CS235062B2 - Rotary parts braking device especially for motor vehicle's wheels with brake booster - Google Patents

Abstract

In a braking arrangement for a rotating member such as an automotive vehicle wheel and which has a fluid pressure actuated brake for slowing the rotating member together with a booster for increasing the fluid pressure imposed on the brake to a pressure higher than the pressure imposed by an operator, a sensor for signalling the occurrence of an excessive rate of retardation of the braked rotating member and a booster spoiler operatively connected with the booster and the sensor and responsive to a signalled occurrence of an excessive rate of retardation for decreasing the increased fluid pressure imposed by the booster. The booster may be either pneumatic or hydraulic, with corresponding variations, in the specific form for the booster

Description

BACKGROUND OF THE INVENTION The present invention relates to an apparatus for braking rotating parts, in particular motor vehicle wheels, comprising a main hydraulic brake cylinder coupled to a booster and a brake, and a sensor of excessive braking intensity.

The principle of the invention is further characterized in that the braking device further comprises an operation jamming device in the form of a control valve, in the housing of which a reciprocating spindle operated by a solenoid is mounted, the winding of which is electrically connected to the sensor conductors and the armature is spring. The power-assist jamming control valve is provided in several alternatives with a solenoid and a spindle, to which are mounted discs alternating between the seat and connecting the control valve to the pressure medium and the atmosphere. The pressure medium is either air when the servo is pneumatic, for example a diaphragm, or hydraulic fluid if the servo is hydraulic. An advantage of the invention is to control the operation of the booster, which prevents the motor vehicle from jamming and skidding.

BACKGROUND OF THE INVENTION The present invention relates to an apparatus for braking rotating parts, in particular motor vehicle wheels, comprising a main hydraulic brake cylinder coupled to a booster and a brake, and a sensor of excessive braking intensity.

Recently, much effort has been devoted to developing brakes for rotating components capable of slowing rotation at optimum speed. The incentive for this development came from motor vehicles, where it is desirable for a car or truck to stop as short as possible while maintaining stability and steering control. In an effort to achieve the shortest braking distance possible, measures have been taken to increase the braking force beyond the limit of the simple physical strength of the vehicle driver. Such control braking systems have been widely used and are widely used.

Although hydraulic brakes have substantially reduced stopping distances, they have caused difficulties in maintaining directional stability and steering control. An inexperienced driver of a motor vehicle equipped with hydraulic brakes can cause a risk of skidding and the like. For this reason, attention has recently been paid to the development of anti-lock brake modulators interrupting and reducing the action of the pressurized fluid on the brake. Such anti-lock modulators have achieved considerable success, but modulators in hydraulic brakes are subject to relatively high hydraulic pressure, which results in rapid wear and requires a special design.

In view of this experience, it has now been found that anti-lock control can be achieved in hydraulic braking systems, or that this control can be at least facilitated by an additional power assist jammer, eliminating the reinforcing effect of the braking system. Thus, the invention relates to the problem of eliminating wheel locks and the risk of skidding that otherwise occurs due to the extremely high braking force, by reducing the effect of the increased braking pressure achieved by the use of hydraulic brakes. The invention solves this problem by controlling the effect of the increased hydraulic pressure exerted by the booster of the hydraulic braking system. The solution consists in treating the booster means with a differential pressure of air on the booster diaphragm and adapting the hydraulic brake fluid pressure to this difference.

In connection with this major problem, the invention relates to a reduction in the braking effect of a hydraulic system as a function of signaling an extremely high deceleration rate of a rotating brake component such as a wheel of a vehicle using a brake modulator or without such a modulator. In carrying out this object of the invention, it has been found that the reduction in the braking effect obtained by canceling the boosting effect appears to decrease and, in some cases, eliminate the tendency to lock the wheels and skid of the vehicle.

It is also an object of the invention to coordinate the operation of the brake modulator and the booster so as to facilitate the reduction of wear on the brake modulators and to achieve wider application in braking systems operating with varying pressures and volumes. In carrying out this object of the invention, the hydraulic pressure build-up caused by the hydraulic booster of the braking system is prevented or reduced during operation of the connected brake modulator.

SUMMARY OF THE INVENTION In an apparatus for braking rotating parts, in particular a motor vehicle wheel, comprising a main hydraulic brake cylinder coupled to the servo and a brake and an excessive braking intensity sensor, it further comprises a servo booster configured as a control valve. the housing of which is provided with a reversibly movable spindle controlled by a solenoid, the winding of which is electrically connected to the sensor wires and the armature is provided with a spring.

