JPH07308812A - Power transmission device for tool - Google Patents

Abstract

PURPOSE:To rotate a tool such as a drill or a tap in normal and reverse directions, successively, during drilling, without the rotation thereof. CONSTITUTION:On the drive side 2, a motor M is secured to a rotary disc 21, and on the driven side 1, a drive arm 11 is secured to a decelerator G. They are then planted thereon with pins, respectively. Further, a connecting rod 6 is pivotally attached to pins so as to transmit a crank motion to the decelerator so as to convert the circular motion into a rectilinear motion. Further, on the decelerator G the rectilinear motion of the drive arm 11 is transmitted to a rotational reciprocating motion. Meanwhile, a tool attaching shaft 3b and a bearing part 4 are threadedly engaged with each other so that normal rotation U3, advance motion, reverse rotation and backward motion which are caused by rotation from the decelerator G are transmitted to a tool 3, and accordingly, a workpiece is machined during the advance motion L, and the tool 3 is pulled back during the backward motion R. Thus, the rotation, and the change-over between the advance and backward motions can be simultaneously carried out, but the change over is moderately carried out while acceleration is smoothly performed until the change-over.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine tool for machining a hole or engraving a screw in the hole, and more particularly to a power transmission device for machining a tool while rotating the tool forward and backward and simultaneously moving forward and backward. .

Not only automobiles and general household furniture but also standardized and used mechanical parts are commonly used. For example, there are many small items such as bolts, nuts, and nails, collars and bushes used for mounting, and small fixed items. Generally, these are manufactured on a press machine and are mass produced.

However, in the case where a screw is rolled such as screw hole machining, the tap is normally rotated to raise the screw, and the motor in the machine tool is normally or reversely rotated for reverse rotation. Also, the switch is used. A method is also adopted in which this switch operation is automatically and smoothly switched by an electric circuit using a clutch or a brake.

In the case of drilling with a drill or reamer or screwing by rolling, for example, a nipple for a vehicle has the longest screw depth in screwing. Since this nipple also has a long screwing length with thin spokes, unlike general nuts, the screw length is at least 2.5 times the hole diameter or more, and the tap often breaks even when threading by automation. Often time wasted for replacement and broken taps were left behind in the screw holes of the product. The nipple for a vehicle has been processed by holding a nipple having no hole on a rotary table with a chuck device, advancing a drill or a tap, and successively performing a pre-hole processing and a tap cutting finish. Therefore, if the cutting speed is too fast in drilling, the drill will break due to burning, and in tapping not only the thread cutting speed, but also the rotation once before rotating backward after tapping. For this reason, small chips are sandwiched between the tap screw and the cut screw, and when it rotates in the reverse direction, it is related to the rotation speed. there were.

[0005]

In the case of the above-mentioned screw hole processing, the rotation is temporarily stopped in order to rotate the tap forward and move forward to engrave the screw, and rotate the tap backward to move backward. is doing. When the rotation is stopped, there is a timing loss only for the time of the stop, and since the tap meshes with the thread groove so as to bite the article during the reverse rotation after the normal rotation, the above-mentioned hiccups that give an impact. Occasionally, the workpiece may be idly rotated in the chucking device or may be detached from the chucking device.
Further, this hiccup is often shown when the tool is worn to a certain extent and the service life is near the end, and the sharpness is poor, and it may be broken even at the beginning of use of the tool. This is due to the fact that the engraved screws and taps are frictionally engaged as if they were meshing, and that there are small chips between the engraved screws and taps that act like a wedge effect. This is because

In order to solve the above problems caused by the temporary stop and reverse rotation, the present invention mechanically connects a motor and a speed reducer, and transmits a crank motion from the motor to the speed reducer. It is designed to smoothly perform forward and reverse rotations continuously.

[0007]

The present invention made in view of the above circumstances will be described with reference to FIGS. 1 and 2. The motor (M) will be described below.
Rotation of the tool is transmitted to the speed reducer (G), and the speed reducer (G) transmits power to the driven side (1) to rotate the tool (3), and the tool (3) rotates the workpiece. In a power transmission device for a tool adapted to machine, a disc-shaped rotary disc (21) is fixed to a drive shaft (20) of the motor (M), and the outer periphery of the rotary disc (21) and the drive Axis (2
0) A pin (22) is erected at a position apart from the center by a predetermined distance, and on the other hand, a drive arm (11) having a shaft (10a) of the speed reducer (G) as a pivot is fixed, and the drive arm is (1
A pin (12) is erected and fixed to one end side of (1), and the pin (1) is erected on the rotary disc (21) and the drive arm (11).
A connecting rod (6) is pivotally connected to the pins (12, 22) so as to allow free rotation, and the connecting rod (6) is rotated with the rotation of the motor (M). Is a turntable (21)
The drive arm (11) is rotated by a predetermined angle (A) by the rotation of No. 1, and the tool (3) is continuously rotated forward (U3) and backward (D3) through the speed reducer (G). And it is possible.

