JPS58133945A - Control device for anti-lock brake device - Google Patents

Abstract

PURPOSE:To prevent noises and improve the durability by connecting a pressure accumulator to a high pressure oil line for supplying pressure oil to the accumulator by an electrically-operated oil pressure switch reacting to the oil pressure in the high pressure oil line when the pressure is lowered under a fixed value to shorten the operating time of the oil pressure pump. CONSTITUTION:For ensuring the oil pressure of anti-lock brake control in a high pressure oil line 45 and a pressure accumulator 46 in each operating process of an anti-lock brake, the oil pressure is monitored by a pressure switch S. When the oil pressure is lowered under the lowest limit set value, the pressure switch S is operated to electrify an electromagnetic acutuator 55, and a relay switch 56 is closed to drive a motor M. Then, the oil pressure is sent to the pressure accumulator 46 by a pump P via the high pressure oil line 45, and increased up to a set pressure. When it reaches to the set value, the pressure switch S is intercepted to stop the supply of the pressure oil. This construction permits to shorten the operating time of the oil pressure pump for preventing noises and improving the durability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for an anti-lock brake device.

Conventionally, such control devices include a control hydraulic chamber provided in a brake device so as to suppress braking force when hydraulic pressure is supplied, an electric hydraulic pump, and a discharge of this hydraulic pump.
It consists of a high-pressure oil passage connected to the oil tank, an oil tank, a low-pressure oil passage connected to the oil tank, and a control valve that alternately controls the control oil pressure chamber to communicate with the high-pressure oil passage and the low-pressure oil passage, and when braking, the braking force is increased. When there is an excess, the high pressure oil passage is communicated with the control hydraulic chamber by the switching action of the control valve, and the excess 1 is controlled by the discharge pressure of the hydraulic pump.
A 31:5 ratio of 17 is known that prevents the wheel locking phenomenon by suppressing the 1i11 power.

By the way, in this conventional cylinder making system, the hydraulic pump is constantly operated.
The surplus pressure oil that is discharged is then returned to the oil tank via a relief valve.In general, there are very few chances that this control device will operate, so the hydraulic pump must be kept running at all times. It is undesirable to leave it in operation due to power loss.

In order to solve this problem, is it possible to accumulate the discharge pressure of the hydraulic pump in the Takasho oil passage? It is conceivable to connect the power supply g to the hydraulic pump and control the energization of the hydraulic pump with a pressure switch that responds to the hydraulic pressure of the pressure accumulator, and drive the hydraulic pump only when the power level falls below the set value. In this case, the writing switch will change the setting value to
Crab 1-y (or immediately ON or O by just 1 drop)
/I'/i'' state, so the pressure switch is often 0 #-Ol='fi'
7) will be repeated, which will only shorten the life of the switch. [<, There are problems such as noise being generated by the pump starting and stopping repeatedly, and the durability of the pump being reduced.

The present invention has been proposed in view of the above-mentioned item 1, and an object of the present invention is to provide a control device for the anti-lock brake device, which can eliminate all of the above-mentioned problems and inconveniences of the conventional devices.

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

First, FIG. 1 shows a vehicle braking device equipped with the device of the present invention,
A control hydraulic circuit is shown that applies a control hydraulic pressure to the braking device to suppress the braking force. In FIG. 1, a brake pedal 30 is connected to a mask cylinder 31 so that the mask cylinder 31 generates all hydraulic pressure when the pedal 30 is depressed. A wheel cylinder 33 corresponding to the mask cylinder 31 is fixed to the vehicle body near a wheel (not shown), and a pair of pistons 35 and 35' are fitted inside the cylinder 33, and between the pistons 35 and 35'. In this case, the control oil extraction chamber 36 is connected to the hydraulic oil chamber of the mask cylinder 31 via the oil passage 32.
．． Rod 37, 37/+i of each piston 35, 35'
″, Ini A1 each penetrates the end wall of the wheel cylinder 33 (
A pair of brake shoes 39 and 39' close to the inner circumferential surface of the brake shoes (not shown) attached to the middle 11 item (example 1ij41) of each rod 37 and 37' extend to an external force. Therefore, when the brake pedal 30 is depressed and the mask cylinder 31 generates braking oil pressure, this braking oil pressure is transferred to the wheel cylinder 3.
The hydraulic pressure is transmitted to the brake hydraulic chamber 36 in each piston 35.3.
When the brake drum is pushed in the opposite direction, each brake shoe 39, 39' is pressed toward the inner periphery of the brake drum, and due to frictional contact with the inner periphery of the brake drum. It is possible to add braking force to heavy wheels. .

