JPS6318537B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake system for automobiles, particularly trucks, crane trucks, mixer trucks, and the like.

In recent years, the brake system of this type of automobile has been modified so that the fluid-operated service brake, which is normally used for braking while driving, can also be used as a parking brake when parking or stopping the vehicle. In addition to the braking force obtained by the parking brake, whose original purpose is to park and stop the vehicle, the system also puts the fluid-operated service brake into a braking state so that it can assist in braking the parking brake. Various methods have been proposed to maintain safety and improve safety during work.

Generally speaking, most of the fluid-operated service brakes in the brake system of such automobiles are equipped with a solenoid valve in the fluid piping system immediately after the brake operating device of the fluid-operated service brake. The valve is connected in series with the main switch and the brake lock switch,
Furthermore, the main switch and brake lock switch were integrated into a control box and placed in the cab of the car.

That is, the fluid-operated service brake was placed in a state where it could be independently locked into a braking state by operating the main switch and the brake lock switch, regardless of braking by the parking brake.

However, considering the safety of work when parking and stopping the vehicle, it is necessary to use the fluid-operated service brake while the parking brake, whose original purpose is to park and stop the vehicle, has sufficient braking force. It is desirable to be able to lock the brake in the applied state and assist in braking the parking brake; therefore, as described above, locking the applied state of the fluid-operated service brake may be accomplished independently. If possible,
There is a possibility that only the fluid-operated service brake is used when the vehicle is parked and stopped, and the braking effect of the parking brake may not be exerted, and the vehicle may be operated in an insufficiently braking state. It was hot.

In addition, those that use a fluid-operated service brake on the condition that the parking brake has a predetermined brake operating force are
- According to Publication No. 427, and a hydraulic service brake is used together with the closing operation of the brake lock switch of the parking brake, and,
If the oil pressure drops below the set value when used in combination, the one that compensates for the drop in oil pressure is
These are disclosed in Publication No. 39942, but when the operating load detection switch or brake lock switch fails, or when the service brake is used in conjunction with the parking brake, the solenoid valve If a circuit switch inserted into an electrical circuit is operated incorrectly, the service
The brakes will no longer be locked in the braking state, which poses a safety risk, and the relay valve may need to be replaced with air.
A solenoid valve is placed in the auxiliary piping connected to the tank, and the air service brake is placed in a braking state when the vessel is lowered, as disclosed in Japanese Utility Model Publication No. 51-45783. However, if the circuit switch was operated incorrectly, the braking state would be released, creating a safety issue.

An object of the present invention is to make it possible to lock a fluid-operated service brake in a braking state when a predetermined operating force is applied to the parking brake and sufficient braking force for the parking brake is obtained, and to prevent damage caused by erroneous operation. The use of only fluid-operated service brakes is avoided and, in such conditions, when the parking service operating switch is energized, the service brake is capable of being locked into a braking state, and so on. Even if either the sensor or the switch fails after the service brake is locked in the braking state, the service brake can be maintained in the braking state, and the braking state during parking and stopping can be maintained. Our goal is to provide an automobile brake system that makes work more reliable and increases work safety.

Hereinafter, preferred specific examples of the automobile brake system according to the present invention will be described with reference to the drawings.

FIG. 1 schematically shows a brake system 10 for a motor vehicle according to the invention, which is applied to a cab-over type truck.

The brake system 10 of the automobile includes an oil service brake 11 having a brake control pipe 26 and a brake control auxiliary pipe 27, a parking brake 30, and its oil service brake.
A solenoid valve 37 provided in the brake control auxiliary piping 27 of the brake 11, a main switch 38 inserted into the electric circuit 39 of the solenoid valve 37, and a self-holding contact 42 connected to the main switch 38 in the electric circuit 39. In the electromagnetic relay 40 connected in series and its electric circuit 39, a self-holding contact 45 is connected in parallel to its main switch 38 and a self-holding contact 42 of the electromagnetic relay 40, and a coil 44 is connected to its main switch 38 and the electromagnetic relay 40 in parallel. Auxiliary electromagnetic relay 4 connected in series to 40 self-holding contacts 42
3, and a parking brake operating force sensor 47 that is energized by a predetermined parking brake operating force or more and excites the coil 41 of the electromagnetic relay 40.
and parking brake hand lever 31
The parking lever operation switch 49 is energized in response to the pulling operation of the parking lever and excites the coil 44 of the auxiliary electromagnetic relay 43.

The oil service brake 11 includes a master cylinder 12 operated by a brake pedal 13, conventional front oil brakes 14, 15 mounted on the front and rear wheels of a cab-over type truck, and a rear oil brake.・Brake 1
6, 17, connected to its master cylinder 12 via brake control piping 26, and its front and rear oil brakes 14, 15,
A booster 19 connected to 16 and 17 via piping 18, and a relay valve 22 of the booster 19
air tank 23 connected via piping 29 to
It is composed of etc.

Of course, the booster 19 integrates a power cylinder 20 containing a power piston (not shown) and a hydraulic cylinder 21 containing a hydraulic cylinder (not shown) on a concentric axis. is connected to the relay of the booster 19.
The valve 22 is connected to the power cylinder 20 via a pipe 24, and the pipe 24 is provided with a double check valve 25.

