JPH11291881A - Brake hydraulic control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small and low-cost brake hydraulic control valve well placed on a vehicle capable of changing the hydraulic control starting point of a brake hydraulic pressure according to the weight and height of the vehicle changed depending on the load of the vehicle, speed reduction during braking and side acceleration during turning. SOLUTION: When the speed reduction of a baking time applied to a vehicle is lower than a set value, a plunger 25 is pressed by a first pressing force generated by a spring 28 to limit its movement and, when a speed reduction applied to the vehicle exceeds the set value, the movement thereof is limited by performing pressing based on a second pressing force smaller than the first pressing force of the spring 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a brake fluid pressure control valve, and more particularly, to a brake fluid pressure control valve capable of adjusting a brake fluid pressure supplied to a wheel cylinder.

[0002]

2. Description of the Related Art Conventionally, a brake fluid pressure control valve has a function of optimizing a distribution ratio of a brake fluid pressure supplied to a front wheel cylinder and a rear wheel cylinder, and locking a rear wheel early during braking of a vehicle. The brake fluid pressure control valve is, for example, a proportioning valve.

As shown in FIG. 10, the brake fluid pressure supplied to the rear wheel cylinder has a constant value a.
When the pressure exceeds the (hydraulic pressure control start point), the rear wheel is prevented from locking early during braking or the like by adjusting the brake fluid pressure so as to suppress the rate of increase.
Here, when the weight of the vehicle changes due to the number of luggage or the number of occupants loaded in the vehicle, a brake hydraulic pressure control valve such as a proportioning valve sets the hydraulic pressure control start point at 1 point.
Since it is fixed (set) at a location, there is a problem that the hydraulic pressure control cannot be started at an optimal time.

In order to solve such a problem, there is, for example, a load sensing proportioning valve as shown in FIG. In FIG. 11, reference numeral 1 denotes a housing which is provided on a spring of a vehicle (not shown) and has an inlet chamber 2 communicating with a master cylinder (not shown) and an outlet chamber 3 communicating with a rear wheel cylinder (not shown). A liquid passage 4 that connects the inlet chamber 2 and the outlet chamber 3 is formed inside. A plunger 5 having a valve seat 5 a formed therein is slidably accommodated in the liquid passage 4 in the direction in which the liquid passage 4 communicates.
a is configured to cooperate with the valve member 6 supported by the housing 1 to cut off or secure communication between the liquid passage 4 and the outlet chamber 3 according to the amount of movement of the plunger 5.

[0005] One end of a pressing member 7 is in contact with one end of the plunger 5.
, A second operating member 9 facing away from the plunger 5, and a plunger interposed between the first and second operating members 8, 9 via the first operating member 8. A first spring member 10 for urging the valve 5 in a valve opening direction (A direction in FIG. 11) and a second operating member 9 interposed between the second operating member 9 and the housing 1 in a direction away from the plunger 5. And a second spring member 11 for biasing.

[0006] A lever 12 is attached to the second operating member 9, and the lever 12 has one end 1 a of the housing 1 so that one end of the lever 12 rotates in the sliding direction of the plunger 5.
And the other end is attached to one end of a coil spring 13 as an elastic member. The lever 12 has one end serving as a fulcrum, the other end serving as a power point, and an attachment point attached to the second action member 9 serving as an action point. The other end of the coil spring 13 is a bracket. Because it is attached to the unsprung part of the vehicle via 14 and specifically to the axle provided at the rear of the vehicle,
When the coil spring 13 expands and contracts according to the relative displacement between the sprung part of the vehicle and the axle, the lever 12 expands and contracts the first and second spring members 10 and 11 of the pressing member 7. Therefore, the load sensing proportioning valve can change the hydraulic pressure control start point of the plunger 5 from the point b to the point c as shown in FIG. 12, for example, and controls the brake hydraulic pressure according to the vehicle weight. be able to. Note that point b in FIG. 12 is a hydraulic pressure control start point when a load is loaded, and point c is a hydraulic pressure start point when an empty load is loaded. The following description is based on the case where the vehicle weight changes due to the load. explain.

[0007]

However, in the conventional brake fluid pressure control valve (load sensing proportioning valve), the fluid pressure control start point is changed from the point b to the point c in accordance with the load weight of the vehicle. However, since the valve must be mounted over the sprung and unsprung parts of the vehicle, it is difficult to mount on the vehicle, the number of parts is large, the size is large, and the cost is high. Problem.

Further, the load sensing proportioning valve varies the hydraulic pressure control starting point by the relative displacement between the sprung and the unsprung of the vehicle due to the load of the vehicle.
Since the brake fluid pressure is not controlled by the relationship between brake fluid pressure and deceleration, if the relative displacement of the vehicle changes over time, the control characteristics of the brake fluid pressure will also change. There's a problem.

By the way, when the vehicle turns, it receives a lateral acceleration (so-called lateral G) to increase the lateral speed. However, the vehicle rolls and the load moves to the outer wheel, and the ground contact load of the inner wheel decreases. The frictional force that can be generated between the tire and the road surface is smaller than when the vehicle is traveling straight. At this time, the vehicle turns while restricting the vehicle from sliding due to the cornering force exerted by the frictional force between the tire and the road surface. For this reason, when braking is performed while the lateral acceleration during turning is large, much of the frictional force that can occur between the tire and the road surface is used in the cornering force,
If the braking force is not reduced, the rear wheels will lock early. Conversely, when the lateral acceleration is small, it is known that since the cornering force is small, much of the frictional force that can be generated between the tire and the road surface can be used for the braking force. For this reason, there is also a demand for controlling the brake fluid pressure according to the lateral acceleration during turning of the vehicle.

Accordingly, the present invention is to change the hydraulic pressure control start point of the brake hydraulic pressure according to the vehicle weight, vehicle height, deceleration during braking, and lateral acceleration during turning that change according to the load of the vehicle. It is an object of the present invention to provide a small and low-cost brake fluid pressure control valve having good on-board properties.

[0011]

According to the first aspect of the present invention,
In order to achieve the above object, a housing in which an inlet chamber communicating with a master cylinder and an outlet chamber communicating with a wheel cylinder are formed and a liquid passage communicating the inlet chamber and the outlet chamber therein are formed, And a plunger which is moved in accordance with the pressure of the brake fluid from the master cylinder introduced from the inlet chamber and cooperates with a valve seat provided in the fluid passage and formed in the plunger in accordance with the movement of the plunger. A valve member for interrupting or securing the communication between the inlet chamber and the outlet chamber; and a valve member provided at one end of the plunger for urging the plunger in a direction to separate the valve seat from the valve member to secure the communication between the inlet chamber and the outlet chamber. And a biasing member, wherein the biasing force of the biasing member is at least a first biasing force and a first biasing force smaller than the first biasing force. Biasing force varying means for varying between biasing forces, state detecting means for detecting a state of the vehicle, and control means for controlling the biasing force varying means based on detection information of the state of the vehicle, It is a feature.

According to a second aspect of the present invention, in order to achieve the above object, in the first aspect of the present invention, the state detecting means detects a deceleration applied to the vehicle during braking, and the control means detects the deceleration. Is smaller than a set value, the urging member is set to a first urging force, and when the deceleration is equal to or larger than a set value, the urging member is set to a second urging force. Is controlled.

According to a third aspect of the present invention, in order to achieve the above object, in the first aspect of the present invention, the state detecting means detects a lateral acceleration applied to the vehicle at the time of turning, and the control means controls the lateral acceleration. Is smaller than a set value, the urging member is set to a first urging force, while when the lateral acceleration is equal to or larger than a set value, the urging member is set to a second urging force. Is controlled.

According to a fourth aspect of the present invention, in order to achieve the above object, in the first aspect of the present invention, the state detecting means detects a deceleration and a lateral acceleration applied to the vehicle at the time of turning, and the control means When the deceleration and the lateral acceleration are smaller than the set values, the urging member is set to the first urging force, and when one of the deceleration and the lateral acceleration is equal to or larger than the set value, the urging member is set to the first urging force. The present invention is characterized in that the biasing force variable means is controlled so as to set the biasing force to two.

According to a fifth aspect of the present invention, in order to achieve the above object, in the first aspect of the present invention, the state detecting means detects a vehicle weight, and the control means detects the vehicle weight when the vehicle weight is equal to or more than a set value. Setting the urging member to the first urging force, and controlling the urging force varying means to set the urging member to the second urging force when the vehicle weight is less than a set value. It is.

