JPS6315090B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to preventing tap breakage in a tap device.

[Conventional technology]

In the past, screw taps were often broken during screw-tapping operations, which reduced the efficiency and processing accuracy of operations including pre- and post-processes, and caused large economic losses. Such breakage accidents occur with various types of taps, and this tendency is particularly noticeable when the diameter of the tap is small compared to the hardness of the workpiece or with release taps. There are various possible causes of the accident, but a major drawback is that the tap is continuously rotated during machining, so there is no escape of chips and the heat generated can cause breakage of the tip of the tap.

[Problem that the invention seeks to solve]

The present invention was devised in view of the above points, and during one machining operation, the taps are rotated in the forward direction R ₁ , R ₃ , R ₅ , R ₇ , R ₉ , . . . ( Figure 1)
While doing this, the return rotation R ₂ , R ₄ ,
The present invention provides a tapping device that performs R ₆ , R ₈ . . . to eliminate the drawbacks of the prior art.

[Means for solving problems and their effects]

In order to solve the above problems, the present invention includes a first drive source attached to a reciprocating tool rest on a table, and a second drive source connected to the output shaft of the first drive source. a second drive source having an output shaft located eccentrically from the axis of the second drive source, and a second drive source connected to the output shaft of the second drive source and located eccentrically from the axis of the second drive source; A cylindrical link having a roller member, and a oscillation including a rotational force in a direction opposite to the continuous rotational movement by the first drive source and the continuous rotational movement by the second drive source by guiding the roller member in a guide groove thereof. and a gear that transmits the dynamic motion to the rotational drive system of the tool holder.

By adopting the above configuration, the first drive source performs continuous rotational motion, and the second drive source performs reciprocating rotation including rotation in the opposite direction at a faster speed than the continuous rotation by the first drive source. By combining this with the oscillating motion, it is possible to perform machining while rotating the tool intermittently.

[Embodiment] Next, an embodiment of the present invention will be described based on the drawings. 1 is a tool rest that can reciprocate on a table; 2 is a hydraulic rotary motor fastened to the tool rest 1 by bolts not shown; 2a is an output shaft of the hydraulic rotary motor 2; 3 is a connecting shaft supported by bearings 4, 4 in the tool rest 1; the output shaft 2a, which is fitted into a socket 3a of the connecting shaft 3, is fixed by a screw 3b; By locking the key 3c with a tightening force of , the connecting shaft 3 rotates together with the output shaft 2a around the axis _X1 .

On the other hand, reference numeral 5 denotes a motor casing, in which the electric motor M and the reduction gear G are housed.
It is sealed by screwing it on.

The cap 6 has through holes 6b and 6f, of which the connecting shaft 3 fitted into the through hole 6b is inserted into the screw hole 6.
By locking the key 6e with the tightening force of the locking screws 6d, 6d screwed into the locking screws 6d, 6c, the motor housing 5 rotates together with the connecting shaft ₃ about the axis X1. Further, a cylindrical link 7 is rotatably fitted into the through hole 6f of the cap 6, and an output shaft 5a of the electric motor M is fitted into a through hole 7a formed in the center of the cylindrical link 7, and is screwed into the screw hole 7b. The cylindrical link 7 is aligned with the output shaft 5a by locking the locking screw 7c with the key 7d with a tightening force.
Rotates around X ₂ times. The cylindrical link 7 has a notch 7e and an eccentric through hole 7f communicating with the notch 7e, and a pin 8a is attached to pass through the through hole 7f.
A roller 8 is rotatably provided at a position protruding from the motor housing 5.

A gear 9 is pivotally supported on the connecting shaft 3 by a needle bearing 9b at a position between the tool rest 1 and the motor housing 5, and the roller 8 engages in a notch or groove 9a of the gear 9. The gear 9 also meshes with the gear 10 at an increased speed, and a male screw member 11 is provided to the gear 10 so as to be movable in the axial direction and transmit rotation through a structure such as a spline, and the male screw member 11 is fixed to the tool post 1. Therefore, when the gear 10 rotates, the tap holder 12 attached to the male screw member 11 rotates at the same time as the gear 10 and moves forward or backward in the axial direction.

Next, the operation of this device will be explained. First, considering the case where the hydraulic rotary motor 2 is rotationally driven and the electric motor M is not driven, the output shaft 2a, the connecting shaft 3, and the motor casing 5 are sequentially rotated around the axis _X1 by the drive of the hydraulic rotary motor 2. , hence the axes X ₂ and X ₃
Similarly, the gear 9 rotates around the axis _X1 , and therefore the gear 9 is also rotated while being pushed by the roller 8. In this case, as long as the oil supply to the hydraulic rotary motor 2 is kept constant, the gear 9 rotates at a constant speed, and therefore the tap T moves forward or backward while rotating at a constant speed, and therefore, when moving forward, it screws into the workpiece. can do. The relationship between the time and the rotation angle of the tap at this time is as shown by straight line A in FIG. Conversely, the electric motor M is rotationally driven, and the hydraulic rotation motor 2
Considering the case where the connecting shaft 3 does not rotate, the posture of the cap 6 and the motor housing 5 and the position of the axis _X2 of the cylindrical link 7 do not change as shown in Figure 5, and the electric motor M is not driven. As a result, the output shaft 5a and the cylindrical link 7 sequentially rotate around the axis _X2 , and therefore the axis _X3 similarly rotates around the axis _X2 , and the gear 9 is pushed by the roller 8 and rotates as shown in FIG. , B, C, and D are repeatedly oscillated. In this case, as long as the output shaft 5a of the electric motor M is driven to rotate at a constant speed, the gear 9 repeats a constant waveform rocking motion, and therefore the tap T also repeats forward and backward motion while making a constant rocking motion. In particular, if steps 2, a, and b are rotated in the same direction as tapping, and steps b, c, and d are rotated in the opposite direction, this oscillating motion becomes a kind of quick return motion. ,
In this case, the relationship between time and the rotation angle of the tap becomes a steady waveform with the wave crest shifted to the right as shown in B in FIG.

