JPH0451389B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an antilock control device that automatically relieves and restores control force for wheel brakes.

Conventionally, in this type of device, a modulator is installed in the brake oil path connecting the master cylinder and the wheel brakes, and when the wheels are about to lock up during control, the modulator cuts off the brake oil path and relieves the braking force of the wheel brakes. There is a known system in which the braking force of the wheel brake is restored via a modulator using hydraulic pressure supplied from a hydraulic pump.

However, a plunger type hydraulic pump is used, and in order to operate the pump plunger only during braking, the pressure receiving part of the pump plunger is exposed to the brake oil passage between the modulator and the master cylinder. Since the hydraulic pressure of the master cylinder is applied to the pressure receiving part to perform the pumping action, it is necessary to reliably seal between the brake oil passage and the pump chamber.
The seal structure becomes complicated.

Furthermore, when the anti-lock is activated, the pumping action of the pump plunger is transmitted to the brake pedal, creating a so-called jerky feeling, which some drivers may not like.

Furthermore, the hydraulic pump is configured so that it does not operate unless the brake pedal is depressed to generate output hydraulic pressure from the master cylinder, so even if the hydraulic pump fails during normal driving, the driver will not be aware of it. Can not.

In view of the above, the present invention makes the pumping action of a plunger-type hydraulic pump performed by a spring force, thereby eliminating the need for the seal structure, eliminating the jerky feeling, and further notifying the driver of a failure of the hydraulic pump during normal driving. It is an object of the present invention to provide an anti-lock control device as described above.

According to the present invention, the above object is achieved by a plunger-type hydraulic pump driven by an eccentric cam that rotates in conjunction with a wheel; having an oil chamber communicating with a discharge port of the hydraulic pump and connecting a master cylinder and a wheel brake; It is installed in the brake oil passage, and when the pressure in the oil chamber is above a predetermined value, the brake oil passage is maintained in a state where the pressure can be increased, and when the pressure is below the predetermined value, the brake oil passage is closed. a modulator configured to shut off and switch to a reduced pressure state that increases the volume of the brake oil passage on the wheel brake side; and a modulator that is interposed between the oil chamber and the oil tank and detects when the wheels are about to lock. a detection valve that opens;
The hydraulic pump includes a fixed pump cylinder, a pump plunger that is slidably engaged with the pump cylinder to define a pump chamber and engages the eccentric cam, and a pump plunger that engages the eccentric cam. When the pump plunger is moved forward by the eccentric cam, the suction stroke of the pump chamber is performed, and when the pump plunger is moved backward by the spring, the discharge stroke is performed, and the pressure in the pump chamber is maintained at a predetermined level. When the pressure exceeds a predetermined value, the pump plunger is prevented from moving back by the spring, and a warning is issued when the pressure in the oil chamber of the modulator falls below a predetermined value while the vehicle is running. This is achieved by connecting a warning means.

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.
Left front wheel (and right front wheel) in type brake piping
It is installed in the brake oil passage L that connects the wheel brake B of the right rear wheel (and the left rear wheel) and the master cylinder M, and is used to prevent the locking phenomenon in the left and right front and rear wheels.

The anti-lock control device A includes a plunger type hydraulic pump P and an oil chamber 6 communicating with the hydraulic pump P.
When the pressure of the control piston 7 is higher than a predetermined value,
A modulator _M0 opens a shutoff valve 5 disposed in the brake oil passage L by sliding it in one direction, and closes the shutoff valve 5 by sliding the control piston 7 toward the other side due to pressure reduction in the oil chamber 6. , a detection valve v that opens a normally closed discharge valve mechanism 10 interposed in an oil drain path 9 connecting the oil chamber 6 and the oil tank 4 by a wheel deceleration detection mechanism 11.

