JPS6333003Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) This invention relates to a linear feed mechanism that converts rotational motion into linear motion.

(Background Art) In general, to convert rotational motion into long-stroke linear motion, for example, a rack and pinion, a screw and a nut are used.

In such a transmission mechanism, the motion characteristics of the driving node (rotating body) directly become the operating characteristics of the driven node (sliding body), but for this reason, especially when the rotating body is driven by a motor, etc., the movement characteristics of the sliding body are There was a problem that shock and vibration were likely to occur at the end.

To prevent this shock and vibration, drive the rotating body,
In other words, a device, such as a servo motor, is required to appropriately control the speed of starting and stopping the drive of a motor, etc., resulting in a disadvantage that the device becomes larger, more complicated, and significantly increases in cost.

Furthermore, in the above transmission mechanism, the stopping position of the sliding body completely depends on the stopping angle of the rotating body, so it is necessary to strictly control the stopping angle of the rotating body in order to accurately maintain the stopping position of the sliding body. However, even if this is done, for example, it is not possible to release the breakdown of the gear mesh, and therefore a high degree of stopping accuracy cannot be expected.

(Purpose of the invention) This invention was made by focusing on these conventional problems, and it is possible to reduce the impact and vibration at the beginning and end of the movement of the sliding body without particularly precisely controlling the drive of the rotating body. The purpose is to improve the positioning accuracy of the sliding body.

(Structure and operation of the device) In order to achieve the above object, in the present invention, rollers are arranged along the sliding direction on the output side sliding body, and rollers arranged at the front and rear are arranged in the intermediate part. The rollers at the intermediate part of the sliding body protrude by a predetermined height from the rollers arranged at equal intervals, and the rollers at the middle part of the sliding body A large-diameter cylindrical cam that engages with the rotary shaft to cause the sliding body to move linearly at a constant speed as the rotating shaft rotates at a constant speed; Two small-diameter cylindrical cams are provided that move the sliding body from activation to a constant velocity range through gentle acceleration, or from a constant velocity range to a slow deceleration and then to a stop. A stop portion is provided to prevent the sliding body from being sent out in any direction via the rollers in the start and stop regions.

According to this, first, the small diameter cylindrical cam located at the front part of the rotating shaft is rotated at a constant speed, and when the roller disposed at the front part of the sliding body climbs up from the stationary part to the shaped part, the above-mentioned The sliding body begins to move through the rollers and increases speed with a gradual rise.

Next, when the sliding body shifts to a constant velocity region, the roller disposed in the middle of the sliding body engages with the large-diameter cylindrical cam, and at about the same time, the above-mentioned roller comes off from the small-diameter cylindrical cam, and thereafter the above-mentioned The sliding body moves straight through a predetermined stroke at a constant speed as the rotating shaft moves at a constant speed via the roller and the large-diameter cylindrical cam.

Finally, when the roller disposed at the rear of the sliding body comes off the large diameter cylindrical cam at approximately the same time as the roller disposed on the small diameter cylindrical cam also located at the rear of the rotating shaft, from this point on The small-diameter cylindrical cam again sends it to the sliding body via the roller as the rotary shaft rotates at a constant speed, gradually decelerating it, and stops the sliding body when the roller moves to the stop portion.

(Example) Hereinafter, an example of this invention will be shown in Figures 1 to 3.
This will be explained based on the diagram.

Reference numeral 1 denotes a rotary shaft rotatably supported in a housing 4 via bearings 2 and 3, and 5 a slider (sliding body) supported in a freely sliding manner in the housing 4 through a guide 6 in a direction parallel to the rotary shaft 1. show.

A plurality of rollers 7, 8 and 9-1 to ₉ -n are arranged on the slider 5 along the sliding direction on the side surface facing the rotating shaft 1.

The rollers 7 and 8, which are placed at the front and rear of the slider 5, have a predetermined height higher than the rollers 9-1 to ₉ -n, which are located in the middle and are arranged at equal intervals. It stands out just because of it.

On the other hand, a large diameter cylindrical grooved cam 10 corresponding to the rollers _9-1 to 9-n at the intermediate portion of the slider 5 is integrally fitted onto the rotating shaft 1.
0 is a groove 11 that engages with the rollers _9-1 to 9-n.
Due to the shape, the slider 5 is caused to move straight at a constant speed as the rotating shaft 1 rotates at a constant speed.

