JPH09202222A - Anti-lock brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To gently increase pressure at anti-lock brake control by providing a first shut-off valve interrupting a first liquid passage at anti-lock brake control, a second shut-off valve arranged on a second liquid passage and interrupting the second liquid passage at pressure reducing control of anti-lock brake control, and an orifice forming valve. SOLUTION: A first shut-off valve 23 opened by the projecting part 7c of a plunger 7 is closed by the action of a spring 23b so as to interrupt a first liquid passage 31, and hence the brake liquid pressure of a wheel cylinder 5 is reduced and lowered so as to avoid lock of a wheel. When the plunger 7 is on the return stroke, a second shut-off valve 27 is immediately opened, and when an orifice forming valve 25 is closed, the brake liquid pressure of the wheel cylinder 5 is also gradually raised through the orifice 7e of the plunger 7 and a first liquid chamber 11a. Hereby, pressure at anti-lock brake control can be gently increased, and as a whole the construction can be simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antilock brake device for preventing wheel lock during braking.

[0002]

2. Description of the Related Art An antilock brake device electronically detects a slip state of a wheel in order to prevent the wheel from being locked during braking, and when the predetermined slip state is exceeded, the brake pressure of a wheel cylinder is reduced. By doing so, the lock is prevented, and then the brake pressure is repeatedly increased again to improve the steering stability during braking and to shorten the braking distance.

As such an anti-lock brake device,
The thing described in Unexamined-Japanese-Patent No. 4-154462 is known.

This is arranged in a first supply passage that connects the master cylinder and the wheel cylinder, and a shut-off valve that shuts off the first supply passage during antilock brake control and a brake fluid supplied to the wheel cylinder. An exhaust sump device, an exhaust liquid passage communicating the wheel cylinder and the sump device, a pressure reducing valve formed of a normally closed two-way solenoid valve provided in the exhaust liquid passage, and a shut-off valve between the master cylinder and the wheel cylinder. Bypass passage that bypasses and communicates with
A flow rate control means disposed in the bypass passage and having a first orifice for limiting the flow of the brake fluid from the discharge side of the master cylinder and the pump to the brake cylinder, and the first orifice of the bypass passage for the brake fluid stored in the sump device. A flow path consisting of a pump that recirculates to the upstream side, a second orifice provided in the discharge liquid passage, and a three-position four-way valve that is arranged in the bypass passage and connects or disconnects the discharge side of the pump and the brake cylinder. And a switching valve.

Then, the pressure on the upstream side of the second orifice is guided to one end surface of the flow path switching valve, and the pressure on the downstream side of the second orifice is guided to the other end surface of the flow path switching valve. The flow path switching valve is switched. That is, the flow path switching valve is set to the first position that shuts off the discharge side of the pump from the wheel cylinder when the wheel cylinder pressure is reduced during the antilock brake control, and the pump is activated when the wheel cylinder pressure is increased during the antilock brake control. The discharge side of the pump is communicated with the flow rate control means, and the discharge side of the pump and the master cylinder and the wheel cylinder are set to the second position where they are communicated only via the first orifice in the flow rate control means.

In this way, when the wheel cylinder is depressurized during antilock brake control, the discharge side of the pump is completely cut off from the wheel cylinder, and the suction side is also completely cut off, so that the brake discharged from the pump is braked. Eliminates liquid consumption and reduces the load on the pump. Further, when the wheel cylinder pressure is increased during the anti-lock brake control, the discharge side of the pump is communicated with the flow rate control means, and the discharge side of the pump and the master cylinder and the wheel cylinder are passed through the first orifice in the flow rate control means. By communicating only with each other, the pressure of the wheel cylinder is increased slowly so as to prevent the braking wheel from being immediately re-locked.

[0007]

However, in such a conventional antilock brake device, the shutoff valve,
The flow path switching valve and the pressure reducing valve are configured as a single valve assembly, and the flow path switching valve is slidably fitted in a cylindrical valve housing having a plurality of radial holes and the axial hole. And a spool valve element and a three-position four-way valve, and the first orifice in the flow rate control means is a fixed orifice slidably fitted in an axial hole of the valve housing. Therefore, there are the following problems.

That is, since the entire structure is complicated and the components are required to have a high processing accuracy, the processing is not easy and the cost is high. Further, since the spool valve element and the fixed orifice that are slidably fitted are used, there is a possibility that impurities in the brake fluid may enter the sliding portion with high accuracy and the stick or the orifice may be clogged. is there.

An object of the present invention is to solve the problems of the prior art, to simplify the structure as a whole, and
An object of the present invention is to provide an anti-lock brake device that does not require the processing accuracy of each component.

It is another object of the present invention to provide an antilock brake device which is free from the risk of clogging of the orifice which contributes to the slow pressure increasing action.

