JPS62125938A - Braking pressure controller - Google Patents

Abstract

PURPOSE:To secure such braking motion that is high in safety, by invalidating the selection mentioned below in the case where output pressure of a brake valve is more than the specified value, in case of a device which is made to be capable of selecting the braking pressure acting on front wheels of an automobile to the weakened side by a selecting device. CONSTITUTION:A braking device of a large-sized car of a bus or the like is provided with pressure tanks 5A and 5B, brake valves 1A and 1B opening or closing fluid pressure out of these tanks, and boosters 4A and 4B connected to the output side in each separate system as to both rear and front wheels. In this case, as for a front wheel system, a limiting and quick release valve 3 is installed interposingly between the brake valve 1B and the booster 4B. In addition, there is provided with a two-way valve 2, being manually operated, between an input port of the said valve 2 and a control input port, while there is also provided with a limiting valve 6 functioning to bypass the said valve 2 when pressure in the input port goes beyond the specified value, in parallel with the said valve 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention artificially limits the brake pressure applied to the front wheels to be weaker compared to that of the rear wheels when the vehicle is traveling on a slippery road surface. (anti-skid) brake pressure control device. The present invention is suitable for use in brake devices for large buses, trucks, etc.

〔overview〕

The present invention relates to a brake pressure control device that artificially limits the brake pressure applied to the front wheels of a vehicle in response to road surface conditions by using a switching means, which includes: an output pressure of a brake valve operated by a driver; When the brake pressure exceeds a predetermined value, the brake pressure restriction is disabled regardless of the switching means, and the driver can obtain strong brake pressure by operating the valve to obtain strong brake pressure.

[Conventional technology]

When a car is driving on a slippery surface such as a wet paved road, the driver manually operates a switching means such as a switching valve to reduce the brake pressure applied to the front wheels and prevent skids. A brake pressure control device is used to prevent this.

That is, in the block configuration diagram of the conventional device shown in FIG. 3, when the driver drives on a slippery road surface,
When the lever 2A of the way valve 2 is tilted to the right in the figure, the communication of air pressure between the passage P3 and the passage P4 is cut off, and the passage P4 leading to the limiting and quick release valve 3 becomes unpressurized. . In this case, this limiting and quick release valve 3 connects air pressure lower than the air pressure in the passage P2 and air booster 4B for the front wheels.
Since the brake pressure is supplied to the front wheels, the brake pressure on the front wheels is weakened.

[Problem that the invention seeks to solve]

However, if the driver leaves the two-way valve lever on the slippery road side and drives on a normal road, the fluid pressure supplied to the front wheel air booster will always be limited to a value lower than the driver's desired value. be done.

The present invention improves this and, when the driver requires strong brake pressure above a predetermined value, a brake pressure control device that can supply the desired fluid pressure to the booster regardless of the position of the lever of the two-way valve. The purpose is to provide

[Means for solving problems]

The present invention includes a pressure tank, a valve for opening and closing the fluid pressure in the pressure tank, and a booster connected to the output pressure system of this valve in separate systems for front wheels and rear wheels, respectively, and the valves are operated by a driver. The front and rear wheels are linked by a brake control means, and the front wheel system includes means for reducing the pressure supplied to the booster by the driver's operation.In the brake pressure control device, the output pressure of the valve is The present invention is characterized in that it includes means for disabling the means for reducing the pressure when the pressure exceeds a predetermined value.

The means for reducing the pressure includes a pressure reducing valve operated by the driver, and the means for disabling the means for reducing the pressure includes a circuit for the pressure reducing valve that bypasses the circuit when the pressure on the input side exceeds a predetermined value. Preferably, it includes a tinging valve.

[For production]

It is sufficient to limit brake pressure reduction in order to prevent tire skids within a range where the brake pressure is small, and there is no need to reduce the pressure when the brake pressure is large.

In the device of the present invention, the above-mentioned pressure reduction restriction is canceled in the range of high brake pressure.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of the above embodiment.

