JPS58105862A - Controller for hydraulic pressure of rear wheel brake - Google Patents

Abstract

PURPOSE:To accurately detect a deceleration without being affected by changes in the viscosity of a working fluid, by a method wherein rear wheel brake pressure is controlled by controlling a solenoid valve on the basis of a signal fed from a deceleration sensor. CONSTITUTION:The solenoid valve 22 is provided between a master cylinder 16 and a rear wheel brake 20, and is controlled by a controlling circuit 30 incorporating a microcomputer. The circuit 30 is supplied with a deceleration signal SG from the deceleration sensor 24 and signals from load sensors 26, 28. The circuit 30 controls the valve 22 in accordance with the deceleration signal SG, thereby controlling the rear wheel brake pressure. Accordingly, since the deceleration sensor 24 is not affected by the viscosity of the working fluid, the rear wheel brake pressure can be controlled with high accuracy.

Description

[Detailed description of the invention]

The invention relates to a hydraulic pressure control device for rear wheel brakes in a vehicle, and more particularly, to a hydraulic pressure control device that performs highly accurate hydraulic pressure control operations without variations in operation caused by the viscosity of 1blliIIJl liquid. . Heavy vehicle 5 Te: - Since the load W moves in the case of I11'b, the rear wheel Ri'i button j force is suppressed compared to the 10 axle braking force. The best thing to do is to lock the rear wheels early if/1.
It is desirable in terms of tl-. One of the measures for this purpose is to use an O valve (inertia valve) to control the fluid between the mask cylinder and the rear wheel brake, and to maintain a constant deceleration (in. Then, according to inertia, the body valve housed in the zero valve moves up the inclined surface and reaches the valve seat, suppressing the dynamic static pressure supplied from the mask cylinder to the rear wheel brake. However, according to the conventional liquid pressure control device 6,
Since the body valve is housed in the valve chamber along with the brake fluid, the operation of the body valve is affected by changes in the viscosity of the brake fluid due to temperature changes, changes over time, etc. 1ill? 11
11 operation was slow. In other words, for example, if the viscosity of the brake fluid increases, the body valve will act! lJ becomes slow and the brake fluid pressure supplied to the rear wheel brakes is suppressed lA+++
The starting point (υ1 point fluid pressure) tends to be higher. The non-invention was made against the background of the above circumstances,
Its purpose is to provide a control device for rear wheel brakes that does not have variations in operation due to the viscosity table of JX brake fluid. The hydraulic pressure control operation of the wheel brakes suppresses the hydraulic pressure supplied from the mask cylinder to the rear wheel brakes, thereby increasing the speed of heavy vehicles.
Hydraulic pressure control operation of rear wheel brakes that adjusts the ratio of transportation braking power and vehicle Hji power, comprising: (1) detecting the deceleration of a vehicle and generating a deceleration signal representing the deceleration of the vehicle; (2) a control device that generates a suppression signal based on the first power level signal and outputs the suppression signal; (3) a control device that connects the self-IJ mask cylinder and the rear wheel brake; circle

[The fluid is inserted into the fluid reading □ and supplied from the mask cylinder to the rear wheel brake according to the suppression signal]
:li! l・I; and 1.1-. Hydraulic pressure to suppress jilil+! Ii: Igoj1 and non1'8 are similar. In this way, the deceleration of the vehicle is transmitted through the brake fluid.