[0011]

In order to achieve such an object, according to one embodiment of the present invention, a first liquid passage that connects a master cylinder and a wheel cylinder is provided, and the first liquid passage is arranged in the first liquid passage. A second shut-off valve that shuts off the first fluid path during anti-lock brake control, and a second shut-off valve that communicates with the master cylinder and the wheel cylinder bypassing the first shut-off valve.
A liquid passage, a second shutoff valve which is arranged in the second liquid passage and shuts off the second liquid passage during depressurization control of the antilock brake control, and a depressurizing pressure of antilock brake control which is arranged in the second liquid passage. An orifice forming valve that opens the second liquid passage during control, closes during pressure increase control, and forms an orifice, a discharge liquid passage that connects the wheel cylinder and a reservoir that stores brake fluid, and a discharge liquid passage that is disposed in the discharge liquid passage. Open / close valve
A circulating fluid passage communicating with the reservoir and an upstream side of the orifice forming valve of the second fluid passage; and a pump arranged in the circulating fluid passage for pumping the brake fluid stored in the reservoir. And

According to another aspect of the present invention, a large-sized orifice is provided which is movably fitted in the cylinder to separate the first liquid chamber and the second liquid chamber from each other and to connect the first and second liquid chambers. A stepped plunger having a diameter portion, a first liquid passage that connects the master cylinder and the wheel cylinder to each other through the first liquid chamber, and the stepped plunger that is arranged in the first liquid passage and is normally in the stepped plunger. A first shutoff valve that is energized to open the first fluid passage and shuts off the first fluid passage during antilock brake control, the master cylinder and the wheel cylinder, the second fluid chamber and the orifice. Through a second fluid passage, a discharge fluid passage that communicates the second fluid chamber with a reservoir that stores brake fluid, an on-off valve disposed in the discharge fluid passage, and a decompression control for antilock brake control. Sometimes the end of the stepped plunger causes the A second shut-off valve for shutting off the liquid passage, and an orifice arranged in the second liquid passage, which is opened by the end of the stepped plunger at the time of pressure reduction control of the antilock brake control and is closed at the time of pressure increase control and forms an orifice. A forming valve, a circulating fluid passage communicating the reservoir with an upstream of the orifice forming valve of the second fluid passage, and a pump arranged in the circulating fluid passage for pumping the brake fluid stored in the reservoir. It is characterized by being provided.

A preferred embodiment of the present invention is characterized in that the stepped plunger, the first cutoff valve, the second cutoff valve, and the orifice forming valve are arranged on the same axis.

In a further preferred aspect of the present invention, the orifice-forming valve includes a ball valve body and a mortar-shaped valve seat having an opening in a central portion, and the valve seat surface has an orifice when the ball valve is seated. Is characterized in that a V-shaped groove is formed in the radial direction.

Yet another aspect of the present invention is a first liquid passage that connects a master cylinder and a wheel cylinder, and the first liquid passage.
It is arranged in the liquid path and is used for the first anti-lock brake control.
First shut-off valve for shutting off the fluid passage of No. 2, a second fluid passage for communicating the master cylinder and the wheel cylinder by bypassing the first shut-off valve, and an anti-lock brake arranged in the second fluid passage. A second shut-off valve that shuts off the second liquid passage during pressure reduction control of the control, a first orifice arranged upstream of the second shut-off valve in the second liquid passage, the wheel cylinder and the brake fluid. A drainage passage communicating with a reservoir for storing,
An on-off valve arranged in the discharge liquid passage, a second orifice arranged in the discharge liquid passage, and a circulating liquid passage communicating with the reservoir and the upstream side of the first orifice of the second liquid passage. A pump that pumps the brake fluid stored in the reservoir and that is disposed in the circulating fluid passage; and an opening / closing control unit that controls opening / closing of the first shutoff valve and the second shutoff valve. .

According to still another aspect of the present invention, there is provided an orifice movably fitted in the cylinder to divide the first liquid chamber and the second liquid chamber from each other and to connect the first and second liquid chambers with each other. A first liquid passage that connects the plunger provided with the master cylinder and the wheel cylinder through the first liquid chamber; and a first liquid passage that is disposed in the first liquid passage and is normally urged by the plunger to move the first liquid passage. A second shutoff valve that opens the fluid passage and shuts off the first fluid passage during antilock brake control, and a second fluid that connects the master cylinder and the wheel cylinder to each other through the second fluid chamber and the orifice. A drain passage for communicating the second fluid chamber with a reservoir storing the brake fluid,
An on-off valve disposed in the discharge liquid passage, a second shut-off valve that shuts off the second liquid passage by the plunger during pressure reduction control of antilock brake control, and a second shut-off valve in the second liquid passage. An orifice disposed upstream, and a recirculating fluid passage communicating the reservoir with the upstream of the orifice of the second fluid passage,
And a pump which is arranged in the circulating fluid passage and pressure-feeds the brake fluid stored in the reservoir.

The second shutoff valve may be a poppet valve opened and closed at the end of the plunger or a spool valve opened and closed at the side of the plunger.