First, referring to the cutoff valve ₅ of the modulator _M0 , in FIG. 15 ₁ and 15 ₂ . The valve body holding cylinder 14 has a valve hole 17 in an inner end wall 16, and a plurality of protrusions 18 surrounding the valve hole 17 are formed on the outer surface of the inner end wall 16. The opening of the valve body holding cylinder 14 is closed by a lid 20 fitted with a seal member 19 interposed therebetween. A threaded member 21 is screwed onto the open end of the cylinder hole 13, and the threaded member 21 connects a shoulder 22 on the outer peripheral surface of the valve body holding cylinder 14 to the cylinder hole 1.
3. The valve body holding cylinder 14 is brought into contact with the stepped portion 23 on the inner circumferential surface.
is fixed in the cylinder hole 13, and the lid body 20 is secured externally.

Disposed within the valve body holding cylinder 14 are a valve body 24 made of an elastic material such as rubber, and a valve spring 26 that biases the valve body 24 toward the valve seat 25 at the mouth edge of the valve hole 17 . An operating rod 27 is loosely inserted into the valve hole 17 and protrudes from the valve body 24 .

An oil passage hole 28 is formed in the peripheral wall of the valve body holding cylinder 14, and the oil passage hole 28 is connected to the oil passage 29 of the cylinder ₃₁ .
The output port of the master cylinder M is communicated with the output port of the master cylinder M through. Further, an oil passage hole 30 is formed near the inner end wall 16 of the valve body holding cylinder 14 in the cylinder ₃₁ , and the oil passage hole 30 communicates with the wheel brake B. Therefore, the oil passage hole 28, the oil passage 29, and the oil passage hole 30 constitute a part of the brake oil passage L between the master cylinder M and the wheel brake B.

Next, referring to the control piston 7 of the modulator M ₀ , the control piston 7 has a cylindrical shape,
The bottom wall 31 of the valve body holding cylinder 14 is slidably fitted into the cylinder hole 13 with its bottom wall 31 facing the inner end wall 16 of the valve body holding cylinder 14 . A seal member 32 is fitted onto the outer peripheral surface of the bottom wall 31 of the control piston 7, thereby defining an oil chamber 6 in the cylinder hole 13 that is isolated from the brake oil path L. A control piston 7 is installed in the oil chamber 6 in a valve body holding cylinder 14.
A spring 33 that urges the side is compressed.

A wide annular oil groove 34 is formed on the outer surface of the peripheral wall of the control piston 7, and a plurality of oil holes 35 are formed in the peripheral wall to communicate the oil groove 34 with the inside of the oil chamber 6.

The control piston 7 slides toward the shutoff valve 5 side due to the pressure accumulated in the oil chamber 6, opens the shutoff valve 5 by pushing the operating rod 27, and slides to the opposite side due to the pressure reduction in the oil chamber 6. By moving away from the operating rod 27, the shutoff valve 5 is closed.

Next, regarding the hydraulic pump P, a drive shaft 36 that is rotated at an increased speed from an axle (not shown) is attached to the casing 12, and as shown in FIG. 2, a pair of bearings 37 ₁ ,
Supported through 37 ₂ . An eccentric ring portion 38 is provided integrally at the intermediate portion of the drive shaft 36,
An eccentric cam 39 made of a ball bearing is fitted into the eccentric ring portion 38.

_A pump cylinder 3 2 is provided in the casing 12 so as to be orthogonal to the drive shaft 36 and integrally with the cylinder 3 ₁ . The cylinder hole 40 has one end opened into the eccentric cam storage chamber 41 and the other end opened into the outer end surface of the pump cylinder 3 ₂ , and the inner diameter is gradually increased from the outer end surface of the pump cylinder 3 ₂ toward the eccentric cam 39 . The first to fifth hole portions 40 ₁ to 4 are made smaller to
Consists of 0 ₅ . The open end of the first hole 40 ₁ is closed by a lid 42 screwed thereon. Fourth hole 40
₄ and the third hole 40 ₃ in the vicinity thereof has a fifth hole 4
An annular plate 44 having the same inner diameter as _0.05 and having a sealing member 43 tightly attached thereto is fitted into a cylinder 45.