In this figure, the air pressure in the rear wheel 5 and front wheel 5B of the air tank 5, which is a pressure tank, is delivered as a desired output pressure by the rear wheel portion IA and front wheel portion IB of the brake valve 1, respectively, which are operated by the driver. Ru. This output pressure is applied to air booster 4A for rear wheels and air booster 4 for front wheels.
B, respectively. In this way, the rear wheels and front wheels of an automobile are designed to generate braking effects using separate systems.

As a brake pressure control device, the output pressure of the front wheel portion IB of the brake valve 1 is branched into passages P2 and P3 via a passage P1, and the passage P2 is a limiting and
It is connected to one passage of the quick release valve 3, and the passage P3 is connected via the two-way valve 2 to the other passage of the limiting and quick release valve 3 by a passage P4'.

Here, the feature of the present invention is that the 2-way valve 2
The passage P3 on the input side of the two-way valve 2 is branched into a passage P3' and a passage P5, and the passage P4 on the output side of the two-way valve 2 is branched into a passage P4' and a passage P6. It may have a bypass function or be connected to the mitting valve 6.

The lever of 2-way valve 2 is pushed to the right side in the figure, and the passage P
4' is unpressurized, and the limiting and quick release valve 3 weakens the pressure in the passage P2 and applies it to the air booster 4B, and the brake valve 1 is pressurized (
When the pressure is stepped on and the passages P1, P3, and P5 become high pressure, the limiting valve 6 becomes conductive and this pressure appears in the passage P4'.

As a result, the limiting and quick release valve 3 becomes conductive, and the pressure in the passage P2 is directly supplied to the air booster 4B.

That is, when driving on a slippery road surface, the driver tilts the lever 2A of the two-way valve 2 to the right as shown in the figure. As a result, communication between the passage P3' and the passage P4 is cut off, so that the pressure in the passage P2 outputted from the front wheel portion IB of the brake valve 1 operated by the driver is weakened by the limiting and quick release valve 3. ,
It is supplied to the air booster 4B for the front wheels. In other words, the brake pressure on the front wheels is lower than the brake pressure on the rear wheels, allowing the driver to perform smooth brake operations on slippery road surfaces.

Next, tilt the lever 2A of the 2-way valve 2 to the left side of the figure, and the limiting and quick release valve 3
Air pressure is conducted to the passage P4'. At this time, an output pressure equal to the pressure in the passage P2 is sent to the air booster 4B.

FIG. 2 shows a detailed structural diagram of the two-way valve 2, the limiting and quick release valve 3, and the limiting valve 6.

In Fig. 2, when the two-way valve 2 assumes the valve position for slippery roads as shown in this figure, the passage P3' and the passage P4 become non-conductive due to the valve 2B, and the passage P
4 and P4' are in an unpressurized state, but the passage P is closed by a brake valve (not shown) operated by the driver.
When the output pressure of the piston 6A becomes higher than a predetermined value, the pressure in the passage P5 that is manually applied to the limiting valve 6 causes the piston 6A to
is pushed down, passage P5 and passage P6 are bypassed,
The passage P4' of the limiting and quick release valve 3 is pressurized, the pressure reduction restriction on the input pressure of the front wheel air booster 4B is released, and strong pressure is input.

Adjust the adjusting part 6B of the limiting valve 6, and adjust the spring 6C.
The predetermined value of the output pressure that releases the pressure reduction restriction can be changed by adjusting.

FIG. 4 shows a characteristic diagram of the output pressure of the brake valve and the booster pressure. In this figure, R indicates the characteristic of the rear wheel, and Fl indicates the characteristic of the front wheel according to this embodiment.

Further, the characteristic F2 is the characteristic of the front wheel in the conventional example.

In the device of the present invention, due to the action of the limiting valve 6, the characteristic Fl in FIG. 4 becomes a stepped characteristic as shown by the arrow.

