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a boring tool according to an embodiment of the present invention, Fig. 2 is an exploded perspective view of its main parts, and Fig.
Figure I[[-[1 & 1 section sectional view, Figure 4 is a perspective view of the lock ring, Figure 5 is an explanatory diagram of the conversion operation, Figure 6 is a line showing the principle of conversion of a cutting tool using an eccentric output shaft. It is a diagram. 1...Human power shaft, 2...Eccentric hole, 3...Output shaft, 3a...To tool, 5...Fixed Housing, 6...
... Rotating means, 7 ... Sun gear, 8
...Internal gear, 9...Planetary gear,
10... Differential gear mechanism, 11... Center adapter, 12... Drive master, 13... Locating block, 12a, t
3a...Latching tooth, 14...Spring, 15...Matching clutch, 16...Relative rotation angle regulating means,
17...Positioning ring, 18...
...Dog, 18a...Spring,
19...Change ring, 18a...Cam groove, ISb...
Side cam, 21...Spring, 23...
-...Drive pin, 24...Return claw,
25...Sleeve, 26...Brake, 27...One-way clutch, 29...
... Lock ring, 30 ... Seal ring. Figure 6 Figure 3 10 Figure 4 14-

Claims (5)

[Claims] (1) It has an input shaft with an eccentric hole on the tip side, and an output shaft that is rotatably held in a fixed position concentrically within the eccentric hole, and the output shaft is divided into equal parts of 360°/n (n≧2). It is a device that rotates and indexes a position, and includes a fixed housing arranged concentrically around the outer periphery of the input shaft, a sun gear attached to the output shaft, an internal gear arranged concentrically within the fixed housing, and an input shaft supported by the input shaft. A differential gear mechanism has planetary gears interposed between gears to transmit the rotation of the input shaft to the output shaft, and when the input shaft reverses, the teeth on the input shaft side escape and the meshing position changes. 36
A one-way dog clutch is provided at a dividing point of 0°/n and transmits the positive rotation of the input shaft to the output shaft at the meshing position of its teeth, and the relative position of the output shaft to the input shaft is 360°.
A rotary indexing device in which a change at an angle of /n is caused by two operations of reverse rotation and forward rotation of an input shaft. (2) One drive pin provided on the input shaft side is brought into contact with n dogs provided at equal pitches on the output shaft side, and the relative rotation angle at the time of reverse rotation between the input shaft and output shaft is set to φ (= 360°/n )that's all,
A means for limiting the angle to a constant angle α of 1.5φ or less, and a change ring with a rotatable dog position on the output shaft are rotated in the forward rotation direction within the range of (α−φ) when the input shaft rotates forward. The apparatus includes means for regulating the amount of relative rotation, which comprises a means for changing the position of the pin, which causes the pin receiving dog to wait on the travel path of the drive pin, and a dog position switching means for retracting the dog that has stopped the drive pin in this conversion from the travel path of the drive pin. A rotary indexing device according to claim (1). (3) A locating block that fixes the above-mentioned one-way dog clutch to the output shaft, a drive master that is attached to the input shaft so that it can move in the axial direction but cannot rotate, and a one-way dog clutch that is provided opposite them. 2. The rotary indexing device according to claim 1, wherein the rotary indexing device comprises a tooth and a means for biasing the drive master toward the locating block. (4) A sleeve and a brake that applies a required rotational resistance to the sleeve are provided in the fixed housing, and the internal gear is connected to the inside of the sleeve via a one-way clutch that is turned on when the gear is reversed. Claim (1), (
2) or the rotary indexing device described in (3). (5) A tool head is provided at the tip of the output shaft of the rotary indexing device according to any one of claims (1) to (4), and n (≧2) cutting tools to be converted are mounted on the outer periphery of this head. A boring tool consisting of multiple pieces installed at a dividing angle of φ.