JPS5841225B2 - Your brake booster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention (L) relates to a hydraulic brake booster that can operate, for example, a brake mask cylinder of a vehicle with a boosted output in response to an input input by a driver. The present invention provides a device that can operate as a power source, and can also operate using the accumulated pressure fluid of an emergency accumulator as a power source in the event of a pump failure.

A hydraulic booster with an emergency accumulator of this type has a first valve that controls the pump fluid pressure and a second valve that introduces fluid from the accumulator, and if the first valve moves too much, the second valve was opened to introduce fluid from the accumulator into the brake booster.

Therefore, even when the pump is operating normally, if the hydraulic brake booster is suddenly activated or activated with excessive operating force due to sudden braking, the second valve opens and drains the accumulated fluid in the accumulator. There was a risk that the pump would fail and the stored fluid would be depleted when fluid from the accumulator was really needed.

The present invention utilizes the deflection movement of the spool valve of the diversion valve provided between the pump and power steering when the pump is stopped, and uses this deflection movement to connect the accumulator and the hydraulic brake booster control valve, thereby preventing pump failure. Only then is the fluid in the accumulator used to operate the hydraulic brake booster via the booster control valve.

The present invention will be described in detail below with reference to the drawings.

This figure shows a state in which the pump 1 is operating and supplying fluid from the reservoir 2 to the circuit.

The pump 1 is driven by a vehicle engine (not shown), and is configured to be able to supply fluid from a reservoir 2 to an inflow port 10 of a hydraulic brake booster via a vibro.

The outflow port 11 of the brake booster 3 is connected to the pipe 8 which leads to the reservoir 2 via the pipe I and the puff steering 5.
The outlet port 12 on the low pressure fluid side is connected to the pipe 8.

Note that another inflow port 13 connects the accumulator 4 and the pipe 9.
It communicates with

One end of the input rod 14 is connected to a brake pedal (not shown), and the brake booster 3 is actuated by the driver.

The brake booster 3 has two stages of cylinders 16 and 17 within the body 15, and a shoulder 18 is formed at the boundary between the large diameter cylinder 16 and the small diameter cylinder 1γ.

The large diameter cylinder 16 has a guide 19 at its open end fixed sealingly to the body 15.
A puff piston 20 is hermetically and slidably housed between the puff piston 20 and a working chamber 21 and a low pressure chamber 22 are formed at both ends of the puff piston 200.

The spring 101 is a return spring for the puff piston 20, one end of which engages with the guide 19, and the other end of which engages with the puff piston 20 to move the puff piston 20 into the body 15.
It is biased so as to come into contact with the shoulder portion 18 of.

Further, the low pressure chamber 22 communicates with the outflow port 12.

A sealed annular chamber 23 is formed between the outer peripheral notch of the power piston 20 and the large diameter cylinder 16, and an output rod 24 is provided at one end of the puff piston 20, a seat 25 is placed in the center of the output rod 24, and a sleeve 26 is provided at the other end. ) 27 and is hermetically fixed.

A spool 29 is slidably housed in the elongated hole 28 in the center of the sleeve 26, and the spool 29 is operatively connected to an input piston 30 connected to the artificial rod 14.

The input piston 30 is slidably housed in a small diameter cylinder IT of the body 15 in a sealed manner, and a large diameter portion 31 at one end of the input piston 30 is slidably fitted into a hole 32 of the nut 21.

The spring 34 has its tape end engaged with the seat 25 and the other end engaged with the rod 35 to bias the large diameter portion 31 of the input piston 300 through the spool 29 so as to abut against the shoulder portion 33 of the bolt 27. are doing.

The sleeve 26 has grooves 36 and 37 and a vertical hole 38 on its inner diameter, and the groove 37 communicates with the hole 3B.

The hole 38 communicates with the low pressure chamber 22 via the central hole 39 of the puff piston 20, and the groove 36 communicates with the vertical hole 40 of the sleeve 26.
It communicates with the annular chamber 23 via the vertical hole 41 of the puff piston 20.