According to a sixth aspect of the present invention, in order to achieve the above object, in the first aspect of the present invention, the state detecting means detects a vehicle height, and the control means determines whether the vehicle height is less than a set value. While the urging member is set to a first urging force,
When the vehicle height is equal to or more than a set value, the urging force variable means is controlled so as to set the urging member to the second urging force.

According to a seventh aspect of the present invention, in order to achieve the above object, in the first aspect of the present invention, the state detecting means detects both a vehicle weight and a lateral acceleration applied to the vehicle at the time of turning, and performs the control. The means sets the urging member to the first urging force when the vehicle weight is equal to or greater than the set value,
When the vehicle weight is less than the set value, the urging member is moved to the second position.
An urging force is set, and the urging force variable means is controlled so as to set the urging member to a second urging force when the lateral acceleration becomes equal to or greater than a set value.

According to an eighth aspect of the present invention, in order to achieve the above object, in the first aspect of the present invention, the state detecting means detects both a vehicle height and a lateral acceleration applied to the vehicle at the time of turning, and The means sets the urging member to the first urging force when the vehicle height is less than the set value, and sets the urging member to the second urging force when the vehicle height is equal to or more than the set value. When the acceleration becomes equal to or more than a set value, the urging force variable means is controlled so as to set the urging member to the second urging force.

According to the first to eighth aspects of the present invention, for example, the deceleration at the time of braking applied to the vehicle, the lateral acceleration at the time of turning, or the vehicle weight is set according to the detected state of the vehicle. The plunger is biased by the biasing member with the first biasing force when the vehicle height is equal to or greater than the value or when the vehicle height is less than the set value, or in combination with the vehicle height, and the movement thereof is restricted. Therefore, when the deceleration is small, the vehicle weight is large, the vehicle height is low, or the lateral acceleration is small due to the large loaded weight of the vehicle, the hydraulic pressure control start timing is variably controlled to start the hydraulic pressure control. The point can be set high, and the braking force can be sufficiently increased.

On the other hand, when the deceleration or the lateral acceleration is equal to or more than the set value, the vehicle weight is less than the set value, or the vehicle height is equal to or more than the set value, or the combination thereof, the plunger is smaller than the first urging force. The movement is restricted by the second biasing force. Therefore, when the deceleration is large, the vehicle weight is small, the vehicle height is high, or the lateral acceleration is large due to the small loaded weight of the vehicle, the hydraulic pressure control start timing is variably controlled to start the hydraulic pressure control. The point can be set low and the braking force can be reduced to a level that does not lock early.

Therefore, when the load weight is large or when the frictional force between the tire and the road surface which can be used for braking during turning can be increased, the urging force for urging the plunger is increased so that the hydraulic pressure control start timing is increased. If the load weight is small or the frictional force between the tire and the road surface that can be used for braking when turning is small, the hydraulic pressure control start timing must be set to a low brake pressure without increasing the urging force. However, there is a variable control of the hydraulic pressure control start time by indirectly detecting the load weight from the vehicle deceleration, vehicle weight or vehicle height, and the frictional force between the tire and the road surface that can be used for braking during turning from the lateral acceleration. And the brake pressure supplied to the wheel cylinder can be appropriately controlled.

According to a ninth aspect of the present invention, in order to achieve the above object, in the invention of the fifth or sixth aspect, an additional detecting member for detecting a running state of the vehicle or a braking state of the vehicle is provided, and Does not change the setting of the urging member based on the detection information from the additional detection means, even if the detection information of the vehicle weight or the vehicle height from the state detection means changes during running or braking of the vehicle. It is characterized by:

In this case, the urging member is set in advance to the first urging force or the second urging force according to the vehicle weight or the vehicle height, and the position of the urging member is changed during running or braking of the vehicle. By not allowing the vehicle to move, a change in vehicle state (disturbance) caused by a dynamic behavior of the vehicle such as a load transfer from the rear wheel to the front wheel (a so-called nose dive) generated during braking.
, And the decompression start timing can be controlled with high accuracy.

According to a tenth aspect of the present invention, in order to achieve the above object, in the first or ninth aspect of the present invention, the state detecting means detects a lateral acceleration applied to the vehicle at the time of turning, and the control means Even if the vehicle is braking at least, the biasing force varying means is controlled so that the biasing member is set to the second biasing force when the lateral acceleration becomes equal to or greater than a set value. .

In this case, by setting the urging member to the second urging force at least when the magnitude of the lateral acceleration is equal to or greater than the set value, the vehicle weight is large because the loaded weight of the vehicle is large, or Even when the vehicle height is low, when the lateral acceleration increases, the hydraulic pressure control start timing can be variably controlled to set the hydraulic pressure control start point low, so that the braking force is not locked early. can do.

According to an eleventh aspect of the present invention, in order to achieve the above object, in the invention according to any one of the first to fourth aspects, the brake fluid pressure reduction speed control start timing is reduced after the first start timing. A controlled low pressure first brake fluid pressure characteristic;
A high-pressure second brake fluid characteristic that is depressurized and controlled at a second start time higher than the first start time, wherein the control means detects the brake fluid pressure in the fluid passage by pressure detection. When the deceleration or the lateral acceleration is less than a set value when the brake fluid pressure is lower than the first start timing, the urging member is set to the first urging force and the second brake fluid is detected. A pressure characteristic is selected, and when the deceleration or the lateral acceleration is equal to or greater than a set value, the urging member is set to a second urging force to select a first brake hydraulic pressure characteristic.

In this case, the original first brake is determined depending on whether the deceleration or the lateral acceleration is smaller than the set value or larger than the set value when the brake fluid pressure reduction control start timing is smaller than the first start timing. By selecting the hydraulic pressure characteristic and the second brake hydraulic pressure characteristic, optimal brake hydraulic pressure control according to the vehicle weight and the lateral acceleration can be performed.

According to a twelfth aspect of the present invention, in order to achieve the above object, in the second aspect of the present invention, the state detecting means detects a lateral acceleration applied to the vehicle at the time of turning. The control means sets the urging member to the second urging force when the lateral acceleration becomes equal to or greater than a set value when the urging force variable member sets the urging member to the first urging force. When the lateral acceleration is less than a set value, the urging force variable member is controlled so as to set the urging member to the first urging force.

This is because the deceleration or the lateral acceleration is less than the set value or greater than the set value when the deceleration control start timing of the brake fluid pressure is smaller than the first start timing. The first brake fluid pressure characteristic and the second brake fluid pressure characteristic are selected depending on whether or not there is a difference between the first and second brake fluid pressure characteristics. When the pressure reduction control is being performed with the brake fluid pressure characteristic of the above, the lateral acceleration may be increased even while the pressure reduction control is being performed with the second brake fluid pressure characteristic which is a high brake pressure adopted when the vehicle weight is large. When the value exceeds the set value, the frictional force between the tire and the road surface that can be used for braking during turning becomes small, so the first brake fluid pressure characteristic that is low brake pressure without increasing the urging force of the urging member. Can be set (changed).

Thereafter, when the degree of turning is eased and the lateral acceleration returns below the set value, the frictional force available for braking also increases (returns), so that the urging force of the urging member is returned to the first urging force. Thereby, the urging force of the urging member can be increased to set (change) the second brake fluid pressure characteristic which is a high brake pressure. Here, the deceleration refers to the magnitude of the temporal change in acceleration at which the speed in the traveling direction of the vehicle decreases when the brake is applied to the vehicle by stepping on the brake during traveling. The lateral acceleration refers to a magnitude of a lateral acceleration that increases the right or left speed of the vehicle in response to a so-called lateral G when turning right or left.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 and 2 are views showing a first embodiment of a brake fluid pressure control valve according to the present invention, and correspond to any one of the first to eleventh aspects of the present invention. First, the configuration will be described. FIG.
, 21 is a housing that houses a brake fluid pressure control valve disposed on the spring of the vehicle, and the brake fluid pressure control valve constructed in the housing 21 is not shown, but is provided on the front wheel cylinder. It is interposed between the master cylinder that supplies brake fluid and the rear wheel cylinder.

The housing 21 has an inlet chamber 22 communicating with the master cylinder and an outlet chamber 23 communicating with the rear wheel cylinder.
A liquid passage 24 is formed to communicate the outlet chamber 23 and the liquid passage 24. A plunger 25 is slidably accommodated in the liquid passage 24. The plunger 25 is guided slidably in the communication direction within the liquid passage 24 by an elastic member 26, and the liquid passage 24 is sealed by the elastic member 26.