According to the present invention, during the antilock brake control, the first fluid passage connecting the master cylinder and the wheel cylinder is shut off by the first shutoff valve. Then, during the pressure reduction control in which the opening / closing valve provided in the discharge liquid passage is opened, the orifice forming valve is opened in the second liquid passage that connects the master cylinder and the wheel cylinder to bypass the first cutoff valve. In this state, it is closed by the second shutoff valve, and the brake fluid in the wheel cylinder is discharged to the reservoir. Then, the brake fluid stored in the reservoir is pressure-fed by the pump to the circulating fluid passage that communicates the reservoir with the upstream of the orifice forming valve of the second fluid passage. At this time, the discharge side of the pump is blocked from the wheel cylinder and its suction side. Therefore, the brake fluid discharged from the pump is not consumed and the load on the pump is reduced. Further, since the brake fluid flows into the orifice forming portion before the orifice forming valve is opened and the second shutoff valve is closed, clogging of the orifice forming portion is prevented.

In the pressure increasing control in which the on-off valve is closed, the second
The shutoff valve is opened and the orifice forming valve is closed to form the orifice. Until the orifice forming valve is completely closed, the brake fluid flows from the second fluid passage to the wheel cylinder to rapidly increase the pressure, but after closing the valve, only the orifice flows so that the pressure increases slowly. .

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will now be described in detail based on the embodiments shown in the accompanying drawings.

FIG. 1 is a circuit configuration diagram showing a basic configuration of a first embodiment of an antilock brake device according to the present invention, in which each component is in a normal brake operating state position. Note that FIG. 1 shows only a channel circuit corresponding to one wheel. Since the number of channels is determined by the vehicle to which it is applied, the channel circuits of FIG. 1 may be provided in parallel according to the number of channels.

In the figure, reference numeral 1 is a brake pedal, 3 is a master cylinder for generating brake fluid pressure in response to depression of the brake pedal 1, and 5 is a wheel cylinder provided corresponding to a wheel.

Reference numeral 7 is a stepped plunger slidably fitted in a hole or a cylinder chamber formed in a block 9 of the apparatus. In the figure, only the inner shape of the block 9 is shown, and the outer shape is not shown for the sake of simplicity. The plunger 7 has a basic shape formed as a stepped plunger having a large diameter portion 7a and a small diameter portion 7b, a lower diameter protruding portion 7c for opening and closing a first cutoff valve described later, and an orifice described later at the upper end. It has a small-diameter projection 7d for opening and closing the forming valve.

On the other hand, the cylinder 9 has a plunger chamber 11 in which the large diameter portion 7a of the plunger 7 is fitted, and the first shutoff valve chamber 1
3 and the orifice forming valve chamber 15 are formed by being coaxially arranged. And the plunger room 11
The first cutoff valve chamber 13 and the first cutoff valve chamber 13 are communicated with each other through a communication hole 17 having a diameter larger than that of the small-diameter protruding portion 7c of the plunger 7, and one of the first liquid passages described later is provided between the small-diameter protruding portion 7c and the communication hole 17. Parts are formed. In addition, between the plunger chamber 11 and the orifice forming valve chamber 15, the protrusion 7 of the plunger 7 described above is centered.
An annular valve seat body 21 having an opening 19 through which d can be inserted is provided, and both chambers are communicated with each other through this opening 19. The plunger chamber 11 is divided by the large diameter portion 7a of the plunger 7 into a first liquid chamber 11a and a second liquid chamber 11b, and both chambers are formed in the large diameter portion 7a and have a throttle passage or a predetermined diameter dimension. The orifices 7e communicate with each other.
A spring 22 is arranged in the second liquid chamber 11b to urge the stepped plunger 7 toward the first liquid chamber 11a. Since the volume of the first liquid chamber 11a becomes substantially zero due to the urging of the spring 22, the lower surface of the large diameter portion 7a of the plunger 7 is formed in the radial direction in order to form a part of the first liquid passage described later. A cutout groove 7f is formed.

Further, in the first shutoff valve chamber 13, a ball valve body 23a and a spring 23b for urging the ball valve body 23a in a direction of shutting off the communication hole 17 are arranged to constitute the first shutoff valve 23. There is. The set load of the spring 22 that biases the plunger 7 is larger than that of the spring 23b, and thus the first load is set when the brake is inactive.
The shutoff valve is kept open.

In the orifice forming valve chamber 15, a ball valve body 25a and a spring 25b for urging the ball valve body 25a toward the valve seat surface on the upper surface of the valve seat body 21 are arranged. A V groove 25c is formed in the radial direction on the valve seat surface.
Thus, in the state where the ball valve body 25a is seated on the mortar-shaped valve seat surface, the ball valve body 25a and the V groove 25c constitute an orifice forming valve 25 that forms an orifice. In addition, the ball valve body 25a is the protrusion 7 of the plunger 7 described above.
It is opened and closed by d.

On the other hand, the outer peripheral edge of the small diameter portion 7b of the plunger 7 constitutes a second shutoff valve 27 which shuts off the communication of the opening 19 by contacting the valve seat body 21 with the valve seat surface of the lower surface thereof. doing.