A chamber 42 between the spool 29 and the seat 25 communicates with the working chamber 21 via a hole 43 and a vertical hole 44 in the input piston 30.

The spool 29 has lands 45, 46 and an outer peripheral groove 47. When the input piston 30 is in contact with the shoulder 33 by the spring 34, the land 45 communicates with the hole 38 and the chamber 42, and the land 45 communicates with the hole 38 and the chamber 42. 46 connects the groove 36 via the groove 47
and 37 are connected.

The output lot 24 forms a chamber 49 in which the sheet 25 is hermetically fitted in the hole 48 , and the ball 50 located in the chamber 49 is urged by a spring 51 into the hole 52 of the sheet 25 .
The chambers 49 and 42 are normally shut off.

The ball 50 engages with the rod 35 by moving the spool 29 to the left by the input piston 30, and the ball 50 engages with the rod 35 to open the chambers 49 and 4.
2 to be able to communicate with each other.

When the spool 29 is moved to the left by the input piston 30, the land 45 first blocks the vertical hole 38 and the chamber 42, and then the ball 50 is moved to the seat 2 via the rod 35.
The chambers 49 and 42 are connected to each other apart from the land 46.
is configured to reduce the passage between grooves 36 and 47.

Also, the land 46 is made slightly smaller than the outer diameter of the spool 29, so that even if the input piston 30 moves to the maximum extent to the extent that it contacts the sleeve 26, an annular orifice is formed between the hole 28 and the land 46. The hole 40 and the groove 3T are configured to communicate with each other through this annular orifice.

Here, the spool 29, the rod 35, and the ball 50 constitute a booster control valve, and the land 45 of the spool 29 serves as a normally open first valve portion that controls the chamber 42 and the hole 38 of the sleeve 26 intermittently. The ball 50 is placed in chambers 42 and 4.
The spool 290 land 46 constitutes a normally open third valve part that controls the flow resistance from the groove 36 of the sleeve 26 to the groove 47 of the spool 29. ing.

The guide 19 forms a hermetic annular chamber 53 between the body 15 on the outer periphery and a hermetic annular chamber 54 between the output rod 24 on the inner periphery, and the chambers 53 and 54 are formed on the guide 19. It communicates through a vertical hole 55 provided in the.

The chamber 54 communicates with the chamber 49 via a vertical hole 56 and a hole 57 of the output lot 24.

A cylinder 58 with an open hole at one end is provided in parallel with the large diameter cylinder 16 of the body 150, a plug 59 is hermetically fixed to the open end of the cylinder 58, and a spool valve 600 is slidably accommodated in the cylinder 58 at both ends. Chambers 61 and 62 are formed in each of the chambers 61 and 62, respectively.

The plug 59 forms a sealed annular chamber 63, 64 with the body 15 at the outer periphery, the chamber 63 communicates with the inflow port 13, and the chamber 64 communicates with the vertical hole 65 of the body 15.
It communicates with the chamber 53 via.

The chamber 64 further includes a first check valve (hereinafter simply referred to as check valve) 66.
The check valve 66 communicates with the inflow port 10 through a horizontal hole 67 and a vertical hole 68 in the body 15.
The chamber 64 is positioned to allow fluid flow from the chamber 64 to the inlet port 10, but prevents fluid flow from the chamber 64 to the inlet port 10.

The plug 59 is provided with a hole 69 on the side of the chamber 61.
A sheet 70 is hermetically fixed to the open end of the sheet 70, a chamber T1 is formed inside, and a chamber 64 and a vertical hole 7 are formed on the outer periphery of the sheet 70.
An annular chamber 73 communicating with the two is formed.

The sheet 70 is provided with a vertical hole 74 passing through both ends in the center thereof, and the hole 14 is communicated with the chamber 13 through a vertical hole 75.