', Since the deceleration is detected by a deceleration sensor that is not connected to the passageway, the deceleration detection force is detected accurately regardless of the viscosity change of the dynamic and static conditions. Hydraulic control operation is obtained. In another aspect, the hydraulic pressure of the rear wheel brake is controlled to adjust the ratio between the front width braking force and the rear wheel braking force of the vehicle by suppressing the brake hydraulic pressure supplied from the mask cylinder to the rear wheel brake. (1) a cart sensor that detects the live load of the vehicle and outputs a load signal representing the live load; and (2) a deceleration sensor that detects the deceleration of the vehicle and represents the deceleration. (3) A deceleration sensor that outputs ``, and (3) a predetermined deceleration point at which to start suppressing the brake fluid pressure supplied to the brake and the vehicle's carrying load. Based on a certain relationship, the deceleration at the turning point when mowing the load represented by the wagon signal in Sit 11 is determined. When the velocity exceeds the sand speed at the breaking point (
(i) a control device that outputs perspiration; (4) fII' which is inserted into a fluid passage connecting the mask cylinder described in 1411 and the rear wheel brake, and is supplied from the mask cylinder to the rear wheel brake in accordance with the suppression signal described in iij; It is characterized in that it includes a hydraulic pressure control valve that suppresses dynamic fluid. In this way, the deceleration of the vehicle is detected by a deceleration sensor that is not connected to the output path that transmits the brake fluid pressure, so the detection of the reducer is accurate regardless of the viscosity of the brake fluid. This makes it possible to obtain consistent hydraulic pressure control operation for high viscosity applications. Moreover, based on a certain predetermined relationship between the degree of depressurization at the turning point at which suppression of the brake fluid pressure supplied to the rear wheel brakes should start and the vehicle's carrying load, the brakes are applied to the actual loaded truck. The point deceleration is determined, and when the deceleration of the vehicle exceeds the deceleration point, the hydraulic pressure control valve is operated, so that a desired rear wheel braking force can be obtained depending on the loaded vehicle. 6-Here, the corner deceleration is the brake supplied from the mask cylinder to the rear wheel brake! It shows the deceleration (if''l) at which the suppression of the hydraulic pressure starts, and the front wheels of the vehicle.
1ljl generated in the mask cylinder: for dynamic fluid (9-tone fluid supplied to the front brake) and a small amount,
In the graph showing the relationship with the H7ll dynamic hydraulic pressure supplied to the brake, the club is mowed when its characteristic curve forms a poor four point. However, one embodiment of the present invention is not shown in the diagram. In FIG. 1, the mask cylinder 10 is provided with a first hydraulic pressure chamber 14 and a second hydraulic pressure chamber 16, in which the inherent braking effect occurs when the brake pedal 12 is operated. The hydraulic pressure chamber 14 is connected to the wheel cylinder 18 of the M11ii brake, and the second liquid storage chamber 16 is connected to the wheel cylinder 20 of the rear wheel brake, and the box 1, which is a control valve, is connected to the wheel cylinder 20 of the rear wheel brake.
They are connected via a magnetic leap valve 22. The vehicle is equipped with a deceleration signal SG that detects the deceleration of the vehicle by 8 degrees and indicates the deceleration.
The deceleration sensor 24 outputs a deceleration sensor 24 that detects the loads applied to the left and right rear wheels according to the vehicle's carrying load, and outputs a left cart signal LW and a right load signal W representing their <= r weight. Left load rectangle sensor 26 and right load width sensor 28
has been removed. The stiffness deceleration signal SG, the left load p signal LW, and the right Tsukuda Juhakugo and W are supplied to the control circuit 30, which is a control device, and the control circuit 30 also outputs a suppression signal S], Kaichi, Magnetic opening J. It is designed to be output to the valve 22. The control circuit 130 is composed of a low-pass filter 32, 34, a revised value adjustment surface h36, a comparison circuit 38, and a U driver counter 40, as shown in the 21st line 1. The low-pass filter 32 includes resistors 42.44.46.4
．． 8. It is a well-known low-pass active filter for noise removal consisting of a capacitor 50, 52 and an operational amplifier 56, and the left load signal LW and right load signal 1 (W0'') llIi!l are human power υ・. The low frequency component of the average value is amplified at a predetermined constant increase rate of 1M, and a "point signal 81) representing the corner deceleration is outputted to the comparator circuit 38 via the & constant value adjustment circuit 36. Setting The value adjustment circuit 36 is
It is a series circuit of a variable resistor 58 and a fixed carrier 60 inserted between the Togame source and the ground terminal, and by operating the variable resistor 58, the corner signal S I) is converted to CM.
mN. Similar to the low-pass filter 32, the low-pass filter 34 has resistors of 62.6 a and 6
4. A low-pass active filter consisting of capacitors 66 and 68 and an operational amplifier 70, which supplies four sets of deceleration signals SG, which are the low frequency components of the input signal from the deceleration sensor 24 multiplied by 1+hX, to the comparator circuit 38. Jl, the comparison circuit 38 compares the input corner signal 8D and the deceleration signal SG, and calculates the deceleration signal SG month "point signal SD".