The liquid passage 24 extends from the inlet chamber 22 to the outlet chamber 23.
A valve member 27 is attached to a reduced-diameter portion adjacent to the outlet chamber 23. A spring (biasing member) is provided at the lower end of the plunger 25.
The spring 28 is provided with a sliding plate 29 slidable in the housing 21 on one end and held by a holder 30 slidable in the housing 21 on the other end. .

When the pressure of the brake fluid introduced into the fluid passage 24 is lower than a set value, the spring 28
25 is urged upward in the figure to ensure communication between the inlet chamber 22 and the outlet chamber 23, and when the brake fluid pressure supplied into the fluid passage 24 exceeds a set value, the plunger 25 is In the drawing, by allowing the plunger 25 to move downward, the valve seat 25a on the upper end side of the plunger 25 is pressed against (cooperates with) the valve member 27 to establish communication between the inlet chamber 22 and the outlet chamber 23. Shut off and start pressure reduction control.

On the other hand, the holder 30 is a plunger made of a magnet.
The plunger 31 is slidably provided in a slide groove 33a formed in a holding member 33 for holding the coil 32, and slides when excited by the coil 32. It protrudes from the moving groove 33a. When the spring 28 protrudes from the sliding groove 33a, the spring 28 is reduced by pressing the holder 30. Further, a stopper member 34 is provided on the inner peripheral surface of the housing 21, and the end of the holder 30 abuts on the stopper member 34 to restrict the movement of the holder 30.

In this embodiment, when the coil 32 is excited,
The plunger 31 presses the holder 30 by the distance L to abut against the stopper member 34, contracts the spring 28, and urges the plunger 25 with the first urging force. When the excitation of the coil 32 is stopped, the spring 28 presses the plunger 31 via the holder 30 to push the plunger 31 into the slide groove 33a, thereby expanding the spring 28 and applying the first urging force. Also, the plunger 25 is urged with a small second urging force. The holder 30, the plunger 31, and the coil 32
Constitutes a biasing force varying means.

On the other hand, the coil 32 is turned on / off (excited / non-excited) by a controller (control means) 35, and the controller 35 includes an acceleration sensor (state detection means) 36 and a hydraulic pressure sensor (pressure sensor). Detection means)
From 37, the coil 32 is turned on / off based on the input signal. The acceleration sensor 36 detects the magnitude of the temporal change in acceleration in which the speed in the traveling direction of the vehicle decreases when the braking force is applied to the vehicle by stepping on the brake during traveling, that is, detecting the deceleration. , The magnitude of this deceleration at a certain point (set value) is detected and the controller 35
Output.

The controller 35 turns on the coil 32 to set the spring 28 to the first urging force when the deceleration is smaller than the set value, based on the detection information of the acceleration sensor 36, while the deceleration becomes equal to or larger than the set value. Sometimes, the coil 32 is turned off to set the spring 28 to the second urging force. Also, the hydraulic pressure sensor 37 is connected to the inlet chamber from the master cylinder.
It is composed of a pressure sensor and the like provided at an arbitrary position in the pipe up to 22. By detecting the brake fluid pressure in this pipe, the brake fluid pressure in the fluid passage 24 is indirectly detected. ing.

The controller 35 turns on / off the coil 32 based on the detection information and the detection information from the acceleration sensor 36.
F control is performed. Next, the operation will be described.
First, when the brake fluid pressure Pm is supplied from the master cylinder into the fluid passage 24 via the inlet chamber 22 during braking of the vehicle,
The brake fluid pressure Pm is supplied from the fluid passage 24 to the rear wheel cylinder via the outlet chamber 23 as the brake fluid pressure Pr, and the rear wheel is braked. When the downward force acting on the plunger 25 by the brake fluid pressure Pm (Pf) supplied into the fluid passage 24 becomes greater than the urging force of the spring 28, the plunger 25 starts moving downward in the figure. Then, the valve seat 25a comes into contact with the valve member 27, and pressure reduction control of the brake hydraulic pressure Pr supplied to the rear wheel cylinder via the outlet chamber 23 is started.

At this time, when the hydraulic pressure sensor 37 is detecting the brake hydraulic pressure Pm below the hydraulic pressure control start point e (first start timing) in FIG. Is detected, the controller 35 excites the coil 32, so that the plunger 31 projects from the sliding groove 33a and presses the holder 30. At this time, since the holder 30 moves by the distance L until it comes into contact with the stopper member 34, the spring 28 contracts and urges the plunger 25 with a large first urging force. Timing), the hydraulic pressure control start timing is shifted so that the supply of the brake hydraulic pressure Pr to the rear wheel cylinder is maintained until the brake hydraulic pressure Pm reaches the high brake hydraulic pressure Pm, and the brake fluid reaches the hydraulic pressure control start point d. When the pressure has shifted to the pressure Pm, the pressure reduction control of the brake fluid pressure Pr is performed at the output fluid pressure indicated by f (second brake fluid pressure characteristic).

As a result, when the deceleration due to the braking of the vehicle is small due to the large load weight, a higher brake fluid pressure Pm can be supplied to the rear wheel cylinder as the brake fluid pressure Pr, and sufficient braking pressure can be obtained when the vehicle goes straight. Power can be obtained. On the other hand, when the acceleration sensor 36 detects a deceleration equal to or more than the set value while the hydraulic pressure sensor 37 is detecting the brake hydraulic pressure Pm below the hydraulic pressure control start point e in FIG. The coil 32 is not excited and remains in the initial state. At this time, the spring 28 urges the plunger 31 via the holder 30 and retracts the plunger 31 into the slide groove 33a, so that the spring 28 expands and urges the plunger 25 with the second urging force.

At this time, the plunger 25 is urged by a small urging force, and the hydraulic pressure control start timing at which the valve seat 25a comes into pressure contact with the valve member 27 is shifted to a low brake hydraulic pressure indicated by a point e in FIG. Brake fluid pressure Pm reaching pressure control start point e
, The pressure reduction control of the brake hydraulic pressure Pr is performed at the output hydraulic pressure indicated by the line g (first brake hydraulic pressure characteristic). As a result, when the deceleration with respect to the brake fluid pressure Pm at the time of braking is large because the load weight is small, the brake fluid pressure Pr which started the pressure reduction control with the low brake fluid pressure Pm can be supplied to the rear wheel cylinder. The braking can be applied without the wheels being locked early.

That is, in the present embodiment, the hydraulic pressure control start point can be changed in two steps from e or d depending on the magnitude of the deceleration applied to the vehicle. As described above, in the present embodiment, when the deceleration at the time of braking applied to the vehicle is less than the set value, the plunger 25 is biased by the first biasing force by the spring 28, and the movement is limited.
When the deceleration is small due to the heavy load of the vehicle, the hydraulic pressure control start timing can be variably controlled to set the hydraulic pressure control start point high, and the braking force can be sufficiently increased.

When the deceleration applied to the vehicle is equal to or greater than the set value, the spring 28 is urged by the second urging force smaller than the first urging force to limit the movement thereof. When the deceleration is large, the hydraulic pressure control start timing can be variably controlled to set the hydraulic pressure control start point low, and the braking force can be prevented from being locked early. .

In particular, in this embodiment, when the deceleration control start timing of the brake fluid pressure is smaller than the point e, the deceleration is indicated by an original line g depending on whether the deceleration is smaller than the set value or larger than the set value. By selecting the first brake fluid pressure characteristic and the second brake fluid pressure characteristic indicated by the line f, it is possible to perform optimal brake fluid pressure control according to the weight of the vehicle.

In this embodiment, the acceleration sensor 36 detects the deceleration at the time of braking of the vehicle. Alternatively, the lateral acceleration at the time of turning of the vehicle may be detected. That is, when the vehicle makes a right or left turn, a so-called lateral acceleration sensor is provided to detect the magnitude of the lateral acceleration that increases the right or left speed of the vehicle in response to the so-called lateral G. Detecting information from the sensor to the controller 35
The controller 35 changes the biasing force of the spring 28 by turning on / off the coil 32 based on the detection information from the lateral acceleration sensor and the hydraulic pressure sensor 37 before the point e.

When the lateral acceleration sensor detects a lateral acceleration smaller than the set value, the controller 35 excites the coil 32 and urges the plunger 25 by the spring 28 with a large first urging force. At this time, the hydraulic pressure control start timing can be variably controlled to set the hydraulic pressure control start point high, and the braking force during turning can be sufficiently increased. When the lateral acceleration sensor detects a lateral acceleration equal to or greater than the set value, the controller 35 stops exciting the coil 32 and urges the spring 28 to the plunger 25 with a smaller second urging force. At this time, the brake fluid pressure Pr whose pressure reduction control has been started at the low brake fluid pressure Pm can be supplied to the rear wheel cylinder, and braking can be applied without locking the rear wheel early during vehicle turning.