Further, the rotating shaft 1 is fed to the slider 5 via rollers 7 and 8 before and after the constant velocity range of the slider 5, and this is activated and the slider 5 is moved through a gentle acceleration range to a constant velocity range.
Alternatively, two small-diameter cylindrical grooved cams 12 and 13 that shift from a constant velocity range to a slow deceleration range to a stop are coaxially fitted with the large-diameter cylindrical grooved cam 10 sandwiched therebetween.

The small diameter cylindrical grooved cams 12 and 13 are provided with stop portions 18 and 19 that prevent the slider 5 from being sent out in any direction via the rollers 7 and 8 in the start and stop regions of the slider 5. In other words,
The grooves 14 and 15 of the small diameter cylindrical grooved cams 11 and 12 are twisted portions (shaped portions) that feed out the rollers 7 and 8 while gently accelerating or decelerating them as described above as the rotary shaft 1 rotates at a constant speed. 16, 17 and rollers 7, 8
Straight line part (stopping part) 18, where the
It consists of 19.

Because of this configuration, when the rotating shaft 1 rotates at a constant speed clockwise (in FIG. 2) from the state shown in FIG. When you get to 16,
As described above, the slider 5 is started to be moved to the left in FIG. 1 via the roller 7, and its sending speed is gradually increased.

Next, when the slider 5 shifts to a constant velocity region, the roller _9-1 and the large diameter cylindrical grooved cam 10 engage with each other at a predetermined rotation angle position, and thereafter the rollers _9-2 to 9-n and the large diameter cylindrical grooved cam 10 engage with each other. As the rotary shaft 1 rotates at a constant speed, the slider 5 moves straight through a predetermined long stroke at a constant speed.

Finally, the roller 8 located at the rear of the slider 5
When the small-diameter cylindrical grooved cam 13 rests on the shaped portion 17 of the small-diameter cylindrical grooved cam 13, the small-diameter cylindrical grooved cam 13 has the opposite effect to that described above, and sends out the roller 8 at a constant speed within a predetermined rotation angle range, but after that, the roller 8 gradually moves forward. While reducing the feed speed, the slider 5 is stopped when the roller 8 moves to the straight section 19.

Therefore, as the rotating shaft 1 rotates at a constant speed, the slider 5 begins to move, accelerates slowly and moves to a constant speed range, and then slowly decelerates again and stops, as shown in FIG. Become.

By the way, according to this embodiment, small-diameter cylindrical grooved cams 12 and 13 and rollers 7 and 8 are provided to gently accelerate and decelerate the slider 5 when it starts and stops, so that the impact at the beginning and end of the slider 5's movement is reduced. , vibration can be removed.

Furthermore, as long as the rollers 7 and 8 are on the straight parts 18 and 19, the cams 12 and 13 will pinch the rollers 7 and 8 and keep the slider 5 in a stopped state even if the rotating shaft 1 rotates a little. To hold the rotating shaft 1
Even if the drive start and stop positions of the slider 5 are not precisely controlled, high positioning accuracy can be obtained for the slider 5.

(Effects of the invention) In summary, according to this invention, even if the drive of the rotating body on the input side is not precisely controlled, the sliding body on the output side can achieve high stopping accuracy, and
Shocks and vibrations at the beginning and end of the movement can be removed, improving the reliability and durability of the device, and reducing costs by eliminating the need for a device (such as a servo motor) that controls the drive of the rotating body. This effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an embodiment of this invention.
FIG. 2 is a side view of the main part thereof, and FIG. 3 is a diagram showing the motion characteristics of the slider. 5...Slider, 7, 8, _9-1 ~ 9-n...
Roller, 1... Rotating shaft, 10... Large diameter cylindrical groove cam, 12, 13... Small diameter cylindrical groove cam, 16, 17
...Shape part (twisted part), 18, 19... Stop part (straight part).

Claims (1)

[Scope of utility model registration request] Rollers are arranged along the sliding direction on the output side sliding body, and the rollers arranged at the front and rear of the rollers protrude by a predetermined height from the rollers arranged at equal intervals in the middle. On the other hand, the input-side rotating shaft disposed along the sliding direction of the sliding body engages with the roller at the intermediate portion of the sliding body, and as the rotating shaft rotates at a constant speed, the sliding body is rotated evenly. A large-diameter cylindrical cam that moves linearly at high speed engages with the front and rear rollers of the sliding body, and the sliding body moves from startup to a constant velocity range through gentle acceleration. Alternatively, two small-diameter cylindrical cams are provided that move from a constant velocity range to a stop through gradual deceleration, and these small-diameter cylindrical cams start the sliding body, and in the stopped range, send the sliding body in any direction via rollers. A linear feed mechanism characterized by having a stop part that prevents the movement from occurring.