JPH0343487Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanism for feeding a table device in which the forward or backward speed of a shaft is determined by the pitch difference of a screw formed on the shaft and by switching a clutch.

Switching devices for rapid traverse, slow traverse, rough traverse, and precision traverse require a complex gear-based transmission mechanism or a combination with a worm gear, in other words, a mechanism in which the axes intersect at right angles, which requires a considerable amount of space and requires high precision. The feeding mechanism is difficult.

In addition, the left and right movement speed of the cutting tool, table, or workpiece (workpiece) can be controlled by gears,
It is difficult to apply power transmission consisting of a complex structure such as a belt chain, link mechanism, cam mechanism, etc. to a single shaft because the entire machine becomes large, and it is difficult to maintain it due to the difficulty of incorporating it into a mechanical device. Inspection is not easy.

In addition, there are spaces above and below one shaft,
A feeding mechanism is known in which screws with different leads are formed, and a floating nut that is screwed onto the screws is fixed or loosened to enable low-speed and fast-speed feeding. ("Automatic Books" published by Taiga Publishing Co., Ltd. on May 1, 1978) In addition, threads of the same direction with different pitches are cut on both sides of a single shaft and are screwed into the fixed side and the movable side, respectively. The mechanism that does this is known. (Showa
("Mechanical Movement Mechanism" published by Gihodo Co., Ltd., October 5, 1932) However, these are just basic principles about screws with different leads and nuts that screw into these screws, and it is not possible to immediately install them on all machines. is impossible.

The object of the present invention is to provide two ball screws with different pitches and a ball spline at the ends of a single shaft, and to connect a non-movable ball screw nut screwed to one of the ball screws to the housing by switching the clutch. An object of the present invention is to provide a feeding mechanism for a table device which enables rapid feeding or slow feeding of a table integrated with a movable ball screw nut by a pitch difference by being fixed to or connected to a ball spline.

For example, when a screw with a pitch of 10 mm and a screw with a pitch of 9.9 mm are set on a single shaft, the difference in pitch is 0.1 mm.

When the non-movable screw is fixed and the shaft rotates once, the movable ball screw nut moves only 0.1 mm per revolution.

When the shaft and the non-movable ball screw nut rotate together, for example, by a pin, the shaft rotates in a fixed position, and the movable ball screw nut moves 10 mm per rotation.

That is, when the movable ball screw nut is fixed to the machine body, it moves 0.1 mm in one rotation.

When the ball screw nut is rotated together with the shaft, it is possible to easily switch between rough feed (rapid feed) and precision feed (fine feed) by inserting and removing a 10mm pin.

In this case, a difference of 100 times is possible.

Conventional mechanisms are very complex and require a large number of parts or feeding mechanisms, and cannot be assembled compactly.The mechanism is complex and uses a large number of parts, resulting in backlash or parts accuracy errors, so precision feeding is required. It is especially difficult for

According to the present invention, there is almost no backlash due to the use of the ball screw nut and ball spline.
Since the mechanism is extremely simple and the number of parts is small, extremely precise feeding is possible.

In the present invention, a non-movable ball screw nut means that a portion of the nut cannot be moved even by rotation of the ball screw.

The gist of the present invention is to provide a shaft in which two or more screws are formed in the same direction, with a spline on one side and an arbitrary interval on the other side, and a shaft in which there is a pitch difference between these screws, and A movable ball screw nut and a non-movable ball screw nut matching the difference are respectively screwed together, and these movable ball screw nuts move forward or backward as the shaft rotates, while the non-movable ball screw nut moves forward or backward as the shaft rotates. A screw that is fixed to a housing or connected to a ball spline by switching, so that rapid feed (rough feed) and slow feed (precision feed) of the movable ball screw nut can be performed with one shaft. An object of the present invention is to provide a feeding mechanism for a table device that utilizes a pitch difference.

A preferred example of the present invention will be described below based on the drawings.