If the braking force is too large, there is a possibility that the wheels will lock. In order to prevent the wheels from locking up, a pair of control hydraulic chambers 40 are provided between each piston 35, 35' and the end wall of the wheel cylinder 33.
Each piston 3
5, 35' to the outside to suppress the braking force described in 1. Next, a control hydraulic circuit for this purpose will be explained.

A high pressure oil line 45 with a check valve 44 interposed in the middle is connected to the discharge port of the hydraulic pump P which is connected to the suction port of the oil tank TK, and this high pressure oil line 45 is connected to the first control valve J/l and the oil It is connected to both control hydraulic chambers 40,40' via channels 48,49. In the high pressure oil passage 45, on the downstream side of the check valve 44, there is a pressure accumulator 46 for accumulating the discharge pressure of the hydraulic pump P.
A return oil passage 50 connected to the
A relief valve 51 is interposed in the middle of the return oil passage 50.

The oil tank T also includes a second control valve V2 and oil passages 52, 49.
A low-pressure oil passage 53 connected to the control oil pressure chambers 40 and 40' is connected through the control oil pressure chambers 40 and 40'. 1st. 2nd control valve 1'l
+V2 is the first valve shown in the figure (the switching is controlled according to the driving condition of the vehicle based on the judgment of the computer).

The pump P is driven by a power motor Af that receives power from a power source 57 via a relay switch 56 .

Relay switch 56&t, pressure switch S is controlled to open and close by an electromagnetic actuator 55 whose operation is controlled by pressure switch S. It is connected to the downstream side via a pressure detection oil passage 54, and closes when the oil pressure of the oil passage 54 falls below the upper limit set value. The present invention is characterized in that it is configured to be opened and stop energizing the electromagnetic actuator 55 when the temperature rises to a second limit setting value, which is higher than the 1,000° limit setting value.

Next, the specific structure of the pressure switch S will be explained based on FIGS. 2 and 3.

The main body 1 of the pressure switch S has a protruding cylinder part 2 which protrudes in the direction of the center line, and a cylindrical part 3 formed on the opposite side of the protruding cylinder part 2. , a contact hole 4 that supports the pressure receiving piston 8 and a rod 9 extending along the center line of the cylindrical portion 2 so as to be able to freely contact the pressure receiving piston 8 in the axial direction. , is formed to penetrate in the direction of the center line. Other than this, the main body 1 is made of magnetic material, and the rod 9 is made of non-magnetic old material.

A large diameter portion is formed at the outer end of the parallel hole 4, and -〇
- In this large-diameter portion, a fitting body 6 is provided through the sealing member 5, which has an opening 1 in the center and supports the tip of the pressure-receiving piston 8 so as to be freely movable thereon, thereby functioning as a stopper for the pressure-receiving piston 8. is inserted and fixed.

The outer periphery on the distal end side of the protruding cylinder portion 2 is screwed into the engagement hole of the connecting body 11 via the sealing member 10, and the connecting body 11 has the above-mentioned groove that communicates with the end surface of the protruding cylinder portion 2. A pressure detection oil passage 54 is formed. Therefore, the pressure oil introduced through the oil passage 54 further passes through the hole 1 and presses the pressure receiving surface of the pressure receiving piston 8, and as a result, the pressure receiving piston 8 responds to the hydraulic pressure of the high pressure oil passage 45 introduced through the oil passage 54. Accordingly, the rod 9 receives a force that tends to move the rod 9 outward from the cylindrical portion 3.

A female threaded portion 16 formed on the inner circumferential surface of the outer end of the cylindrical portion 3 has a male thread 14 formed on the outer circumferential surface, and a pair of axially elongated holes 15 at positions facing each other in the radial direction. ,
15' is formed between the annular stepped portion formed on the inner circumferential side of the cylindrical portion 3 and the inner end surface of the spring pressure adjusting cylinder 13, and is made of a magnetic material. They are screwed together so as to sandwich the outer periphery of the annular movement limiting plate 20.

When the pressure receiving piston 8 is not receiving fluid pressure, a stepped portion 18 of the main body 1 is located at the portion of the rod 9 near the pressure receiving piston 8.
A large-diameter portion 17 that extends into the rod 9 is integrally formed, and a magnet 19 is fitted onto the rod 9 adjacent to the large-diameter portion 17 . Further fitted onto the rod 9, adjacent to the magnet 19, is a spring seat 21 having a boss portion 22 passing through the center hole of the movement limiting plate 20. A pair of elongated holes 1 of a spring pressure adjusting cylinder 13 are provided in a portion near the outer end of the rod 9.
A spring seat 24 having a pair of protruding arms 25 and 25' protruding radially outward from 5 and 15' is fitted to the rod 9 so as to be able to freely move along the rod 9.
1, a pressure spring 23 is interposed between the two. and,
Each protruding arm 25 is attached to the male thread 14 of the spring pressure adjustment cylinder 13.
, 25' are screwed together so as to make pressure contact with them, and by rotating this adjustment wheel 26, the pressing force of the 4f11 spring 23 can be adjusted.