Further, the double check valve 25 is connected to the air tank 23 via the brake control auxiliary piping 27.
A solenoid valve 37 and a pressure reducing valve 28 are respectively provided.

In addition, the parking brake 30 is
Cab floor for over-type trucks (not shown)
A parking brake hand lever 31 rotatably supported via a ratchet (not shown), a conventional parking brake main body 32 attached to the rear wheel, and the parking brake hand lever 31 The base side of the brake lever 33 of the parking brake body 32
Parking brake cable 3 connecting
The parking brake cables 34 and 35 are connected to the parking brake operating force sensor 47 and the idle lever 3.
They are connected via 6.

That is, the parking brake operating force sensor 47 detects a state in which the parking brake hand lever 31 is pulled up with a force greater than a predetermined operating force, and sufficient braking force is obtained by the parking brake body 32. For example, a casing with an operating force detecting element (not shown) built into it so as to be able to reciprocate through a setting spring (not shown), and the operating force detecting element (not shown) ), and one end of the operating force detection element (not shown) is connected to one end of the above-mentioned parking brake cable 34. The casing is connected to one end of an idle lever 36 rotatably supported on the vehicle body side, and the idle lever 36
The other end is connected to one end of the parking brake cable 35 described above.

In addition, the oil service brake 1 mentioned above
1, the booster 19 and the master cylinder 1
The solenoid valve 37 provided in the oil passage 18 between the
It is connected to a battery 51 via an electric circuit 39, and a main switch 38 is inserted into the electric circuit 39.

Further, in the electric circuit 39, an electromagnetic relay 40 is connected in series to the main switch 38.

The electromagnetic relay 40 has a coil 41 connected to the main switch 38 and, via a circuit 48, to an electrical contact (not shown) of the above-mentioned parking brake operating force sensor 47, and a coil 41 connected to the main switch 38. 38 and a self-holding contact 42 connected in series to the solenoid coil of the solenoid valve 37 described above.
2 is energized.

Further, in the electric circuit 39, an auxiliary electromagnetic relay 43 is connected to the main switch 38.

The auxiliary electromagnetic relay 43 is connected to the electric circuit 39
The coil 44 connected to the main switch 38
and a self-holding contact 45 connected in parallel to the solenoid coil of the solenoid valve 37 described above.
Therefore, when a current flows through the coil 44 and the coil 44 is excited, the self-holding contact 45 is energized.

Furthermore, the coil 44 of the auxiliary electromagnetic relay 43
is connected to the parking lever operating switch 49 via a circuit 50.

The parking lever operation switch 49 is
It is configured to be biased in response to the pulling up operation of the parking brake hand lever 31.

Of course, the parking lever operation switch 4
Unlike the parking brake operating force sensor 47 described above, the parking brake operating force sensor 9 is almost independent of the predetermined operating force applied to the parking brake hand lever 31, and the parking brake operating force sensor 9 detects the parking brake.
It is sufficient that the hand lever 31 is energized when it is simply pulled up; for example, an existing parking lamp switch may be used.

Further, in the automobile brake system 10 of the present invention described above, the main switch 38, the electromagnetic relay 4
Of course, it is also possible to incorporate the auxiliary electromagnetic relay 43 into the control box 46 and arrange it in the cab in a unitized state.

Next, a description will be given of an operation method when the oil service brake 11 is used together with the parking brake 30 in the automobile brake system 10 of the present invention.

First, the main switch 38 is energized and the parking brake hand lever 31 is pulled up so that the parking brake 30 is placed in the braking state.

In that way, the parking brake
When the hand lever 31 is pulled up and its operating force reaches a predetermined operating force or more, the parking brake operating force sensor 47 is energized, current flows through the coil 41 of the electromagnetic relay 40, and the coil 41 is energized.

When the coil 41 of the electromagnetic relay 40 is energized, the self-holding contact 42 of the electromagnetic relay 40 is energized, and current therefore flows through the solenoid coil of the electromagnetic valve 37, opening the electromagnetic valve 37. .

When the solenoid valve 37 is released, the compressed air supplied from the air tank 23 is sent through the double check valve 25 into the power cylinder 20 of the booster 19, thus The pressure oil increased by the force device 19 is applied to the front and rear oil brakes 14, 15, 16,
Sent to 17, oil service brake 11
is maintained in a braking state.

Of course, if the parking brake hand lever 31 is pulled up as described above, the parking lever operation switch 49 is already in the energized state simply by the pulling up operation, and moreover, the above-mentioned electromagnetic relay 40 is already activated. self-holding contact 42
Since auxiliary electromagnetic relay 43 is energized,
A current flows through the coil 44 of the auxiliary electromagnetic relay 43 to energize it, and the self-holding contact 45 of the auxiliary electromagnetic relay 43 is energized.

Therefore, even if either the parking brake operation force sensor 47 or the parking lever operation switch 49 should fail,
Since either the self-holding contact 42 of the electromagnetic relay 40 or the self-holding contact 45 of the auxiliary electromagnetic relay 43 is energized, the solenoid valve 37 is maintained in a closed state.