'' twice, an output signal (J-Level) is supplied to the driver circuit 40. The driver circuit 40 has a bias month 1
It is composed of a resistor 69 and a Langistaffe 1, and when a signal is input from the comparator circuit 38, the transistor 71 is activated to supply a suppression signal SL, that is, a drive current, to the electromagnetic on-off valve 22. 9- Here, the suppression of the brake fluid pressure supplied to the rear wheel brake 91j
The starting point, that is, the turning point signal SI) represents the flashing longitude, which is a hypothetical change in which the ratio of the front wheel drive power to the rear wheel power is 1 + ij, depending on the change in loading and unloading vehicles. In order to obtain as much light weight as possible while preventing the rear wheels from locking up, certain conditions have been established in accordance with No. 31. In the IJII %f low-pass filter 32, Masuaki, 1 year is determined based on 1L Sekiho (slope) G, and it is manually operated or "car signal", W, RW
When the power ratio is calculated, the wide f I + i", : L, teze1 I:D, which represents the degree of pressure reduction at the υf point to obtain the power ratio, the white signal 8D is now output. In other words, when the carrying load is small, the rear wheel is likely to lock up when the deceleration is relatively small (Ri11 Dohatsukawa), so the turning point is reduced. It is necessary to reduce the speed, and conversely, when the live load is large! Ko,
The bale axis will not lock until the rear wheel load is large and the deceleration is large (until the braking effect becomes large), so
Increase the corner deceleration and rear axis i iI5! It is necessary to make the I jlD force as large as possible. The first valve 22 closes the fluid fBj h from the second liquid chamber 16 of the mask cylinder 10 to the wheel cylinder 20 in accordance with the suppression signal SL, and the braking semi-low or suppression signal supplied to the wheel cylinder 20: It's like a lick. That is, as shown in FIG. 4, the first boat 72 and the wheel cylinder 20, which communicate with the second hydraulic chamber 16, are
A second boat 74 for passing through is formed in the housing 76, and a valve cover 78 is screwed onto the housing 76, thereby forming a valve chamber 80 that connects the first boat 72 and the second boat 74. Inside the valve chamber 80, a poppet valve 86 is biased toward 1l=lt84 by a spring 82, and the poppet valve 86 is separated from the second boat 74 by cutting into the valve seat 84. Valve chamber 80
Communication is now cut off. Inside the housing 76, there is a cylindrical solenoid 90 fixed by a lower cover 88 screwed to the bottom of the housing 76, and a non-magnetic solenoid fixed to the lower cover 88 by a liquid thread and inserted into the thread/id 90. body sleeve 92 and sleeve 9
A cylindrical core 94 is provided within the poppet valve 86, which is inserted into the poppet valve 86 before the axial rotation and abuts against the lower protrusion of the poppet valve 86. And between the core 94 and the lower lid 88,
A spring 96 is interposed to move the poppet valve 86 and core 94 against the urging force of the spring 82. Therefore, in the electromagnetic on-off valve 22, when the solenoid 90 is not energized, the poppet valve 86 is separated from the valve seat 84, the first boat 72 and the second boat 74 are communicated, and the solenoid 90 is connected via the lead wire 92. When excited, the core 94 is absorbed against the biasing force of the spring 96, and the poppet valve 86 is seated on the valve seat 84, so that the space between the first boat 72 and the second boat 74 is cauterized 1. It has become. In addition, the poppet valve 86 is operated by the pressure of the second boat 74 or the valve chamber 8.
When the pressure rises above 0, it is forced to the P# position against the force of the spring 82, so the electric/value on/off valve 22 also has the function of a check valve. Further, a through hole 98 is formed in the core 94 so as to pass through it in the axial direction in order to equalize the pressure on both end faces of the core 94, so that the operation of the core 94 is not inhibited by the brake fluid pressure. The operation of this embodiment will be explained below. Regarding the operation of the brake pedal 12, the mask cylinder 1
When the brake fluid pressure generated at zero is supplied to the wheel cylinders 18,20, the vehicle begins to decelerate slightly due to the braking forces generated at the front and rear wheels of the vehicle. At the start of such braking, the left and right load signals LW, 凇W
Each fold represented by is large, and the corner signal 8D is the deceleration. Since it is larger than the signal SG, the suppression signal SL is not supplied to the iiJ & on-off valve 22, and the electromagnetic on-off valve 22 is not supplied to the second hydraulic chamber 1.