The deceleration at the time of braking of the vehicle is detected by one acceleration sensor 36. Instead, the deceleration and the acceleration are detected by both the acceleration sensor and the lateral acceleration sensor to control. You may. That is, in addition to the acceleration sensor 36, a lateral acceleration sensor for detecting the magnitude of the lateral acceleration is provided, and the detection information from both sensors is output to the controller 35, whereby the controller
35 turns on / off the coil 32 based on the detection information from the lateral acceleration sensor and the hydraulic pressure sensor 37, and
Variable the biasing force of 28.

That is, when the acceleration sensor and the lateral acceleration sensor detect a deceleration and a lateral acceleration smaller than the set values at a certain Pm value before the point e, the controller 35
Excites the coil 32 and the plunger 25 by the spring 28
Is biased with a large first biasing force. At this time, the hydraulic pressure control start timing is variably controlled so that the hydraulic pressure control start point can be set high, and the braking force can be sufficiently increased.

When one of the acceleration sensor and the lateral acceleration sensor (both may be simultaneous) detects a deceleration or a lateral acceleration exceeding a set value, the controller 35 controls the excitation of the coil 32. It stops and urges the plunger 25 to the spring 28 with a smaller second urging force. At this time, the brake fluid pressure Pr whose pressure reduction control has been started at the low brake fluid pressure Pm can be supplied to the rear wheel cylinder, and braking can be applied without the rear wheel being locked early.

The vehicle weight may be detected instead of the acceleration sensor 36 or the lateral acceleration sensor. As this sensor, a load sensor may be provided somewhere on the member that receives the sprung weight of the vehicle, and the load sensor may detect the sprung weight, and may detect the distortion of the member that receives the sprung weight of the vehicle. A sensor may be provided. In the present embodiment, since the hydraulic pressure of the rear wheels is controlled, these sensors may be arranged so as to be able to detect the weight of the vehicle that the rear wheels cover.

When the vehicle weight is less than the set value, the coil 28 is not excited and the initial state is maintained.
Is set to the second biasing force, and when the vehicle weight becomes equal to or greater than the set value, the coil 32 is excited and the spring 28 is set to the first
By setting the biasing force, when the vehicle weight is large due to the large load weight of the vehicle, the hydraulic pressure control start timing can be variably controlled to set the hydraulic pressure control start point low,
In addition to being able to prevent the braking force from being locked early, when the vehicle weight is small due to the small loaded weight of the vehicle, the hydraulic pressure control start timing is variably controlled to start the hydraulic pressure control. Can be set high, and the braking force can be sufficiently increased.

Further, instead of detecting the acceleration sensor, the lateral acceleration sensor or the vehicle weight, the vehicle height may be detected. In this case, the sprung distance of the vehicle with respect to the ground may be directly detected, or the relative distance between the sprung and the unsprung may be detected. When the vehicle height is equal to or higher than the set value (the vehicle height is high), the coil 28 is not excited and the spring 28 is set to the second biasing force while the initial state is maintained, while the vehicle height is lower than the set value (the vehicle height is lower). (Low), the coil 32 is excited to set the spring 28 to the first biasing force, so that when the load weight is small and the vehicle height is high,
The start point of the hydraulic pressure control can be variably controlled to set the start point of the hydraulic pressure control high, so that the braking force can be sufficiently increased, and in addition, when the vehicle height is low due to the heavy load of the vehicle. In addition, the hydraulic pressure control start timing can be variably controlled to set the hydraulic pressure control start point low, so that the braking force can be prevented from being locked early.

In addition to detecting either the vehicle weight or the vehicle height, the brake fluid pressure may be controlled based on detection information from a lateral acceleration sensor. That is, the controller 35 detects both the vehicle weight and the lateral acceleration applied to the vehicle at the time of turning. Based on the detection information from the lateral acceleration sensor and the weight sensor, when the vehicle weight is equal to or more than the set value, the controller 28 applies the first biasing force to the spring 28. On the other hand, when the vehicle weight is less than the set value, the spring 28 is set to the second urging force, and when the lateral acceleration is equal to or more than the set value, the spring 28 is set to the second urging force. Control the variable means.

The controller 35 detects both the vehicle height and the lateral acceleration applied to the vehicle at the time of turning. Based on the detection information from the lateral acceleration sensor and the vehicle height sensor, the controller 28 activates the spring 28 when the vehicle height is less than the set value. While the first urging force is set, when the vehicle height is equal to or higher than the set value, the spring
28 is set to the second urging force, and the urging force variable means is controlled so as to set the spring 28 to the second urging force when the lateral acceleration becomes equal to or greater than the set value.

In any of these controls, when the vehicle weight is large, the vehicle height is low, and when the lateral acceleration is small, the hydraulic pressure control start timing is variably controlled because the vehicle weight is large. The hydraulic control start point can be set high, and the braking force can be sufficiently increased. On the other hand, when the weight of the vehicle is small, the vehicle weight is small, the vehicle height is high, or when the lateral acceleration is large, the hydraulic pressure control start timing is variably controlled to set the hydraulic pressure control start point low. Therefore, the braking force can be prevented from being locked early.

Therefore, when the load weight is large and the frictional force between the tire and the road surface that can be used for braking during turning can be increased, the urging force for urging the plunger is increased to increase the hydraulic pressure control start timing. If the load weight is small or the frictional force between the tire and the road surface that can be used for braking when turning is small, the hydraulic pressure control start timing is set to low brake pressure without increasing the urging force. It is necessary to indirectly detect the load weight from the vehicle weight or the vehicle height of the vehicle and the frictional force between the tire and the road surface that can be used for braking during turning from the lateral acceleration, and variably control the hydraulic pressure start timing. Thus, the brake pressure supplied to the wheel cylinder can be appropriately controlled.

When the brake fluid pressure is controlled by detecting the vehicle weight or the vehicle height, it is detected that the vehicle is running or braking by a sensor that detects the running or braking state of the vehicle. When the vehicle is running or braking, the setting of the urging member (setting of the first urging force or the second urging force) is changed even if the detection information of the vehicle weight or the vehicle height changes. It is conceivable not to do so.

The running state may be detected, for example, by directly detecting that the vehicle speed (or wheel speed) may be generated, by releasing the parking brake, or by setting the transmission to the running mode. This may be detected and substituted. In short, it is only necessary to detect that the vehicle is in a running state. The detection of the braking state may be, for example, detection of operation of a brake pedal, occurrence of brake fluid pressure, or occurrence of vehicle deceleration. The point is that it is only necessary to detect that the braking has started.

Specifically, according to the vehicle weight or the vehicle height (between ignition 0N and before the vehicle starts running or braking), the spring 28 is set to the first urging force or the second urging force. If set, that is, if the vehicle weight is large or the vehicle height is low, the controller 35 excites the coil 32 to increase the urging force of the spring 28, and if the vehicle weight is small or the vehicle When the height is high, the coil 32 is not excited by the controller 35, and the biasing force of the spring 28 is reduced in the initial state.

By maintaining this state after the running or braking of the vehicle is started, for example, dynamic movement such as load movement from the rear wheel side to the front wheel side (so-called nose dive) generated at the start of braking, and the like. Therefore, it is possible to control the decompression start timing with high accuracy by eliminating a change (disturbance) in the vehicle state caused by the unusual behavior. In addition, even when the vehicle is being braked, based on the detection information from the lateral acceleration sensor, the biasing force variable means may be controlled so that the spring 28 is set to the second biasing force when the lateral acceleration becomes equal to or more than the set value. It is possible.

In this manner, when at least the magnitude of the lateral acceleration is equal to or greater than the set value, the spring 28 is set to the second urging force, so that the weight of the vehicle is large and the weight of the vehicle is large. , Or even at low heights,
When the lateral acceleration increases, the hydraulic pressure control start timing can be variably controlled to set the hydraulic pressure control start point low, and the braking force can be prevented from being locked early.

FIGS. 3 and 4 are views showing a second embodiment of the brake fluid pressure control valve according to the present invention, and correspond to the twelfth aspect of the present invention. In the present embodiment, since the configuration of the brake fluid pressure control valve is the same as that of the first embodiment,
Although the same configuration as that of the first embodiment will be described with reference to FIG. 1, in the present embodiment, the acceleration sensor 36 performs the same operation as the first embodiment with one or more parameters of deceleration, vehicle weight, and vehicle height. The control is performed by adding the lateral acceleration as an essential parameter to the control.