Therefore, the master cylinder 3 and the wheel cylinder 5 are communicated with each other through the first liquid passage 31.
1 is a first shutoff valve chamber 13, a communication hole 17, a first liquid chamber 11a
Or, the cutout groove 7f is included in a part thereof. Further, the master cylinder 3 and the wheel cylinder 5 are communicated with each other by a second liquid passage 33 which is a bypass liquid passage bypassing the first shutoff valve, and the second liquid passage 33 is connected to the orifice forming valve chamber 15,
The opening 19, the second liquid chamber 11b, and the throttle passage or the orifice 7e are included in a part thereof.

Reference numeral 35 is a reservoir for storing the brake fluid discharged from the wheel cylinder 5, and the second fluid chamber 1
1b and the reservoir 35 are communicated with each other by a discharge liquid passage 37, and the discharge liquid passage 37 is provided with an opening / closing valve 39 including a two-position solenoid valve or the like.
Are arranged. The open / close valve 39 is open / close controlled by a control signal from an antilock brake control controller (not shown). The reservoir 35 and the upstream of the orifice forming valve 25 of the second liquid passage 33 are communicated with each other by a circulating liquid passage 41, and a pump 43 for pumping the brake fluid stored in the reservoir 35 is arranged in the circulating liquid passage 41. There is. Although not shown, check valves are provided on the discharge side and the suction side of the pump 43 to prevent backflow.

Further, the on-off valve 39, the reservoir 35 and the pump 43 described above are also integrally provided in the block 9.

The operation of the first embodiment of the present invention configured as described above will be described below.

In the normal braking state shown in FIG. 1, the open / close valve 39 is in the closed position and the first shutoff valve 23 is in the open position.
When the brake pedal 1 is depressed, the master cylinder 3
Brake fluid is sent to the wheel cylinder 5 through the first shutoff valve 23, the first fluid chamber 11a, and the first fluid passage 31 including the notch groove 7f in the radial direction of the plunger 7, and a predetermined brake fluid pressure is generated. To be done. At this time, the orifice forming valve 25 is closed, and the inflow of the brake fluid from the second fluid passage 33 is very small only through the orifice formed by the ball valve body 25a and the V groove 25c. . Therefore, the pressurization of the wheel cylinder is satisfactorily performed by the brake fluid from the first fluid passage 31 without being affected by the throttling on the way.

When the brake pedal is released, the brake fluid returns from the wheel cylinder 5 to the master cylinder 3 in the reverse direction of the first fluid passage 31 and the brake is released.
Also at this time, the first liquid passage 31 is not particularly restricted,
No worries about pedal return delays.

When the wheels are about to lock in the above-mentioned braking state, a control signal is sent from a controller (not shown) to drive the pump 43 and at the same time the on-off valve 39.
Is activated. That is, when the opening / closing valve 39 opens, the brake fluid in the second fluid chamber 11b is discharged to the reservoir 35,
Due to the pressure difference between the liquid chamber 11a and the second liquid chamber 11b, the plunger 7 resists the biasing force of the spring 22 and moves to the depressurized position shown in FIG. As a result, the plunger 7
The first shutoff valve 23 that has been opened by the protruding portion 7c is closed by the action of the spring 23b, and the first liquid passage 31 is shut off. At this time, the brake fluid in the wheel cylinder 5 passes through the first fluid chamber 11a, the orifice 7e formed in the large diameter portion 7b of the plunger 7 and the second fluid chamber 11b, and is discharged to the reservoir 35 via the on-off valve 39. As a result, the brake fluid pressure in the wheel cylinder 5 is reduced and the locking of the wheels is avoided.

Further, when the plunger 7 strokes, the outer peripheral end of the small diameter portion 7b abuts the valve seat body 21 and the second shutoff valve 27 is closed. At the same time, plunger 7
The projection 7d at the tip of pushes up the ball valve element 25a of the orifice forming valve 25 to completely open the orifice forming valve 25.

The state of the depressurized state will be described in further detail with reference to FIG. 4. When the depressurized signal, that is, the open signal of the on-off valve 39 is issued from the controller at time t1 in the normal braking state, The opening / closing valve 39 is opened. The opening of the opening / closing valve 39 causes the plunger 7 to start a stroke as described above, and first, the first shutoff valve 23
Is closed. However, the second shutoff valve 27 is not closed during the stroke of the plunger 7, and
Since the orifice forming valve 25 is in the process of being opened, the second
From the liquid passage 33 through the second shutoff valve 27, the second liquid chamber 11
There is an instantaneous inflow of brake fluid at b, and the discharge from the wheel cylinder 5 is reduced accordingly. Therefore, although the pressure reduction is moderate at the beginning of the pressure reduction during the stroke of the plunger 7, the impurities in the V groove 25c forming the orifice are removed due to the inflow through the second cutoff valve 27, and the orifice is clogged. It is prevented.

When the plunger 7 makes a full stroke (time t2), the second shutoff valve 27 is completely closed as described above, so that the brake fluid pressure of the wheel cylinder 5 is suddenly reduced.