〔Effect of the invention〕

As explained above, according to the present invention, even if the driver operates the manual part of the device to a position that generates weak brake pressure, when strong brake pressure is required, the necessary brake pressure is automatically generated. Get strong brake pressure. therefore,
Limiting the brake pressure on the front wheels is effective only at the low brake pressure required for anti-skid, and provides reasonable braking characteristics.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention. FIG. 2 is a structural explanatory diagram of the main parts of the above embodiment. FIG. 3 is a block diagram of a conventional example. FIG. 4 is a characteristic diagram of brake valve output pressure and booster pressure. 1... Brake valve (IA: rear wheel part, IB: front wheel part), 2... 2-way valve, 2A... lever, 2B
...Valve, 3...Limiting and quick release valve, 4A...Air booster for rear wheels,
4B... Air booster for front wheels, 5... Air tank (5A: For rear wheels, 5B: For front wheels), 6... Limiting valve, 6A... Piston, 6B... Adjustment part, 6
C...Spring, P1 to P6, P3', P4'...
aisle. Patent applicant Hino Motors Co., Ltd. ~ Agent
Patent Attorney Nao Ide Takazume 1 Figure Example Conventional Example 3 [21 v Characteristic Chart JY14 [21 Procedural Amendment February 25, 1988 Commissioner of the Patent Office Kuro 1) Mr. Akio, Incident Display 1985 Patent Application No. 265564 60 Name of the invention Brake pressure control device Address 3-1-1 Hinodai, Hino-shi, Tokyo Name (546)
Hino Automatic Military Industries Co., Ltd. Representative Shunyu Fukasawa, Agent Date of amendment order (voluntary amendment) 6. Number of inventions increased by amendment None 7. Subject of amendment 8. Contents of amendment (11 Specification attached) (2) Amend Figure 2 of the drawing as shown in Figure 2 of the attached drawing. 9. Attached documents + 11 1 copy of the revised specification (2) 1 copy of the drawing (Figure 2) Correction Description 1, Name of the invention Brake pressure side '4'B device 2, Claims (11) Pressure tank (5A, 5B) and brake valve (IA, IB) that opens and closes the fluid pressure in this pressure tank
and a booster (4) connected to the output pressure system of this valve.
A, 4B> are provided in separate systems for the rear wheels and front wheels, and the above-mentioned valves are configured to operate in conjunction with each other for the front wheels and rear wheels, and the pressure supplied to the above-mentioned booster is reduced in the front wheel system by operation by the driver. 3. Detailed Description of the Invention [Industrial Application Field] The present invention provides a brake pressure control device including a means for controlling the pressure of the brake pressure when the vehicle is traveling on a slippery road surface. The present invention relates to an anti-skid brake pressure control device that limits the brake pressure applied to the front wheels to be weaker than that of the rear wheels. The present invention is suitable for use in brake devices for large buses, trucks, etc. [Summary] The present invention relates to a brake pressure control device that artificially reduces the brake pressure applied to the front wheels of a vehicle in response to road surface conditions using a switching means, which controls the brake pressure operated by the driver. When the output pressure of the valve exceeds a predetermined value, the brake pressure restriction is disabled regardless of the switching means, so that the driver can obtain strong brake pressure by operating the valve. This is what I did. [Prior Art] When an automobile drives on a slippery road surface such as a wet paved road, the driver manually operates a switching means such as a switching valve to reduce the brake pressure applied to the front wheels. A brake pressure control device that prevents the occurrence of skids is known. That is, in the block configuration and configuration diagram of the conventional device shown in FIG. 3, when the driver drives on a slippery road surface,
When the two levers of the two-way pulp 2 are pushed to the right in the figure, the air pressure communication between the passage P3 and the passage P4 is cut off.
The passage P4 leading to the limiting and quick release valve 3 is unpressurized. In this case, the limiting and quick release valve 3 reduces the air pressure in the passage P2 and supplies it to the front wheel air booster 4B, so the brake pressure on the front wheels is weakened. When driving on a normal road surface, the driver tilts the two-way valve 2 shown in FIG. 3 to the left in the figure. At this time, a pressure equal to that of the passage P2 appears in the passage P4, and the limiting
