I would like to design in a piece of furniture, a support (sheet metal or tubular structure?) to support a jack of about 30kg, the jack will have to lift a load of about 80kg but I don't know if a simple 2 or 3mm sheet metal support can do the trick. In addition, I can only attach myself to the green sides of my furniture. (as on the attached documents ) For your information, the height from the bottom of the cabinet to the bottom of the cylinder is 350mm. Any tips are welcome
According to the screenshot and the elements you give, the 2mm sheet metal cylinder support seems "light" to me. I already think that a slightly thicker support and a reinforcement in the thrust axis of the cylinder would be welcome.
Thank you for this feedback, I increased the thickness to 3mm as a result + reinforcement on each side as in pj. to avoid adding an additional piece that would support in the axis... Any opinion?
I would like to hear from @contact_168(whom I salute in passing).
However, a small note: most electric actuators and other technology have a rear clevis which is precisely designed to absorb the load provided for the actuator.
The body of the cylinder (the lining housing) is not designed to support the load (you will point out that it all depends on the load lifted ;-) ) If it's a TV it's not heavy.
It would therefore be better to use a screed with a wedge underneath possibly to make the dimension.
I may have expressed myself badly, what I mean by "jack" is a telescopic column that allows a force up to 2500N. It's not for a TV, it's for lifting a seat assembly of about 80Kg. So this cylinder is designed to be fixed from the bottom, that's why I'm trying to find a solution to make a sheet metal piece that would support the whole.
Can the jack be fixed on the bottom of the furniture (+ sheet metal to avoid crushing the furniture if it is made of wood)?
And add a spacer on the cylinder's push axis, paying attention to buckling. With the guide at the top of the furniture + stop (always the top of the furniture) to prevent crushing of the cylinder.
The problem with this "telescopic column" system is that it has a guiding function in addition to its motorization function. This means that the load, even if it is vertical, can be off-center in relation to the axis of the cylinder. This is obvious if it is a seat on which the occupant can move... The effect on the support in the lower part can be significant, with regard to buckling, or more simply to its bending deformations. Personally, I would go for a sheet metal solution, with a general trapezoidal shape, 2 mm thick, with box folds that increase the flexural rigidity (see image below). It is clear that a static FE simulation gives elements of an answer in terms of stresses or deformations. Only a few input data on the conditions of use are missing: - vertical load or not, - offset from the cylinder axis, - maximum load value... Personally, I applied a vertical load of 1200 N, offset by 200 mm from the axis of the cylinder, to which is added a horizontal component of 200 N. With the box shape imagined above, the maximum stress is more than 200 MPa. Difficult to accept if it is a question of lifting an individual... Displacements and constraints in the support... Are the efforts inadequate? Are the charging conditions realistic? We would have to say more about your study to be more precise...
To answer you, the jack will be installed on a sheet steel furniture and not wood.
@stefbeno thank you, your first solution will be the simplest I think from an economic point of view/ feasibility
@m.bltthank you very much for this analysis which will already allow me to have a good idea of the design of the part, I don't have all the information to give you yet but the seat will not be designed for someone to climb on it but it will be mounted on an articulated arm (for rotation) of the seat, this arm will be about 1200mm long above the body, and the whole (arm + seat) will not exceed 80kg...
I think I will be inspired by your part in 3mm thickness, would it be possible to recover your CAD file
Despite your description, I still have a hard time imagining the system, especially since it is based on a seat that is not "designed for someone to ride on"... ;o) That being said, the model of the support that I imagined is attached, modified for a thickness of 3 mm (SW 2021).
I have noted your skepticism about a support of this kind for the effort to be absorbed finally if I manage to mount the cylinder on a U-shaped crossbar which will be the width of the furniture and which will be at the same height, will it improve the mechanical resistance? Kind regards
I'm not skeptical about the shape of the support and its ability to support loads... The question that arises is to know where the forces resisting the movement of the cylinder are located, which are at the origin of its action, and therefore of the stresses and deformations of its support. In applications using a cylinder, the cylinder is frequently hinged at both ends, which involves forces acting in the direction of its axis of travel.
In the case of a telescopic column, the connection with its support is generally a recess, and the effort it must exert to move the load depends on the position and orientation of the load, and therefore on the geometry of the mechanism it sets in motion. Manufacturers' documents also indicate a maximum moment value that the column is able to withstand, which means that the force can be off-center or oblique.
Without having at least a diagram of the structure and its approximate dimensions, it is impossible to say anything about these forces. You talk about an articulated arm: where is the load on this arm (seat)? Where is the driving column, the pivot axis, horizontal or vertical, located? Putting a U-shaped crossmember will not change this observation: what is missing is to know what is above the jack...
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