Inside the chamber 71, a ball T6 is biased via a retainer 77 by one end of a spring 78 so as to isolate the chamber 71 from the hole 74, and the other end of the spring 78 is engaged with the plug 59 via a valve 79. It matches.

Further, a hole 81 on the outer periphery of the plug 59 that communicates with the chamber 63 communicates with the chamber 71 via a valve 79, and the valve 79 has an orifice 80 that communicates the hole 81 with the chamber 71.

The sheet 10 has a hole 84 communicating with the chamber 61 on the side opposite to the chamber 11.
A valve seat 83 is provided at the boundary between the hole 84 and the hole 74.
is formed.

A rod 82 is slidably accommodated in the hole 14, and a ball 86 and a rod 85 are accommodated in the hole 84. The ball T6, the rod 82, and the ball 86 and rod 85 are operatively connected, respectively. .

In the state shown in the figure in which the ball 16 blocks the chamber 11 and the hole 14 by the spring 78, the ball 86 is separated from the valve seat 83 by the rod 82, one end of the rod 85 protrudes into the chamber 61, and the spool valve 60 is separated from the valve seat 83 by the rod 82. It is arranged so that it can be engaged with.

When the rod 85 is pushed to the left by the spool valve 60, it pushes the ball 86 against the valve seat 83 and connects the hole 74 and the chamber 6.
1 and the spring 7 via the rod 82.
8, the ball 76 is separated from the seat 7G, and the chamber 71 and the hole 74 are communicated with each other.

Therefore, the seat 10 and the ball T6 serve as a switching valve.

Inner circumferential grooves 87 and 88 are provided in the cylinder 58 of the body 15, and these grooves are connected to the first groove by the spool valve 60.
A variable orifice 89 and a second variable orifice 90 are formed, respectively, and the first variable orifice 89 communicates with the inflow port 10 via the outer circumferential groove 91 of the spool valve 60 (7) and the hole 68 of the body 15. 92 communicates with chamber 61, and second variable orifice 90 communicates with chamber 62.

The groove 8T communicates with the outflow port 11, and the groove 88 communicates with the body 1.
It communicates with the annular chamber 23 through the vertical hole 93 of No. 5.

A hole 94 is provided on the side of the chamber 62 of the spool valve 60,
The hole accommodates a spring 95 whose one end engages with the body 15, and the spool valve 60 is biased in the direction of closing the first variable orifice 89 and engaging the rod 85; 10 is shown in which fluid is supplied by the pump 1 and flows into the outflow port 11 via the first variable orifice 89, so in this state the spool valve 60 and the rod 85 are in a non-engaged relationship.

The chamber 62 communicates with the vertical hole 98 of the body 15 via the hole 94° vertical hole 96 of the spool valve 60 and the groove 91 on the outer periphery, and the hole 98 is adjusted by the hole 98 and the tip of the screw 100. Holes 67 and 68 through orifice 99
, and are in communication with the inflow port 10, respectively.

The spool valve 60 is moved into the chamber 61 by the force of the spring 95.
When the first variable orifice 890 passage is moved in the direction of , the first variable orifice 890 passage is made smaller and the second variable orifice 900 passage is made larger; when the first variable orifice 890 passage is moved in the direction of the chamber 62 against the spring 95, the first variable orifice 890 passage is enlarged. Second variable orifice 9
0 passage is configured to be small.

Therefore, when the fluid supplied to the inflow port 10 flows to the outflow port 11 via the first variable orifice 89, the pressure difference between the chambers 61 and 62 will be It is determined by the force of 95 and is approximately constant.

Specifically, if the force of the spring 95 is 4 Kg and the cross-sectional area of the spool valve 60 is 2 cyl, the pressure difference in the chamber 61 is set higher than the force balance m by 4 Ky/2 tsl = 2 Kg/crtl. be done.

