JPS5844038Y2 - Pressure booster for two-system master cylinder - Google Patents

Description

[Detailed explanation of the invention] Explanation of the gist This invention is a device related to a pressure booster attached to a two-system mask cylinder for automobiles. A pair of two-stage cylinders are provided for each system, and a second-stage piston fitted in each of the pair of two-stage cylinders and a machining formed on the large diameter side end surface of the second-stage cylinder are provided. The pressure chambers and the sub-pressure chambers formed between the mutual step parts of the second-stage cylinder and the second-stage piston are connected to each other, and the pressurizing chambers are connected to the pressure chamber of the mask cylinder at the small-diameter end of the second-stage cylinder. The pressurized chamber of the part is connected to the brake cylinder, and in the event of failure of the first system, the other system can increase the hydraulic pressure sent to cover the braking force.This is a two-system mask cylinder pressure booster. It is an idea.

Prior Art-9: A two-system brake mask cylinder is used for automobiles, and the front and rear brake cylinders are operated separately for each system.

However, with conventional two-system mask cylinders, if one system becomes inoperable due to an accidental brake oil leak, only the other system will be braked, so for example, with a tandem master cylinder, the braking force is normally It's four o'clock,
Therefore, in order to obtain the desired braking force, it is necessary to extremely increase the pedal depression force, which has the disadvantage of interfering with safe driving.

Purpose of the invention The purpose of this invention is to solve the technical problem of the brake circuit due to the two-system mask cylinder based on the above-mentioned conventional technology. It is an object of the present invention to provide an excellent pressure increase device for a two-system mask cylinder that can be secured and is beneficial to the field of brake application in the automobile industry.

Structure of the invention In order to solve the above-mentioned problems, the structure of this invention, which is based on the above-mentioned purpose and the scope of the above-mentioned utility model registration claims, is such that during normal operation, the hydraulic pressure generated in the hydraulic chamber of the mask cylinder when the brake pedal is depressed is For each system, the air passes through the sub-pressure chambers formed at the mutual stepped portions of one two-stage cylinder and the two-stage piston fitted thereto, and reaches the pressurizing chamber at one end of the other two-stage cylinder. , without moving the second-stage piston, the pressure is transmitted from the pressurizing chamber to the brake cylinder through the passage and the pressurized chamber at the other end of the second-stage cylinder, and the hydraulic pressure generated in the hydraulic chamber of the mask cylinder is increased. The brake cylinder operates the brake without being activated, and when the brake pedal is depressed with the hydraulic circuit of the first system being defective, hydraulic pressure is generated only in the hydraulic chamber of the first system, so that one of the two stages is The balance between the pressurized chamber and the auxiliary pressure chamber of the cylinder is affected by the brake pedal force as the second stage piston moves toward the pressurized chamber and the passage to the pressurized chamber is closed. The bending force is a technical measure in which sufficient braking force is obtained by operating the brake cylinder with the increased pressure that is increased in the pressurized chamber.

Embodiment - Configuration Next, one embodiment of this invention will be described below based on the drawings.

In Fig. 1, (1) is a two-system mask cylinder pressure booster that describes the gist of this invention, and (2) is a well-known two-system tandem master cylinder, and (3, 4) are the front side,
This is a well-known brake cylinder in a rear brake device.

In the pressure booster 1, the casing 5 forms a pair of two-stage cylinders 6 and 7 having the same shape and opposite directions, and the two-stage pistons 8 and 9 each have a diameter of the cylinder 6.7. D10
Seal 10.10 on the large diameter part and the small diameter part of diameter D2.
It is urged toward the larger diameter side by the elastic action of each elastic spring 13゜1 installed in the auxiliary pressure chamber 11. It is provided.

Also, inside the two-stage piston 8.9, there is a passage 1 in the axial direction.
4.14' is drilled and the passageway 14.14' allows the passage 14.14' to
Pressurizing chamber 15 formed on the large diameter side end surface of stage piston 8.9
．． 16 and pressurized chambers 17 and 18 formed on the small diameter side end surface are in communication.

In addition, in the pressurizing chamber 15.16, the large-diameter end surface of the two-stage piston 8.9 abuts against the bottom surface of the cylinder via the protruding foot 19.19', and the piston in the pressurizing chamber 15.16 The pressurizing area is arranged to cover approximately the entire diameter D1.

L20.21 is a poppet valve as a check valve, and an elastic spring 22 is installed at the large diameter end of the passages 14 and 14'.
．． 23, the end of which is connected to the pressurizing chamber 15.
．． 16, that is, the valve opens when the second stage piston 8.9 moves to the large diameter side as shown in the figure, and closes when the second stage piston 8.9 moves to the small diameter side. There is.