The quick release valve 3 supplies the pressure in the passage P2 to the air booster 4B without reducing the pressure. [Problem to be solved by the invention] If the driver leaves the lever of the two-way valve 2 on the side of a slippery road surface and drives on a normal road surface,
The fluid pressure supplied to the front wheel air booster 4B is always reduced. This also applies if the driver desires very high brake pressure. The present invention improves this and, when the driver requires strong brake pressure above a predetermined value, a brake pressure control device that can supply the desired fluid pressure to the booster regardless of the position of the lever of the two-way valve. The purpose is to provide [Means for Solving the Problems] The present invention provides a pressure tank, a valve for opening and closing the fluid pressure in the pressure tank, and a booster connected to the output pressure system of this valve for rear wheels and front wheels, respectively. In preparation for separate systems, the valve is configured to operate in conjunction with the front wheels and the rear wheels, and for the front wheel system, the brake pressure control device includes means for reducing the pressure supplied to the booster by operation of the driver. The input port and output port of the limiting and quick release valve (3) are connected between the brake valve (IB) and the booster (4B), and the input port of the limiting and quick release valve is connected between the brake valve (IB) and the booster (4B). A two-way valve (2) connected between the port and the control input port and operable by the driver,
The present invention is characterized in that a limiting valve (6) is provided in parallel with this two-way valve, which bypasses this two-way valve when the pressure at its input port exceeds a predetermined value. [Function] It is sufficient to limit the brake pressure reduction in order to prevent tire skidding when the brake pressure is small, and there is no need to reduce the pressure when the brake pressure is large. In the device of the present invention, the pressure reducing effect is automatically disabled in the range of high brake pressure, and the high brake pressure is directly supplied to the booster. That is, when driving on a normal road surface, the driver operates the two-way valve in the open state so that the limiting and quick release valve is not activated. When driving on a slippery road surface, the driver closes the two-way valve. At this time, the stopping and quick release valve is activated and the brake pressure for the front wheels is reduced. When the driver presses the brake pedal hard or otherwise opens the brake valve, large pressure is applied to the limiting valve, which becomes conductive and bypasses the two-way valve. For this reason, limiting and
The quick release valve becomes inactive, and the unreduced brake pressure is supplied directly to the booster. [Example] An example of the present invention will be described with reference to the drawings. The tenth is a block configuration diagram of the above embodiment. In this figure, the air pressure in the rear wheel 5A and front wheel 5B of the air tank 5, which is a pressure tank, is sent out as desired output pressure by the rear wheel portion IA and front wheel portion IB of the brake valve 1, respectively, which are operated by the driver. . This output pressure is applied to air booster 4A for rear wheels and air booster 4 for front wheels.
B, respectively. In this way, brake pressure is generated for the rear wheels and front wheels of an automobile through separate systems. Here, a brake valve 1 is used as a brake pressure control device.
The output pressure of the front wheel portion IB is transmitted through the passage P2 through the passage P1.
and P3, the passage P2 is connected to one inlet of the limiting and quick release valve 3, and the passage P3 is connected to the other part of the limiting and quick release valve 3 via the two-way valve 2 by a passage P4'. connected to the population of The input side passage P3 of the two-way valve 2 further includes a passage P3.
3' and a passage P5, and the passage P4 on the output side of the two-way valve 2 is branched into a passage P4' and a passage P6, and has a function of bypassing the passage P5 and the passage P6. 6. In such a device, when the two-way valve 2 is tilted to the left side in the figure and the passages P3 and P4 are in communication, the passage P
2 and P4' are always equal, and air booster 4B
The pressure in the passage P2 is supplied as is. When driving on a slippery road surface, the lever of the two-way valve 2 is moved to the right side in the figure. In this case, passages P3 and P4'
