JP2013132999A - Brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automobile brake device which assists braking power by supplying negative pressure to a brake booster.SOLUTION: In a brake device, a negative pressure generating device is disposed in a cooling water flow passage. The negative pressure generating device generates a negative pressure area by increasing a flow velocity. Furthermore, the negative pressure area and brake booster are communicated with each other. Moreover, in the brake device, a gas/liquid separation means can be formed in a flow passage from the negative pressure generating device to a cooling target portion.

Description

The present invention relates to a brake device that can provide negative pressure to a brake booster of an automobile without using a vacuum pump.

In the automobile brake device, a vacuum booster type brake booster is used to assist the driver's brake pedal depression force. For example, in a gasoline engine vehicle, negative pressure is supplied to a brake booster using intake negative pressure of the engine (see, for example, Japanese Patent Application Laid-Open No. 2007-303346).

On the other hand, in an electric vehicle, the intake negative pressure of the engine cannot be used, and in order to supply the negative pressure to the brake booster, it is necessary to separately mount an electrically driven vacuum pump (for example, JP-A-5-338528). Gazette), the number of parts and the cost increase.

In the case of a hybrid vehicle or an idle stop vehicle, the intake negative pressure of the engine can be used for the brake booster, but the brake negative pressure may be insufficient while the engine is stopped. Therefore, in such a case, it is necessary to restart the engine in order to ensure the brake negative pressure. Specifically, when the engine is stopped during traveling, the engine is restarted when the brake is strongly depressed or the brake is depressed many times. In such a case, the engine stop time cannot be ensured and the fuel efficiency is affected.

JP 2007-303346 A JP-A-5-338528

The present invention was created in view of the above circumstances, and an object thereof is to provide a brake device capable of supplying negative pressure to a brake booster without using a separate vacuum pump.

In order to achieve the above object, the present invention provides an automobile brake device that assists braking force by supplying negative pressure to a brake booster, and increases the flow velocity in the flow path of the cooling water to reduce the negative pressure region. A brake device is provided, characterized in that a negative pressure generating device for generating the pressure is disposed, and the negative pressure region and the brake booster are in communication.

According to the brake device of the present invention, since the negative pressure generating device is provided by using the existing cooling water circulation system as it is, even in an electric vehicle, the brake booster can be provided without providing a vacuum pump. Negative pressure can be supplied. Therefore, it is possible to achieve cost reduction, weight reduction, and power saving of the brake device.

Moreover, in this brake device, the engine stop time can be extended in the idle stop vehicle, and the fuel efficiency can be improved. This is because according to this brake device, the engine is not restarted due to insufficient negative pressure even in an idle stop vehicle.

Further, providing an external EGR that uses exhaust gas again for intake in a gasoline engine vehicle is disadvantageous for securing the intake negative pressure of the engine. However, if this brake device is used, it is advantageous because the intake negative pressure is not used.

Moreover, it is preferable that this brake device forms a gas-liquid separation means on the flow path from the said negative pressure generator to a cooling object site | part.

According to this brake device, the gas mixed in the cooling water can be removed from the flow path to the portion to be cooled with the cooling water by the gas-liquid separation means (reservoir tank).

The brake device of the present invention can provide negative pressure to the brake booster by using an existing cooling water circulation system without using a vacuum pump. Therefore, this brake device can provide negative pressure to the brake booster at low cost, light weight, and power saving.

(A) is a system diagram of a cooling water circulation system showing the brake device 10 of the present invention and its peripheral devices in an automobile, and (b) is a system diagram of an existing cooling water circulation system (vacuum pump). Is not mentioned). It is an enlarged view from the negative pressure generator in FIG. 1 (a) to a brake booster. One specific configuration example for forming the nozzle 11a and the diffuser 11b is shown.

Then, the brake device concerning one embodiment of the present invention is explained in detail, referring to drawings.

FIG. 1 shows a system diagram of a cooling water circulation system showing a brake device 10 of the present invention and its peripheral devices in (a) of an automobile, and (b) shows an existing cooling water circulation system. A system diagram (not referring to the vacuum pump) is shown.

First, as can be seen from FIG. 1B, an automobile is generally provided with a cooling water circulation system, and this circulation system circulates the cooling water by a water pump 15 using a condenser 19 as a power source. Then, the radiator 18 passes through a portion to be cooled such as an engine (not shown) and the temperature of the cooling water is increased. In addition, a reserve tank 17 is connected to the circulation system, and water can be poured from the upper opening 17a when the cooling water in the circulation system is reduced. The reserve tank 17 also has a role of venting air mixed inside before circulating to the part to be cooled. Furthermore, if regenerative energy is used for the power of the water pump 15, power can be saved.