24.25 is a communication passage, which connects one pressurizing chamber 16 and the other auxiliary pressure chamber 11 in the above-mentioned l pair of two-stage cylinders 6.7.
．． The pressurizing chamber 15 on one side and the sub-pressure chamber 12 on the other side are interconnected.

Furthermore, inlet ports 26 and 27 are provided in each of the secondary pressure chambers 11 and 12, and one inlet port 26 is connected to the tandem master cylinder 2 through a pipe 28.
The inlet port 27 of the other side is also communicated with the other hydraulic chamber 31 via the piping 30.

In addition, 32 and 33 are pistons and tandem master cylinder 2
Further, 34.35 is an elastic spring for urging the piston 32.33 to return, 36 is a bushing rod, which has a brake pedal 37, and 38
is an oil reservoir tank located above the tandem master cylinder 2.

Further, reference numeral 38.39 is an outlet boat, which is opened in the pressurized chamber 17.1B and connected to the brake cylinder 3.4 via a pipe 40.41.

Embodiment - Operation In the above-described configuration, during normal operation, that is, when braking is performed in a state where there is no oil leakage or the like in each of the two piping systems, when the brake pedal 37 is depressed, the bushing rod 36 The piston 32 and piston 33 of the tandem master cylinder 2 are pushed,
Braking pressure is generated in the hydraulic chamber 29°31.

The hydraulic pressure generated in the hydraulic chamber 29 of one of the tandem master cylinders 2 by the above-mentioned braking operation flows from the piping 28 through the inlet port 26 into the auxiliary pressure chamber 11 of one of the two-stage cylinders 6, and further passes through the communication passage. 24 through the other 2
The hydraulic pressure that is led out to the pressurizing chamber 16 of the stage cylinder 7 and generated in the other hydraulic chamber 31 of the tandem mask cylinder 2 is also passed through the auxiliary pressure chamber 12 of the second stage cylinder 7 via the piping 30 to the communication passage. 25 is led out into the pressurizing chamber 15 of the two-stage cylinder 6.

Therefore, when focusing on one of the two-stage cylinders 6, the secondary pressure chamber 1
The hydraulic pressure generated in the hydraulic chamber 29 in the mask cylinder 2 introduced into the mask cylinder 2 together with the elastic force of the spring 130 [presses the second stage piston 8 toward the larger diameter side, and the pressing force is applied to the mask introduced into the pressurizing chamber 15. The pressing force of the elastic spring 13 is set to be larger than the pressing force in the small diameter side direction due to the hydraulic pressure generated in the hydraulic chamber 31 in the cylinder 2.

As a result, the second stage piston 8 is brought to its initial position at the dead center on the large diameter side as shown in FIG. The hydraulic pressure generated in the hydraulic chamber 31 introduced into the pressurized chamber 15 for valve operation flows from the poppet valve 20 through the passage 14 as shown by the dotted line, passes through the pressurized chamber 17, and is transferred to the outlet port 3.
8 and piping 40 also reach the brake cylinder 4 to operate the rear brake in a predetermined manner.

On the other hand, the second-stage cylinder 7 side is also in a similar operating state, and the hydraulic pressure generated in the hydraulic chamber 29 introduced into the pressurizing chamber 16 passes through the poppet valve 21 and reaches the pressurized chamber 18 from the passage 14'. Cylinder 3 is reached and the front brake is operated in a predetermined manner.

In other words, under normal conditions, the balance between the hydraulic pressures of the two systems
The step piston 8.9 does not move substantially, so that the hydraulic pressure generated in the hydraulic chamber 29.31 is used for the braking action of each brake cylinder 3.4 without being amplified.

Next, we will explain the operation when one system is unexpectedly damaged and only the other system is left, based on Figure 2. Let us now assume that an oil leak, etc. has occurred accidentally in one of the □ piping 28 systems. Then, of course, the brake pedal 37
When the pedal is depressed, hydraulic pressure is generated only on the hydraulic chamber 31 side and not on the hydraulic chamber 29 side.

As a result, in the second stage cylinder 6.7, the inside of the secondary pressure chamber 11 in the second stage cylinder 6 and the other second stage cylinder 6.
Since the oil pressure in the pressurizing chamber 16 becomes zero due to the loss of each piping system 28, one of the two-stage pistons 9 maintains a stationary state without operating.

Further, the hydraulic pressure generated in the hydraulic chamber 31 passes through the piping 30, one of the auxiliary pressure chambers 12, and the communication passage 25, and reaches the pressurizing chamber 15 of the second-stage cylinder 6.

