JPH049603Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a stroke regulating device for an electric cylinder.

Electric cylinders are used as linear operating machines for opening and closing dampers, operating valves, or as linear operating machines for pushing up and pulling heavy objects. That is, in this electric cylinder, a drive screw shaft is rotated by a motor that rotates forward and backward, and a piston rod is linearly reciprocated in the axial direction via a nut member screwed onto the drive screw shaft. Therefore, in terms of operation, it is necessary to always regulate the operating stroke at both end positions.

Conventionally, as this type of stroke regulating device, the movement of the actuating member of an electric cylinder is detected by a limit switch outside the cylinder, or
There is a method using a cam mechanism as in Publication No. 55446, but the former has a limit switch mounted outside the cylinder, which causes defects in terms of appearance, waterproofing and dustproofing, and the latter has a complicated configuration and is expensive. However, there remain problems with operability.

This idea was created in view of the above-mentioned circumstances.
It is an object of the present invention to provide a stroke regulating device for an electric cylinder that has a simple configuration and can surely regulate stroke at low cost.

Hereinafter, the present invention will be explained based on embodiments shown in the drawings. First, the first embodiment shown in FIGS. 1 and 2 will be explained. The device of the present invention includes a motor 12 on a base frame 1 that rotates forward and backward, transmission gears 10a, 10b, 10c, 11, and a drive screw shaft 5. In an electric cylinder in which the sliding rod 3 is reciprocated in the axial direction by a nut 7 screwed onto the drive screw shaft 5 via the Switch operating screw shaft 13 attached to gear shaft 5a
A striker 15 is screwed onto the operating screw shaft 13 and reciprocated in the axial direction by forward and reverse rotation of the operating screw shaft 13, and a striker 15 is attached to the switch mounting body 18 fixed to the base frame 1. The striker 15 is arranged at both end positions of the stroke.
a pair of limit switches 16, 16' that are operated by the motor to stop the motor 12, and a cover attached to the base frame 1 to house these components 13, 15, 16, 16', 18 inside. A case 17 is provided. Reference numeral 2 denotes a cylinder jacket which is attached to the base frame 1 and has trunnion shafts 23, 23' fixed to both sides thereof, and restricts the nut 7 from rotating in the circumferential direction. Drive screw shaft 5
For example, a right-handed thread is formed on the outer periphery.
It is rotatably supported by the base frame 1 by bearings 8 that receive radial and thrust thrust. A nut 7 screwed onto the drive screw shaft 5 reciprocates as the screw shaft 5 rotates forward and backward. A sliding rod 3 with a connecting hole 4 is attached to the nut 7,
This sliding rod 3 is reciprocated in the axial direction together with the nut 7 using the inside of the cylinder jacket 2 as a guide. 6
is a stopper located at the end of the stroke, and also fixes the bearing 8 to the base frame 1.
9 is a fixing screw that tightens and fixes the bearing 8 to the drive screw shaft 5. Reference numeral 11 denotes a gear attached to the end of the drive screw shaft 5, and this gear 11 receives forward and reverse rotational force from a motor 12 fixedly attached to a bracket 22 of the base frame 1 protruding inside the cover case 17. are intermediate gears 10a, 10b, 10c
The deceleration is transmitted via. Further, an operating screw shaft 13 is attached and fixed to the shaft end 5a of the drive screw shaft 5 by a set screw 14, and the operating screw shaft 13 has, for example, a right-handed thread formed on its outer periphery. It rotates forward and backward as it rotates forward and backward. The striker 15 screwed onto the operating screw shaft 13 is reciprocated by the forward and reverse rotation of the screw shaft 13. In addition,
In this case, the thread pitch of the operating screw shaft 13 and the thread pitch of the drive screw shaft 5 can be used depending on the purpose. In the case of this embodiment, the thread pitch of the actuating screw shaft 13 is made smaller to reduce the size of the stroke setting portion. As a result, the limit switches 16, 16' for stroke regulation and their constituent parts can be downsized and easily housed in the cover case 17. That is, if the thread pitch of the driving screw shaft 5 is 4 mm and the thread pitch of the operating screw shaft 13 is 0.4 mm, the switch component only needs to be 1/10 the size for the same stroke. The switch mounting body 18 is fixedly attached to a bracket 22 on the base frame 1. Switch mounting body 18
There are long holes 20, 20' along the operating screw shaft 13.
are provided in the elongated holes 20, 20', and limit switches 16, 16' are mounted so as to be movable and adjustable along the operating screw shaft 13, whereby the cam rollers 19, 19 of the limit switches 16, 16' are adjusted.
The operating position where the striker 19' and the striker 15 come into contact can be set.