is shut off, and the passage P4' becomes unpressurized. Therefore, the limiting and quick release valve 3 reduces the pressure in the passage P2 and applies it to the air booster 4B. At this time, when the brake pedal is strongly depressed and the brake valve 1 opens wide, and the pressure in the passages P1, P3, and P5 becomes large, the limiting valve 6 automatically conducts, and the pressure in the passage P5 is transferred to the passage P4'. appear. As a result, the limiting and quick release valve 3 becomes conductive, and the pressure in the passage P2 is directly supplied to the air booster 4B. FIG. 2 shows a detailed structural diagram of the two-way valve 2, the limiting and quick release valve 3, and the limiting valve 6. The two-way valve 2 includes a valve body 21 and a valve body 2.
1, a knob 2A that moves the plunger up and down, a valve 2B that opens and closes by moving the plunger 22 up and down, a spring 23 that presses this valve 2B upward, and a spring 23 that holds this spring 23. It consists of a camp 24 that presses the plunger upward, and a spring 25 that presses the plunger upward. The cap 24 has a pipe hole 27 in its center for connecting a pipe,
Further, a hole 26 is formed on the side of the valve body for supplying air to the limiting and quick release valve 3 when the valve 2B is opened. When the lever 2A is manually pushed to the right in FIG. 2, the holes 26 and 27 are shut off as shown in FIG. Holes 26 and 27 are in communication. In the limiting and quick release valve 3, a piston 32 with a small outer diameter on the upper side and a large outer diameter on the lower side is inserted inside a valve body 31.
A cylindrical hole 33 and a hemispherical hole 34 are integrally provided at the center of the hole 33 and below the cylindrical hole 33, respectively. Further, a communicating hole 35 is provided below the piston 32. A rod 36 is inserted vertically through this hole 35, and rubber ball-shaped valves 37 and 38 are fixed to the upper and lower ends of the rod 36, respectively. Two grooves 39 and 40 are provided around the piston 32,
O-rings 41, 42 are fitted into these grooves. Grease is applied around the piston 32 so that the piston 32 slides smoothly inside the valve body 31. On the lower side of the valve body 31, a cover 43 is fastened to the valve body with four bolts (not shown) via packings 44. A cylindrical hole 45 is provided in the center of the cover 43, and a forest-like portion 4 is provided in the center of the cover 43.
6 and an exhaust passage 47 are provided, and a hole 55 communicating with the air booster 4B is provided in the side wall of the cylindrical hole 45. A guide 48 is fixed to the support 36 and is adapted to slide up and down on the inner surface of the cylindrical hole 45 of the cover 43. This guide 48 also has a plurality of holes 49 that communicate with each other vertically.
is the provision. Brake valve IB is installed in the valve body 31.
A hole 50 for receiving braking air from the piston 32 is formed on the top surface, and a hole 51 communicating with the two-way valve 2 is formed on the side surface of the valve body 31 at a position such that air pressure acts on the stepped portion 52 of the piston 32. It is provided. A spring 54 is provided between the piston 32 and the guide 48, and presses the piston 32 so that it comes into close contact with the valve 37. This limiting and quick release valve functions to reduce the air pressure from the brake valve IB to the air booster 4B that operates on the front wheels. That is, when the air pressure from the two-way valve 2 or the limiting valve 6 is not applied to the hole 51 on the side of the valve body, the air pressure from the brake valve IB is transferred to the passage P2.
It acts on the upper surface of the limiting and quick release valve 3 via. This air pressure is the piston 32
and acts on the upper surface of the valve 37 to push down the piston 32 and the valve 37. At this time, the lower valve 3
8 contacts the slope 46, the exhaust hole 47 is closed. When the air pressure further increases, the valve 37 cannot be lowered by the rod 36, so only the piston 32 lowers, creating a gap between the valve 37 and the spherical surface 34 of the piston 32. Air flows from this gap through the passage 35 and the hole 49, and further through the hole 55 to operate the air booster. By the way, the piston 32 has different cross-sectional areas on the upper and lower sides, so now the area on the upper side is a1, and the area on the lower side is at(az >
a, ), and the upper air pressure is p1 and the upper and lower air pressures are pl. When p+'a+=pz ° aZ, the piston stops moving, and the piston and valve 37
The gap disappears and the air supply is cut off. At this time, 1) z=9+, and as a result, the air booster 4B for the front wheels has at
Reduced air pressure is supplied to /az, and the braking force is smaller than that of the rear wheels to prevent skids. Next, 2-way valve 2