Reference numeral 10 in the figure is the housing of various machines,
A flange 16 of a nut case 11, a spring case 17 of a shaft speed adjusting device 12, and a ball spline 13 are attached to the housing 10.
bearing cases 14 are attached via bolts 15, respectively.

An inner ring 19 is fitted to the inner peripheral surface of the nut case 11 via a needle bearing 18, and a first non-movable ball screw nut 20 of a double nut type is fitted to the inner surface of the nut case 11.

The first non-movable ball screw nut 20 is arranged on the left and right with a shim plate in the middle, and a shaft 22 forming a first screw 21 is screwed together via a ball.
On the other hand, the sliding surface 2 of the flange 16 of the nut case 11
The sliding surface 25 of the intermediate joint member 24 that contacts the ball screw nut 20 is coaxially arranged, and the radially inner flange 26 of the intermediate joint member 24 is connected to the flange 28 of the ball screw nut 20 via the bolt 27. Fixed.

Reference numeral 29 is a cap-shaped joint member with a brim in cross section having a depression in the center, and a sliding surface 31 of a flange 30 at one end of the joint member 29 abuts against a sliding surface 31' of the intermediate joint member 24.

One end flange 30 of the joint member 29, the intermediate joint member 24, and the flange 16 of the nut case 11.
Knock pin through holes 32, 33, and 34 are formed on the same axis.

The end member 35 of the joint member 29 has a through hole 3 in the center.
6 is formed, and the flange 38 of the ball spline 13 is fitted into the axial notch 39 of the end member 35 and fixed with bolts 37, 37.

A spline 41 of a ball spline shaft 40 is slidably fitted into the inner surface of the ball spline 13 via a ball.

A metal bushing 42 is fitted on the outer periphery of the ball spline 13, and the metal bushing 42 is attached to the bearing case 14.

An end cover 43 is attached to the end of the ball spline 13 via screws, and the end cover 43 has a space 44 corresponding to the amount of movement of the shaft 22, which moves forward or backward while rotating.

A key groove is formed on the outer periphery of the ball spline 13 and the sprocket 46, and a flat key 45 is fitted into the key groove and fixed, and the sprocket 46 is attached between the bearing case 14 and the end cover 43.

Also, the end cover 4 is removed from the sprocket 46.
One end of a connecting rod 48 is attached to the ring body 47 protruding toward the third side, and a handle 49 is attached to the other end.

Reference numeral 50 denotes a knock pin indicating one of the switching mechanisms of the clutch. Ball 56 is fitted.

The ball 56 is fitted into a through hole 57 formed at a desired location in a cylindrical sleeve 54 attached to the outer end 53 of the flange 30 of the joint member 29, and the sleeve 54 is inserted in order to prevent the ball 56 from falling off. A cylindrical cover 64 is attached to the spring 58 on the outer periphery.
It is fitted by interposing it.

A push/pull/stopper 60 is provided at one end of the drive pin 51, and the drive pin 51 is connected to the through holes 32, 33 of the joint member 30 and the intermediate joint member 24.
When sliding, the stopper 60 comes into contact with the end 59 of the cylindrical cover 64 and stops.

On the other hand, the driven pin 52 is divided into left and right halves by a flange 61 formed at an arbitrary location, and the right side is divided into two by a flange 61 formed at an arbitrary location.
The spring 63 is inserted into the spring case 17 with the spring 63 interposed therebetween.

The spring 63 constantly presses the knock pin 50 in the right direction.

Reference numeral 65 denotes a second screw formed on the left side of the shaft 22. The second screw has the same direction as the first screw 21, and is formed smaller in pitch than the first screw 21.

66 is a second movable ball screw nut of a double nut that is screwed into the second screw 65;
The movable ball screw nut 66 has nuts 68 and 69 arranged on the left and right sides with a shim plate 67 in the middle.

