JPS63302151A - Turbine type brake - Google Patents

Abstract

PURPOSE:To cause the turbine of an air compressor to consume crankshaft energy and obtain an auxiliary brake without necessity of cooling and troublesome adjustment by connecting the turbine to the crankshaft of an internal combustion engine and providing a throttle part at the delivery port of the air compressor. CONSTITUTION:The turbine 4 of an air compressor 3 as an auxiliary for a main brake is connected to the crankshaft 2 of an internal combustion engine 1. Also, the output shaft 5 of the crankshaft 2 is connected to a wheel power transmission shaft 6 and fitted with an increasing gear 7. Furthermore, the input shaft 8 of the turbine 4 is molded monolithically with the output shaft 9 of the increasing gear 7. On the other hand, the air compressor 3 is so constituted as to have a delivery port 13 in the radial outward direction of an impeller 10 in a casing 11 and a throttle part 14 and a valve 15 for adjusting the opening area thereof at the delivery port 13. And whenever necessary, a switch 21 is turned ON and a driving means 16 is operated, thereby driving the valve 15 and opening the delivery port 13. According to the aforesaid system, braking power working on the crankshaft 2 is augmented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a turbine type brake, and more particularly to a turbine type brake provided with an air compressor for deceleration braking.

[Prior Art] Generally, in vehicles such as large buses and trucks in which a large amount of heat is converted due to one movement of a friction wheel, a device (deceleration brake) to assist the main brake is required. Conventionally, this heel deceleration brake drives an internal combustion engine or a rotating resistor from the input side, that is, from the wheel side, causing resistance losses.
It was starting to gain braking power.

Among deceleration brakes that utilize rotational resistors, fluid-type and electric-type retarders are widely known and have been put into practical use.

As shown in FIG. 4, the fluid retarder a is provided in the middle of a power transmission shaft d that connects the internal combustion engine and the wheels C.
Rotor fixed on the output side.

A fluid (water, water,
It causes a thin flow of oil (oil, etc.) and converts the absorbed energy into heat. This fluid is circulated while being cooled by a heat exchanger provided in the fluid tank g. Further, the braking force is adjusted by adjusting the flow rate of the fluid using the valve i.

In addition, an electric retarder rotates a rotor similar to the one described above between electromagnets, and dissipates the eddy current generated when metal moves in a magnetic field in the form of ohmic heat.

[Problems to be Solved by the Invention] By the way, in the above retarder, the torque on the output side is ultimately converted into thermal energy, and that amount becomes braking energy, so in order to increase braking efficiency, In this case, a device for cooling the working medium (fluid or rotating resistor) is essential, which poses a major problem in terms of space and cost.

Meanwhile, the present inventors were developing a "turbo compound engine" that recovers exhaust gas and makes effective use of it.

As shown in Fig. 5, this system supplies high-temperature exhaust gas to a turbine t of a supercharger installed in an internal combustion engine j to increase its efficiency, and also connects a crankshaft m downstream of the turbine t. The idea was to increase the engine braking force by using the power required for this drive as a braking force.

According to this proposal, since the cooling devices (g, h) are not required, the above-mentioned problem is solved to some extent. However, since it is a turbine that uses exhaust gas, there is a natural limit to its braking power.

In view of the above circumstances, the present invention was devised as a turbine brake in order to provide a deceleration brake that does not require a cooling device and can provide a desired braking force.

[Means for Solving the Problems 1] The present invention is such that a turbine of an air compressor is connected to the crankshaft of an internal combustion engine, and a throttle portion is provided at the discharge port of the turbine.

[Operation] When the crankshaft rotates and the turbine of the air compressor is driven, energy corresponding to its characteristics is consumed, and a force that brakes the operation of the internal combustion engine is generated, acting as a deceleration brake. The throttle part adjusts the discharge amount of the air compressor to generate a desired braking force.

[Example] Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a turbine type brake according to the present invention.
Air compressor 3 to assist the main brake (not shown)
The turbines 4 are connected to each other.

The output shaft 5 of the crankshaft 2 is connected to a power transmission shaft 6 for driving wheels (not shown), and has a speed increasing gear 7 for a turbine type brake formed at a predetermined gear ratio. ing. The input shaft 8 of the turbine 4 is formed integrally with the output shaft 9 of the speed increasing gear 7, and is connected to the crankshaft 2 via the gear 7.

As shown in FIG. 2, the air compressor 3 includes an impeller 10,
It consists of a casing 11 for accommodating this. A suction port 12 is formed in the casing 11 on the axially outer side of the input shaft 8 , and a discharge port 13 is formed on the radially outer side of the impeller 10 . In this embodiment, the discharge port 13 is provided with a constriction portion 14 for obtaining a predetermined air flow rate. A valve body 15 is provided so as to be rotatable around a rotation shaft provided therein. The valve body 15 is designed to have a maximum area when it is parallel to the discharge direction B (open) and a minimum area when it is rotated substantially across the discharge direction (closed). It is possible to enlarge and reduce.