A pump plunger 46 that engages with the eccentric cam 39 is slid in the cylinder hole 40, and the pump plunger 46 is divided into a first rod portion 46 ₁ and a second rod portion 46 ₂ . The first rod portion 46 ₁ has a small diameter portion 48 which is slidably fitted into the third hole portion 40 ₃ via the seal member 47 ₁ and a seal member 47 ₂ which is inserted into the second hole portion 40 ₂ .
A pump chamber 50 is defined between the outer circumferential surface of the small diameter portion 48 and the inner circumferential surface of the second hole 40 ₂ . A stepped portion between the small diameter portion 48 and the large diameter portion 49 of the first rod 46 ₁ that defines the pump chamber 50 functions as a pressure receiving surface 46 a. Second rod part 46
₂ is a fifth hole 40 ₅ , a small diameter portion 51 that is slid on the annular plate 44 and the cylindrical body 45 , and a large diameter portion that is slid on the third hole 40 ₃ and has the same diameter as the small diameter portion 48 of the first rod portion 46 . 5
2, and a suction oil chamber 53 is defined between the outer peripheral surface of the small diameter portion 51 and the inner peripheral surface of _{the third} hole portion 403.

The pump plunger 46 has a first rod portion 46 thereof.
A suction port 54 is formed that extends in the axial direction from the outer end surface of the _second rod portion 46 to the middle portion of the second rod portion 46 ₂ , and the opening of the suction port 54 is closed by a plug body 56 fitted thereto via a sealing member 55 . The plug 56 is prevented from being removed by a circlip 57 fixed to the open end of the suction port 54.

The inlet 58 of the suction port 54 is connected to the suction oil chamber 53.
The outlet 59 opens into the pump chamber 50 . A suction valve 61 that allows hydraulic oil to flow only in one direction from the inlet 58 to the outlet 59 is disposed in the valve chamber 60 defined by the plug 56 . The suction valve 61 has a valve seat 62 formed on the end wall of the valve chamber 60.
and a spherical valve body 63 that can be seated on the valve seat 62.
It consists of a valve spring 64.

Between the outer end surface of the first rod portion 46 ₁ and the inner surface of the lid body 42,
A spring 65 is compressed to urge the plunger 46 to engage with the eccentric cam 39, and a spring 65 is provided between the outer end surface of the cylinder 45 and the large diameter portion 52 _of the second rod portion 462.
A connecting spring 66 is provided to connect the first rod portion 46 ₂ to the first rod portion 46 ₁ .

Discharge ports 67 are provided on the peripheral walls of both cylinders 3 ₁ and 3 ₂ .
is formed, and the pump chamber 50 and the oil chamber 6 communicate with each other via the oil groove 34 and the oil passage hole 35 of the control piston 7 through the discharge port 67 . A one-way valve 68 is located in the middle of the discharge port 67 and allows hydraulic oil to flow in only one direction from the pump chamber 50 to the oil chamber 6.
is interposed.

Next, describing the normally closed discharge valve mechanism 10 of the detection valve V, a part of the oil drain passage 9 is formed in the casing 12 passing through the suction oil chamber 53 of the hydraulic pump 8.
A normally closed discharge valve mechanism 10 is interposed between the suction oil chamber 53 and the oil chamber 6 in the oil drain passage 9 .

As shown in FIG. 2, the discharge valve mechanism 10 is disposed in a recess 71 that opens into the space 70 of the casing 12 as follows.

The recess 71 is a large diameter hole 71 that opens into the space 70.
₁ and a small-diameter hole 71 ₂ connected thereto, the large-diameter portion 729 ₁ of the valve body holding cylinder 72 connects to the large-diameter hole 71 _{1 via the seal member 73 1 ,} and the small-diameter portion 72 ₂ connects to the seal member. They are respectively fitted into the small diameter holes 71 ₂ via the holes 72 ₂ . The small diameter portion ₇₂₂ is formed with a bent discharge hole 76 having an inlet 74 located on one end surface and an outlet 75 located on the outer peripheral surface, and a pin-shaped valve that can be seated on a valve seat 77 provided at the bent portion. The body 78 is slid onto the large diameter portion 72 ₁ . Further, an actuator 79 is slid onto the large diameter portion 72 ₁ coaxially with the valve body 78 to prevent it from coming off, and one end of the actuator 79 is connected to the diaphragm 8 .
0, and the other end protrudes into the space 70.