On the other hand, when the risk of wheel locking disappears, the braking force is required again, and the opening / closing valve 39 is closed while the pump 43 is still driven. When the opening / closing valve 39 is closed, the pressure in the second liquid chamber 11b is recovered due to the leakage from the second shutoff valve 27, and the plunger 7 starts the return stroke. The second stroke when the plunger 7 returns
The shut-off valve 27 opens immediately and the orifice-forming valve 25 comes to close. When the orifice forming valve 25 is closed, the brake fluid is supplied to the second liquid chamber 11b from the second liquid passage 33 through the orifice formed by the ball valve body 25a and the V groove 25c. As a result, the brake fluid pressure of the wheel cylinder 5 is also increased by the orifice 7 of the plunger 7.
e and gradually rises via the first liquid chamber 11a.

The state of the increased pressure will be described in further detail with reference to FIG. 4.
When the controller outputs a pressure increase signal, that is, a closing signal of the opening / closing valve 39 at time t 4, the opening / closing valve 39 is closed as described above. By closing the opening / closing valve 39, the plunger 7 starts the return stroke as described above, and first, the second cutoff valve 27 is opened. However, since the orifice forming valve 25 is in the process of being closed at the initial stage of the return stroke of the plunger 7, the orifice forming valve 25 and the second shutoff valve 27, which are not completely closed, are used to discharge from the second liquid passage 33. There is an instantaneous inflow of brake fluid into the second fluid chamber 11b, and the brake fluid pressure in the wheel cylinder 5 is suddenly increased for a moment. Therefore, although the pressure increase becomes abrupt at the beginning of the return stroke of the plunger 7, the V groove 25c forming the orifice is formed by the inflow as in the case of the pressure reduction control.
The impurities are removed and clogging of the orifice is prevented.

When the orifice forming valve 25 is completely closed at time t5 during the return stroke of the plunger 7, the orifice formed by the ball valve body 25a and the V groove 25c is formed in the second liquid chamber 11b. The brake fluid is supplied only through the brake fluid, and the brake fluid pressure in the wheel cylinders 5 is gradually increased at an increasing rate set by the size of the orifice. Therefore, it is prevented that the wheels are immediately locked again.

Further, when the plunger 7 is completely returned, the first cutoff valve 23 is opened at time t6, the brake fluid pressure in the wheel cylinder 5 is rapidly increased, and the normal braking state is restored.

During the anti-lock brake control described above, when the wheel is within the predetermined range with respect to the predetermined target slip ratio S, the brake fluid pressure of the wheel cylinder 5 is maintained within the predetermined fluid pressure range. Although the holding control is performed, in such a case, the controller may continuously generate the opening / closing signal of the opening / closing valve 39 and repeatedly open / close the opening / closing valve 39 to create an apparent holding state (time in FIG. 4). See t3 to t4).

Next, according to the second embodiment of the present invention,
This will be described with reference to FIGS. In this embodiment, the apparatus is simplified without providing an orifice forming valve. Therefore, only different parts will be described, and the other basic configurations are the same as in the previous example, and therefore, the same functional parts will be denoted by the same reference symbols and redundant description will be avoided.

That is, in FIGS. 5 to 7, the plunger as the opening / closing control means of this embodiment is configured as the plunger 70 having the same diameter, and is arranged upside down with respect to the previous example. A protrusion 70c is provided at the upper end of the plunger 70, and this opens and closes the first shutoff valve 23 as in the previous example.

On the other hand, a ball valve body 27a is provided at the lower end of the plunger 70, and together with the valve seat body 27b projecting into the second liquid chamber 11b, the second poppet valve type for shutting off the communication of the opening 19 is formed. Of the shutoff valve 27.

Therefore, the master cylinder 3 and the wheel cylinder 5 are communicated with each other through the first liquid passage 31.
1 is a first shutoff valve chamber 13, a communication hole 17, a first liquid chamber 11a
Or, the notch groove 70f is included in a part thereof. Further, the master cylinder 3 and the wheel cylinder 5 are communicated with each other by a second liquid passage 33 which is a bypass liquid passage bypassing the first shutoff valve, and the second liquid passage 33 has a fixed orifice 34 as a first orifice. Is provided. The second liquid passage partially includes the opening 19, the second liquid chamber 11b, and the orifice 70e as the second orifice.

The operation of the second embodiment will be described. At the time of normal brake operation shown in FIG. 5, the first cutoff valve 23 is opened by the protruding portion 70c of the plunger 70 as in the first embodiment. Therefore, master cylinder 3
The brake fluid pressure is applied to the wheel cylinder 5 via the first fluid passage 31. Even if the depression of the brake pedal 1 is released, the first cutoff valve 23 remains open,
Contrary to the above, the brake fluid in the wheel cylinder 5 is the first
It is returned to the master cylinder 3 via the liquid passage 31.

When the brake pedal 1 is suddenly depressed, the valve body 23a is biased in the valve closing direction, but the opening / closing valve 39 remains closed, so that the hydraulic pressure lock of the second liquid chamber 11b is performed. Therefore, the plunger 70 does not move, and the first shutoff valve 23 does not close.