In this state, the orifice 99 communicates the chambers 61 and 62, so the pressure difference between the chambers 61 and 62 is constant, and the flow rate flowing from the orifice 99 to the chamber 62 is also approximately constant and supplied to the hole 93. be done.

In this way, the spool valve 60 cooperates with the orifice 99 and the spring 95 to constitute a flow divider valve, and the port 1
If fluid is supplied to port 11 or hole 93
Although it moves back and forth due to the pressure of
When the pressure in the inlet port 10 and the chamber 61 falls to OKV'cfIl, the spool valve 60 is deflected to the left by the spring 95 and only engages with the rod 85.

In the above configuration, its operation will be explained. When the pump 1 is driven, the fluid in the reservoir 2 is supplied to the chamber 61 from the inflow port 10 via the vibro, and the pressure in the chamber 61 is reduced by the spring. 95, open the first variable orifice 89 and pipe 7° from the outflow port 11 to the puff steering 5. It is returned to the reservoir 2 via the pipe 8.

At this time, from the hole 61 to the orifice 99, the chamber 62, the hole 93,
A certain amount is simultaneously flowing into the pipe 8 via the annular chamber 23, the holes 41 and 40, the groove 36, the groove 41 of the spool 29, the groove 31, the hole 38, the low pressure chamber 22, and the outlet port 12.

In this state, the working chamber 21 communicates with the chamber 42 and the hole 3.
Since the power piston 20 is in communication with the low pressure chamber 22 through the piston 8, the power piston 20 is not subjected to any force in the front and rear directions, and is in a non-operating state in which the output rod 24 is not activated.

Now, when the power steering 5 is operated, the pressure in the circuit up to the pump 1 increases via the pipe 1, outflow port 11, inflow port 10, and vibro.

At this time, the pressure in the chamber 61 increases equally, but the spool valve 60 receives this pressure and controls the second variable orifice 90 to increase the pressure in the throttle chamber 62 by the same amount, so that the pressure difference between the chambers 61 and 62 remains constant. held and passed through orifice 99 to chamber 6
The flow rate through hole 93 through 2 is also kept constant.

The pressure in port 10 is determined by the pressure in hole 67, check valve 66, chamber 64,
5. Chamber 53° Fluid is transmitted to chamber 49 via hole 55, chamber 54, and holes 56 and 57, but since ball 50 blocks communication between chamber 49 and chamber 42, the fluid does not flow to chamber 42. do not have.

Further, since the working chamber 21 and the low pressure chamber 22 communicate with the chamber 42 through the hole 38, the puff piston 20 is in an inactive state.

When the pressure in the chamber 64 increases, the hole 7 communicating with the chamber 64
4 also increases, the ball 76 is opened against the spring 78 by the pressure in the hole 14, fluid is supplied to the chamber 71, the orifice 80, the hole 81, the chamber 63, the inlet port 13,
Pressurized fluid is stored in the accumulator 4 via the pipe 9 .

This is repeated, and when sufficient fluid is supplied to the accumulator 4, the check valve action of the ball 16 stops the fluid from flowing from the chamber T1 to the hole T4, and the accumulated fluid in the accumulator 4 becomes extremely It remains stored for the time being.

When the driver operates the input piston 30 via the brake pedal and the rod 14 while the puff steering 5 is in operation and the pressure in the chamber 49 communicating with the inflow port 10 via the check valve 66 is high, the spool 29 The rod 35 moves to the left against the spring 34 together with the rod 35, and the land 45 of the spool 29 blocks the chamber 42 and the hole 38, thereby cutting off communication between the low pressure chamber 22 and the working chamber 21, and the rod 35 moves to the ball 50.
is removed from the seat 25 against the pressure of the spring 51 and the chamber 49.

As a result, the high pressure fluid in the inflow port 10 flows into the chamber 49 and the hole 52.
, is introduced into the working chamber 21 via the chamber 42, and the pressure of the chamber is increased.

