JPH0241386Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is equipped with a nut that is screwed onto an electrically driven screw shaft, and as the screw shaft rotates, the rod connected to the nut is guided back and forth and attached to the tip of the rod. This invention relates to a rod structure for a linear actuator that provides back and forth motion to a driven body using a connecting fitting.

BACKGROUND ART FIG. 4 shows a nut guiding structure in a conventional linear actuator, in which a nut 3 is screwed onto an electric rotary screw shaft 2 provided concentrically within an outer cylinder 1 surrounding a rod that moves back and forth. The nut 3 is guided and moved back and forth while being prevented from turning by two fixed tie rods 4 passing through it. In this case, the nut 3 is attached to the outer cylinder 1 in order to improve air circulation within the outer cylinder 1 as the nut 3 moves back and forth.
A large gap 5 is provided between the two.

Problems that the invention aims to solve In the above conventional structure, since the gap 5 is large, it is not possible to increase the lateral load on the rod, and if the stroke becomes long, twisting and chatter may occur between the tie rod 4 and the nut 3. This has the disadvantage that the problem is more likely to occur, and if the connecting fitting between the rod and the driven body is integrally constructed with the rod, the orientation of the connecting fitting cannot be changed, so if you want to change it, use another compatible one. There is an inconvenience that the rod must be replaced or the connecting fitting and the rod must be constructed separately.

The object of the present invention is to provide a rod structure for a linear actuator that eliminates the above-mentioned conventional drawbacks and inconveniences.

Means for Solving the Problems This proposal consists of a main body that supports the base end of the electric rotating screw shaft, an outer cylinder that fits concentrically with the base end screw shaft on the main body, and an outer cylinder that is screwed onto the screw shaft. A rod that is connected to a nut that guides and slides inside, moves back and forth by the rotation of the screw shaft, and has a connecting fitting fixed to its tip, a rod receiver that is attached to the tip of the outer cylinder and guides and supports the rod, and a rod that is attached to the nut on the circumference. The gist is a rod structure for a linear actuator having two screws that pass through four grooves or holes provided at intervals and fix the rod receiver to the main body together with the outer cylinder.

Function The rod is guided and supported by a rod receiver attached to the tip of the outer cylinder and a nut that slides inside the outer cylinder, and the smooth circumferential surfaces of the two screws that fix the rod receiver to the main body together with the outer cylinder are attached to the nut. The four grooves or holes provided prevent the nut from turning, and the two grooves or holes through which the screws do not pass facilitate air circulation.

Embodiment In FIGS. 1 to 3, a screw shaft 7 is provided in the main body 6.
The screw shaft 7 is rotatably driven by an electric motor 8 via a differential gear device 9. An outer cylinder 10 is fitted to the front part of the main body 6, a rod 12 concentric with the screw shaft 7 is attached to a nut 11 which is screwed onto the screw shaft 7 and slides into the outer cylinder 10, and the rod 12 is fitted onto the tip of the outer cylinder 10. The rod 12 is guided and supported by the installed rod receiver 13.

The nut 11 has four grooves 14 equally spaced on the circumference, and the rod receiver 13 is inserted into two centrally symmetrical grooves 14.
It is fixed to the main body 6 together with the outer cylinder 10 by two screws 15 passing through the outer cylinder 10. A connecting fitting 16 for connecting to a driven body is fixed to the tip of the rod 12.

In the above structure, the outer periphery of the nut 11 is the outer cylinder 1.
0 and can be guided back and forth, while at the same time being prevented from rotating by sliding contact between the groove 14 and the screw 15.
Since the screw 15 firmly fixes the rod receiver 13 to the main body 6 via the outer cylinder 10, the nut 11 can smoothly move back and forth without twisting or chattering between it and the screw 15 even if the stroke is long. Can be done. Further, the groove 14 through which the screw 15 does not penetrate facilitates the flow of air within the outer cylinder 10 when the nut 11 moves back and forth.

To change the orientation of the connecting fitting 16 when the connecting fitting 16 is integrally connected to the rod 12,
After removing the screw 15 and rotating the rod 12 by 90 degrees or 180 degrees, the outer cylinder 10 and the rod receiver 13 may be fixed to the main body 6 using the screw 15 again.

The same effect can be obtained by providing a hole through which the screw 15 passes in place of the groove 14. When the nut 11 is injection molded from synthetic resin, the groove 14 is more advantageous.

Effects of the invention The present invention has the above-mentioned structure, and the four grooves or holes provided in the nut are used both for preventing the nut from rotating and for air circulation, and the nut is brought into sliding contact with the outer cylinder, and the rod receiver is also used. Since the nut is prevented from rotating by a screw that is fixed to the main body through the outer cylinder, the nut can move back and forth smoothly, without twisting or chattering, and can withstand large lateral loads. This has the effect that the direction can be easily changed along with the rod.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of one embodiment of the present invention, Figure 2 is a partially cutaway elevation view showing the fixing structure of the rod receiver, Figure 3 is a side view, and Figure 4 is a view of the area around the conventional nut. It is a cross-sectional view showing a stop structure. 6...Main body, 7...Electric rotating screw shaft, 10...
Outer cylinder, 11...nut, 12...rod, 13...
...Rod receiver, 14...groove or hole, 15...screw.

Claims (1)

[Scope of utility model registration request] A main body that supports the base end of an electric rotating screw shaft, an outer cylinder whose base end fits into the main body concentrically with the screw shaft, and a nut that is screwed onto the screw shaft and slides guided inside the outer cylinder. A rod that moves back and forth by the rotation of a screw shaft and has a connecting fitting fixed to its tip, a rod receiver that is attached to the tip of the outer cylinder to guide and support the rod, and four grooves or grooves provided on the nut at equal intervals on the circumference. A rod structure for a linear actuator having two screws that pass through a hole and fix the rod receiver to the main body together with the outer cylinder.