SU721580A1 - Differential-thread fastening member - Google Patents

Description

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The invention relates to mechanical engineering, and more specifically to the connection and m of machine parts.

The connection of D .-, -.-- and mine is known with the help of a threaded element. There are two of it with a thread of a hydrographic direction 1.

The disadvantages of such a connection are the complexity of simultaneous installation of several translations; elements due to the possibility of ne,: m (wasp of the parts to be joined.

Most closely to the proposed technical essence is a fastener with a differential thread, containing two threaded sections with threads of the same direction, with the thread pitch of one section different from the thread pitch of the other section 2.

However, due to the danger and misalignment of the parts being joined and the clamping of the adjacent bolts, this fastener element is used primarily as a single piece.

The purpose of the invention is to use by creating a cross member with g, differential thread for a group threaded connection and to facilitate the assembly of the parts to be joined.

In order to accomplish this goal, the proposed fastening element is provided with (|) a curb mounted on one m. Thread.

the fastening element, made in the form of a pin, and the other threaded section of the said stud is threaded, at least 2 times larger than the first, the turnkey head is made between

threaded sections, wherein the pitch of the inner thread of the futork and the threaded portion of the stud interacting with it is made equal to the pitch of the thread of the opposite threaded portion of the stud, and the outer thread of the stitch is large

thread pitch of the mentioned thread sections.

In another embodiment, the pin has been replaced with propellers cut along the entire length with an outer. Or internal hexagon.

Assembled, the stud (bolt) and the futorka are a differential thread bolt.

FIG. 1 and 2 depict 2 variants of the proposed fastener with differential thread; in fig. 3 shows an example of the use of a bolt with a differential thread in a group connection (for example, when connecting two cylindrical bodies through an intermediate ring) with a section along A-A; in fig. Figure 4 shows an example of using a bolt in a flange joint with reduced radial dimensions (in two projections).

The device consists of a stud (screw) 1 with a turnkey head 2 having holes for locking 3. The hairpin (screw) is screwed with a futher 4 having a slotted head 5 and holes for locking 6. A fastening element connects parts 7 and 8, between which a spacer ring 9 is installed. The stud has a thread pitch Si, a futork on the outer diameter is a step 5 g.

The connection of the part is carried out as follows.

The studs 1 with their long ends are screwed in up to the stop by the heads 2 into the housing 7, and the sockets 4 are screwed into the housing 8 so that between the heads of the formers 5 and the end surface of the housing 8 there remains a gap equal to (1 - 2) 5. In the specified position of the futorka, the stopper of the vehicle (for example, with the help of a wire or with special brackets through the holes 6). Shells 7 and 8 through the intermediate ring 9 are installed in this way. In order for the short ends of the studs to stand against the stubs (in Fig. 3, the upper differential bolt is shown in the initial position), after which all the studs are twisted out of the housing 7 and screwed with the short ends up to the stop by the heads 3 into the stubs 4 (the stitches can additionally be held by the key for the slotted head 5). In this way, the housings 7 and 8 are joined (in Fig. 3, see the bottom and middle bolts).

The joint is tightened (after the preforming of the futhor) by successively turning the studs 1 by the head 2. In this case, the studs and the reinforcements work together, like the famous bolt with a differential thread, i.e. parts 7 and 8 are fastened. In order to ensure the minimum thread deformation of the adjacent bolts (relative to the bolt to be wrapped), the joint is tightened in several stages with each bolt turned at a small angle (20, ..., 30 °).

FIG. 4 shows an example of a flange connection with a screw with a differential thread. The installation and operation of this variant is analogous to that described.

The present invention has several advantages: simplifying the assembly of the joint, the possibility of using it in group joints, and the possibility of obtaining lightweight joints with small radial dimensions.

Claims (2)

Invention Formula . Differential threaded fastener containing a turnkey head and two threaded sections with a thread of the same direction, with the thread pitch one of the sections is different from the pitch of the thread of another section, characterized in that, in order to expand the field of use, it is provided with a fastener mounted on one threaded section of a fastener made in the form of a pin, and the other threaded section of said pin is threadedly cut, at least twice than the first, the turnkey head is made between the threaded sections, with the internal thread pitch. the stubs and the threaded portion of the stud interacting with it are made equal to the thread pitch of the opposite threaded portion of the stud, and the outer thread of the stitch is in increments greater than the thread pitch mentioned threaded sections. 2. The fastener according to claim 1, characterized in that the inner thread of the futher is made on a part of its length, and the fastener cooperating with the futher has a turn-key on the side opposite to the futher. Sources of information taken into account in the examination 1. Orlov, P. I. Basics of Design, Part 111, M., 1977, fig. 173. 2. Ibid, -ris. 171, 172. I / vXXXXVW