6 and the wheel cylinder 20 are communicated with each other. Figure 4 shows this state.0 When the braking effect of the vehicle appears and its deceleration increases, the deceleration 4@@SG increases, but due to the load shift, the left and right load signals LW, RW
The load represented by this decreases, and the corner signal 8D becomes smaller. When the deceleration signal SG exceeds the corner signal 8D, an output signal is output from the 13-comparison circuit Th88 and the driver circuit &
A suppression signal SL 'N is supplied from the z40 to the magnetic opening/opening valve 22. For this reason, the @M on-off valve 22 is closed, so the braking fluid pressure supplied from the second hydraulic pressure chamber 16 to the wheel cylinder 20 is cut off from then on, and the front wheel braking force is prevented from increasing. rise is limited. In such an operation, if the load on the vehicle changes significantly, the left and right load signals L'W and R'W increase accordingly, so the corner signal 8D increases. Therefore, when the braking effect of the vehicle becomes even greater and the deceleration increases, the deceleration signal 8G exceeds the υ11 signal 8D, and is supplied from the second hydraulic pressure chamber 16 to the wheel cylinder 20. Suppression starts when the brake fluid pressure reaches an even larger value. As a result, in the characteristic diagram showing the relationship between wheel axle power and rear wheel braking force in Figure 5, we can obtain the characteristics shown by the two-point squared line that closely approximates the ideal curve shown by the solid line at each load. Yes = 14- In other words, when using the conventional G valve, the height of the vehicle is 1
If the temperature exceeds a certain level, the brake fluid pressure that is uniformly supplied to the rear wheel brakes will be withstand regardless of the loaded vehicle, so as shown by the broken line in Fig. While you can't get it, it's true! t (by +U, the corner signal 81 supplied to the comparator circuit 38 in view of the vehicle's live load) is changed so that an ideal braking force ratio between the front wheels and the rear wheels can be obtained. Therefore, the point at which suppression of the brake fluid pressure supplied to the wheel cylinder 20 starts (fold A fluid)
is changed to a position suitable for each load, so there is no shortage of rear wheel braking force. Note that the braking force of the brake and the braking fluid pressure supplied to the wheel cylinder are approximately proportional to each other. In this embodiment, the acceleration of the vehicle is detected by the deceleration sensor 24, which is not related to the flow of the fluid to which the brake fluid is transmitted, and therefore is affected by the deceleration rate or the change in the viscosity of the brake fluid. This effectively eliminates variations in hydraulic pressure control operation. In addition, in this embodiment, the magnetically-independent opening valve 22 is configured to open when power is not applied, so even if a failure occurs in the control circuit 30, solenoid 90, etc., operation of the rear wheel brake is ensured. Well, there is one advantage that is very safe. Furthermore, according to this embodiment, the load sensor 26, 28 and the electromagnetic opening M valve 22, which is a hydraulic pressure control valve, have no mutual relationship; they are each mounted at a unique location t1. Therefore, there is no need to attach it to the suspension 7jl, which detects the load, as in the conventional load sensing type hydraulic pressure control valve. Therefore, there is an advantage that a ready-to-use hydraulic pressure control valve can be commonly used in most vehicle types without having to make a different shape for each vehicle. Next, other embodiments of the present invention will be explained. It should be noted that in the following embodiments, parts that are common to the embodiments described in 11th above will be given the same names and descriptions will be omitted. Although in the implementation and example described herein, the control circuit 30 is constructed from analog circuitry, it may be constructed from digital circuitry as follows. In FIG. 6, a control circuit 100 is constituted by a digital circuit, and a deceleration signal SO output from a deceleration sensor 24 is supplied to an Al1) converter 102 via a low-pass filter 34. Similarly, the left load signal LW and right cart signal B are output from the left load sensor 26 and the rightward l sensor 28. They are averaged by passing through a low-pass filter 32, and A is used as a load signal SW representing the rear wheel load.
/D converter 102. The A/D converter 102 converts an analog signal into a digital code signal representing the magnitude of the analog signal, and converts the input wagon signal SW and deceleration signal SG into digital code signals, respectively, and connects the data bus line to the digital code signal. CPU104, RAM106, ROM IQ8, I
10 boats 110. The CPII 104 is an arithmetic control unit that performs arithmetic control using the memory function of the tAM 106 (according to a program stored in advance in the JM 108), and also outputs signals to the outside through the R (10 port) 110. 17- Receive the external signal input. The I10 boat 110 has brake pedals 12 (7
) A brake switch 112 that is activated in conjunction with the operation of the vehicle is connected, and a pedal operation signal SP indicating that the brake pedal 12 has been operated is output. Then, the suppression signal SL is output from the driver 1 (10 port) 110.