Hereinafter, a specific description will be given with reference to FIGS. In the first embodiment, the original g (first brake hydraulic pressure) is determined based on the deceleration, the lateral acceleration, the vehicle weight, and the vehicle height before reaching the hydraulic pressure control start point e (first start timing). Characteristic) and f (second brake hydraulic pressure characteristic) are controlled by a straight line. That is, when the acceleration sensor 34 detects that the deceleration and lateral acceleration are less than the set value, the vehicle weight is equal to or more than the set value, and the vehicle height is less than the set value before reaching the point e, the controller 35 detects the coil 32.
And the spring 28 is set to the first urging force to urge the plunger 25 with a high urging force, thereby performing pressure reduction control with the original brake fluid pressure characteristic indicated by f.

On the other hand, before reaching the point e, the acceleration sensor 34
Before reaching the point e, the acceleration sensor 34 determines that the deceleration and lateral acceleration are equal to or greater than the set value, the vehicle weight is less than the set value,
When it is detected that the vehicle height is equal to or higher than the set value, the spring 35 is set to the second urging force and the plunger 25 is applied with a low urging force without exciting the coil 32 (in the initial state) by the controller 35. As a result, the pressure reduction control is performed with the original brake fluid pressure characteristic indicated by g.

On the other hand, in the present embodiment, regardless of the value of the brake fluid pressure (Pm) (regardless of whether it is less than the point e or more), the control of the biasing force variable member based on the detection information of the lateral acceleration is performed. Things. Specifically, in the case where the vehicle information is set to the first urging force in the detection information other than the lateral acceleration, the second urging force is set when the lateral acceleration becomes equal to or greater than the set value regardless of Pm. After that, when the lateral acceleration becomes less than the set value, the original first urging force is set.

FIGS. 3 (a) and 3 (b) show that while the pressure reduction control is being performed with the original brake fluid pressure characteristic indicated by f beyond the point e, the lateral acceleration exceeds the set value and the deceleration, Regardless of any value of the vehicle weight, vehicle height, and brake fluid pressure, the controller 35 stops exciting the coil 32, reduces the urging force of the spring 28, and sets the brake fluid pressure characteristic in g. This is an example in the case where the brake fluid pressure characteristic is changed (shifted) as shown.

On the other hand, FIGS. 4 (a) and 4 (b) show that since the lateral acceleration has become equal to or greater than the set value before the point e, the pressure reduction control is performed by using the original brake fluid pressure characteristic indicated by g after the point e. When the lateral acceleration returns to a value less than the set value, the controller 35 excites the coil 32 by the controller 35 regardless of the values of any parameters such as deceleration, vehicle weight, vehicle height, and brake fluid pressure. The brake fluid pressure characteristic is changed to the brake fluid pressure characteristic indicated by f by increasing the urging force (shift).
This is an example in the case of performing.

It should be noted that the characteristic change (shift) diagram may be a combination of the above-described examples depending on when the lateral acceleration exceeds the set value or returns to below the set value during the pressure reduction control. Also, the shift may be repeated. This is because the frictional force between the tires available for braking and the road surface changes based on the turning state of the vehicle accompanying the turning operation independent of the braking operation (the larger the lateral acceleration, the more available friction (The force decreases.) Therefore, regardless of the braking operation state (the magnitude of Pm), if the lateral acceleration exceeds the set value, shift to low brake pressure, and if the lateral acceleration returns below the set value, shift to high brake pressure. It is to make it.

FIG. 5 is a view showing a third embodiment of the brake fluid pressure control valve according to the present invention, and corresponds to any one of the first to twelfth aspects of the present invention. In the present embodiment, a brake fluid pressure valve of a type that detects a failure of brake fluid supplied to the front wheel cylinder is taken as an example, and the same components as those in the first embodiment are denoted by the same reference numerals. The description is omitted. Further, since the contents of the control are the same as those of the first and second embodiments, only a method of detecting a brake failure will be described.

An auxiliary inlet chamber into which the brake fluid pressure Pf which is not subjected to fluid pressure control and is branched from the front wheel cylinder and is communicated with the master cylinder is input to the housing 21.
The auxiliary inlet chamber 122 is provided with a brake fluid pressure Pf to be supplied to the front wheel cylinder at the rear end of the plunger 25 which slides in the fluid passage 24 and communicates with the inside of the fluid passage 24 so that the spring 28 The brake fluid pressure for sliding the plunger 25 against the elastic force is supplementarily input.

Accordingly, the brake fluid pressure Pf supplied to the auxiliary inlet chamber 122 serves as a brake fluid pressure for detecting the occurrence of a failure in the brake system of the front wheel cylinder.
The plunger 25 acts on the rear end of the plunger 25 and pushes the plunger 25 downward in the drawing. However, if a failure occurs in the brake system of the front wheel cylinder, the brake fluid pressure Pf acts on the rear end of the plunger 25. Disappears. For this reason, the plunger 25
If the brake fluid pressure Pm supplied into the fluid passage 24 alone does not move by a predetermined amount or more against the urging force of the spring 28, the pressure reduction control of the brake fluid pressure Pr supplied to the rear wheel cylinder can be started. Can not.

As a result, when a failure occurs in the brake system of the front wheel cylinder, the vehicle can be braked by supplying a higher brake fluid pressure Pm to the rear wheel cylinder than in a normal case. Brake system failure is compensated. 6 and 7 are views showing a fourth embodiment of the brake fluid pressure control valve according to the present invention, and correspond to any one of the first to twelfth aspects. The present embodiment is an example in which the brake fluid pressure control valve is applied to a dual valve type.

The second embodiment is characterized in that two plungers are provided to make the brake system independent from the brake fluid pressure control shown in the first embodiment. The same reference numerals are given and the description is omitted, and the same brake fluid pressure control as in the first and second embodiments can be obtained, but the description is omitted. The brake fluid pressure control valve is a master cylinder that supplies brake fluid to a fluid chamber side of a master cylinder that supplies brake fluid to a right front wheel cylinder and a left rear wheel cylinder, and a brake fluid to a left front wheel cylinder and a right rear wheel cylinder. It is used for a so-called X pipe that is interposed between two brake fluid passages on the fluid chamber side of the cylinder.

A pair of inlet chambers 22 and a pair of outlet chambers 23 corresponding to the respective liquid passages 24 are formed in the housing 21, and one side of the inlet chamber 22 is provided with a brake from one of the liquid chambers of the master cylinder. The brake fluid is supplied to the other side of the inlet chamber 22 from the other fluid chamber of the master cylinder. The sliding plate 29 is engaged with an engaging plate 41 via a projection 40, and the engaging plate 41 holds the pair of plungers 25 from below with the projection 40 as a fulcrum.

In this embodiment, when the acceleration sensor 36 detects a deceleration lower than the set value, the controller 35 excites the coil 32, so that the plunger 31 projects from the sliding groove 33a and presses the holder 30. I do. At this time, since the holder 30 moves until it comes into contact with the stopper member 34, the spring 28 contracts and urges the pair of plungers 25 with a large first urging force.

When the acceleration sensor 36 detects a deceleration equal to or greater than the set value, the controller 35 stops exciting the coil 32. At this time, the spring 28
In order to urge the plunger 31 via 30 and to retract the plunger 31 into the slide groove 33a, the spring 28 expands and urges the pair of plungers 25 with a small second urging force. As a result, the same effect as in the first embodiment can be obtained.

FIG. 8 is a view showing a fifth embodiment of the brake fluid pressure control valve according to the present invention, and corresponds to any one of the first to twelfth aspects of the present invention. In the present embodiment, the first
The same components as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted. The brake fluid pressure control is the first,
The same one as in the second embodiment can be obtained, but the description is omitted.

A plunger 25 is slidably housed in the liquid passage 24. The plunger 25 is slidably guided in the liquid passage 24 by a guide member 51.
An elastic member 52 such as rubber is provided between the guide member 25 and the guide member 51 to seal the inside of the liquid passage 24. Further, a spring 53 as an urging member is provided in the liquid passage 24, and the spring 53 is interposed between the retainer 54 and the plunger 25,
By urging the plunger 25 upward in FIG. 8, the valve seat 25a is separated from the valve member 27, and the communication between the liquid passage 24 and the outlet chamber 23 is ensured.

A plunger 55 made of a magnet is opposed to the lower end of the plunger 25. The plunger 55 is a sliding groove 57a formed in a holding member 57 for holding the coil 56.
Are slidably provided, and are urged by a spring 58 to be retracted into the sliding groove 57a. At this time, the plunger
When the brake fluid pressure greater than the urging force of the spring 53 alone is supplied into the fluid passage 24, the bracket 25 moves downward in FIG.