The inlet 74 of the discharge hole 76 is connected to the oil chamber 6 and the outlet 7
5 communicate with the oil tank 4 through a suction oil chamber 53, respectively.

Further, the actuator 79 is pressed by a wheel deceleration detection mechanism 11, which will be described later, to seat the valve body 78 on the valve seat 77, so that the drain hole 76 and therefore the oil drain path 9 are normally closed.

Wheel deceleration detection mechanism 1 in the next detection valve V
1, one end of the drive shaft 36 protrudes outside the casing 12 to receive rotational force from the axle, and the other end protrudes into the space 70.
In the space 70 , a flywheel 81 is slidably and rotatably supported on the drive shaft 36 via a bearing metal 82 , and a thrust plate 84 is attached to the drive shaft 36 via a half-moon key 83 on the outside of the flywheel 81 . is supported. A stop ring 85 is attached to the shaft end of the drive shaft 36 via the stop ring 85 and a spring pin 86 passing through the shaft end, and the thrust plate 84 is prevented from coming off by the stop ring 85.

An actuating plate 88 is rotatably supported by a hub 87 of the flywheel 81 facing the thrust plate 84, and between the actuating plate 88 and the thrust plate 84 is a ball 89 and a pair of inclined grooves that engage with the ball 89. 90,91
A thrust generating mechanism 92 consisting of the following is interposed. A friction type overrunning clutch 93 is provided between opposing surfaces of the actuation plate 88 and the flywheel 81.

A retaining plate 94 that prevents the bearing 37 ₂ and the valve body retaining cylinder 72 of the discharge valve mechanism 10 from coming off is attached to the inner wall surface of the space 70 with a pair of screws 95 ₁ and 95 ₂ . A return spring 96 is compressed between the wheels 81.

The screw 95 near the discharge valve mechanism 10 has a support pin portion 97 on its head, and an actuation lever 98 is swingably supported on the support pin portion 97. Actuation lever 98
One end faces the actuator 79 of the discharge valve mechanism 10,
A spring 99 is compressed between the other end and the casing 12, and the elastic force of the spring 99 causes the operating lever 9 to
An arcuate protrusion 100 protruding from the middle part of the valve body 8 is brought into contact with the flywheel 81, and one end thereof pushes the actuator 79 to close the valve body 78 as described above.

A warning means 103 having an oil pressure switch 101 and a warning lamp 102 is connected to the oil chamber 6 of the modulator _M0 , and when the pressure in the oil chamber 6 falls below a predetermined value during normal driving of the vehicle, the oil pressure switch 101 The system detects this and lights up a warning lamp 102. Warning lamp 102
may be a warning generating member such as a buzzer.

In Fig. 1, Bpb is a brake pedal connected to the input rod of the master cylinder.

Next, the operation of this embodiment will be explained. During normal running of the vehicle, the drive shaft 36 rotates at a predetermined speed faster than the axle, and as a result, the flywheel 81 also rotates with the thrust plate 84, the ball and the inclined groove 89. , 90, 91, the operating plate 88, and the overrunning clutch 93 to rotate at the same speed as the drive shaft 36. Therefore, no pressing force is applied to the actuating lever 98, so that the drain valve mechanism 10 is in a state where the oil drain path 9 is blocked.

On the other hand, the eccentric cam 39 rotates together with the drive shaft 36, and the pump plunger 46 of the hydraulic pump P comes into contact with the eccentric cam 39 by the elastic force of the spring 65, so that the pump plunger 46 reciprocates. When the pump plunger 46 is reciprocated by the eccentric cam 39, a suction stroke is performed in which the suction valve 61 is opened and the hydraulic oil in the suction oil chamber 53 is sucked into the pump chamber 50 through the suction port 54. When the pump plunger 46 moves back by the spring 65, the suction valve 61 is closed to compress the hydraulic oil in the pump chamber 50, and the discharge port 6
A discharge stroke is performed to supply oil to the oil chamber 6 of the modulator M ₀ through the oil pump 7 . By repeating this, a certain amount of oil pressure is accumulated in the oil chamber 6. This oil chamber 6
The pressure causes the control piston 7 to slide toward the shutoff valve 5 side, and the outer surface of the bottom wall 31 comes into contact with the protrusion 18 of the valve body holding cylinder 14. As a result, the operating punch 27 is pushed by the control piston 7, and the valve body 24 opens the valve 17 and conducts the brake oil passage L, so that the master cylinder M and the wheel brake B are communicated with each other.