If both the hydraulic rotary motor 2 and the electric motor M are driven to rotate, the relationship between the time and the rotation angle of the tap is a combination of the above-mentioned constant velocity rotation A and the oscillating motion B of the standing wave. Because it becomes
As shown in Fig. 6C, the motion alternately repeats 180° forward rotation and 90° reverse rotation. In this way, by performing tapping while rotating in the forward direction and releasing chips while rotating in the reverse direction, breakage of the tip of the tap can be prevented.

The angles of normal rotation and reverse rotation that should be repeated alternately in this manner are explained as 180° and 90° in the above embodiment, but are not limited to this, and may vary depending on the type of tool,
The angle can be set or changed as appropriate depending on the diameter, hardness of the workpiece, etc. To change both angles, adjust the throttle valve of the hydraulic rotary motor 2 to adjust the amount of oil fed. . Changing the meshing ratio between gears 9 and 10; Providing and adjusting a variable reduction gear G between the motor M and the output shaft 5a; Changing the distance of the roller axis _X3 from the rotation center _X2. ,
What is necessary is to change the distance of the axis _X2 from the rotation center _X1 . Further, although the ratio of the advance of the tap T in the axial direction to the rotation angle is constant in the device shown in the second figure, it may be of a so-called variable type by changing the pitch of the screws 11 and 1a.

〔Effect of the invention〕

The present invention has the above configuration, and its effects are summarized as follows.

Since tapping is performed while the tool is intermittently returned and rotated, chips are released during the return rotation, and the heat generation of the tool is suppressed to prevent the tip of the tap from breaking. Therefore, in addition to the economic loss of the tool itself, It is possible to avoid economic losses caused by defective products that are machined after tool breakage and before replacement, loss of labor and time required for tool replacement work, and the possibility that it becomes a hindrance to previous and subsequent processes.

A large amount of chips do not intervene during the machining process, heat generation of the tool is suppressed, and machining accuracy is improved because the same machining is performed twice during one machining operation, before and after the return rotation. .

It can be applied to various types of taps such as small-diameter taps, taper taps, and release taps, and the rotation angle, angular acceleration, or advance of forward and reverse rotations can be adjusted.

Because continuous rotational motion and oscillating motion are combined,
Depending on the machining needs, by operating only a continuous rotational motion by operating a motor switch, it is also possible to perform screw tapping without return rotation as in the conventional method.

Since the second drive source is carried in the output system of the first drive source, rotation synthesis is simple and reliable, and the structure is simple.

A hydraulic rotary motor is used as the first drive source, and a hydraulic rotary motor is used as the second drive source.
By employing an electric motor as the drive source, it is possible to obtain sufficient and adjustable rotational driving force and swinging driving force with a small size.

If a quick return mechanism is used for the swing motion by the second drive source, the maximum speed in forward and reverse rotation of the tap can be kept below a predetermined value, and the time required for machining can be shortened as much as possible.

[Brief explanation of the drawing]

The drawings relate to embodiments of the present invention, and the drawings are of the first embodiment.
The figure is a graph showing the rotation angle of rotation including intermittent reversal to be applied to the tap, FIG. 2 is a partially sectional side view showing the main parts of the tap device according to one embodiment, and FIG.
The figure is a perspective view showing a longitudinal section of the motor housing cap used in the tap device shown in Fig. 2, Fig. 4 is a perspective view showing the same longitudinal section of the cylindrical link used in the tap device shown in Fig. FIG. 6 is an explanatory diagram showing the mutual relationship between the gear, the roller, the cylindrical link, and the motor housing cap during the oscillating motion of the gear.
3 is a graph showing the relationship between the rotation angle of a tap obtained by the tap device shown in the figure and time. 1...Turret post, 2...Hydraulic rotation motor, 2a...
...Output shaft, 3...Connection shaft, 5...Motor casing, 5a
... Output shaft, 6 ... Cap, 7 ... Cylindrical link, 8 ... Roller, 9 ... Gear, 10 ... Gear,
M...Motor, G...Reduction device, T...Tool.

Claims (1)

[Claims] 1. A first drive source attached to a reciprocating tool post on a table, a connecting shaft that is connected to the output shaft of the first driving source and rotates integrally with the second driving source, and the connecting shaft a second drive source having an output shaft at a position eccentric from the axis of the second drive source; a cylindrical link connected to the output shaft of the second drive source and having a roller member at a position eccentric from the axis; The guide groove guides the continuous rotational movement by the first drive source and the swinging movement including rotational force in the opposite direction to the continuous rotational movement by the second drive source to the rotational drive system of the tool holder. A tap device characterized by comprising a gear that rotates.