RU2289710C2 - Compression brake for truck internal combustion engines - Google Patents

Abstract

FIELD: mechanical engineering; truck engine compression brakes.

SUBSTANCE: proposed compression brake fro truck engines has discharge valve with drive installed in engine cylinder head to hold discharge valve open at compression stroke in near dead center made in form of actuating cylinder and connected with the latter by control line of pressure source made in form of standard fuel pump. Compression brake contains additional control member of standard fuel pump connected to injection line. Control member of fuel pump is made in form of distributing device with one input and two outputs. Input of distributing device is connected to fuel pump, and outputs, to actuating cylinder and injecting nozzle, respectively. Brake is provided with check valve placed between fuel pump and actuating cylinder, additional valve with control input connected between actuating cylinder and tank. Injecting nozzle drain is placed in line connecting additional valve with fuel tank. Additional valve is connected by pressure line to pneumatic main line including receiver, control cock, air distributor and intake valve. Control cock is electrically connected with distributing device and pneumatically connected, through air distributor and pipeline, with intake valve and pneumatically connected by pipeline with receiver.

EFFECT: improved efficiency and reliability of compression brake, provision of safety at braking.

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Description

The invention relates to the field of internal combustion engines, in particular to compression brakes of truck engines.

The closest in technical essence to the proposed one is a compression brake for internal combustion engines of trucks (USSR Patent No. 1828499, F 01 L 13/06, 1993), containing an exhaust valve with an actuator installed in the cylinder head of the engine to ensure that the exhaust valve is held open on the compression stroke in the region of top dead center, made in the form of an executive cylinder, and a pressure source connected to the latter by means of a control line, made in the form of a standard fuel sucker, and the compression brake is equipped with an additional control unit for the standard fuel pump connected to the injection line, and the control unit for the fuel pump is designed as a switchgear with one input and two outputs, while the input of the latter is connected to the fuel pump, and the outputs, respectively, to the executive the cylinder and the injection nozzle, the brake is equipped with a check valve connected between the fuel pump and the actuating cylinder, an additional valve with a control input connected between an executive cylinder and a fuel tank, and drainage of the injection nozzle is connected to a line connecting the additional valve to the fuel tank.

However, during operation of the known compression brake, the braking moment developed by the engine in braking mode is not sufficient for braking the car, since a rarefaction is created in the engine cylinders at the beginning of the compression stroke, and therefore, the upward resistance of the piston will be low.

Structurally, the prototype does not provide for changing the resistance to the upward movement of the piston, and therefore, to regulate the braking torque.

All these disadvantages reduce the effectiveness and reliability of the compression brake.

The technical result is aimed at improving the efficiency and reliability of the compression brake, as well as ensuring traffic safety during braking.

The technical result is achieved by the fact that the compression brake for internal combustion engines of trucks contains an exhaust valve with an actuator installed in the cylinder head of the engine to ensure that the exhaust valve is kept open at the compression stroke in the region of top dead center made in the form of an actuating cylinder, and connected to the latter, through a control line, a pressure source made in the form of a standard fuel pump connected to the injection line, and the control then the fuel pump is made in the form of a switchgear with one input and two outputs, while the input of the latter is connected to the fuel pump, and the outputs are respectively to the actuator cylinder and the injection nozzle. The brake is equipped with a check valve connected between the fuel pump and the Executive cylinder, an additional valve with a control input connected between the Executive cylinder and the fuel tank, and the injection nozzle drain is connected to the line connecting the additional valve to the fuel tank.

The additional valve is connected via a pressure line to a pneumatic line, including a receiver, a control valve, an air distributor and an inlet valve, while the control valve is electrically connected to a distribution device, pneumatically through an air distributor and a pipe with an inlet valve and pneumatically, through a pipe with a receiver.

Distinctive features of the prototype is that the additional valve is connected by its control input via a pressure line to a pneumatic line including a receiver, a control valve, an air distributor and an inlet valve. In this case, the control valve is electrically connected to the switchgear, pneumatically through an air distributor and a pipe with an inlet valve, and pneumatically through a pipe with a receiver.

The figure 1 shows a compression brake; figure 2 - combined valve with an additional compression brake valve.

The compression brake comprises a fuel pump 1 (FIG. 1) connected by an injection line 2 to an injection nozzle 5; a dispenser 6 connecting the injection line 2 by means of a check valve 7 and a control line 3 to a combination valve 14, which is connected by means of a discharge line 8 to a leak line 5a connecting the injection nozzle 5 to the fuel tank 12, connected to the fuel pump 1 by the make-up line 17. In addition, the compression brake includes a pneumatic line 18, which includes a receiver 19, a control valve 9, an air distributor 4 and a combination valve 14. The control valve 9 is also connected to a distribution device PTO 6 using power line 11.