When the pressure in the pump chamber 50 exceeds a predetermined value, the pressure acts on the pressure receiving surface 46a of the first punch portion ₄₆₁ of the pump plunger 46, causing the pump plunger 46 to resist the elastic force of the spring 65 and move away from the eccentric cam 39. The pump plunger 46 is biased in the direction of separation.
Therefore, the hydraulic pump P stops its pumping action and does not apply unnecessary load to the drive shaft 36.

During braking, if you step on the brake pedal Bp and generate output hydraulic pressure from the master cylinder M,
Since the shutoff valve 5 is open, the output oil pressure is transmitted to the wheel brake B via the brake oil path L, and the wheels are braked. When the braking force of the wheel brake B is small and does not cause a wheel lock phenomenon, the deceleration detection mechanism 11 is inactive, and the discharge valve mechanism 10 blocks the oil drain path 9. Shutoff valve 5 is held open.

When the braking force of the wheel brake B is large due to sudden braking or the like and there is a risk of wheel locking, the drive shaft 36 is decelerated in accordance with the deceleration of the wheels, so the deceleration detection mechanism 11 is activated. .
That is, the flywheel 81 rotates at a higher rotational speed than the drive shaft 36 due to its inertia, and the operating plate 88 rotates together with the flywheel 81, so the ball 89 climbs the inclined groove 90 of the thrust plate 84, thereby causing The flywheel 81 slides toward the operating lever 98 and pushes it, so the operating lever 98
swings counterclockwise in FIG. 2, and the pressing force on the actuator 79 of the discharge valve mechanism 10 is released.

Since the pressure of the oil chamber 6 is acting on the valve body 78 of the discharge valve mechanism 10, the pressure causes the valve body 78 to move away from the valve seat 77, and the oil drain path 9 is conducted, so that the oil chamber 6
is depressurized. Due to the pressure reduction, the control piston 7 receives the hydraulic pressure on the wheel brake B side and slides in the direction away from the cutoff valve 5, and eventually separates from the operating punch 27, so that the valve body 24 closes the valve hole 17 and connects with the master cylinder M. The brake oil path L between the wheel brakes B is shut off. Therefore, the oil pressure of the wheel brake B does not increase any further, and the volume between the bottom wall 31 of the control piston 7 and the inner end wall 16 of the valve body holding cylinder 14 increases due to the sliding movement of the control piston 7. Therefore, the hydraulic pressure of the wheel brake B is reduced and the braking force is relaxed, thereby avoiding the wheel lock phenomenon.

The reduced pressure in the oil chamber 6 causes the hydraulic pump P to operate and supply oil pressure to the oil chamber 6, but since the discharge valve mechanism 10 communicates with the oil drain path 9, no oil pressure is accumulated in the oil chamber 6. In this case, since the hydraulic pump P is independent from the brake fluid path L between the master cylinder M and the wheel brake B, the pumping action of the hydraulic pump P is not transmitted to the brake pedal Bp side, and therefore the pumping action is not transmitted to the brake pedal Bp side. There is no feeling.

After the valve body 78 of the discharge valve mechanism 10 is completely opened, the actuating plate 88 rotates together with the thrust plate 84 while keeping the distance between the actuating plate 88 and the thrust plate 84 wide, and the flywheel 81 slides the overrunning clutch 93 and closes the actuating plate. Rotates independently from 88.