When you tilt it to the left, valve 2B opens, so the limiting
Also, in the left side hole 51 of the and quick release valve,
The same pressure acts on the passage 50 in the upper surface of the valve body 31. That is, the air pressure in the passage p also acts on the stepped portion 52 of the piston 32. At this time, the pressure balance equation is p+ aI + (az aI) p+ = pz a
zFrom this p+ az =I)z at・°・pl
pl, and the air pressure in the brake valve IB acts on the air booster 4B without being reduced. Next, the limiting valve 6 will be explained. A cylindrical hole 62 is provided inside the main body 61 of the limiting valve 6. A valve 63 is inserted into this hole. A seal 64 is adhered to the top surface of the valve 63 to prevent air leakage. The HaruPro 3 is pressed upward by a spring 65.
The spring 65 can adjust the force with which it presses the Harpro 3 using an adjusting screw 66, so that the pressure for opening and closing the valve can be adjusted. On the side of the valve body 61, there is a limiting and
A cap 69 is fixed to the valve body with screws 70, and has a hole 67 for piping leading to the quick release valve 3, and a hole 68 in the center of the cap 69 for receiving air pressure from the brake valve IB. A screw 71 is attached to the outer peripheral surface of the adjusting screw 66.
is cut out and moves up and down, and its movement is controlled by lock nut 7.
Fixed by 2. With this structure, the pressure in the passage P5 is reduced by the spring 6.
5, the valve 63 is pressed against the lower surface of the camp, and air does not flow from passage P5 to P6. Next, when the force of the driver's depression of the brake valve exceeds a predetermined value, the air pressure in the passage P5 pushes down the valve 63, creating a gap between the seal 64 and the lower surface of the cap 69, from which the hole 67 and the passage P6 are opened. Air flows through the hole 51 of the limiting and quick release valve 3. FIG. 4 shows a characteristic diagram of the output pressure of the brake valve and the booster pressure. In this figure, R indicates the characteristic of the rear wheel, and Fl indicates the characteristic of the front wheel according to this embodiment. Further, the characteristic F2 is the characteristic of the front wheel in the conventional example. In the device of the present invention, due to the action of the limiting valve 6, the characteristic F1 in FIG. 4 becomes a stepped characteristic as shown by the arrow. [Effects of the Invention] As explained above, according to the present invention, even if the driver operates the two-way valve to a position that generates weak brake pressure, when strong brake pressure is required, Automatically obtains the necessary strong brake pressure. Therefore, limiting the brake pressure of the front wheels is activated only when the brake pressure is low enough to prevent anti-skid, which has the effect of providing highly safe braking characteristics. 4. Brief Description of the Drawings FIG. 1 is a block diagram of one embodiment of the present invention. FIG. 2 is a structural explanatory diagram of the main parts of the above embodiment. FIG. 3 is a block diagram of a conventional example. FIG. 4 is a characteristic diagram of brake valve output pressure and booster pressure. 1... Brake valve (IA: rear wheel part, 1B: front wheel part), 2... 2-way valve, 2A... lever, 2B
... Valve, 3... Limiting and quick release valve, 4A... Air booster for rear wheels,
4B...Air booster for front wheels, 5...Air tank (5A: for rear wheels, 5B: for front wheels), 6...Limiting valve, 6A...Piston, 6B...Adjustment M part, 6
C...Spring, P1 to P7, P3', P4'...
aisle.

Claims (2)

[Claims] (1) A pressure tank, a valve that opens and closes the fluid pressure in this pressure tank, and a booster connected to the output pressure system of this valve are provided in separate systems for the front and rear wheels, respectively, and the above valve is connected to the driver's The brake pressure control device has a configuration in which the front wheels and the rear wheels are linked by a brake control means, and for the front wheel system, the brake pressure control device includes means for reducing the pressure supplied to the booster by operation of the driver, so that the output pressure of the valve is set to a predetermined value. A brake pressure control device characterized by comprising means for disabling the means for reducing the pressure when the pressure exceeds the above value. (2) The means for reducing pressure includes a pressure reducing valve operated by the driver, and the means for disabling the means for reducing pressure includes bypassing the circuit when the pressure on the input side exceeds a predetermined value. The brake pressure control device according to claim 1, comprising a limiting valve.