A support member 2 is provided on the inner peripheral side of the outer end of the spring pressure adjustment cylinder 13.
A contact switching device 28 having a contact switching actuator 29 inside is supported via γ. The input side terminal of this contact switching device 28 is connected to the electromagnetic actuator 55, and its output terminal is grounded. less than the axial spacing between the movement limit &2o;
Further, since the main body 1 and the movement limiting plate 20 are both formed of magnetic material #1, the rod 9 and the magnet 19 are constantly subjected to the pressing force by the pressing spring 23 via the spring seat 21, and the pressure receiving piston 8 When not receiving fluid pressure, the magnet 19 is pressed against the main body 1 by magnetic force. At this time, the tip of the rod 9 is separated from the contact switching actuator 29, so that the contact switching device 28 is placed in the contact state.

Now, the pressure receiving piston 8 receives oil pressure from the high pressure oil passage 45, and this oil pressure causes a pressing force on the pressure receiving piston 8 to be applied to the magnet 19.
When the pressure force between the body 1 and the pressure spring 23 is overcome, the rod 9 and the magnet 19 are compressed and moved toward the contact switching device 28 side, and the magnet 19 is pressed against the movement limiting plate 20. , the tip of the rod 9 presses the contact switching actuator 29 to switch the contact switching device 28 to the disconnected state. In this state, even if there is some downward fluctuation in the oil pressure acting on the pressure receiving piston 8, the magnet 19 will not be affected by its magnetic force. The state of pressure bonding to the movement limiting plate 20 is maintained continuously.

Then, even if the pressing force corresponding to the hydraulic pressure acting on the pressure receiving piston 8 becomes sufficiently small and cooperates with the pressing force between the magnet 19 and the moving 11jll limit plate 20, the pressing force by the pressing spring 23 is resisted. "When we meet, rod 9 and magnet 1
9 moves toward the main body 1, the magnet 19 is again pressed against the main body 1, and the tip of the rod 9 is separated from the contact switching actuator 29, thereby switching the contact switching device 28 to the contact state again.

FIG. 4 shows the force applied to the rod 9 and the magnet 19 in the side direction of the main body 1 in response to the axial displacement of the rod 9 and the magnet 19, with the horizontal axis representing the displacement and the vertical axis representing the magnitude of the force. The magnitude of pressure is shown graphically. here,
The point 02 on the horizontal axis corresponds to the position of the rod 9 and the magnet 19 relative to the main body 1 when the magnet 19 is pressed against the main body 1.
This corresponds to the position of the rod 9 and the magnet 19 relative to the main body 1 when the magnet 19 is pressed against the movement limiting plate 20. straight line a
indicates the change in the pressing force of the pressing spring 23, and the curve is 6'E
It shows the change in the algebraic sum of the pressing force of the zeta stone 19 and the pressing force of the pressing spring 23. Therefore, the shaded area in the figure shows the change in the pressing force of the magnet 19 against the main body 1 or the movement limiting plate 20. As is clear from this Figure 4,
When the magnitude of the pressing force due to the hydraulic pressure acting on the pressure receiving piston 8 is greater than the magnitude of the force indicated by AO, the magnet 19 separates from the main body 1 and moves together with the rod 9. The rod 9 presses against the movement limiting plate 20, and at the same time presses the contact switching actuator 29.In addition, in this state, the magnitude of the pressing force due to the fluid pressure acting on the pressure receiving piston 8 is the force indicated by BO2. It is only when the magnet 19 becomes smaller than that that the magnet 19 separates from the movement limiting plate 20, moves together with the rod 9, and presses against the main body 1, and at the same time, the rod 9 separates from the contact switching actuator 29.

Moreover, when the magnet 19 is located at an intermediate position between the main body 1 and the movement limiting plate 20, the balance of forces is extremely unstable, so that as soon as the magnet 19 separates from the main body 1, it is pressed against the movement limiting plate 20, and It exhibits the property of being crimped onto the main body 1 as soon as it is separated from the movement limiting plate 20.

Next, the operation of the embodiment of the present invention will be explained.

While the vehicle is running, while there is no possibility of the wheels locking even when braking or not, the first control valve V1 is activated as shown in FIG. 1 based on the judgment of a computer (not shown). on the right side, and the second control valve V2 on the left side,
Each has been switched. At this time, each control hydraulic chamber 40, 40' is connected to the second control valve V2 and the low pressure oil passage 53.
Since the braking force is communicated with the inside of the oil tank 1 through the braking force, the braking force can be increased freely.