And by relaxing the braking force of wheel brake B,
The rotational speed of the wheels increases and therefore the drive shaft 36
When the rotational speed of the flywheel 81 becomes equal to that of the flywheel 81, the flywheel 81 slides away from the operating lever 98 by the elastic force of the return spring 96, so that the drain valve mechanism 10 blocks the oil drain path 9 again. Then, hydraulic pressure is supplied to the oil chamber 6 from the hydraulic pump P, and the control piston 7 slides toward the shutoff valve 5, so that the hydraulic pressure of the wheel brake B gradually increases, and the braking force is restored.

Thereafter, when the control piston 7 opens the shutoff valve 5, the master cylinder M and the wheel brake B are communicated again.

During normal driving, if the pressure in the oil chamber 6 is maintained at a predetermined value, the oil pressure switch 101 will be open and the warning lamp 102 will be off. However, if the pressure in the oil chamber 6 falls below the predetermined value, the oil pressure switch 10
1 is detected and closed, the warning lamp 102 lights up.

If the pressure in the oil chamber 6 decreases in this way, it means that an abnormality has occurred in the hydraulic pump P and it is no longer possible to increase the pressure, so it is necessary to avoid sudden braking.

As described above, according to the present invention, the pumping action of the hydraulic pump is performed by spring force, so that the hydraulic pump side and the master cylinder side are completely disconnected, and thereby the brake that connects the wheel brakes and the master cylinder. A seal structure between the oil passage and the pump chamber can be omitted.

Further, since the pumping action of the hydraulic pump is not transmitted to the master cylinder side when the anti-lock is activated, there is no so-called jerky feeling on the brake pedal, and this makes it possible to improve the feeling of pressing the brake pedal.

Furthermore, the discharge pressure of the hydraulic pump is contained in the oil chamber of the modulator, and the brake oil passage is made conductive by the pressure, which is effective in preventing malfunction of the modulator and also in preventing oil loss.

Furthermore, there is an advantage that the driver can be notified of a hydraulic pump failure while the vehicle is running by warning of a drop in pressure in the oil chamber of the modulator.

Further, when the pressure in the pump chamber exceeds a predetermined value, the spring prevents the pump plunger from moving back and its pumping action is stopped, thereby eliminating power loss.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a front view of the entire main part taken longitudinally, and FIG. 2 is a longitudinal side view of the detection valve. A...Antilock device, B...Wheel brake, L...Brake oil path, M...Master cylinder, Mo...Modulator, P...Hydraulic pump,
V...Detection valve, 3 ₂ ...Pump cylinder, 4...
Oil tank, 6...Oil chamber, 39...Eccentric cam, 46...
Pump plunger, 50... Pump chamber, 65...
Spring, 67...Discharge port, 103...Warning means.

Claims (1)

[Claims] 1. A plunger-type hydraulic pump driven by an eccentric cam that rotates in conjunction with the wheels; having an oil chamber communicating with the discharge port of the hydraulic pump, and interposed in a brake oil path connecting the master cylinder and the wheel brake; When the pressure in the oil chamber is above a predetermined value, the brake oil passage is maintained in a state where it can be increased in pressure, and when the pressure is below the predetermined value, the brake oil passage is shut off and the brake oil passage is closed. a modulator configured to switch to a reduced pressure state that increases the volume on the wheel brake side; a detection valve that is interposed between the oil chamber and the oil tank and opens when it detects that the wheels are about to lock; The hydraulic pump includes a fixed pump cylinder, a pump plunger that is slidably engaged with the pump cylinder to define a pump chamber and engages the eccentric cam, and urges the pump plunger to engage the eccentric cam. a spring, when the pump plunger is moved forward by the eccentric cam, the suction stroke of the pump chamber is performed, and when the pump plunger is moved backward by the spring, the discharge stroke is performed, and the pressure in the pump chamber is equal to or higher than a predetermined value. If the pressure in the oil chamber falls below a predetermined value while the vehicle is running, the oil chamber of the modulator is configured to prevent the pump plunger from moving back by the spring, and a warning means is provided to issue a warning when the pressure in the oil chamber falls below a predetermined value while the vehicle is running. Connected,
Antilock control device for wheel brakes.