Reference numeral 75 denotes a table, and linear bearing bodies 77, 78 are fixed to the lower surface of the table 75 in the front, rear, left, and right directions with bolts, and the linear bearing bodies 77, 78 are fitted into tracks 81, 82, respectively ( (See Figure 4).

The tracks 81 and 82 are attached to holders 83 and 84 formed in the housing 10 via holders 85 and 86 and bolts 87 and 88.

The operation of the above embodiment will be explained.

First, by pulling the drive pin 51 to the right as viewed in the drawing, the end face of the drive pin 51 and the driven pin 52 move to the right, and the end face is connected to the flange 30 of the joint member 29 and the intermediate joint member 29. It is located between the sliding surfaces 31 and 31' (see Fig. 1).

Next, when the shaft 22 is rotated to the left by rotating the handle 49 or starting the stepping motor 93, the spline shaft 40 is rotated together with the ball spline 13, and at the same time, the joint member connected to one end of the ball spline 13 is rotated. 29 are rotated at the same speed.

Sliding surface 3 of one end flange 30 of the joint member 29
1 only slides on the sliding contact surface 31' of the intermediate joint member 24, and no power is transmitted to the first immovable ball screw nut 20.

Therefore, the shaft 22 is connected to the first stationary ball screw nut 20 (fixed to the housing).
The vehicle moves backward (to the right as viewed in the figure) while being guided by the first screw 21 of the vehicle.

Further, the shaft 22, which rotates to the left, has a second movable ball screw nut 66 which is screwed into a second screw 65 formed coaxially (the pitch thereof is smaller than that of the first non-movable ball screw nut 20). ) is moved forward toward the left toward the figure.

The speed of the second movable ball screw nut 66 is a slow feed in the right direction corresponding to the pitch difference of the first non-movable ball screw nut 20.

For example, assuming that the pitch of the first non-movable ball screw nut 20 is 10.1 mm and the pitch of the second movable ball screw nut is 10.0 mm, the speed difference of the second movable ball screw nut 66 is 0.1 mm.
It becomes a very slow feed of mm.

Conversely, when the shaft 22 is rotated to the right, the feed is performed at a very low speed in the left direction.

Next, when performing fast forwarding, by pressing the driving pin 51 to the left while facing the figure (see Figure 2), the drive pin 51 moves to the left with the end surface of the driving pin 51 and the driven pin 52 in contact with each other. and both pins 51, 52
The end face of the nut case 11 is located between the sliding surface 23 of the flange 16 and the sliding surface 25 of the intermediate joint member 24.

Next, when the shaft 22 is rotated to the left, the joint member 29 rotates simultaneously with the ball spline 13.
The intermediate joint member 24 is rotated in the same direction by the hook pin 50.

By simultaneously rotating the first non-movable ball screw nut 20 and the shaft 22 together with the intermediate joint member 24, the shaft 22 neither advances nor retreats, but the second
The movable ball screw nut 66 advances to the left as viewed in the figure.

Conversely, when the shaft 22 is rotated clockwise, it moves forward to the right.

FIG. 5 shows another embodiment of the device according to the present invention.
A slow feed switching device is directly attached to the shaft 22.

Reference numerals 101 and 102 indicate both side walls of the housing, and a stop plate 104 for stopping the rotation of the first field is attached to the left side of the side wall of the right housing 102 with screws 103 or the like as viewed from the drawing. A field core 106 having a built-in annular excitation coil 105 is attached to the side surface by welding or the like.

A rolling bearing 1 is provided on the inner periphery of the field core 106.
07 is fitted, and a rotor 109 with a hub 108 is fitted on the inner periphery of the rolling bearing 107.

The rotor 109 with the hub 108 has the excitation coil 1
05 and the field core 106, a rotating disk 110 is formed in the radial direction, a flange 111 is formed at the tip, and a hub 10 in the axial direction is formed.
The hub 8 has a gap such that its inner surface 118 does not come into contact with the outer peripheral surface 117 of the ball spline shaft 40, and the side wall 102 is formed to slightly protrude from the through hole 112.
A cup-shaped joint member 114 is fitted through 13.