14, and is supplied to the value on/off valve 22. In the control circuit 100 configured as described above, It(J
Create the program as shown in the flowchart of FIG. 7 according to the program stored in Rj108! + That is, first, in step 81, the operating state of the brake switch 112 is determined, and if the pedal operation signal SP has not yet been generated, step S1 is repeated. Brake pedal 12i1 made and pedal operation signal 8P
is supplied to the CPU 104 via the I10 port 110, steps S2 to S5 are executed. That is,
The load W indicated by the front vehicle signal SW in step S2
is read, and in step S3, 18
- From the relationship (corresponding data) between the loaded truck and the corner deceleration shown in FIG. 3 stored in advance in the ROM 108, the pay point speed 84G here 1llfi' Hikishinp SO
Regardless, the current deceleration Y of the vehicle is determined, and in step S5 it is compared and determined whether the deceleration Y is greater than the analyzed depressurization trace I5X. At the beginning of the control, the deceleration Y of the vehicle is still small compared to the point I point depressurization X, so steps S6 and S7 are executed, and the output of the suppression signal SL is set to l51 (without stopping, the Na valve between the two 22 is simultaneously held in the open Vζ state, and the operating state of the brake switch 112 is determined.If the operation of the brake pedal 12 is insufficient and the pedal operation signal SP disappears, a step of opening the open valve 22 is performed. It is executed from step 77'S1 after passing through S8, but when the brake pedal 1
If the operation of step 2 continues and the pedal operation signal SP continues to occur, the process is executed from step S4. While the above operation is repeated at high offshore, when the braking effect of the vehicle is large and the Y for decelerating the vehicle exceeds 8 degrees X off the coast, steps S9 and S7 are executed previously. Ru. That is, in step S9 & here, the suppression signal S L is transmitted from the I10 hoard 110 to the city squid opening/closing method 22 via the line 114, and the second trial period - room 1 is transmitted.
The dynamic hydraulic pressure 911j supplied from 6 to the wheel cylinder 20 is suppressed by the spring 1 production of the spring valve 22, and thereafter the same operation as described above is performed in step S7. be. Therefore, the corner deceleration X is
A special gift for H1? The ratio between the 6tl power and the rear wheel braking power is determined based on the relationship between the predetermined power and the brake load, so that the ratio is close to the ratio depending on the load. Even in this actual cooperation, the relationship between the front wheel braking force and the rear wheel braking force, which is indicated by the two-dot chain line in FIG. 5, is the same. In this way, in addition to obtaining the same effect as in the above-described embodiment, the present embodiment provides the advantage that the loaded vehicle W represented by the load signal SW is not affected by the brake pedal 12 when the vehicle is still stable.
Since it is read at the start of the operation, it is possible to easily eliminate fluctuations in the load signal SW caused by unevenness and zero, and it is possible to obtain a more orderly hydraulic control operation. The relationship between the loading vehicle and the degree of fold A cross-cutting is such that the loading direction 4W is the same as the stability W of the vehicle is also detected. , Since it is composed of 100 digital circuits, it operates extremely well compared to analog circuits, even in the noise and harsh temperature environments that often occur in vehicles (and the thermal lift caused by this). Furthermore, this embodiment has the advantage that even if the relationship shown in FIG. 3 is non-linear, there is no risk of changing the circuit configuration. 1 + goben is Buddhist altar and 1 valve is 22
However, as described below, the brake fluid pressure supplied to the rear wheel brakes is blocked by the electromagnetic on-off valve 22 or the brake fluid pressure of the mask cylinder 10. It can also be configured to be connected to a device that applies hydraulic pressure and reduces the pressure at a constant rate. In FIG. 8, the pressure reducing device 116 is
118 and 2nd baud) 1207) f master cylinder 1
It is connected to the second hydraulic pressure chamber 16 of No. 0 and the wheel cylinder 20 of the rear wheel brake, and is connected in parallel to the electromagnetic on-off valve 22. Housing] 22 to 1. J1 valve lid 12
4 are screwed together to form a large-diameter cylinder bore 126 in the form of a circular hole with an eave formed in the housing 122 and the valve lid 12.
A cavity 130 is formed which opens opposite to a small diameter cylinder bore 128 in the form of a circumferential circular hole formed in 4, and a large diameter piston 132 and a small diameter piston 13 are formed in the large diameter cylinder bore 126 and the small diameter cylinder bore 128, respectively.
4 is slidably fitted. That piston 1
12 and 114 are brought into contact with each other, and a compression coil spring 1 is disposed between the valve cover 124 and the spring receiver 136 which is located on the side of the cavity 130 of the large diameter piston 132.