If there is a possibility of wheel locking during braking, the first
While the control valve V1 remains switched to the right side, the second control valve V2
is switched to the right side. At this time, each control hydraulic chamber 4
The control oil in the pistons 35 and 407 is placed in a side chain state, which compensates for the further outward movement of each piston 35 and 35', so that the braking force is kept constant to prevent any further increase. dripping

When the braking force becomes even greater and the wheels are about to lock, the first control valve V is switched to the left, and the second control valve V2 remains switched to the right. At this time, each control hydraulic chamber 40, 40' is connected to the oil tank T.
The control hydraulic chambers 40 and 4 are isolated from each other.
o' contains a high pressure oil passage 45 and a first
Since control oil is injected through the control valve V, the pistons 35.degree. 17-35' move toward each other and the braking force decreases.

Through each of the above-mentioned operating processes, the high-pressure oil passages 45 and 7, and therefore the pressure accumulator 46, always maintain the control oil pressure necessary to properly control the anti-lock valve L-1-λ. (r) However, the ilt control oil pressure in this pressure accumulator 46 is adjusted and controlled as follows. That is, when this control oil pressure falls below the lower limit setting candy, the contact switching device 28 of the above-mentioned 1. [2. Drive pump P3
As a result, pressure oil is supplied from the hydraulic pump P to the pressure accumulator 46 via the high pressure oil passage 45, and the i in the pressure accumulator 46 is
When the Ii control oil pressure is in the upper row shift 1, and the opening side l oil pressure exceeds the upper limit set value, which is higher than the lower limit set value, the contact switching device 28 of the pressure switch S is disconnected, and the electromagnetic actuator 18 is turned off. - The relay switch 55 is de-energized, which causes the relay switch 5
6 is opened to de-energize the electric motor M and also stop the pump I).

During this period, even if the control oil pressure fluctuates up and down within a range that does not exceed the lower limit set value, the electric motor M and therefore the pump will not repeatedly start and stop, and their operation or deactivation will be prevented. The operating state continues.

As described above, according to the present invention, a pressure accumulator is connected to a high-pressure oil passage in a control device for an anti-lock brake system, and this pressure accumulator is electrically powered by a pressure switch that responds to the oil pressure of the high-pressure oil passage. Since pressure oil is supplied and replenished from the hydraulic pump in a timely manner, there is no need to drive the hydraulic pump while the vehicle is running, and the operating cost can be reduced.

The pressure switch energizes the hydraulic pump when the oil pressure in the high-pressure oil passage falls below a lower limit set value, and when the oil pressure rises above an upper limit set value higher than the lower limit set value, the pressure switch energizes the hydraulic pump. Since the hydraulic pump is configured to stop energizing, as long as the oil pressure in the high pressure oil path fluctuates between the above and lower limit set values, the pressure switch will not be switched. , there is no risk of problems such as the switching operation of the switch being repeated frequently even with slight fluctuations in the oil pressure, causing the pump to start and stop repeatedly, and of course the switch itself.
The durability of the pump can also be increased, and noise generation due to repeated starting and stopping of the pump can be suppressed.

[Brief explanation of drawings]

Fig. 1 is an overall schematic diagram showing an embodiment of an anti-lock brake device equipped with the device of the present invention, Fig. 2 is a longitudinal sectional front view of a pressure switch used in the embodiment, and Fig. 3 is a diagram of the same pressure switch. The side view, FIG. 4, is a graph showing the operating characteristics of the same pressure switch. P... Hydraulic pump, S... Pressure switch, T...
Oil tank, V,, V2...control valve, 40.40'...control hydraulic chamber, 45...high pressure oil path,
46... Pressure accumulator, 53... Low pressure oil line patent applicant Honda Motor Co., Ltd. 21- Figure 3 Figure 4

Claims (1)

[Claims] A control hydraulic chamber provided in the brake device so as to suppress the braking force when hydraulic pressure is supplied, an electric hydraulic pump, a pressure oil passage connected to the discharge port of this hydraulic pump, an oil tank, and this oil tank. A series of low-pressure oil passages, a control valve that alternately controls communication of the control hydraulic chamber with the high-pressure oil passage and the low-pressure oil passage, a pressure accumulator connected to the high-pressure oil passage, and a pressure accumulator that responds to the pressure of the high-pressure oil passage. and a pressure switch that controls energization of the hydraulic pump, and the pressure switch energizes the hydraulic pump when the oil pressure in the high-pressure oil passage falls below the lower limit setting. A control device for an anti-lock brake device, characterized in that the control device is configured to stop energization of the hydraulic pump when the value rises to or above an upper limit setting value.