RU175386U1 - AUTOMATIC MECHANICAL CONTINUOUS TENSIONER OF THE GAS DISTRIBUTION MECHANISM OF THE INTERNAL COMBUSTION ENGINE - Google Patents

Abstract

The utility model relates to the automotive industry, in particular to internal combustion engines, namely to the timing chain tensioners. The proposed utility model is aimed at improving the reliability of the tensioner. The technical result is achieved by the fact that a slot for a screwdriver is made on the drive axis from the cap nut side , the external thread of the fastener is cut on the housing, and an inlet is drilled in the middle part of the housing at the place of oil supply from the engine to the tensioner; inside the case there is a thread groove forming a restrictive step, the adjusting screw has an annular protrusion and a through hole of variable cross section ending with a bending collar for a nose, in which a groove for a shoulder and a through outlet of variable cross section is made.

Description

The utility model relates to the automotive industry, in particular to internal combustion engines, namely to the timing chain tensioners.

Known automatic rack-type tensioner containing a housing, a rail, a coil spring and a retainer (AE Khrulev. Repair of engines of foreign cars. Publishing house "Behind the wheel", 1998).

Its disadvantages are:

- step regulation;

- lack of compensation for significant changes in engine temperatures;

- weak mechanical strength of the rack interface.

Hydraulic-type automatic tensioners are also known, such as on ZMZ, Mercedes, SSANYONG, Chevy Niva and others engines. Consisting of a plunger pair, coil spring and bypass ball valves. (AE Khrulev. Repair of engines of foreign cars. Publishing house "Behind the wheel", 1998).

Significant disadvantages of these tensioners are the precision design of parts sensitive to engine oil purity. A slight clogging of the check valve, as well as oil flowing through the increased clearance gaps of the housing-plunger, puts this tensioner out of action, which leads to serious engine damage.

A known prototype is a chain tensioner for a camshaft of an internal combustion engine, comprising a housing, a drive axis with a spring, a latch and an adjusting screw (Patent No. 2281426, publ. 10.08.2006).

Its disadvantages are:

- the absence of restrictions on the output of the adjustable screw, which can lead to its loss in the engine;

- lack of compensation for thermal expansion of the engine;

- the inability to reload the tensioner without removing it from the engine;

- lack of oil supply to the gas distribution circuit.

The proposed utility model is aimed at improving the reliability of the tensioner.

The specified technical result is achieved by the fact that a slot for a screwdriver is made on the axis of the drive from the cap nut side, an external fastening thread is cut on the housing, and an inlet is drilled in the middle part of the housing in the place where the oil is supplied from the engine to the tensioner; inside the case there is a thread groove forming a restrictive step, the adjusting screw has an annular protrusion and a through hole of variable cross section ending with a bending collar for a nose, in which a groove for a shoulder and a through outlet of variable cross section is made.

The inventive device is new and is not described in the literature. The proposed essence of the utility model is illustrated in FIG. 1, where:

1 - housing;

2 - spring;

3 - cap nut;

4 - a clamp;

5 - a slot for a screwdriver;

6 - supporting washer;

7 - annular protrusion;

8 - restrictive step;

9 - internal thread;

10 - external thread of the tensioner;

11 - groove;

12 - flange bending;

13 - a through outlet of variable cross-section;

14 - “nose”;

15 - through passage hole of variable cross section;

16 - adjusting screw;

17 - drive axis;

18 - hole for oil intake.

A thread groove is made inside the tensioner housing 1, and the adjusting screw is made with an annular protrusion 7, compressed and formed in its upper part into a rectangular section larger than the diameter of the internal thread of the housing. This solution defines and limits the operating output of the adjusting screw during operation, preventing the screw from falling out and therefore the engine failure.

The upper end of the axis of the actuator 17 is elongated and a slot 5 is made thereon for a screwdriver. This solution makes it possible to recharge the tensioner without removing it from the engine, which is convenient for repairs. In this version of the axis, it became possible to control chain wear. Knowing the total number of revolutions of the screw 16, when it is forcibly unscrewed, it is possible to calculate and determine the wear of the chain without partially disassembling the engine. The full screw exit is limited by stage 8 and the annular projection 7 of the screw 16.

The area (diameter) of the supporting part of the “nose” 14 of the screw 16 is enlarged and made integral, since it is impossible to make such a solution (increasing the diameter of the supporting surface) with the integral production of the screw, which makes it impossible to assemble the case-screw pair, since the extended annular projection 7 of the screw 16 will not pass into the internal thread 9 of the housing. Such a composite solution with an enlarged bearing surface makes it possible to install the tensioner on engines with solid, without metal inserts, plastic shoes used for most automobile engines. The fixation of the nozzle 14 in the screw body, in addition to being pressed in, is secured by the specially made end part of the adjusting screw, in which the edges of the screw hole are bent inwardly 12 — the shoulder, thereby rolling the axis of the nose in its groove 11. The screw inlet 18, the through hole 15 of screw 18 and the oil outlet 13 allows you to install it on engines instead of regular hydraulic ones, where additional lubrication of the chain through the tensioner is provided, in particular Mercedes and Sanyong engines, etc. To eliminate excessively e is the oil pressure inside the tensioner housing, the oil inlet is made of a smaller diameter than the outlet, in a ratio of about 1: 2, 1: 3.

The latch 4 is not made in the form of a ball, but from a piece of aluminum wire. The tensioner automatically works not only in the direction of tension, but also in the opposite direction, thereby compensating for the thermal expansion of the engine and the circuit itself, but not weakening it beyond the operating limits, removing only overload, since the tensioner pressure force and the chain pressure force from the shoe side are aligned in a small range of spring force at full screw output, and thermal expansions work rigidly in such a scheme and only shift the working area of the screw in one direction or another, equivalent to if the tensioner worked with different wear chains. Checked repeatedly on many cars, video shot. The operating range of the tensioner is achieved by selecting the thread pitch 9 of the tensioner and the spring force 2.

The inventive device operates as follows.

Having screwed (charging) the spring 2 of the axis 17 with a screwdriver through the slot 5, we screw the adjustment screw 16 inside the tensioner housing 1 and lock the axis through the retainer 4 with the bottom of the cap nut 3, thereby immobilizing the axis, pressing it to the supporting washer 6, to bring the tensioner into working condition after installing it on the engine using the external thread of the tensioner 10, the cap nut 3 is unscrewed and the latch 4 is removed, after which the cap nut 3 is screwed into place and the freed axis 17 unscrews the adjusting screw 16, select shouting slack chain. Specially selected for a specific engine, the thread pitch of the case-screw 9 and the spring force 2 during vibration of the running engine automatically adjust the screw force regardless of the temperature fluctuations of the engine, thereby providing automatic adjustment of the chain tension. The holes for the inlet 18 and the outlet 13 of the oil through the spout 14 of the adjusting screw 16 provide additional lubrication of the chain, prolonging its service life.

The proposed device improves the reliability and durability of the circuit.

Claims (1)

An automatic mechanical non-step chain tensioner for a gas distribution mechanism of an internal combustion engine, comprising a housing, a drive axis with a spring, a lock and an adjustment screw, characterized in that a slot for a screwdriver is made on the drive axis from the cap nut side, an external fastening thread is cut, and in the middle part of the body at the place of oil supply from the engine to the tensioner is drilled inlet; inside the case there is a thread groove forming a restrictive step, the adjusting screw has an annular protrusion and a through hole of variable cross section ending with a bending collar for a nose, in which a groove for a shoulder and a through outlet of variable cross section is made.

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