88 is inserted, and the large diameter piston 132 is always urged toward the bottom 85 of the large diameter cylinder bore 126. Furthermore, 2
2- The first boat 118 and the second boat 120 communicate with the small diameter cylinder bore 128 and the large diameter cylinder bore 126, respectively. Therefore, when the suppression signal 81- is not yet supplied to the electromagnetic quantity 1■ valve 22, the braking hydraulic pressure in the second hydraulic pressure chamber 16 is directly supplied to the wheel cylinder 20 through the electromagnetic on-off valve 22, which is in a state where it cannot be opened. Along with that 1tili
As the dynamic fluid pressure increases, the large diameter piston 132 is moved toward the cavity 130 against the biasing force of the compression coil spring 138. Next, when the brake 8, 11 signal S] is supplied and the electromagnetic on-off valve 22 is closed, the F4-force applied to the small diameter piston 134 according to the brake #tsubo supplied through the first boat 118 and the compression coil The large-diameter piston 132 is moved by the biasing force of the spring 138, and the braking fluid pressure generated in the large-diameter cylinder bore 126 as the large-diameter piston 132 moves is supplied to the wheel cylinder 20 through the second bow 120. At this time, since the diameter of the small-diameter piston 134 is set smaller than the diameter of the large-diameter piston 132, the 1111 dynamic fluid pressure in the large-diameter cylinder bore 126 increases at a constant ratio compared to the increase in braking fluid in the small-diameter cylinder bore 128. It will rise at the same value as the depressurization. When the large-diameter piston 132 comes into contact with the bottom of the large-diameter cylinder bore 126, the increase in braking fluid pressure supplied to the wheel cylinder 20 is stopped. Until the increase in the ftjl dynamic fluid pressure reaches the 11th point, the brake fluid I-
It is determined by the movement of the large-diameter piston 132 against the biasing force of the coil spring 138, which is compressed by the magnitude of F. As a result, as shown by the two-dot chain line in the 91st wheel I, the improvement of the power load is achieved by n1+wheel itj:,1 power which is more similar to the ideal & (solid line). This allows the ratio of physical properties to the rear wheel braking force to be obtained. In FIG. 10, a proportional control valve 140 has a first port 144 and a second port 144 provided in its housing 142.
-3rd boat 15 changed to 146 and its valve cover 148
0, the first port 144 of which is connected to the mask cylinder 1
0 to the second hydraulic pressure chamber 16, and between the first boat 144 and the second port 146 is an electromagnetic on-off valve 2.
2 is connected to the wheel cylinder 20 of the rear brake, and the housing 1
A stepped hole-shaped valve chamber is formed within the valve chamber 42 by screwing the valve cover 148 therein, and a cup-shaped elastic valve seat 152 is disposed in the stepped hole.
A valve piston 154 passing through is disposed to be movable in the axial direction. A valve element 15 is provided with a pressure receiving surface at the tip of the valve piston 154 and can be seated on the elastic valve seat 152.
6 is provided in a large diameter shape, and the small diameter side of the valve chamber is connected to the third boat 150 and the large diameter first boat 144 with the elastic valve seat 152 as a boundary. - million, housing 1
The lower cover 1 has a cylinder bore 157 formed in the lower part of the lower cover 42.
58 are screwed together to form a spring 162 that separates the valve chamber from the partition wall 160. In the spring chamber 162, a coil spring 25- is inserted between a piston 164 fitted in a cylinder bore 157 (a movable opening) and a spring catch 166 that abuts the valve piston 154 that protrudes through the partition wall 160. 168 is inserted, and the valve piston 154 is biased in a direction in which its valve element 156 is separated from the resilient valve seat 152. And the second boat 14
6 communicates with the inside of the cylinder bore 157. If the suppression signal S L is not yet supplied to the electromagnetic on-off valve 22 , the braking fluid pressure in the second fluid E chamber 16 is supplied to the first boat 144 and the second boat 146 . . For this reason, the piston 164 or the second boat 14
8i1: Dynamic hydraulic pressure applied to the valve piston 154 increases the force applied to the valve piston 154 from the coil spring 168, increasing the force applied to the valve piston 154. piston 15
4 is maintained at an inclination angle 4 in which its valve element 156 is spaced from the resilient valve seat 152. As a result, the first port 144 and the third
Since the boat 150 is maintained in communication with the boat 150 through the valve chamber, the braking fluid in the second hydraulic pressure chamber 16 is supplied to the brake fluid 111 and the wheel cylinder 20. Next, the signal S1 is applied to the suppressor 11i1, and the magnetic opening 1
When the Y1 valve 226-2 is activated, the rise in the brake fluid pressure supplied to the second valve 146 is prevented, and the piston 164 stops moving, and from then on, a constant force is applied from the coil spring 168 to the valve. provided to the piston 154. On the other hand, when the side shell 1 hydraulic pressure supplied to the first boat 144 is increased, the valve piston 154 is moved toward the spring chamber 162 against the biasing force of the coil spring 168, and the valve piston 154 is moved toward the spring chamber 162 side.