Further, to release the braking state of the oil service brake 11 and parking brake 30, the main switch 38 is deenergized and the parking brake hand lever 31 is pushed down.

FIG. 2 shows a parking brake 30 applied to a cab-over type truck using an air pump.
Another specific example 60 of the brake system for a motor vehicle according to the present invention that allows a service brake to be used in combination is schematically shown.

The brake system 60 of the automobile applies an air service brake to a fluid-operated service brake, and the configuration other than the configuration directly related to the air service brake is the specific example shown in FIG. 10, the explanation and illustration of those structures will be omitted.

The air service brake consists of an air tank 61, normal front air brakes 62, 63 and rear air brakes 64, 65 attached to the front and rear wheels, and a relay valve 66.
and an air brake valve 67.

That is, the air tank 61 is connected to the piping 68.
is connected to the supply side inlet port of the relay valve 66 via a pipe 70, and to the air brake valve 67 via a piping 70.

The relay valve 66 has its control port via brake control line 71 to the air brake valve 67 and its supply outlet port via line 69 to its front and rear air brake valves. 62, 63, 64, and 65, respectively.

Further, the service brake control pipe 71 is provided with a double check valve 73, and the double check valve 73 is connected to the air tank 61 via a brake control auxiliary pipe 72.

Further, the brake control auxiliary piping 72 is provided with a solenoid valve 37, and the electric circuit 39 of the solenoid valve 37 is connected to the oil service valve shown in FIG.
As in the case of the brake, an electromagnetic relay (not shown), an auxiliary electromagnetic relay (not shown), etc. are connected, respectively.

In the brake system 60 of the automobile, the operation method when the air service brake is used together with the parking brake is described in the above-mentioned specific example 1.
Since the operation method is the same as that in 0, the explanation of that method will be omitted.

According to the above invention, the electromagnetic relay connects the self-holding contact in series to the main switch in the electric circuit of the electromagnetic valve provided in the brake control auxiliary piping of the fluid-operated service brake, and the auxiliary electromagnetic relay connects the self-holding contact in series to the main switch. , in the electrical circuit, a self-holding contact is connected in parallel with the self-holding contact of the main switch and the electromagnetic relay, and a coil is connected in series with the self-holding contact of the main switch and the electromagnetic relay, and the parking brake operation A force sensor detects a predetermined parking position of the parking brake.
The parking lever operating switch is energized in response to the pulling up of the parking brake hand lever, energizing the coil of the electromagnetic relay when the brake operating force is exceeded, and the auxiliary electromagnetic relay is activated. Since the fluid-operated service brake is configured to excite the coil of the parking brake, the fluid-operated service brake will be in the braking state if a predetermined operating force is applied to the parking brake and sufficient braking force is obtained for the parking brake. In particular, since the electromagnetic relay and the auxiliary electromagnetic relay are configured to be self-holding, when the service brake is used in conjunction with the parking brake, either the operating force sensor or the operating switch Even if one fails, either the self-holding contact of that solenoid relay or the auxiliary solenoid relay will remain energized, that solenoid valve will remain closed, and that service brake will remain in the braking state. If the main switch is accidentally operated, the self-holding contacts of the auxiliary solenoid relay are energized, so that the solenoid valve remains closed and the service The brake is reliably locked in the braking state, i.e. the service brake is prevented from being disengaged, and furthermore, when the service brake is used in combination with the parking brake, it is possible to prevent the service brake from being used alone due to erroneous operation. The use of the service brake is avoided, the braking operation of the service brake used in combination with the parking brake is ensured, and the braking state is more secure, and the braking state during parking and stopping is more reliable, The safety and practicality of parking and stopping work is increased.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a brake system for an automobile according to the present invention applied to a cab-over type truck, and FIG. 2 is a schematic diagram showing another example of the brake system for an automobile according to the present invention. 10, 60... Brake system of automobile, 11... Oil service brake, 12... Master cylinder, 26... Brake control piping, 27... Brake control auxiliary piping, 30... Parking brake, 3
1...Parking brake hand lever, 3
7... Solenoid valve, 38... Main switch, 39... Electric circuit, 40... Electromagnetic relay, 41... Coil, 43... Auxiliary electromagnetic relay, 44... Coil, 47... Parking/brake operating force sensor, 49... Parking/
Lever operated switch.

Claims (1)

[Scope of Claims] 1. A fluid-operated service brake having a brake control pipe and a brake control auxiliary pipe, a parking brake, a solenoid valve provided in the brake control auxiliary pipe of the fluid-operated service brake, and the like. A main switch inserted into the electrical circuit of the solenoid valve; An electromagnetic relay in which the self-holding contact is connected in series with the main switch in that electrical circuit; an auxiliary electromagnetic relay connected in parallel to the self-holding contact and whose coil is connected in series with its main switch and the self-holding contact of the electromagnetic relay; a parking brake operating force sensor that energizes the parking brake operating force sensor; and a parking lever operating switch that is energized in response to the pulling up of the parking brake hand lever and energizes the coil of its auxiliary electromagnetic relay. .