When the plunger 55 is excited by the coil 56, the plunger 55 resists the urging force of the spring 58.
Project from the sliding groove 57a and come into contact with the plunger 25. At this time, the plunger 25 is
When a brake fluid pressure larger than the combined force of the urging force of the coil 56 and the exciting force of the coil 56 is supplied into the fluid passage 24, it moves downward in FIG.

That is, in this embodiment, as in the first embodiment, the coil 56 is turned on / off based on the output signal from the controller 35, so that the urging force for urging the plunger 25 upward is the first. The biasing force is changed between a biasing force and a second biasing force smaller than the first biasing force. In this embodiment, the plunger 55 and the coil
The spring 56 and the spring 58 constitute biasing force variable means.

Next, the operation will be described. This embodiment is different from the first embodiment only in the structure of the brake fluid pressure control valve, and the control method is the same as that of the first embodiment. Therefore, only the brake fluid pressure control based on the acceleration sensor 36 is performed. Will be described. When the acceleration sensor 36 detects a deceleration less than the set value during braking of the vehicle, the controller 35 excites the coil 56, so that the plunger 55 projects from the sliding groove 57a against the urging force of the spring 58. Contact the plunger 25. At this time, the plunger 25 is urged by the urging force of the spring 53 and the exciting force of the coil 56.

Then, the brake fluid pressure Pm is
8, the plunger 25 moves downward in FIG. 8 against the urging force of the spring 53 and the exciting force of the coil 32, and the valve seat 25a comes into pressure contact with the valve member 27. At this time, at point d in FIG. As shown, the hydraulic pressure control start timing is shifted so that the supply of the brake hydraulic pressure Pr to the rear wheel cylinder is maintained until the brake hydraulic pressure Pm reaches the high brake hydraulic pressure Pm. At the time of the shift, the pressure reduction control of the brake hydraulic pressure Pr is performed at the output hydraulic pressure indicated by f.

As a result, when the deceleration due to the braking of the vehicle is small due to the large load weight, a higher brake fluid pressure Pm can be supplied to the rear wheel cylinder as the brake fluid pressure Pr, and sufficient braking pressure can be obtained when the vehicle goes straight. Power can be obtained. On the other hand, when the acceleration sensor 36 detects a deceleration equal to or greater than the set value, the controller 35 stops exciting the coil 56. At this time, the plunger 55 is retracted into the slide groove 33a by the urging force of the spring 58, and the plunger 25 is urged by the spring 53 alone.

At this time, the plunger 25 is urged by the small urging force of the spring 53 alone, and the valve seat 25a is
The hydraulic pressure control start timing which is in contact with 27 is shifted to a low brake hydraulic pressure indicated by a point e in FIG. 2, and when the brake hydraulic pressure Pm reaches the hydraulic pressure control start point e, the output hydraulic pressure indicated by a line g , Pressure reduction control of the brake fluid pressure Pr is performed. As a result, since the load weight is small, the brake fluid pressure Pm during braking is reduced.
When the deceleration is large, the brake fluid pressure Pr whose pressure reduction control has been started with the low brake fluid pressure Pm can be supplied to the rear wheel cylinder, and braking can be applied without the rear wheels being locked early. . Other controls are the same as those in the first embodiment, and a description thereof will not be repeated.

FIG. 9 is a view showing a sixth embodiment of the brake fluid pressure control valve according to the present invention, and corresponds to the invention according to any one of claims 1 to 12. Note that, in the present embodiment, an example is shown in which the brake fluid pressure control valve of the present invention is applied to an X pipe compatible type, and only a configuration different from the first embodiment will be described. The brake fluid pressure control can be the same as in the first and second embodiments, but the description is omitted.

First, the configuration will be described. In FIG. 9, 61
Reference numeral denotes a housing which is disposed on a spring of the vehicle and constitutes a brake hydraulic pressure control valve. Also, the housing 61
The inlet chamber 63 communicates with a master cylinder (not shown) and the outlet chamber communicates with a rear wheel cylinder (not shown).
64a and 64b are formed, and the plug 62 has an inlet chamber 62a communicating with the master cylinder.

The brake fluid pressure control valve is not shown, but one of the fluid chambers of the master cylinder for supplying brake fluid to the right front wheel cylinder and the left rear wheel cylinder, the left front wheel cylinder and the right rear wheel It is used for a so-called X pipe which is interposed between two brake fluid passages in the other fluid chamber of the master cylinder that supplies the brake fluid to the cylinder.

For this reason, the brake fluid is supplied to the inlet chamber 63 from one fluid chamber of the master cylinder, and the brake fluid is supplied to the inlet chamber 62a from the other fluid chamber of the master cylinder. Also, there is an entrance chamber inside the housing 61.
A liquid passage 65 communicating with 63 and the outlet chamber 64a is formed. A plunger 66 is slidably housed in the liquid passage 65, and an elastic member 67 such as rubber is fitted to a lower portion of the plunger 66. The guide member 67 seals the inside of the liquid passage 65.

A liquid passage 66 is provided on the inner periphery of the plunger 66.
a poppet valve (valve member) 68 is slidably provided in the liquid passage 66a.
Is biased toward the free piston 69 by a spring 68a. This free piston 69 has a housing 61
Are slidably held by a holding member 70 housed in a large-diameter inner peripheral portion 61a of the liquid crystal device. Liquid passages 70a and 70
The liquid passages 70a and 70b communicate the inlet chamber 62a and the outlet chamber 64b.

A poppet valve 71 is slidably provided in the liquid passage 70a. The poppet valve 71 is urged toward a free piston 69 by a spring 72. A valve seat 70c is provided at the lower end of the liquid passage 70a. The valve seat 70c is a poppet valve 71 that is biased by a spring 72 when the free piston 69 moves in a direction away from the valve seat 70c. And the communication between the liquid passage 70a and the liquid passage 70b is cut off, and the communication between the inlet chamber 62a and the outlet chamber 64b is cut off.

The liquid passage 66 formed in the plunger 66
a communicates with a liquid passage 73 formed between the liquid passage 65, the free piston 69 and the inner peripheral large-diameter portion 61a, and the brake fluid supplied from the inlet chamber 63 into the liquid passage 65 is supplied to the liquid passages 66a and 73a. Through the outlet chamber 64a. A valve seat 66b is provided at the upper end of the plunger 66. When the plunger 66 moves in the direction away from the free piston 69, the poppet valve 68 comes into contact with the valve seat 66b so that the valve seat 66b is in contact with the liquid passage 66a. The communication between the passage 73 is interrupted and the entrance chamber 63 and the exit chamber 64
The communication of a is cut off.

On the other hand, the plunger 66 is urged upward in FIG. 9 by the spring 28, and the upper end of the plunger 66 is urged by the spring 28 to contact the free piston 69, so that the poppet valve 71 is When the poppet valve 71 is retracted into the liquid passage 70a against the urging force of the spring 72, the poppet valve 71
The liquid passage 70a and the liquid passage 70b are communicated with each other to secure communication between the inlet chamber 62a and the outlet chamber 64b.

Next, the operation will be described. This embodiment is different from the first embodiment only in the structure of the brake fluid pressure control valve, and the control method is the same as that of the first embodiment. Therefore, only the point that the brake fluid pressure control is performed based on the acceleration sensor 36 will be described. I do. In the initial state, that is, when the brake fluid pressure is zero and braking is not performed, the plunger 66 is urged upward in FIG. 9 by the spring 28, and at this time, the plunger 66 presses the free piston 69. The free piston 69 is formed inside the holding member 70 by a step 70d.
The poppet valve 68 retracts into the liquid passage 66a against the urging force of the spring 68a to abut the poppet valve 68, so that the poppet valve 68 is separated from the valve seat 66b to ensure communication between the liquid passage 66a and the liquid passage 73. ing.

Further, the poppet valve 71 is connected to the free piston 69
And the liquid passage 70a against the urging force of the spring 72.
By retracting the inside, the poppet valve 71 is separated from the valve seat 70c, and communication between the liquid passage 70a and the liquid passage 70b is secured. On the other hand, when the vehicle is braked, the brake fluid pressure Pm (1) is supplied from one fluid chamber of the master cylinder to the fluid passage 65 via the inlet chamber 63, and the brake fluid is supplied to the fluid passage.
The brake fluid pressure Pr (1) is supplied to the rear wheel cylinder through the fluid passage 66a, the fluid passage 73 and the outlet chamber 64a.