56 is seated on a resilient valve seat 152. For this reason, the pressure received by the valve piston 154, the biasing force based on the difference in surface Pa, and the coil splinter 16
The valve piston 154 moves slightly so that the urging force of the third port 15 is balanced, and the third port 15
Braking hydraulic pressure of 0 or hi of the first boat 144; soil 51. with a constant rate lower than the rate of increase of the dynamic hydraulic pressure. ``Mu de'' was promoted to the second rank. As a result, as shown by the two points l#41+ in FIG. 11, the konsōkyoku #l! corresponds to the staged live load! This results in a ratio characteristic between the front wheel braking force and the rear wheel braking force that is more similar to (solid line). Although the embodiment of the present invention has been described above based on the drawings, the present invention can also be applied to other embodiments. For example, the brake fluid pressure generated in the mask cylinder 10 is
It is configured to be transmitted to the wheel cylinders 18 and 20 of each wheel through a so-called Of course, this is also a good thing. However, in this case, a hydraulic pressure IIJ control valve is inserted in each of the left and right piping system rough reinforcements, but since the hydraulic pressure control on the left and right: the turning point hydraulic pressure of 11P is made to match, the fluctuation in the braking force of the left and right rear wheels is reduced. This has the advantage that most of the problems are eliminated. Since it is sufficient to suppress the hydraulic pressure supplied to the wheel cylinder 20 of the rear wheel brake, it is sufficient to use a check valve that simply has an opening function while leaving the check valve nose 1-1. It doesn't matter if there is. In the above embodiment, the passenger load sensor 26 and the right load sensor 28 are used to detect the vehicle's live load, but the live load may be detected by a single load sensor. . However, there is a problem with loquat loading vehicles.
If there is a problem, the load can be accurately detected by providing load sensors 26 and 28 on both the right and left candies, and the rear wheel lock can be more reliably prevented. The aforementioned control time h! 6100 can be constructed entirely or entirely by an F'TW microcomputer,
Furthermore, the microcomputer can be used for the purpose of Tsukuda 1 at the same time. The load sensors 26 and 28 described in ``Put'' may be configured to be mounted on the loading platform and directly detect the load of the vehicle, but they may be configured to directly detect the load on the vehicle by utilizing the deformation of the vehicle's suspension system. The entire load may be indirectly detected by detecting the relative movement with the lower phase or by detecting the air pressure of the air valance system, vehicle height adjustment device, etc. Further, in steps S1 and S2 of the embodiment shown in FIG. 7, the loading load W may be read in advance using another timing signal generated when the vehicle is stationary. =29- Furthermore, in the embodiment described above, the load sensor 26.
28 is provided to improve the corner deceleration according to the vehicle's carrying load, or the vehicle's...J wheel load and rear wheel load, or the brake fluid pressure of the mask cylinder. A point deceleration may be determined, and in the case of a vehicle in which the load does not increase to a large extent, the corner deceleration may be a predetermined constant value. In such a case, the load sensor 26.2
8 or unnecessary, and the control circuit 80.100,
This is different from a control device that outputs a suppression signal when the vehicle's tJ# speed exceeds a predetermined constant turning point deceleration. In that case, the deceleration sensor and control device are as follows.