The booster jammer is provided in several alternatives and is connected either in the pneumatic or hydraulic circuit. In one embodiment, the booster control valve is diaphragm-shaped, connected to a conduit connecting the booster diaphragm to a vacuum source, such as an intake manifold of an internal combustion engine with a compressor or the like, and a reciprocating spindle attached to a pair of discs alternately one disc is spring loaded and the control valve housing is provided with a venting duct and a central duct with atmosphere. A non-return valve is connected between the breather duct and the atmosphere, the plug of which is loaded by the pre-tensioning control spring and is movable between the inlet duct and the stop.

The pre-tensioning spring and stop are adjustable screws. In another embodiment, the power steering jammer control valve is connected through the power steering diaphragm and through the master hydraulic cylinder to a hydraulic pressure modulator connected to a line connecting the master hydraulic cylinder to the brake. In another embodiment, a servo valve comprising a reciprocating spindle carrying a pair of additional seated discs, one of which is spring-biased, and a diaphragm housed in the housing, the central channel of the servo valve being connected to a pipe to which the vent pipe connected to one vent channel is connected, on the one hand to the other three vent channels, two of which connect to the atmosphere the space in the control valve housing and the third channel connects the servo valve vent to the atmosphere. SUMMARY OF THE INVENTION In an embodiment with a hydraulic power steering jammer, the power steering jammer control valve is connected by channels provided in the control valve spindle to a hydraulic circuit between the tank and the power steering cylinder coupled to the pedal rod and piston to the brake master cylinder. In another embodiment, the control valve spindle is provided with further oblique channels.

An advantage of the invention is that the power steering jammer in any of the above embodiments achieves control of the power steering of the braking system, thereby eliminating the risk of blocking of the rotating component, in particular of locking and skidding of the motor vehicle wheels.

Above, only some features of the invention have been set forth, further illustrated by the following description, taken in conjunction with the accompanying drawings, in which Fig. 1 is a partially schematic, partly sectional view of a brake arrangement according to the invention particularly suitable for a pneumatic vacuum booster; Fig. 2 is similar to Fig. 1 and illustrates a brake arrangement with one embodiment of a brake modulator; Fig. 3 is another embodiment of the invention of Fig. 1 showing a brake arrangement with a pneumatic booster for compressed air; Fig. 4 is a sectional view similar to that of Fig. 1, illustrating a booster jammer with an auxiliary servo valve for larger volumes of air flow; Fig. 5 shows an embodiment of the invention with a hydraulic brake booster; Fig. 6 is an alternative embodiment of Fig. 5 with a hydraulic brake booster.

A self-propelled vehicle, not shown, is shown in all embodiments (Fig. 1,

2, 3, 4, 5, 6] equipped with hydraulic means for slowing the rotation speed of its wheels and pneumatic or hydraulic means for increasing the force of the braking means. Excessive operation of these boosters is controlled according to the invention by a pneumatic or hydraulic jammer.

The booster jammer is provided in all embodiments of Figs. 1, 2,

3, 4 as a control valve connected to pneumatic lines, in the embodiment of FIGS. 5, 6 connected to the hydraulic circuit of the braking system of a motor vehicle.

The hydraulic brake cylinder 11 is connected to a known booster 12 increasing the hydraulic pressure applied to the brake 10 to a value higher than the pressure exerted by the main hydraulic brake cylinder 11. In the embodiment of Fig. 1, the booster 12 has the shape of a vacuum actuated diaphragm. The booster 12 is coupled to the main hydraulic brake cylinder 11 and cooperates therewith to effect a differential pressure across the entire booster diaphragm.

A conduit 14 disposed between the diaphragm booster and a corresponding vacuum source, such as an intake manifold of an internal combustion engine, acts on the booster 12, resulting in a liquid pressure difference across the entire diaphragm surface. Instead of a vacuum source, a compressor 51 (Fig. 3j, acting on the booster diaphragm 12) by the difference between atmospheric pressure and a pressure greater than atmospheric pressure may be used to achieve the differential pressure.