When the wheels are about to lock in the above-described brake operating state, a control signal is sent from a controller (not shown) to drive the pump 43 and simultaneously operate the on-off valve 39. That is, when the opening / closing valve 39 is opened, the brake fluid in the second fluid chamber 11b is discharged to the reservoir 35,
Due to the pressure difference between the first liquid chamber 11a and the second liquid chamber 11b before and after the orifice 70e, the plunger 70 resists the biasing force of the spring 22 and strokes to the pressure reducing position shown in FIG. As a result, the first cutoff valve 23 opened by the protrusion 70c of the plunger 70 is closed by the action of the spring 23b, and the first liquid passage 31 is cut off. At this time, the brake fluid in the wheel cylinders 5 is transferred to the first fluid chamber 11
a, the orifice 70e of the plunger 70, the second liquid chamber 11
Since it passes through b and is discharged to the reservoir 35 via the on-off valve 39, the brake fluid pressure in the wheel cylinder 5 is reduced and the locking of the wheels is avoided.

Further, when the plunger 70 is further stroked, the ball valve body 27a at the lower end thereof abuts the valve seat body 27b, and the second shutoff valve 27 is closed. As a result, the master cylinder 3 and the wheel cylinder 5 are completely cut off, and the inflow of brake fluid into the wheel cylinder 5 is prevented.

On the other hand, when the risk of wheel locking disappears, the braking force is required again, and the opening / closing valve 39 is closed while the pump 43 is still driven. When the opening / closing valve 39 is closed, the flow of the brake fluid from the first fluid chamber 11a to the second fluid chamber 11b is stopped, and the pressure difference before and after the orifice 70e disappears. Therefore, the plunger 70 is returned by the urging force of the spring 22 to return stroke. To start. When the plunger 70 makes a return stroke, the second shutoff valve 27 is immediately opened, and the second liquid passage 33 communicates with the wheel cylinder 5. However, since the urging force of the spring 22 is smaller than the force due to the pressure in the first shutoff valve chamber 13, the first urging force is not changed as shown in FIG.
The shutoff valve 23 is kept closed. The brake fluid of the master cylinder 3 is supplied to the wheel cylinder 5 via the orifice 34 of the second fluid passage 33 and the orifice 70e of the plunger 70. As a result, the brake fluid pressure in the wheel cylinder 5 also gradually increases. Before and after the orifice 70e of the plunger 70, the second liquid chamber 11b to the first liquid chamber 11
A pressure difference is generated by the flow of the brake fluid to a, and an upward force is applied to the plunger 70 in FIG. 7. The sum of this force and the urging force of the spring 22 is the first shutoff chamber 13
The first shut-off valve 2 does not overcome the force due to the internal pressure.
No. 3 remains closed.

By further increasing the pressure, the wheel cylinder 5
When the pressure difference between the master cylinder 3 and the master cylinder 3 becomes equal to or less than a predetermined value, the sum of the force due to the pressure difference between the orifice 70e of the plunger 70 and the urging force by the spring 22 becomes the first shutoff chamber
The hydraulic pressure in the wheel cylinder 5 rapidly surpasses the force due to the pressure in the hydraulic cylinder 3 until it becomes equal to the hydraulic pressure in the master cylinder 3.

Next, FIGS. 8 to 10 show a third embodiment of the present invention.

In this embodiment, the form of the second shut-off valve 27 in the above-mentioned second form is replaced with the spool valve form from the poppet valve form, and the other constitution and operation are the second embodiment. Since it has the same form as
The same functional parts are designated by the same reference numerals and duplicate description will not be given.

That is, the opening 19 of the second liquid passage 33 is formed in the cylinder wall 9 so as to face the second liquid chamber 11b, and the opening 19 is opened and closed by the end side portion of the plunger 70.
The shutoff valve 27 is configured.

Further, FIG. 11 shows a fourth embodiment of the present invention.

In this embodiment, the form of the spool valve type second shutoff valve 27 in the above-mentioned third form is changed to the second form.
This is replaced by changing the position of the opening 19 of the liquid passage 33, and other configurations and actions are described in the third section.
Since it is the same as the embodiment described above, the same functional parts are designated by the same reference numerals and duplicate description will not be given.

That is, the opening 19 of the second liquid passage 33 is formed in the cylinder wall 9 so as to face the side portion of the plunger 70, and the plunger 70 communicates with the first liquid chamber 11a and the second liquid chamber 11b. An in-plane passage 70g is formed which communicates the passage with the side portion and is orthogonal to the axis of the plunger. The opening 19 constitutes a second cutoff valve 27 that is opened and closed by the side portion of the plunger 70.

[0059]

As is apparent from the above description, according to one embodiment of the present invention, in particular, the first shutoff valve that shuts off the first liquid passage during the antilock brake control and the second shutoff valve during the pressure reduction control thereof. Since the second cutoff valve for shutting off the liquid passage and the orifice forming valve for opening the second liquid passage for closing the pressure control and closing the pressure for increasing the pressure and forming the orifice are provided similarly, The pressure can be increased slowly, the structure can be simplified as a whole, and the processing accuracy of each component is not required so much.
Moreover, it is possible to obtain an anti-lock brake device that is free from the risk of clogging of the orifice that contributes to the gradual pressure increase action.