This can also be configured. For example, an inertia sensor that moves by inertia, which corresponds to a deceleration sensor, may be straddled with a splinter that applies a preload corresponding to the corner deceleration, or a slope corresponding to the corner deceleration may be provided. In addition, it may be configured to include a switch operated by the movement of the inertial force. In other words, the amount of movement of the inertial member corresponds to the deceleration signal, and the spring or inclination direction and switch that preliminarily limit the movement of the inertia f'A'=U cause the deceleration signal to reach a predetermined constant value. This corresponds to a control device that outputs a suppression signal when the point deceleration is exceeded. In short, the control device may be one that generates and outputs the ``1141+'' signal based on the deceleration signal. It should be noted that the above is just one embodiment of the present invention,
The present invention allows for extreme care to be applied within the range G without departing from the spirit of the invention. As described in detail, in the rear wheel brake hydraulic pressure control device of the present invention, the deceleration of the vehicle is detected by the flow to which the hydraulic fluid B is transmitted, and by the deceleration sensor that is not related to the flow of the hydraulic fluid B. Therefore, detection of deceleration is not affected by shadow 1≧ due to viscosity change of the IIIIElj liquid, and highly accurate hydraulic control operation without variation can be obtained. In addition to the above-mentioned effects, in another aspect, the braking fluid pressure supplied to the rear wheel brake is set to a predetermined amount in order to obtain as large a braking force as possible while locking the rear wheel (ρJ-tf). Based on a certain relationship between the one-point deceleration at which suppression should start and the loaded truck of the vehicle, the UI point decompression drag corresponding to the actual loaded truck is determined, and the deceleration of the vehicle is determined at that turning point. Since the hydraulic control valve will not operate when the deceleration exceeds the deceleration, it is desirable to reduce the load to the load.
;It is possible to obtain power.

[Brief explanation of the drawing]

FIG. 1 is an illustration showing the configuration of an embodiment of the present invention. FIG. 2 shows 1li1. of the embodiment shown in FIG. FIG. 1 is a diagram illustrating a control circuit. FIG. 3 is a graph showing a predetermined relationship between the load car and the decompression speed used in the control circuit of FIG. FIG. 4 is a side view showing the structure of the electromagnetic on-off valve in the embodiment of FIG. 1. FIG. 5 illustrates the operation of the embodiment shown in FIG. This is a graph of Ij. FIG. 6 is a block diagram showing a control device in another embodiment of the present invention. Fig. 7 1 is a flowchart for clarifying the operation of the control device shown in Fig. 6, and Figs. "Preaching"
This is a diagram. Figures 9 and 11 respectively represent the 8th
10 is a graph illustrating the operation of the embodiment of FIG. 10. FIG. 10: Mask cylinder 24: Deceleration sensor Applicant: Toyota Motor Corporation -33= ■Figure 3 Load load: 4° Figure 7 Figure 9 Figure 11 Front @ Skewer 1 power rod 10-7 58

Claims (2)

[Claims] (1) A rear wheel brake hydraulic pressure control device that adjusts the difference between the front wheel braking force and the rear wheel meter power of a vehicle by controlling the brake fluid pressure supplied to the rear wheel brakes from a mask cylinder, , a deceleration sensor that detects the deceleration of a vehicle and outputs a deceleration signal representing the sea speed of the vehicle, and a control device that generates a suppression signal based on the deceleration speed signal and outputs the suppression signal. and a hydraulic pressure control valve that is inserted in the front 3 [fluid passage connecting the mask cylinder and the rear wheel brake] and suppresses the brake fluid pressure supplied from the mask cylinder to the rear wheel brake in accordance with the suppression signal. A rear wheel brake hydraulic pressure control device comprising: (2) Rear wheel brake hydraulic pressure that increases the ratio of the front wheel braking force to the rear wheel braking force of the vehicle by 1ill'+-51' by suppressing the brake hydraulic pressure supplied from the mask cylinder to the rear wheel brakes. A control device comprising: a load sensor that detects the vehicle's live load and outputs a load signal without indicating the load; and a load sensor that detects the deceleration of the vehicle and determines the degree of deceleration that affects the deceleration. The deceleration sensor outputs a signal, and the suppression of the brake fluid pressure applied to the Ij+ recorder brake is started based on a predetermined constant relationship between the one-point deceleration and the load car of the vehicle. Then, determine the corner deceleration corresponding to the force j on the coffin car indicated by the nIj recording signal, and reduce the
As the deceleration of the vehicle indicated by the speed traction signal increases,
a control device that outputs a suppression signal when the temperature exceeds the WTB degree; and a control device that connects the mask cylinder and the rear wheel brake, and is inserted into a body passage and supplies the control signal from the mask cylinder to the rear wheel brake according to the suppression signal A hydraulic pressure control device for a rear wheel brake, comprising: a hydraulic pressure control valve for suppressing the brake hydraulic pressure applied to the rear wheel brake.
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