A flange 38 of the ball spline 13 is fitted into the axial notch 116 of the end member 115 of the joint member 114 via a bolt 37 and fixed with the bolt 37.

Flange 2 of first immovable ball screw nut 20
The radially inner flange 121 of the cylindrical intermediate joint member 120 that fits into the cylindrical intermediate joint member 8 is fixed via bolts 27 .

A radially outer flange 123 is formed extending in the axial direction with a gap between the inner periphery 122 of the intermediate joint member 120 and the shaft 22, and a first armature is formed on one end surface 124 of the outer flange 123. 1
25 is fixed via a bolt 126, and a second armature 128 is fixed to the other end surface 127 via a bolt 126.
6.

A nut case 11 is attached to the left housing 101.
A flange 16 is attached via bolts 15.

The end face of the first armature 125 and the first rotor 1
A slight gap C is formed with the end face of 09.

An inner ring 19 is fitted to the inner peripheral surface of the nut case 11 via a needle bearing 18, and a first non-movable ball screw nut 20 of a double nut type is fitted to the inner surface of the nut case 11.

A screw 103 is installed on the right side wall of the housing 101.
A detent plate 129 is attached to stop the rotation of the second field, and a second field core 131 having a built-in second annular coil 130 is attached to the side surface of the detent plate 129 by means such as welding.

A second rotor 1 is provided on the side surface of the field core 131.
32 is attached, and a slight gap C is formed between the end surface of the second rotor 132 and the end surface of the second armature 128.

The operation of the second embodiment will be explained.

First, when the shaft 22 is rotated to the left by rotating the handle 49 or starting the stepping motor 93, the spline shaft 40 is rotated together with the ball spline 13, and at the same time the joint member connected to one end of the ball spline 13 is rotated. 114 are rotated at the same speed.

Subsequently, the rotation of the joint member 114 is transmitted to the rotor 109 with the hub 108 via the key 113.

A rotor 109 with a hub 108 has a rolling bearing 10
7 allows free rotation regardless of the annular excitation coil 105 of the dry single-plate electromagnetic clutch.

Therefore, the shaft 22 moves backward (to the right as viewed in the figure) while being guided by the first screw 21 of the first non-movable ball screw nut 20 (fixed to the housing 101).

When the shaft 22 reaches a predetermined position, the electromagnetic clutch is energized by the operation of a limit switch (not shown), and a magnetic flux is generated between the annular excitation coil 105, the hubbed rotor 109, and the first armature 125. 125 is strongly attracted to the friction surface of the rotor 109 with a hub, and the friction force connects the clutch, and the ball spline 1
3, the intermediate joint member 120 is simultaneously rotated in the same direction, that is, to the left.

Since the first non-movable ball screw nut 20 and the shaft 22 are simultaneously rotated together with the intermediate joint member 24, the shaft 22 neither advances nor retreats, but the second movable ball screw nut 66 Since the shaft 22 is screwed into the second screw 65, the shaft 22 tends to move toward the figure and retreat to the right while being guided by the second movable ball screw nut 66 (see FIG. 1).
2 is in a fixed state, the second movable ball screw nut 66 moves forward to the left.

Next, when the current to the electromagnetic clutch is cut off and the dry single-plate electromagnetic brake is energized, the second annular excitation coil 130, the second field core 131, and the second rotor 132 are magnetized, and the second armature 128,
The intermediate joint member 120 and the first armature 125 are strongly attracted to the left, and the clutch is disengaged.

Therefore, a brake is applied to the intermediate joint member 120 and the first non-movable ball screw nut 20, and the rotation of both is momentarily stopped, and the first
The screw 21 is the first non-movable ball screw nut 20
You will be guided to retreat.