The braking system according to FIG. 1 further comprises, according to the invention, a known sensor 16, indicating the excessive speed of the braking rotating vehicle wheel. The sensor 16 includes an electrical switch transmitting electrical signals of excessive deceleration rate by sending a signal to the respective conductor 17.

The booster 15 is comprised of a control valve connected by a device for signaling the pressure difference in the booster diaphragm 12 and cooperating with the sensor 16, and at least in part the pressure difference caused by the differential device. In the embodiment shown in FIG. 1, suitable for vacuum diaphragm boosters 12 of relatively small dimensions such as used in light travel vehicles, the control valve consists of a spindle 18 mounted and reciprocating in the housing 19. A pair of discs 20 are mounted on the spindle 18. The disc 21 and the seat 23 with which it cooperates are directly connected to the conduit 14 and regulate the flow through the conduit 14, while the second disc 20 cooperating with the seat 22, it is controllable and provides a connection between the booster 12 and the atmosphere thereby venting the booster 12 in a controlled manner.

The discs 20, 21 are connected to each other by a spindle 18 such that when one disc abuts the respective seat 22, 23 or 23, 22, the other is located outside the seat. The biasing spring 25 normally presses the disc 20 into engagement with the corresponding seat 22, thereby closing the venting of the booster diaphragm 12 and allowing the booster 12 to operate normally, the connection of which via a conduit 14 provides a central channel 26 in the housing 19.

In addition, the position of the spindle 18 is controlled by a solenoid consisting of the winding 28 and the armature 29. The winding 28 is electrically connected to the conductors 17 of a sensor 16 responsive to an electrical command signaling that the deceleration of the braking wheel reaches excessive speed by moving the spindle 18 and the disks 20; When the spindle 18 is so displaced, the disc 21, which is normally outside the seat, abuts its corresponding seat 23, while the disc 20, which normally fits into the seat 22, is lifted from that seat. The booster diaphragm 12 is therefore vented to the atmosphere through the central duct and vent duct 30 passing through the housing 19.

A controllable non-return valve is connected between the atmosphere and the vent channel 30 to control the rate of reduction of the effect of the booster 12 and to prevent foreign matter from entering the housing 19. This valve 31 consists of a plug 32 which is displaceable relative to the inlet duct 34 as a function of the bias of the control spring 35. and the distances defined by the stop 36. The rate of venting of the booster diaphragm 12 and the venting of the pressure permissible in the booster diaphragm 12 is controlled by the threaded and adjusting spring screws 38, 39 and the stop 36. the channel opened by adjusting the stop 36, the speed and the degree of reduction of the braking effort achieved according to the invention are controlled.

In one embodiment (FIG. 2) of the braking system arrangement of the invention, a hydraulic pressure brake modulator 59 (FIG. 2) is provided and is not specifically described. The elements of the embodiment of Fig. 2 corresponding to the elements of the embodiment of Fig. 1 are designated with the same reference numerals and the appendix "a" and there will be no descriptions.

The brake modulator 50 is connected to a line 13a connecting the control valve of the disturbance 15a of the booster 12a through the booster diaphragm 12a and via the master hydraulic brake cylinder 11a to the brake 10a.

The modulator 50 operates depending on the booster command of the sensor 16a as well as the jammer 15a operation command of the booster 12a. In the largest number of cases of switching on the modulator 50 and the jammer 15a operation of the booster 12a may be simultaneous. however, it is contemplated that the diversity of the design of the sensor 16a or of the electrical circuit will allow the modulator 50 to be turned on. and the jammer 15a operating the booster 12a at any time different from each other and in terms of sensing excessive speed of deceleration of the wheels.

Fig. 3 shows an embodiment of a braking system ¹ of the invention in which a pneumatic-type booster 12b is supplied from a motor 37b through a compressor 51. The elements of Fig. 3 corresponding to the elements shown in Figs. with the addition of the letter "b" and the description of those elements will not be repeated here.

A variation of the booster 15 of the power booster 12 of the present invention, which may be used with pneumatic boosters with larger surfaces, is shown in Figure 4, wherein the parts corresponding to those described above in Figure 1 are designated with the same reference numerals, but by one. higher order. The difference between the booster jammer 15 of Figure 1 and the booster jammer of Figure 4 is that the solenoid consisting of the coil 128 and the armature 129 biased by the return spring 125 regulates and controls the reciprocating spindle 118 actuating the servo valve consisting of The disc 141 is biased by a spring 149, the servo valve being actuated by the same vacuum source supplying the vacuum booster 12 of the vehicle braking system. The operation of the servo-operated servo valve jammer 115 is substantially the same as that of the servo-operated booster jammer 15 directly as described above.