According to another aspect of the present invention, in particular,
A stepped plunger, a first shutoff valve that is normally energized by the stepped plunger to open the first fluid passage and shuts off the first fluid passage during antilock brake control, and the end of the stepped plunger during depressurization control. A second shutoff valve for shutting off the second liquid passage by means of a portion, and at the same time, an orifice forming valve which is opened by the end of the stepped plunger during pressure reduction control and closes and forms an orifice during pressure increase control. As with the one embodiment of the present invention, it is possible to gradually increase the pressure during anti-lock brake control, simplify the structure as a whole, and do not require the processing accuracy of each component so much. Moreover, it is possible to obtain an anti-lock brake device in which there is no risk of clogging of the orifice contributing to the gradual pressure increase action.

According to a preferred embodiment of the present invention, the stepped plunger, the first shutoff valve, the second shutoff valve,
Since the orifice forming valve and the orifice forming valve are arranged on the same axis, the processing is facilitated and the assembly is facilitated.

According to a further preferred aspect of the present invention, the orifice-forming valve includes a ball valve body and a mortar-shaped valve seat having an opening in the center thereof, and the seat surface of the ball valve is seated on the valve seat surface. Since the radial V-shaped groove for forming the orifice is sometimes formed, the orifice can be easily formed and the size thereof can be easily set.

According to yet another aspect of the invention, in particular:
A first shutoff valve that shuts off the first fluid passage during antilock brake control, and a second shutoff valve that shuts off the second fluid passage during depressurization control.
A shutoff valve, a first orifice arranged upstream of the second shutoff valve in the second liquid passage, and a second orifice arranged in the discharge liquid passage.
Since the first and second orifices are arranged in series in the second liquid passage, the residual pressure is unlikely to remain in the wheel cylinder even if a leak occurs in the second shutoff valve during depressurization. The effect can be obtained.

According to still another embodiment of the present invention, in particular, the first liquid chamber and the second liquid chamber are separated from each other by being movably fitted in the cylinder and the first and second liquid chambers are separated from each other. A plunger having an orifice communicating with it, a first shutoff valve that is normally biased by the plunger to open a first fluid passage and shuts off the first fluid passage during antilock brake control, the master cylinder and the A second liquid passage that communicates the wheel cylinder with the second liquid chamber via the orifice; a second shutoff valve that shuts off the second liquid passage by the plunger during depressurization control; and a second liquid passage And an orifice arranged upstream of the second cutoff valve of
It is possible to simplify the structure as a whole, does not require the processing accuracy of each component so much, and since two orifices are arranged in series in the second liquid passage, in case of decompression, the second cutoff should be performed. Even if the valve leaks, it is possible to obtain the effect that residual pressure is unlikely to remain in the wheel cylinder.

Further, when the second shut-off valve is composed of a poppet valve opened / closed at the end of the plunger or a spool valve opened / closed at the side of the plunger, the structure can be simplified. Moreover, it is possible to completely prevent the brake fluid from flowing into the wheel cylinder due to a leak.

[Brief description of drawings]

FIG. 1 is a basic circuit configuration diagram of an embodiment of an antilock braking device according to the present invention, showing a normal braking state.

FIG. 2 is a diagram showing a pressure reduction control state of the embodiment of FIG.

FIG. 3 is a diagram showing a pressure increase control state of the embodiment of FIG.

FIG. 4 is a time chart for explaining a state of antilock brake control of an embodiment of the antilock brake device according to the present invention.

FIG. 5 is a basic circuit configuration diagram of another embodiment of the antilock brake device according to the present invention, showing a normal braking state.

FIG. 6 is a diagram showing a pressure reduction control state of the embodiment of FIG.

FIG. 7 is a diagram showing a pressure increase control state of the embodiment of FIG.

FIG. 8 is a basic circuit configuration diagram of still another embodiment of the anti-lock brake device according to the present invention, showing a normal braking state.

FIG. 9 is a diagram showing a pressure reduction control state of the embodiment of FIG.

FIG. 10 is a diagram showing a pressure increase control state of the embodiment of FIG.

FIG. 11 is a basic circuit configuration diagram of still another embodiment of the anti-lock brake device according to the present invention,
Indicates a normal braking state.

[Explanation of symbols]

 3 Master Cylinder 5 Wheel Cylinder 7,70 Plunger 11a First Liquid Chamber 11b Second Liquid Chamber 13 First Shutoff Valve Chamber 15 Orifice Forming Valve Chamber 19 Opening 21 Valve Seat Body 23 First Shutoff Valve 25 Orifice Forming Valve 25a Ball Valve Body 25c V groove 27 2nd cutoff valve 31 1st liquid path 33 2nd liquid path 35 Reservoir 37 Discharged liquid path 39 Open / close valve 41 Reflux liquid path 43 Pump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Motoko Kosaka, 2 Takaracho, Kanagawa-ku, Kanagawa, Nissan Nissan Motor Co., Ltd. 72) Inventor Hideaki Inoue 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd.