At the same time, the brake fluid pressure Pm (2) is supplied from the other fluid chamber of the master cylinder to the fluid passage 70a via the inlet chamber 62a, and the brake fluid is supplied through the fluid passage 70b and the outlet chamber 64b. The pressure Pr (2) is supplied to the rear wheel cylinder. As a result, braking of the rear wheel is performed. When the braking of the vehicle is started, the brake fluid pressure Pm rises. When the brake fluid pressure Pm becomes larger than the urging force of the spring 28, the plunger 66 moves downward in FIG.

At this time, when the acceleration sensor 36 detects a deceleration less than the set value, the controller 35
Plunger 31 protrudes from sliding groove 33a and presses holder 30. At this time, since the holder 30 moves until it comes into contact with the stopper member 34, the spring 28 contracts and urges the plunger 66 with a large first urging force.

At this time, when a brake fluid pressure Pm (1) greater than the urging force of the spring 28 acts on the plunger 66, the plunger 66 moves downward in FIG. At this time, as the plunger 66 moves down,
The spring 68a is urged by the spring 68a to move so as to protrude from the liquid passage 66a, abut on the valve seat 66b to cut off the communication between the liquid passage 66a and the liquid passage 73, and to move the free piston 69 downward. , The poppet valve 71 is urged by the spring 72 and moves so as to protrude from the liquid passage 70a, and the valve seat 70c
To interrupt the communication between the liquid passage 70a and the liquid passage 70b.

Therefore, the hydraulic control start timing shifts to the high brake hydraulic pressure as shown by d in FIG. 2, and the brake hydraulic pressures Pr (1) and Pr (2) start from the hydraulic control start point d. Is performed. On the other hand, when the acceleration sensor 36 detects a deceleration equal to or greater than the set value, the controller 35
Stop exciting 32. At this time, the spring 28 urges the plunger 66 via the holder 30, and the plunger 31
Is retracted into the sliding groove 33a, the spring 28 expands and urges the plunger 66 with the second urging force.

At this time, when the plunger 66 is urged by a small urging force and a brake fluid pressure Pm greater than the urging force of the spring 28 acts on the plunger 66, the plunger 66 moves downward in FIG. Also at this time, as described above, the poppet valve 68 comes into contact with the valve seat
a and the liquid passage 73, and the poppet valve 71
Abuts on the valve seat 70c to cut off the communication between the fluid passage 70a and the fluid passage 70b, the hydraulic pressure control start timing shifts to the low brake hydraulic pressure as shown in FIG. After e, pressure reduction control of the brake fluid pressures Pr (1) and Pr (2) is performed.

The brake hydraulic pressure control valve of the present embodiment is moved in accordance with the brake hydraulic pressure difference acting on the upper end and the lower end of the free piston 69, so that the brake hydraulic pressure P
By performing the pressure reduction control in synchronization with the brake fluid pressures of r (1) and Pr (2), the brake fluid pressure supplied to the rear wheel cylinder can be maintained at the same level. In the present embodiment, the same effects as in the first embodiment can be obtained. Further, the other control is the same as that of the first embodiment, and the description is omitted.

The biasing force variable member described in each of the above embodiments is applied to a known brake fluid pressure control valve (for example, a so-called proportioning valve, cut valve, etc.) other than that described in each of the above embodiments. Needless to say, it is good.

[0104]

According to the first to eighth aspects of the present invention, depending on the detected vehicle state, for example, the deceleration during braking applied to the vehicle, the lateral acceleration during turning, is less than a set value, or the vehicle weight. Is greater than or equal to a set value, or when the vehicle height is less than a set value, or by a combination in the future, the plunger is urged by the urging member with the first urging force, and its movement is restricted. Therefore, when the deceleration is small, the vehicle weight is large, the vehicle height is low, or the lateral acceleration is small due to the large loaded weight of the vehicle, the hydraulic pressure control start timing is variably controlled to start the hydraulic pressure control. The point can be set high, and the braking force can be sufficiently increased.

On the other hand, when the deceleration or the lateral acceleration is equal to or more than the set value, the vehicle weight is less than the set value, or the vehicle height is equal to or more than the set value, or the combination thereof, the plunger is smaller than the first urging force. The movement is restricted by the second biasing force. Therefore, when the deceleration is large, the vehicle weight is small, the vehicle height is high, or the lateral acceleration is large due to the small loaded weight of the vehicle, the hydraulic pressure control start timing is variably controlled to start the hydraulic pressure control. The point can be set low and the braking force can be reduced to a level that does not lock early.

Therefore, when the load weight is large or when the frictional force between the tire and the road surface which can be used for braking during turning can be increased, the urging force for urging the plunger is increased to reduce the hydraulic pressure control start timing to the high brake time. If the load weight is small or the frictional force between the tire and the road surface that can be used for braking when turning is small, the hydraulic pressure control start timing must be set to a low brake pressure without increasing the urging force. However, there is a variable control of the hydraulic pressure control start time by indirectly detecting the load weight from the vehicle deceleration, vehicle weight or vehicle height, and the frictional force between the tire and the road surface that can be used for braking during turning from the lateral acceleration. And the brake pressure supplied to the wheel cylinder can be appropriately controlled.

According to the ninth aspect of the present invention, the urging member is set to the first urging force or the second urging force in advance in accordance with the vehicle weight or the vehicle height, so that the urging member can be set during running or braking of the vehicle. By not changing the position of the biasing member,
High-precision control of decompression start timing by eliminating changes in vehicle state (disturbance) due to dynamic behavior of the vehicle such as load transfer from the rear wheels to the front wheels (so-called nose dive) that occurs during braking can do.

According to the tenth aspect of the present invention, by setting the urging member to the second urging force at least when the magnitude of the lateral acceleration becomes equal to or larger than the set value, the load weight of the vehicle is increased. Even when the vehicle weight is large or the vehicle height is low, when the lateral acceleration increases, the hydraulic pressure control start timing can be variably controlled to set the hydraulic pressure control start point low, so that the braking force can be reduced early. It is possible to prevent locking.

According to the eleventh aspect of the present invention, it is determined whether the deceleration or the lateral acceleration is less than the set value or greater than the set value when the brake fluid pressure reduction control start timing is smaller than the first start timing. By selecting the original first and second brake fluid pressure characteristics, optimal brake fluid pressure control according to the weight and lateral acceleration of the vehicle can be performed.

According to the twelfth aspect of the present invention, even when the pressure reduction control is set by the second brake fluid pressure characteristic which is a high brake pressure employed when the vehicle weight is heavy, the braking state (brake state) Irrespective of the magnitude of the hydraulic pressure Pm), the frictional force between the tire and the road surface, which can be used for braking during turning, becomes smaller when the lateral acceleration exceeds the set value, so that the urging force of the urging member is increased. It is possible to set (change) the first brake fluid pressure characteristic, which is a low brake pressure, without doing so.

Further, when the degree of turning is reduced and the lateral acceleration returns to below the set value, the frictional force between the tire and the road surface which can be used for braking also increases (returns), so that the urging force of the urging member is increased. Thus, it is possible to set (change) the second brake fluid pressure characteristic which is a high brake pressure.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a first embodiment of a brake fluid pressure control valve according to the present invention.

FIG. 2 is a diagram showing hydraulic characteristics of the first embodiment.

FIG. 3 is a diagram showing a second embodiment of the brake fluid pressure control valve according to the present invention, and is a diagram showing the fluid pressure characteristics thereof.

FIG. 4 is a diagram showing hydraulic characteristics of a second embodiment.

FIG. 5 is a side sectional view showing a third embodiment of the brake fluid pressure control valve according to the present invention.

FIG. 6 is a front sectional view showing a fourth embodiment of the brake fluid pressure control valve according to the present invention.

FIG. 7 is a sectional view taken along the line AA of FIG. 6;

FIG. 8 is a side sectional view showing a fifth embodiment of the brake fluid pressure control valve according to the present invention.

FIG. 9 is a side sectional view showing a brake hydraulic pressure control valve according to a sixth embodiment of the present invention.

FIG. 10 is a diagram showing hydraulic characteristics of a conventional proportioning valve.

FIG. 11 is a configuration diagram of a conventional load sensing proportioning valve.