Electrical supply DO- winding has 128 'results in the armature' 129 moves against the force of return spring 125, which moves the stem 118 in the housing 119 so that changes engaging wheels 120 to ^121: the respective seats 122, 123. Intermediate channel 126 will therefore be. closed, thereby disrupting its normal connection with the atmosphere through the duct 130 and the reduced pressure in the conduit 114 extending to the space 146 in which it acts on the diaphragm 148 whose second surface is exposed to the ducts 151,152 at atmospheric pressure. By pressure difference on the diaphragm 148, the servo-valve spindle 140 is displaced, thereby altering the alignment of the discs 141, 142 carried by the spindle to the corresponding seats 144, 145. By changing the alignment of the servo-valve discs 141, 142 booster (not shown), venting to atmosphere.

In the embodiment shown in Fig. 4, a valve 132 is mounted on the adjustable screw 138 to control its position relative to the seat 134. Adjusting the position of the valve 132 relative to the channel 130a and the seat 134 changes the rate of increase in braking force achieved by using the servo. reducing the operation of the booster jammer 115;

Figures 5 and 6 show in more detail the dual mode of use of the invention with respect to the braking system by which a booster effect is achieved using a hydraulic circuit. In each example, the individual components of the systems shown in Figures 5, 6 corresponding functionally to the components shown in Figure 1 are indicated by the same reference numerals, differing only in the binary or triangulated order. In each example, the booster cylinder 250 and 350 is coupled between the brake master cylinder 211, 311 and the lever assembly by which the operator actuates the brake master cylinder 211, 311 as shown in the form of the brake pedal 251, 351.

In the embodiment of FIG. 5, pump 252 draws hydraulic fluid from tank 254 and feeds channels 219 in the control valve to the booster cylinder 250. The fluid flows through a channel 255 in the piston 256 forming part of the booster cylinder 250 and sliding within the cylinder so that the liquid pumped from the tank 254 by the pump 252 returns to the tank 254. By means of a truncated cone-shaped tip 258 formed on the brake rod 259 connected to the pedal 251, the fluid flow flowing through the channel 255 is reduced when the driver acts on the pedal 251, thereby obtaining a booster assist force by the hydraulic pressure exerted by the pump 251 256.

According to the invention, the booster 215 of the hydraulic braking system illustrated in Figure 5 is embodied as a control valve connected to a hydraulic circuit between the tank 254 and the booster 250 designed to rectify the forces exerted by the hydraulic pressure and otherwise acting in the hydraulic circuit as described in more detail. 5, the valve spindle 218 is normally held in the first position by the spring force 225. In this position, the necessary functional connections provide channels allowing normal hydraulic fluid flow from the pump 252 and back to the tank 254. By supplying power to the windings 228 and by sliding the armature 229, the valve spindle 218 is moved, thereby providing waste channels through which the hydraulic fluid flow from pump 252 returns directly to the reservoir 254. At the same time, the hydraulic fluid pressure created on the piston 256 of the booster cylinder 250 is equalized or canceled. and the effect of the operation of the booster 250 is attenuated until completely ceased.

Unlike the arrangement of FIG. 5, the arrangement of FIG. 6 employs a reversing control valve booster 315. The channels 319 in the control valve stem 318 allow pressure fluid to flow into the hydraulic booster 350, transverse channels 320 reverse the forces exerted by the hydraulic fluid pressure difference. In this case, the effect of the booster 350 will not only be canceled when the system is actuated, but the pump 352 will assist in generating the opposite direction by counteracting the force exerted by the driver.