Claims (8)

[Claims] 1. A first liquid passage communicating with a master cylinder and a wheel cylinder; a first shutoff valve disposed in the first liquid passage to shut off the first liquid passage during antilock brake control; A second fluid passage that connects the master cylinder and the wheel cylinder to bypass the first shutoff valve, and a second fluid passage that is disposed in the second fluid passage and shuts off the second fluid passage during pressure reduction control of antilock brake control. A second cutoff valve; an orifice forming valve which is disposed in the second liquid passage, opens the second liquid passage during pressure reduction control of antilock brake control, closes it during pressure increase control, and forms an orifice; An exhaust fluid passage communicating with a reservoir for storing brake fluid; an on-off valve arranged in the exhaust fluid passage; and a circulating fluid passage communicating between the reservoir and an upstream of an orifice forming valve of the second fluid passage, The ring Anti-lock braking system, characterized in that it comprises a pump disposed in the fluid path for pumping the brake fluid stored in the reservoir, the. 2. A step having a large diameter portion which is movably fitted in a cylinder to divide a first liquid chamber and a second liquid chamber and which has an orifice communicating with the first and second liquid chambers. An attached plunger; a first liquid passage that connects the master cylinder and the wheel cylinder to each other through the first liquid chamber; and a first liquid passage that is disposed in the first liquid passage and is normally energized by the stepped plunger. A second shut-off valve that opens the fluid passage of No. 2 and shuts off the first fluid passage during anti-lock brake control, and a second shut-off valve that connects the master cylinder and the wheel cylinder through the second fluid chamber and the orifice. A fluid passage, a discharge fluid passage that communicates the second fluid chamber with a reservoir that stores the brake fluid, an opening / closing valve disposed in the discharge fluid passage, and a stepped plunger of the stepped plunger during depressurization control of antilock brake control. The second liquid path is blocked by the end A second cutoff valve; an orifice forming valve which is disposed in the second liquid passage and is opened by an end portion of the stepped plunger during pressure reduction control of antilock brake control; and is closed during pressure increase control and forms an orifice; A circulating fluid passage communicating with a reservoir and an upstream side of the orifice forming valve of the second fluid passage; and a pump arranged in the circulating fluid passage for pumping the brake fluid stored in the reservoir. Anti-lock brake device. 3. The stepped plunger, the first cutoff valve, the second cutoff valve, and the orifice forming valve are arranged on the same axis. Anti-lock brake device. 4. The orifice-forming valve comprises a ball valve body and a die-shaped valve seat having an opening in the center, and the valve seat surface has a radial direction that forms an orifice when the ball valve is seated. 2. A V-shaped groove is formed.
The anti-lock brake device according to any one of 1 to 3. 5. A first fluid passage that connects the master cylinder and the wheel cylinder, a first shutoff valve that is disposed in the first fluid passage and shuts off the first fluid passage during antilock brake control, A second fluid passage that connects the master cylinder and the wheel cylinder to bypass the first shutoff valve, and a second fluid passage that is disposed in the second fluid passage and shuts off the second fluid passage during pressure reduction control of antilock brake control. A second cutoff valve, a first orifice arranged upstream of the second cutoff valve in the second liquid passage, a discharge liquid passage communicating the wheel cylinder with a reservoir storing the brake liquid, and the discharge An on-off valve arranged in the liquid passage, a second orifice arranged in the discharge liquid passage, and a circulating liquid passage communicating between the reservoir and the upstream side of the first orifice of the second liquid passage, It is installed in the circulating fluid path and is stored in the reservoir. An anti-lock brake device comprising: a pump that pumps the brake fluid that has been discharged; and an opening / closing control unit that controls opening / closing of the first cutoff valve and the second cutoff valve. 6. A plunger provided with an orifice that is movably fitted in the cylinder, separates the first liquid chamber and the second liquid chamber, and has an orifice communicating the first and second liquid chambers, and a master cylinder. A first liquid passage communicating with the wheel cylinder via the first liquid chamber, and an antilock brake control which is arranged in the first liquid passage and normally urged by the plunger to open the first liquid passage. A first shut-off valve that sometimes shuts off the first liquid passage; a second liquid passage that connects the master cylinder and the wheel cylinder through the second liquid chamber and the orifice; and the second liquid chamber. And a reservoir for storing brake fluid, an opening / closing valve provided in the drainage passage, and a second shutoff for shutting off the second fluid passage by the plunger during pressure reduction control of antilock brake control. A valve and the second fluid passage 2 An orifice disposed upstream of the shutoff valve, a circulating fluid passage communicating the reservoir with an upstream side of the orifice of the second fluid passage, and a brake fluid disposed in the circulating fluid passage and stored in the reservoir An anti-lock brake device, comprising: 7. The antilock brake device according to claim 6, wherein the second cutoff valve is a poppet valve which is opened and closed at an end of the plunger. 8. The antilock brake device according to claim 6, wherein the second cutoff valve is a spool valve that is opened and closed by a side portion of the plunger.