The combination valve 14 comprises an actuating cylinder 24 (FIG. 2), in which a piston 21 with a spring 34 is mounted; exhaust valve body 30 with exhaust valve 32, spring 35 and differential valve 33; an intake valve body 28 connected to a pneumatic line 18 (FIG. 1) and comprising an intake valve 26 (FIG. 2) with a spring 29; the housing of the additional valve 23, connected with the cavity of the actuating cylinder 24 and the discharge line 8 (Fig. 1), and containing the spool of the additional valve 25 (Fig. 2) with a spring 20. In addition, an air outlet 31 is made in the body of the exhaust valve 30 from cylinder 13 (FIG. 1) to the exhaust pipe, and in the actuating cylinder 24 (FIG. 2), an opening 36 is made for supplying fuel from the fuel pump 1 (FIG. 1).

Compression brake operates as follows.

When the pedal 9a is pressed from the control valve 9 via the power line 11, a control signal is supplied to the switchgear 6, which closes the fuel path from the fuel pump 1 through the control line Za to the injection nozzle 5 and connects the control line 3a to the line 3b leading to the combination master cylinder valve 14. Fuel from the fuel pump 1 at the end of the compression stroke, approximately 20-30 ° to the top dead center, through the switchgear 6, the check valve 7, the control line 3 enters the actuator dr 24 (figure 2) of the combined valve 14 (figure 1) and acts on the piston 21 (figure 2), which opens the exhaust valve 32. The compressed air in the cylinder exits through the open exhaust valve 32 and the outlet 31 in the housing of the exhaust valve 30 into the channel a connected to the exhaust pipe. During the expansion, exhaust and intake strokes, the exhaust valve 32 of the combination valve 14 remains open, since the fuel is locked in the actuating cylinder 24 under pressure by the check valve 7 (FIG. 1) and the spool of the auxiliary valve 25 (FIG. 2).

Also, when you press the pedal 9a, the control valve 9 closes the air line to the atmosphere and connects it to the receiver 19. At the beginning of the compression stroke, the air from the receiver 19 passes through the control valve 9 to the air distributor 4, and then through the inlet 27 (Fig. 2 ), the inlet valve 29, the differential valve 33, and the exhaust valve 32 of the combination valve 14 are supplied to the engine cylinder. When air is supplied, the differential valve 33 also closes the outlet opening 31 in the body of the exhaust valve 30, preventing intake air from entering the exhaust pipe. Simultaneously with the air supply to the cylinder, under the pressure of the air, the additional valve 25 spool moves, which communicates the cavity of the actuator cylinder 24 with the exhaust line 8 (Fig. 1), dropping the fuel in the actuator cylinder under pressure through the leak line 5a to the fuel tank 12. After the end of the air supply, the exhaust valve 32 closes under the action of the spring 35, and the spool of the additional valve 25 blocks the message of the cavity of the actuating cylinder 24 with the discharge line 8 under the action of the spring 20.

Next, the cycle repeats.

With an increase in the initial compression pressure due to the inlet of additional air into the cylinder, the resistance to upward movement of the piston increases, and hence the braking torque on the crankshaft of the engine.

Using the control valve 9, the amount of air supplied to the engine cylinder changes depending on the amount of pressing the pedal 9a. This allows you to adjust the braking torque. When braking stops, the fuel from the actuator cylinder 24 of the combination valve 14 is discharged to the leak line 5a due to the fact that the control valve 9 switches off the electric signal to the switchgear 6 before the air supply to the inlet 27 of the combination valve 14 stops.

Claims (1)

Compression brake for internal combustion engines of trucks, comprising an exhaust valve mounted in the cylinder head of the engine with an actuator to ensure that the exhaust valve is kept open at the compression stroke in the top dead center region, made in the form of an actuating cylinder, and connected to the latter via a source control line pressure, made in the form of a standard fuel pump, the compression brake is equipped with an additional control element of the standard fuel pump a wasp connected to the injection line, and the fuel pump control is made in the form of a switchgear with one input and two outputs, the input of the latter being connected to the fuel pump, and the outputs to the actuator cylinder and the injection nozzle, respectively, the brake is equipped with a check valve included between the fuel pump and the actuator cylinder, an additional valve with a control input connected between the actuator cylinder and the fuel tank, and to the line connecting the additional valve to the fuel in the other tank, an injection nozzle drain is connected, characterized in that the additional valve is connected via a pressure line to a pneumatic line including a receiver, a control valve, an air distributor and an inlet valve, while the control valve is electrically connected to a distribution device, pneumatically through an air distributor and an inlet pipe valve and pneumatically through the pipeline with the receiver.

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