The puff piston 20 receives the pressure in the working chamber 21 and transmits the amplified output to the outside through the output rod 24 against the force of the spring 101.

The pressure in the working chamber 21 simultaneously provides a counteracting force to the operator's operating force on the input piston 30, allowing the operator to control the pressure in the working chamber 21.

If the pressure in the working chamber 21 rises to be equal to the pressure in the inflow port 10 due to the operation of the puff steering 5, and it is necessary to further increase the pressure in the working chamber 21, the driver further moves the spool 29 to the chamber 42 via the input piston 30. When the land 46 of the spool 29 is moved in the direction of the annular chamber 23 from the hole 93,
Holes 41 and 40. By constricting the passage of fluid flowing from the groove 36 to the groove 41, the pressure in the chamber 62 increases, and the spool valve 60 moves in the direction of the chamber 61, constricting the fourth variable orifice 89, causing the pump 1 to flow from the chamber 61 and the inlet port 10. The pressure can be further increased.

Accordingly, the pressure in the chamber 49 communicating with the inflow port 10 increases, making it possible to introduce even higher pressure into the working chamber 21.

Also, when the power steering 5 is not operating, the spool 29 closes the chamber 42 and the hole 38, and the rod 35 closes the ball 5.
0 from the seat, the inflow port 10 and the working chamber 21
Further, the land 46 increases the pressure in the chamber 62, and at the same time increases the pressure in the chamber 61 and the inflow port 10, so that the pressure in the working chamber 21 also increases, and the puff piston 20 can operate. .

Next, when the driver operates the input piston 30 with excessive operating force, the input piston 20 contacts the three 726,
The spool 29 moves to the maximum, the land 45 blocks the chamber 42 and the hole 38, the rod 35 communicates the chambers 49 and 42, and the land 46 creates a minimum area annular orifice between the slot 28. Form.

Therefore, the fluid pressure supplied from the hole 93 rises to the set upper limit value and does not rise any further.

Therefore, the pressure in the working chamber 21 connected to the inflow port 10 is also set to a higher upper limit pressure than the constant differential pressure reduction chamber 62, and the fluid supplied to the port 10 is not consumed due to the increase in the working chamber 21. It is supplied to the puff steering 5 from the outflow port 11 via the first variable orifice 89 .

When the driver releases the input piston 30, the input piston 30 is returned to the right along with the spool 29 by the pressure in the working chamber 21 and the spring 34, and the ball 50 seats on the seat 25 and connects the chambers 49 and 42. The land 45 communicates the chamber 42 and the hole 38 and releases the fluid in the working chamber 21 from the hole 38 to the low pressure chamber 22.
Land 46 relieves fluid resistance from groove 36 to groove 47.

As a result, the pressure in the working chamber 21 becomes equal to that in the low pressure chamber 22, and the power piston 20 is moved to the shoulder 18 by the spring 101.
is returned to the inoperative position in abutment.

During the above operation, the spool valve 60 does not engage the rod 85 in any way, so the fluid pressure in the accumulator 4 is consumed and reduced.

When the pump 1 stops operating for some reason, the pressure in the chamber 61 becomes OKg/crri because no fluid is supplied to the inlet port 10.

Then, the spool valve 60 has about 4 kg of spring 95.
The rod 85 acts in a direction to separate the ball 16 from the seat 70 via the ball 86 and the rod 82.

In this case, the ball 76 is approximately 50 K9/crA in the chamber 71.
f) The ball T is pressed against the hole 74 of Sea) 70 by hydraulic pressure, but the area of the hole 140 is about 0.05 crA, so the ball T
The force with which 6 is pressed against the sheet 70 is 0.05 cox
50 Kg/crtt = 2.5 to 4.

Also, the force of the spring 18 pushing the ball 76 is approximately o,
I kg, the total force required to release the ball 76 from the seat 70 is 2.6 times 9.