As described above, the rotation of the intermediate joint member 120 is driven and stopped by the electromagnetic clutch and electromagnetic brake directly incorporated into the shaft 22, that is, the switching between fast feed and slow feed of the second non-movable ball screw nut is instantaneously performed.

"Effect of the invention" In the device of the present invention, in addition to the screws, a ball spline is formed on one shaft, and a second movable ball screw nut, which is screwed onto the plurality of screws, moves forward or forward as the shaft rotates. While the first non-movable ball screw nut is fixed to the housing by switching a clutch or connected to a ball spline, the second movable ball screw nut can be moved rapidly or slowly. Moreover, the feeding mechanism of the table device that utilizes the screw pitch difference takes full advantage of the high precision and excellent wear resistance that are the features of ball screws and ball splines, without requiring a complicated mechanism, to ensure long-term accuracy. It has the characteristics of easy maintenance and can be easily installed on any machine.

In addition, the device of the present invention can be incorporated into a grinding wheel cutting device, a cutting tool cutting device, a three-dimensional reading device, etc., so that it can be commercially available and effectively used as a slow feed device for table devices of various machines.
Extremely practical.

Further, a spline is formed in addition to the plurality of screws, and a second movable ball screw screwed into the plurality of screws moves forward or backward as the shaft rotates, whereas a spline is formed on the first non-movable ball screw. The screw is fixed to the housing by switching the clutch or connected to the ball spline, which enables rapid or slow feed of the second movable ball screw.Moreover, the power transmission mechanism utilizes the pitch difference of the screw. It takes full advantage of the high precision and excellent wear resistance that characterize ball screws, and has the feature of being able to maintain precision for a long period of time.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the device of the present invention applied to slow feed of a table of a machine tool, Fig. 2 is a sectional view of the main part showing the moving state of the dowel pin during rapid feed of the device of the present invention, and Fig. 3 is a sectional view of the device of the present invention. A partially sectional front view of the ball spline, FIG. 4 is a cross-sectional view of FIG. 1,
FIG. 5 is a longitudinal sectional view showing another embodiment of the device of the present invention. 10: Housing, 11: Nut case, 1
3: Ball spline, 20: First non-movable ball screw nut, 24: Intermediate joint member, 25: Sliding surface, 29: Joint member, 50: Knock pin, 66:
Second movable ball screw nut.

Claims (1)

[Scope of claims for utility model registration] (1) A table device using the pitch difference of screws that meets the following conditions (A), (B), (C), (D), (E), and (F). Feeding mechanism. (A) Shaft 22 on which two or more screws 21, 65 are formed, and these screws 21, 6
5, and the screws 21,
In the feeding mechanism of a table device, a movable ball screw nut 66 and a non-movable ball screw nut 20 are screwed together to match the pitch difference of 65. (B) A spline 41 to be fitted into a ball spline is formed on one side of the shaft 22 where the screw 21 and the screw 65 are oriented in the same direction. (C) The movable ball screw nut 66 moves forward or backward as the shaft 22 rotates. (D) Selectively allows or prevents the rotation of the immovable ball screw nut 20, transmits the rotational torque of the shaft 22 to the immovable ball screw nut 20 when the rotation of the immovable ball screw nut 20 is allowed, and transmits the rotational torque of the shaft 22 to the immovable ball screw nut 20 when rotation is prevented. 2
There is a switching means for not transmitting the rotational force of No. 2 to the immovable ball screw nut 20. (E) The movable ball screw nut 66 is attached to the table 75. (F) Screw 65 of movable ball screw nut 66
is formed smaller than the pitch of the fixed ball screw 21. (2) When the clutch is switched, the driving pin 51 is engaged with or disengaged from the driven pin 52 by the push-pull operation of the knock pin 50 or the electromagnetic clutch operation, so that the intermediate joint member 24 is connected to the flange 16 of the nut case 11 or the joint member 2.
9, or is detached from the flange 16 of the nut case 11 or the flange 30. Feeding mechanism.