The drive shaft (10) of the speed reducer (G)
A large gear (5) is provided in b) and a small gear (3a) is provided in the tool shaft (3e) to transmit power.

Furthermore, on the driven side (1),
A screw is engraved on the tool mounting shaft (3b), and the bearing portion (4) is screwed as a nut so that the positive side (U) of the driven side (1) is screwed.
3) With the reverse (D3) rotation, the tool (3) can continuously move forward (L) and forward (U3) and backward (R) and reverse (D3) with respect to the workpiece. It is characterized by having done.

[0010]

The disk-shaped rotary disk (21) is fixed to the drive shaft (20) of the motor (M), and the drive arm (11) is attached to the speed reducer (G).
The length of the drive arm (11) is fixed to the drive shaft (2
0) Since the pitch from the center to the pin (22) is equal to or more than the pitch, the pin (22) is guided so as to make a circular motion by the rotation of the turntable (21). Then, the circular motion causes the drive arm (11) connected through the connecting rod (6) to rotate by a predetermined angle (A), and the pin (12) moves upward (U1) and downward (D1) in a side view. That is, a linear movement of the moving amount (H2, H1) is performed. And
The linear motion continuously transmits the power of the motor (M) to the speed reducer (G) from deceleration to acceleration and then deceleration so as to draw a sine waveform. Therefore, since the drive arm (11) repeats a smooth linear motion, the drive arm (11) rotated by a predetermined angle (A) passes through the tool (3) via the speed reducer (G). The forward rotation (U3) and the reverse rotation (D3) are continuously switched without stopping.

The rotation angle (A) of the drive arm (11) transmitted to the reduction gear (G) is transferred from the drive shaft (10b) of the reduction gear (G) to the large gear (5) to the tool shaft ( It is transmitted to the small gear (3a) provided in 3e), and the rotation direction is obtained together with the rotation speed required for the tool (3).

Further, on the driven side (1),
When the tool mounting shaft (3b) and the bearing portion (4) are engraved with screws and screwed together, when the drive side (1) is in the normal rotation (U3), the tool (3) is rotated by the rotation. In the case of receiving the thrust force of forward (L) and the reverse rotation (D3), the tool (3) retracts (R) in the direction opposite to the cutting direction. Therefore, the thrust force during the forward movement (L) has an effective function for cutting.

The reference numerals in the parentheses are for the purpose of contrast with the drawings, but do not limit the configuration of the present invention in any way.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to FIGS.

First, the drive side 2 has a drive shaft 20 for the motor M.
A disk-shaped turntable 21 is fixed by a key (not shown) and is rotated together with the rotation of the motor M. The drive shaft 2 is provided at one place on the outer circumference of the turntable 21.
The pin 22 is planted and fixed at a position (pitch) separated from the 0 center by a predetermined distance. That is, the pin 22 is placed at a position separated by the predetermined distance.
The rotation causes a circular motion to enable a vertical movement, that is, a movement amount H2.

The driven side 1 is provided with a speed reducer G at a position separated from the drive side 2, and a shaft 10 of the speed reducer G is provided.
A drive arm 11 is fixed to a by a fixing means such as a key stop (not shown), and a pin 12 is vertically fixed to the end of the drive arm 11. The position of this pin 12 is the same as that of the rotary table 2
The pin 22 is planted at the same position (pitch) as the position (pitch) of the pin 22 fixed on the first plant, or at a pitch slightly longer than that.
Then, the pin 12 and the pin 22 erected on the turntable 21 rotate the turntable 21 about the pins 12 and 22 as pivots by the connecting rod 6, thereby moving the moving amount H2 of the pin 22. The drive arm 11 is transmitted to the pin 12, and the movement thereof causes the drive arm 11 to repeatedly move upward U1 and downward D1, and the shaft 10a can be rotated by a predetermined angle (rotation angle) A each time. That is, the connecting rod 6 transmits the crank motion and moves the moving amount H1 to move the drive arm 11 up and down.