That is, by adjusting and setting the distance between the limit switches 16, 16' and their positions, the stroke end positions at which the limit switches 16, 16' are operated and the motor 12 is stopped can be set. Moreover, on the switch mounting plate 18,
A long hole 20'' is provided along the operating screw shaft 13,
An engagement protrusion 21 protruding from the striker 15 is engaged with this elongated hole 20'' to prevent the striker 15 from rotating together with the operating screw shaft 13.
The cover case 17 is removably attached to the base frame 1 with attachment screws 24.

The operation of the device of the present invention configured as described above will be explained. When the motor 12 rotates forward (clockwise when viewed from the end of the motor shaft), the intermediate gears 10a, 10
b, 10c, the gear 11 is rotated, the drive screw shaft 5 is rotated at a reduced speed in the same direction as the motor 12, and the sliding rod 3 is guided by the cylinder jacket 2 by the nut 7 screwed onto the drive screw shaft 5. An extrusion operation is performed. At this time, as the driving screw shaft 5 rotates, the operating screw shaft 13 rotates in the same direction, and the striker 15 screwed onto the operating screw shaft 13 moves the gear 1.
1, the striker 15 operates the cam roller 19 of the limit switch 16 and stops the motor 12, whereby the sliding rod 3 is stopped at a predetermined end position in the stroke extrusion direction. Furthermore, when the motor 12 rotates in the opposite direction (counterclockwise when viewed from the end of the motor shaft), all movements are reversed and the sliding rod 3 is pulled back. In this case, the striker 15 also moves in the opposite direction to the above, and the striker 15 switches the limit switch 1.
When the cam roller 19' of 6' is operated, the nut 7
The motor 12 is stopped before the stroke reaches the stopper 6, and the sliding rod 3 is stopped at a predetermined end position in the stroke retraction direction.

FIG. 3 shows a second embodiment of the present invention, in which a motor 12 is provided on the base frame 1 outside the cover case 17, and an operating screw shaft 13 is attached to the shaft 10c' of the intermediate gear 10c. The other configurations are the same as those of the first embodiment.

This second embodiment is suitable for cases where it is more convenient to attach the actuating screw shaft 13 to the intermediate gear, such as when there is a problem with the installation location of the motor 12 due to the design, or when the drive screw shaft 5 moves in the axial direction. The operating screw shaft 13 may be attached to any one of the gear shafts of the transmission gears extending from the motor 12 to the drive screw shaft 5.

As described above, in the present invention, the operating screw shaft 13, the striker 15, the limit switches 16, 16', the switch mounting plate 18, etc. are mounted on the base frame 1, and each of these components is also mounted on the base frame 1. Since it is configured to be stored inside the cover case 17, it can be made compact with an extremely simple configuration, and it can be made at low cost.
The cover case 17 makes it completely dustproof and dripproof.

Further, the limit switches 16, 16' can be moved in the direction of the stroke, making it easy to adjust the stroke.

In addition, in the present invention, for example, in the case of a model with a long operating stroke, by making the thread pitch of the actuating screw shaft 13 smaller than that of the driving screw shaft 5, the space stored in the cover case 17 can be reduced. However, if the operating stroke is short, contrary to the above, the thread pitch of the operating screw shaft 13 can be made larger than that of the driving screw shaft 5. , delicate stroke settings are possible.

In addition, in each of the above embodiments, the drive screw shaft 5 and the operating screw shaft 13 may each be formed with left-hand threads, and the same implementation as described above can be carried out, and one of the screw shafts 5 may be formed with a right-hand thread (or left-hand thread). and the other screw shaft 1
3 can also be left-handed (or right-handed).

[Brief explanation of drawings]

1 and 2 show a first embodiment of the present invention, FIG. 1 is a plan sectional view, FIG. 2 is a front sectional view of the same essential parts, and FIG. 3 is a second embodiment of the present invention. FIG. 1...Base frame, 5...Drive screw shaft, 1
3... Operating screw shaft, 15... Striker, 16,
16'...Limit switch, 17...Cover case, 18...Switch mounting plate.

Claims (1)

[Claims for utility model registration] (1) A motor that rotates forward and backward on the base frame;
In an electric cylinder in which a sliding rod is reciprocated in the axial direction by a nut screwed onto the drive screw shaft via a transmission gear and a drive screw shaft, any one of the transmission gears leading from the motor to the drive screw shaft. The operating screw shaft for the switch is attached to two gear shafts, and the operating screw shaft is screwed to the operating screw shaft.
a striker that is reciprocated in the axial direction by forward and reverse rotation of the operating screw shaft; and a switch mounting body that is fixed to the base frame and is disposed at both end positions of the stroke and is actuated by the striker. A stroke regulating device for an electric cylinder, comprising: a pair of limit switches for stopping the motor when the motor is stopped; and a cover case attached to the base frame to house these components. (2) Utility model registration claim No. 1 in which the limit switch is movable and adjustable along the operating screw axis.
Stroke regulating device as described in section. (3) The stroke regulating device according to claim 1 or 2, wherein the thread pitch of the operating screw shaft is smaller or larger than the pitch of the driving screw shaft.