In the second-stage cylinder 6, the pressure force on the large-diameter side toward the second-stage piston 8 is only the elastic force of the elastic spring 13, so the hydraulic pressure introduced into the pressurizing chamber 15 is at the initial stage of brake operation. At this point, the elastic force of the elastic spring 13 is overcome and the two-stage piston 8 is moved to the smaller diameter side.

As a result, as shown in FIG. 2, the poppet valve 20 opens immediately due to the elastic pressure of the elastic spring 22, and from then on, the hydraulic pressure in the pressurizing chamber 15 presses the second stage piston 8 toward the small diameter side with the entire surface of the large diameter side of the cylinder. Therefore, on the pressure chamber 17 side, the oil pressure is (D1/D2) according to Pascal's principle.
)2, and the braking force applied to the rear brake by the brake cylinder 4 is also increased.

That is, even if a failure occurs in one hydraulic system, an increased braking force will be generated in the other operable brake cylinder with the same brake depression force.

In addition, contrary to the above-mentioned case, even if a defect such as an oil leak occurs on the hydraulic chamber 31 side, the pressure increase operation is performed in the same way on the second stage cylinder 7 side, and the front brake of the brake cylinder 3 is increased. Pressure action is applied.

The embodiments of this invention are not limited to the above-mentioned embodiments, and various other embodiments can be adopted. For example, the passage 14
．． Of course, the mask cylinder 14' may be bored inside the casing 5 without being bored inside the two-stage piston 8.9, and the mask cylinder may be of a type other than the tandem type.

Effects of the invention As described above, according to this invention, a pair of two-stage cylinders are interconnected in a pressure booster for a two-system mask cylinder that is interposed between the hydraulic chamber of the two-system mask cylinder and the brake cylinder. However, during normal operation, the two-stage piston is balanced, and if one hydraulic system is damaged, a pair of two-stage pistons are
Since only one of the stage pistons forms a pressure booster piston, even if one of the oil supply systems of the two mask cylinders is damaged, the normal oil supply system of the other system is amplified, so the same brake pedal force is applied. The braking force of the brake mechanism on the normal side is immediately increased to cover the defective side, which has the excellent effect of ensuring safe driving in the same way as when normal.

Further, since the structure is simple, small and lightweight, there is an advantage that a self-recovery type brake oil supply system can be formed by simply installing it alongside the tandem master cylinder.

Thus, the stepped portion of the two-stage cylinder and the stepped portion of the two-stage piston fitted therein form an auxiliary pressure chamber, which has the effect of allowing an elastic spring to be interposed therein.

In addition, the small diameter pressurized chamber at one end of the two-stage cylinder and the pressurized chamber at the large diameter section at the other end are connected via a passage with a check valve, so that during normal operation, the front side, Hydraulic pressure is transmitted to the rear side, and when one side is defective, the check valve prevents the second-stage piston from operating, and the other two-stage piston is pressurized by the pressure difference across the stepped portion to operate the brake. effect is produced.

[Brief explanation of drawings]

The drawings are explanatory diagrams of one embodiment of this invention, and FIG. 1 is a partial sectional view illustrating the entire brake system, and FIG. 2 is a sectional view illustrating the operation when the I system is defective. 2...2 system master cylinder, 29.31...
...Hydraulic chamber, 3.4...Brake cylinder, 6.7...Two-stage cylinder, 8.9...
・Two-stage piston, 13゜13'... Resilience spring, 15.16... Pressure chamber, 17.18...
... Pressure chamber, 20.21 ... Valve, 14゜1
4'... Passage, 11.12... Sub-pressure chamber, 24.25... Communication passage, 1... Pressure increase device.

Claims (1)

[Scope of utility model registration request] In a pressure booster for a two-system mask cylinder interposed between a hydraulic chamber of a two-system mask cylinder and a flake cylinder, each of a pair of two-stage cylinders has a stepped portion in the middle. A two-stage piston is fitted, and a pressurized chamber is formed on the large-diameter end face of each second-stage piston and two-stage cylinder, and a pressurized chamber is formed on the small-diameter end face of each second-stage piston and two-stage cylinder. A passage connecting the two-stage piston with the chamber is provided through the second-stage piston, and a check valve is provided on the pressurizing chamber side of the passage via an elastic spring. The pressurizing chamber at the end of one two-stage cylinder, the sub-pressure chamber formed by the step of the other two-stage cylinder, and the step of the second-stage piston are in communication with each other, and each of the above-mentioned pressurizing chambers is A pressure increase device for a two-system mask cylinder, characterized in that the pressure chamber is connected to the hydraulic chamber of the mask cylinder via an auxiliary pressure chamber, and the pressurized chamber is connected to the brake cylinder, respectively.