Next, as shown to Fig.1 (a), it turns out that this brake device 1 is added as it is to the circulation system of the cooling water of Fig.1 (a). As will be described in detail later, in the brake device 1, a negative pressure generator 11 is generally provided in the flow path of the cooling water, and the negative pressure generator 11 supplies a negative pressure to the brake booster 12. A check valve 13 is provided in the flow path between the negative pressure generator 11 and the brake booster 12.

In addition, when the cooling water always passes through the negative pressure generator 11, useless pressure loss occurs when the negative pressure is unnecessary. In order to prevent this, in the brake device 1, for example, a bypass flow channel 16 is provided so that cooling water flows in the negative pressure generator 11 only when a predetermined condition is satisfied, and otherwise flows in a normal flow channel. Yes. This switching of the flow path is performed by the switching valve 14. Specifically, for example, a negative pressure threshold value that can be determined to be insufficient for the negative pressure to the brake booster 12 is set, and the normal cooling water flow path and the bypass flow path are switched at this threshold value. As a result, the negative pressure can be supplied by the negative pressure generator 11 only when the negative pressure is required. Since the brake booster 12 has a negative pressure switch that activates the water pump 15 when the brake negative pressure is insufficient as an existing facility, the electrical signal of the negative pressure switch is also used for the switching valve 14. .

FIG. 2 shows the details from the negative pressure generator 11 to the brake booster 12 in FIG. The negative pressure generator 11 has a nozzle 11a and a diffuser 11b arranged side by side from upstream to downstream in a flow path in the pipe. As indicated by an arrow X on the left side of the drawing, the cooling water is discharged from the tip of the nozzle 11a from the large upstream flow area by the tapered nozzle 11a. At this time, the flow velocity increases in inverse proportion to the distribution area. And the discharged | emitted cooling water flows in into the diffuser 11b again. The diffuser 11b has a configuration in which the flow area increases toward the downstream. That is, as indicated by an arrow X on the right side of the page, the flow rate of the cooling water decreases as it travels through the diffuser 11b, and returns to the flow rate before entering the negative pressure generator 11.

Further, an opening 11c for fluidly connecting to the lower pipe 20 is provided in the lower part of the flow path between the nozzle 11a and the diffuser 11b. The negative pressure generator 11 can supply the negative pressure of the air flow upward (see arrow Y) into the pipe 20 through the opening 11c. The negative pressure increases as the flow velocity increases. If the gap 11d outside the nozzle 11a and the diffuser 11b (see the shaded area) is large in the pipe, the leakage of cooling water may increase and the generation of negative pressure may be slightly delayed. May be filled.

The pipe 13 between the negative pressure generator 11 and the brake booster 12 is provided with a check valve 13 on its path. With this check valve 13, even if the flow of the cooling water becomes weak and the cooling water flows down through the pipe 20, leakage to the brake booster can be blocked.

FIG. 3 shows one specific configuration example for forming the nozzle 11a and the diffuser 11b. A nozzle 11a is formed downstream of the pipe 11h (on the right side of the drawing), and a thread (male thread) is formed on the outer periphery upstream thereof. On the other hand, the pipe 11i is formed with a thread groove 11g in the order of the inner wall from the upstream side, and then a spacer 11f that is in the same state as a normal pipe inner wall for a predetermined distance, from which a diffuser 11b is formed. . Then, the pipe 11h and the pipe 11i are positioned on the same axis X, and are inserted into the pipe 11i in a nested manner while rotating the tip of the nozzle 11a. At this time, the thread 11e of the pipe 11f and the thread groove 11g of the pipe 11i are coupled, and the distance between the nozzle 11a and the diffuser 11b is adjusted by advancing or retreating the thread coupling of both the pipes 11h and 11i as indicated by arrows. To do.

As mentioned above, although the embodiment and the concept of the brake device of the present invention have been described, the present invention is not limited to this and is within the scope not departing from the spirit and teaching described in the claims and the description. Those skilled in the art will understand that variations and improvements of the above are obtained.

DESCRIPTION OF SYMBOLS 10 Brake apparatus 11 Negative pressure generator 12 Brake booster 13 Check valve 14 Switching valve 15 Water pump 16 Bypass flow path 17 Reserve tank 18 Cooling apparatus 20 Piping

Claims (2)

In automobile brake devices that assist braking force by supplying negative pressure to the brake booster,
A negative pressure generator that generates a negative pressure region by increasing the flow velocity in the flow path of the cooling water is disposed,
The brake device, wherein the negative pressure region and the brake booster communicate with each other. The brake device according to claim 1, wherein gas-liquid separation means is formed in a flow path from the negative pressure generating device to a portion to be cooled.