The position of the pin 12 of the driving arm 11 is the same as the position (pitch) of the pin 22 fixed to the rotary table 21 upright, or the pitch of the pin 22 is slightly longer than that. This is because when the position of the pin 12 is shorter than the position, the drive arm 11 is rotated in one direction. Therefore, the rotation angle A obtained by the movement amount H1 of the drive arm 11 can be made large by setting the pitch slightly longer than half the movement amount H2. On the other hand, when the pin position (pitch) of the drive arm 11 is increased, the movement amount H1 of the pin 12 of the drive arm 11 equal to the movement amount H2 of the pin 22 of the turntable 21 is obtained, and the rotation angle is proportional to the pitch. Since A becomes small, when it is transmitted to the tool 3 side to be converted and rotated as described later, for example, the normal rotation U3 is changed to the reverse rotation D3 or vice versa. The deceleration section becomes longer, and the timing of alignment with the workpiece becomes easier.

The drive shaft 10b of the speed reducer G includes
The large gear 5 is fixed to the shaft 10b by keying (not shown). A small gear 3a is formed at the rear end of the tool 3 supported by a bearing portion 4 fixed on the machine body F, and meshes with the large gear 5. Therefore, the gear 5
Engages with the small gear 3a to change gears (according to the rotation ratio of the worm and the worm wheel incorporated in the speed reducer G) associated with the rotation angle A of the speed reducer G from the large gear 5 to the engaged small gear 3a. Transmitted. The gear wheel 5 repeats left rotation U5 and right rotation D5 based on the rotation angle A to the upper U1 and the lower D1 where the drive arm 11 moves, whereby the tool 3 rotates right (forward) rotation U3 and left (reverse). The rotation U3 is transmitted.

As described later, the large gear 5 has a wide width so that the tool 3 can move forward L when the tool 3 is in the forward rotation U3 and can move backward R when the tool 3 is in the reverse rotation D3. Therefore, the small gear 3a can be slid while the large gear 5 and the small gear 3a are meshed with each other. Therefore, the small gear 3a may be made wider and the width of the large gear 5 may be made smaller so as to be slidable. As another method, the large gear 5
And the small gear 3a may have the same width, and spline connection may be made at the tool shaft 3e portion of the tool 3. Instead, the small gear 3a
Even if the tool shaft 3e and the tool shaft 3e are connected by a spline, the purpose can be achieved.

In the tool 3, the tip 3c is a cutting edge portion such as a drill in the case of drilling, a reamer in the case of drilling a hole, and a rotation such as a tap in the case of screwing, and a shank portion. It is connected to 3d, but this shank part 3
Although not shown by d, the tool tip 3c may be exchangeable by mounting a chuck used in a general hole machine. The tool mounting shaft 3 is attached to the shank portion 3d.
Although b is held by the bearing portion 4, a male screw is engraved on the tool mounting shaft 3b, and a nut in which a female screw is engraved is formed in the hole 4b of the bearing portion 4. Have been combined. This screw may be a ball screw at the time of general drilling, but when the screw is processed on a workpiece, it is convenient to use a screw having the same screw pitch as the screw. When the small gear 3a rotates as described above, the tool shaft 3e, the tool mounting shaft 3b, the shank portion 3d, and the tip 3c are integrally rotated forwardly U3 to move forward L.
Since it is machined by continuously rotating in the reverse direction D3 and retreating (advancing) R, it is effective when the thrust is applied to the tip 3c and when it is pulled back. Therefore, in the case of thread processing, by providing a screw in the tool mounting shaft 3b and the hole 4b of the bearing portion 4, the screw is guided by the screw during forward movement L and rotates rightward, and during backward R, leftward. The cutting speed (advancing pitch) and the returning pitch of the screw by rotating will be limited.

Next, the operation will be described.

When the motor M rotates (in the direction of the arrow), the turntable 21 also rotates, and the connecting rod 6 connecting the pin 22 and the pin 12 operates to move the drive arm 11 upward by the moving amount H2 of the pin 22. The movement amount H1 (= H2) is transmitted so as to draw an arc of U1 and lower D1. At this time, pin 22
Is a circular motion, so in the X-axis direction (the position indicated by the moving amount H2) of the rotary table 21, the upper U1 and the lower U of the drive shaft 11 are the same as the relationship between the top dead center and the bottom dead center of the crank motion. D1
Corresponds to the switching point in the moving direction of the drive arm 11, and the drive shaft 10b on the output side has the fastest rotation speed on the Y-axis center line, and when switching, slowly.
While rotating, it accelerates but slowly decelerates.
As long as the turntable 21 is rotating, it is performed without stopping.