Claims (8)

SUBJECT Apparatus for braking rotating parts, in particular motor vehicle wheels, comprising a main hydraulic brake cylinder coupled to a servo and a brake and an excessive braking intensity sensor, further comprising a jammer (15, 15a, 15b, 215, 315) operating the booster (12, 12a, 12b, 250, 350) as a control valve, in the housing (19, 19a, 19b, 119, 219, 319) of a reciprocating spindle (18, 18a, 18b, 118, 218) (318) controlled by a solenoid whose winding (28, 28a, 28b, 128, 228, 328) is electrically coupled to the sensor lead (16, 16a, 17b, 217, 317) 21 (17, 17a, 17b, 217, 317) to the brake pedal 351 when the sensor 317 Wheel Deceleration sent a signal that the wheels could lock. The flow control device and the speed and magnitude of the reduction or reversal of the booster 350 can be applied to the hydraulic pressure brake systems of Figures 5 and 6 as well as to the pneumatic brake systems of Figures 1-4. The invention can be used in various variations. In probably the simplest form, a single sensor coupled functionally to one or more vehicle wheels will correspond to a single master brake cylinder with a single booster or a booster. In somewhat more complex systems, several boosters may be used, each provided with a corresponding booster jammer, each booster jammer being controlled by one or more sensors. In such arrangements, single wheels without a drive or a pair of driven wheels may be provided with sensors. In addition, the individual drive wheels may be provided with the sensors, the sensors controlling the disturbance of the servo-assist of the corresponding wheels working in pairs. Said solutions may be further varied, for example all wheels may be provided with wheel speed retardance sensors, the front and rear axles being equipped with a power steering jamming device. It is also possible to provide a separate deceleration sensor and a power steering jamming device with both rear wheels, whereas the front wheels have a wheel speed deceleration sensor and a power steering jammer. Finally, each wheel may have its own wheel speed deceleration sensor and its own booster jammer. The use of braking modulators can be varied either by providing one modulator for the whole system or by providing one modulator for each wheel or by providing an arrangement in different variations. It is contemplated that the invention will be used in all such arrangements. OF THE INVENTION 16b) and the armature (29, 29a, 29b, 129, 229, 329) is provided with a spring (25, 25a, 25b, 125, 225, 325). Device according to claim 1, characterized in that the control valve of the jammer (15, 15a, 15b, 115) of the diaphragm-assisted booster (L2, 12a, 12b) is connected to a pipe (14, 14a, 14b, 114) connecting a booster diaphragm (12, 12a, 12b) having a vacuum source, for example, an intake manifold of an internal combustion engine, a compressor (51), etc., and a pair of discs (20, 20a, 20b, 120) attached to its reciprocating spindle (18); 21, 21a, 21b, 121) abutting their seats (22, 22a, 20b, 220, 225) alternately is loaded by a spring (25, 25a, 25b, 125) of the armature (29, 29a, 29b, 129) and the housing The control valve (19, 19a, 19b, 119) is provided with a venting duct (30, 30a, 30b, 130) and a central duct (26, 26a, 26b, 126) with atmosphere. Apparatus according to claim 2, characterized in that a non-return valve (31, 31a, 31b) is connected between the breather channel (30, 30a, 30b) and the atmosphere, the plug of which (32, 32a, 32b) is loaded with a biasing spring. (35, 35a, 35b) is slidable between the inlet channel (34, 34a, 34b) and the stop (36, 36a, 36b). Device according to claim 3, characterized in that the biasing spring (35, 35a, 35b] and the stop (36, 36a, 36b) are adjustable screws (38, 38a, 38b, 39, 39a, 39b). Device according to claim 1, characterized in that the booster control valve (15a) of the booster (12a) is connected via a booster diaphragm (12a) and a main hydraulic brake cylinder (11a) to a hydraulic pressure modulator (50) connected to a pipe (13) connecting the main hydraulic brake cylinder (11a) to the brake (10a). 6. Apparatus according to claim 1, characterized in that a servo valve consisting of a reciprocating spindle (140) carrying a pair of additional disks (141, 142) with seats (144, 145), is further provided in the housing (119). wherein one disc (141) is biased by a spring (149) and from a diaphragm (148) housed in a housing (146) of the housing (119), the central port (126) of the servo valve being connected to a duct (114) to which the venting is connected a pipe (150) connected to the venting duct (130), on the one hand connected to other venting ducts, of which the ducts (151, 152) are connected to the atmosphere of the space (146) and the duct (130a) of the valve (32) . Device according to claim 1, characterized in that the jammer control valve (215, 315) is connected by channels (219, 319) provided in the control valve stem (218, 318) to the hydraulic circuit between the tank (254, 354) and the cylinder. the booster (250, 350) connected by a rod (259, 359) to the pedal (251, 351) and by means of a piston (355) to the brake master cylinder (211, 311). Device according to Claims 1, 7, characterized in that the control valve stem (318) is provided with further inclined channels (320).