The valve body 15 is provided with a moving means 16, as shown in FIG. 1 above. The driving means 16 includes an air cylinder 17 having a biasing force so that the valve body 15 rotates to minimize the area, and an air tank 18 for storing compressed air having a pressure exceeding the biasing force in the cylinder 17.
It is formed by a solenoid valve 20 provided in the middle of a supply path 19 that communicates the air tank 18 and the air cylinder 17, and a switch 21 for opening and closing the solenoid valve 20.

The switch 21 consists of a neutral switch 22, a clutch switch 23, and a turbine brake switch 24, which are connected in series so that the solenoid valve 20 is opened when all of them are set to rONJ. The neutral switch 22 is set to "oN" when the transmission (not shown) is in a position other than the neutral position, and the clutch switch 23 is set to "oN" when a clutch (not shown) for turning on and off the wheel drive is engaged. It is formed to be.

Next, the operation of this embodiment will be explained.

During normal operation, when the crankshaft 2 of the internal combustion engine 1 is rotated, the speed increasing gear 7 increases the rotation speed appropriately.
Turbine 4 is driven.

At this time, the valve body 15 is rotated toward the closing side by the air cylinder 17, and the area A of the discharge port 13 is formed to be the minimum. Then, the force for driving the air compressor 3, that is, the braking force of the turbine brake, is also minimized, and the operation of the internal combustion engine 1 is not affected.

When braking force to supplement the main brake is required before stopping or on a long downhill slope, turn the switch 21 of the solenoid valve 20 on.
At this time, the engine brake is applied. When the solenoid valve 20 is opened, the air cylinder 17 is pushed by compressed air to rotate the valve body 15 toward the opening side against the urging force, and the discharge port 13
is opened to a predetermined area A. The force acting on the crankshaft 2 is now at its maximum, generating a braking force on the internal combustion engine 1 and decelerating it.

In this way, by giving kinetic energy to the air as a working medium, the braking force, which is the energy consumed by this, is obtained, so that the deceleration brake can be applied simply by raking the valve body 15 of the throttle part 14. can be obtained freely.

The present inventors conducted an experiment regarding the relationship between the area A of the constricted portion 14 and the III power in accordance with the configuration of this embodiment. In the turbine type brake, C: Constant pressure proportional heat of air G: Air flow rate■o2 Atmospheric temperature P. Quantity Atmospheric pressure P: Compression pressure by the air compressor: Specific heat ratio a: Constant Y: Efficiency of the air compressor, that is, if other conditions remain the same, change the area A of the throttle section 14 (airflow fL G ) as appropriate. It is possible to control the braking force F by . An example of this relationship is shown in Figure 3. Based on the relationship shown by the solid line C in Figure 3, the area A of the discharge port 13 (throttled portion 14) should be formed so as to obtain the desired braking force F. The figure also shows a case where a throttle valve is provided on the suction port 12 side and its area is changed (broken line D), but in this case, when compared with the same throttle area A, Since the braking force obtained is smaller than when provided at the discharge port 13, it has been found that it is more advantageous to provide the constriction portion 14 at the discharge port 13 as shown in this embodiment.

[Effects of the Invention] In summary, according to the present invention, the following excellent effects are achieved.

Instead of the retarder conventionally used as a deceleration brake, the air compressor's turbine is connected to the crankshaft, eliminating the need for a device to cool the working medium, saving space and reducing costs for the deceleration brake. be done.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the turbine type brake according to the present invention, Fig. 2 is a side sectional view showing the air compressor thereof, and Fig. 3 is a diagram showing the aperture area for explaining its operation. - Braking force relationship diagram; FIG. 4 is a configuration diagram showing a hydraulic retarder, which is a conventional deceleration brake; FIG. 5 is a system diagram of a turbo compound engine. In the figure, ■ is an internal combustion engine, 2 is a crankshaft, 3 is an air compressor, and 4 is its turbine.

Claims (3)

[Claims] (1) A turbine-type brake characterized in that a turbine of an air compressor is connected to the crankshaft of an internal combustion engine, and a throttle portion is provided at the discharge port of the air compressor. (2) The turbine brake according to claim 1, wherein the throttle portion has a valve body for enlarging/reducing the opening area of the discharge port. (3) The turbine of the air compressor has a connecting shaft for connecting with the crankshaft, and a speed change gear is interposed on the connecting shaft. Turbine brake.