When the drive arm 11 rotates by a predetermined angle A, the rotation of the shaft 10a is input to a worm and a worm wheel (not shown) in the speed reducer G, and the input is the drive shaft 10.
b is transmitted to the large gear 5 to rotate the large gear 5,
The small gear 3a meshed with is rotated. In the bearing part 4,
Since the hole 4b and the tool mounting shaft 3b are screwed together,
On the basis of the screw of the screw, the small gear 3a is rotated to move forward L in the normal rotation U3 and advance the tool 3 while rotating in the workpiece direction, and when the rotation direction is switched to the reverse rotation D3. The predetermined cutting is completed and the rearward R is performed.

That is, the circular motion of the turntable 21 transmitted to the connecting rod 6 causes the drive arm 11 to perform a crank operation for linear motion to the upper U1 and the lower D1, and the linear motion of the drive arm 11 is applied to the speed reducer G. The large gear 5 is rotated by transmitting the rotation angle A to the small gear 3a, and the large gear 5 transmits the rotation to the small gear 3a.
A forward rotation U3 based on the rotation of the pinion 3a and a forward movement L are transmitted to a hole to be machined in a workpiece (not shown) fixed in front of the tip 3c of the tool 3. A certain amount of the hole processing (forward L
, The reverse rotation D
Then, by screwing the tool mounting shaft 3b and the bearing portion 4 into each other, the machined hole is drilled while rotating in the backward R direction. When the retreat R is completed, the rotary table (not shown) is rotated so as to position the next workpiece to the front of the tip 3c, and the workpieces are sequentially processed.

Therefore, since the turntable 21 is circular,
The linear motion of the drive arm 11 continuously transmits smooth acceleration and deceleration similar to a curve drawn by a sine curve, and imparts thrust L of forward L and backward R with rotation to the tool 3, The rotation direction is switched while decelerating along with the acceleration.

[0026]

As described above, according to the structure of the present invention, the rotation of the turntable causes the drive arm to make a linear motion, and the linear motion causes the rotation of the tool and the forward and backward movements by the structure of the bearing portion to simultaneously switch the drive source. Since it can be done without performing, the machining time can be shortened, and its rotation, forward movement and backward movement can be accelerated / decelerated based on a sine curve, and ideal thrust can be supplied by screws.
Switching can be performed without a hiccup phenomenon that gives a shock to the work piece, and abnormal torque can be avoided even for a tool for rotary cutting, so that the cutting life of the tool is extended.

[Brief description of drawings]

FIG. 1 is a side view showing the concept of the present invention.

FIG. 2 is a front view taken along the line XX in FIG.

[Explanation of symbols]

 1 Driven Side 2 Driven Side 3 Tool 3a Small Gear 3b Tool Mounting Shaft 3e Tool Shaft 5 Large Gear 6 Connecting Rod 10a Shaft 10b (Reducer G) Drive Shaft 11 Drive Arm 12 Pin 20 (Motor M) Drive Shaft 21 Rotating disk 22 pin A Predetermined angle (rotation angle) U1 Upward U3 Forward rotation D1 Downward D3 Reverse rotation G Reducer M Motor L Forward R Reverse H1, H2 Moving amount

Claims (3)

[Claims] 1. A power of a tool for transmitting a rotation of a motor to a speed reducer, the speed reducer transmitting power to a driven side to rotate the tool, and processing a workpiece by the tool. In the transmission device, a disk-shaped rotary disk is fixed to the drive shaft of the motor, and pins are set up on the outer circumference of the rotary disk and at a position spaced apart from the center of the drive shaft by a predetermined distance. The drive arm having the axis of the axis as a pivot is fixed, and a pin is erected and fixed to one end side of the drive arm, and the connecting rod is attached to the pin erected on the rotary disk and the drive arm with respect to the pin. It is pivotally connected to allow free rotation, and as the motor rotates, the connecting rod cranks by the rotation of the turntable, the drive arm rotates a predetermined angle, and the tool is passed through the speed reducer. The forward rotation and the reverse rotation can be continuously performed. Ingredients of the power transmission device. 2. The power transmission device for a tool according to claim 1, wherein a large gear is provided on a drive shaft of the reduction gear and a small gear is provided on a tool shaft to transmit power. 3. On the driven side, a screw is engraved on a tool mounting shaft, and a bearing portion is screwed as a nut, and the tool is attached to a workpiece with forward and reverse rotation of the driven side. hand,
The power transmission device for a tool according to claim 1 or 2, wherein forward movement and forward rotation and backward movement and reverse rotation can be continuously operated.