FIG. 12 is a diagram showing hydraulic characteristics of the load sensing proportioning valve shown in FIG. 11;

[Description of Signs] 21, 61 Housing 22, 62a, 63 Inlet chamber 23, 64a, 64b Outlet chamber 24, 65 Liquid passage 25, 66 Plunger 25a Valve seat 27 Valve member 28, 53 Spring (biasing member) 30 Holder (Variable urging force means) 31, 55 Plunger (Variable urging force means) 32, 56 Coil (Variable urging force means) 35 Controller (Control means) 36 Acceleration sensor (State detection means) 37 Hydraulic pressure sensor (Pressure detection means) 58 Spring (variable biasing force) 66b Valve seat 68 Poppet valve (valve member)

[Procedure amendment]

[Submission date] May 8, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction contents]

The invention of claim 11, wherein, in order to achieve the above object, in the invention described in any one of claims 1 to 4, vacuum reduced pressure control start timing of the brake fluid pressure in the boundary of the first start time A controllable low-pressure first brake fluid pressure characteristic, and a high-pressure second brake fluid pressure characteristic controlled to reduce pressure at a second start timing higher than the first start timing. The means detects the brake fluid pressure in the fluid passage by a pressure detecting means, and when the brake fluid pressure is lower than the first start timing, and when the deceleration or the lateral acceleration is less than a set value, the urging member Is set to the first biasing force and the second
Selecting the first brake hydraulic pressure characteristic by setting the urging member to a second urging force when the deceleration or the lateral acceleration is equal to or more than a set value. It is.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0053

[Correction method] Change

[Correction contents]

Further, instead of detecting the acceleration sensor, the lateral acceleration sensor or the vehicle weight, the vehicle height may be detected. In this case, the sprung distance of the vehicle with respect to the ground may be directly detected, or the relative distance between the sprung and the unsprung may be detected. When the vehicle height is equal to or higher than the set value (the vehicle height is high), the coil 28 is not excited and the spring 28 is set to the second biasing force while the initial state is maintained, while the vehicle height is lower than the set value (the vehicle height is lower). (Low), the coil 32 is excited to set the spring 28 to the first biasing force, so that when the load weight is small and the vehicle height is high,
The hydraulic pressure control start timing can be variably controlled to set the hydraulic pressure control start point low, so that the braking force can be locked early.
In addition to the fact that the vehicle weight is large and the vehicle height is low, the hydraulic pressure control start timing can be variably controlled to set the hydraulic pressure control start point high , The braking force can be sufficiently increased .

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0058

[Correction method] Change

[Correction contents]

In the case where the brake fluid pressure is controlled by detecting the vehicle weight or the vehicle height, the sensor detects the running state or the braking state of the vehicle so that the vehicle is in the running state or the braking state . When it is detected, that is, when the vehicle is traveling or braking, even if the detection information of the vehicle weight or the vehicle height changes, the setting of the urging member (the first urging force or the second urging force) is performed. It is conceivable not to change the setting.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0061

[Correction method] Change

[Correction contents]

By maintaining this state after the running or braking of the vehicle is started, for example, a load shift (so-called nose dive) from the rear wheels to the front wheels, which is caused by the start of braking , is performed. The change in the vehicle state (disturbance) due to the dynamic behavior can be eliminated, and the pressure reduction start timing can be controlled with high accuracy. In addition, even when the vehicle is being braked, based on the detection information from the lateral acceleration sensor, the biasing force variable means may be controlled so that the spring 28 is set to the second biasing force when the lateral acceleration becomes equal to or more than the set value. It is possible.

Claims (12)

[Claims] A housing formed with an inlet chamber communicating with the master cylinder and an outlet chamber communicating with the wheel cylinder, and a liquid passage formed therein for communicating the inlet chamber and the outlet chamber; and a housing housed in the housing A plunger that moves in response to the pressure of the brake fluid from the master cylinder that is introduced from the inlet chamber and a valve seat that is provided in the fluid passage and that is formed in the plunger in accordance with the movement of the plunger. A valve member provided at one end of the plunger for urging the plunger in a direction to separate the valve seat from the valve member to secure communication between the inlet chamber and the outlet chamber. And a biasing member, wherein the biasing force of the biasing member is at least a first biasing force and a second biasing force smaller than the first biasing force. Biasing force varying means for varying the state of the vehicle, state detecting means for detecting a state of the vehicle, and control means for controlling the biasing force varying means based on detection information of the state of the vehicle. Brake fluid pressure control valve. 2. The state detecting means detects a deceleration applied to the vehicle during braking, and the control means sets the urging member to a first urging force when the deceleration is less than a set value. 2. The brake fluid pressure control valve according to claim 1, wherein when the deceleration becomes equal to or more than a set value, the urging force variable unit is controlled so as to set the urging member to the second urging force. 3. The state detecting means detects a lateral acceleration applied to the vehicle during a turn, and the control means sets the urging member to a first urging force when the lateral acceleration is less than a set value. 2. The brake fluid pressure control valve according to claim 1, wherein the biasing force variable means is controlled to set the biasing member to a second biasing force when the lateral acceleration becomes equal to or greater than a set value. 4. The state detecting means detects a deceleration and a lateral acceleration applied to the vehicle at the time of turning, and the control means applies a first urging force to the urging member when the deceleration and the lateral acceleration are less than set values. On the other hand, when any one of the deceleration and the lateral acceleration becomes equal to or more than a set value, the urging force variable means is controlled to set the urging member to the second urging force. The brake fluid pressure control valve according to claim 1. 5. The state detecting means detects vehicle weight, and the control means sets the urging member to the first urging force when the vehicle weight is equal to or greater than a set value, while the vehicle weight is less than the set value. 2. The brake fluid pressure control valve according to claim 1, wherein said urging force variable means is controlled to set said urging member to a second urging force. 6. The state detecting means detects a vehicle height, and the control means sets the urging member to the first urging force when the vehicle height is less than a set value, while the vehicle height is equal to or more than the set value. 2. The brake fluid pressure control valve according to claim 1, wherein the urging force variable means is controlled so as to set the urging member to the second urging force. 7. The state detecting means detects both the weight of the vehicle and the lateral acceleration applied to the vehicle when turning, and the control means sets the urging member to the first urging force when the vehicle weight is equal to or greater than a set value. On the other hand, when the vehicle weight is less than the set value, the urging member is set to the second urging force, and
2. The brake fluid pressure control valve according to claim 1, wherein the biasing force variable means is controlled to set the biasing member to a second biasing force when the lateral acceleration becomes equal to or greater than a set value. 8. The state detecting means detects both the vehicle height and the lateral acceleration applied to the vehicle at the time of turning, and the control means sets the urging member to the first urging force when the vehicle height is less than a set value. On the other hand, when the vehicle height is equal to or more than the set value, the urging member is set to the second urging force, and when the lateral acceleration is equal to or more than the set value, the urging member is set to the second urging force. 2. The brake fluid pressure control valve according to claim 1, wherein the biasing force varying means is controlled as described above. 9. An additional detecting member for detecting a running state of the vehicle or a braking state of the vehicle, wherein the control means detects the state during running or braking of the vehicle based on detection information from the additional detecting means. 7. The brake fluid pressure control valve according to claim 5, wherein the setting of the urging member is not changed even if there is a change in vehicle weight or vehicle height detection information from the means. 10. The state detecting means detects a lateral acceleration applied to the vehicle at the time of turning, and the control means controls the urging when the lateral acceleration becomes equal to or more than a set value even at least during the braking of the vehicle. 2. The apparatus according to claim 1, wherein said urging force varying means is controlled to set the member to a second urging force.
Or the brake fluid pressure control valve according to 9. 11. A low-pressure first brake fluid pressure characteristic in which the brake fluid pressure reduction control start timing is reduced after the first start timing, and a second start timing higher than the first start timing. A high-pressure second brake fluid pressure characteristic controlled to be reduced at the boundary, wherein the control means detects a brake fluid pressure in the fluid passage by a pressure detecting means, and is lower than the first start timing. When the deceleration or the lateral acceleration is less than a set value at the time of the brake fluid pressure, the urging member is set to the first urging force, and the second brake fluid pressure characteristic is selected. The brake hydraulic pressure control valve according to any one of claims 1 to 4, wherein when the pressure is equal to or more than a set value, the urging member is set to a second urging force to select the first brake hydraulic pressure characteristic. 12. The state detecting means detects a lateral acceleration applied to the vehicle at the time of turning, and the control means sets the urging member to a first urging force when the urging force variable member sets the urging member to a first urging force. When the lateral acceleration is equal to or more than a set value, the urging member is set to a second urging force, and when the lateral acceleration is less than a set value, the urging member is set to a first urging force. 11. The brake fluid pressure control valve according to claim 2, wherein the biasing force variable member is controlled.