Therefore, the ball 76 is released by the spring 95 via the rod 82, the ball 86, the rod 85, and the spool valve 60, and the ball 86 is pressed against the seat 700 and the valve seat 83. Be cut off.

By communicating the chamber 71 with the hole 74, the accumulator 4 is connected to the pipe 9, the inflow port 13, the chamber 63, the hole 81, and the chamber 1.
1. It communicates with the chamber 49 in the output lot 24 via the holes 74 and 75, the chamber T3, the hole 72, and the chamber 64.

At this time, the fluid &L check valve 66 in the chamber 64 prevents the fluid from flowing back from the inlet port 10 to the pump 1 side.

In this state, when the driver operates the input piston 30 via the rod 14, the spool 29 and rod 35 are moved toward the chamber 42 against the spring 34, and the spool 29 is moved so that the land 45 is connected to the chamber 42 and the hole 38. The communication is closed and the rod 35 disengages the ball 50 from the seat 25 to introduce fluid into the working chamber 21 through the chamber 42 into the chamber 49 which communicates with the accumulator 4 .

As a result, the pressure in the working chamber 21 increases, and the puff piston 20 operates against the spring 101, transmitting the increased output to the outside via the output rod 24.

Further, when a large flow rate flows from the accumulator 4 to the working chamber 21, the valve 79 moves away from the contact surface of the plug 59 against the force of the spring 78, thereby automatically increasing the fluid passage from the hole 81 to the chamber 11.

When the operation of the input piston 30 is released, the spool 29 and the rod 35 are returned to the right by the spring 34, and the ball 50 seats on the seat 25, cutting off the chambers 49 and 42, and the chamber 42 is opened through the hole 38. and communicates with the low pressure chamber 22.

As a result, the pressure in the operating chamber 21 becomes equal to the pressure in the low pressure chamber 22, and the puff piston 20 is returned to its non-operating state by the spring 101.

Next, with pump 1 stopped, hydraulic brake booster 3
When all the fluid stored in the accumulator 4 is used by operating the input piston 30, the input piston 30 comes into contact with the sleeve 26, so the puff piston 20 and the output rod 24 are manually operated. It can be done by transmitting force to the parts.

In the above structure and operation explanation, when the pump 1 is operating, the spool valve 60 of the brake booster 3 does not engage with the rod 85 in any case, so the pressure accumulated fluid in the accumulator 4 is not consumed, and in case of emergency When the pump 1 is in the M position, the spring 95 deflects the spool valve 60 and pushes the rod 85 to ensure communication between the accumulator 4 and the chamber 49, ensuring that the fluid stored in the accumulator 4 is used only for the original emergency purpose. It is highly safe.

Also, a pole 50 for introducing fluid from the accumulator 4 into the working chamber 21. can be used in common with the valve that introduces fluid from the pump 1, so there is no need to provide a second valve that introduces fluid from the accumulator 4 in addition to the conventional valve that controls pump pressure, making the booster control valve simple. It has excellent effects such as:

[Brief explanation of the drawing]

The drawing is a central longitudinal sectional view of the invention. 1...Pump, 20...Puff piston, 60...Spool valve, 30...
Input histone, 50... Valve, 76...
...No, Kurup, 4... Accumulator, 45
, 46... Land, 41... Groove, 95
······spring.

Claims (1)

[Claims] 1 A body having an inlet port communicating with the pump, an outlet port communicating with the power steering, and an outlet port communicating with the reservoir, a puff piston located within this body, and a working chamber located on the end side of the body. A power piston operated by hydraulic pressure, an input piston located at one end of the puff piston and operated by a brake pedal, an output piston located at the other end of the power piston, and an input piston located at one end of the puff piston. a control valve actuated by the input piston, the control valve having a normally open first valve portion, a normally closed second valve portion, and a normally open third valve portion;
A hydraulic oil introduction passage that leads the hydraulic oil in the inflow port to the working chamber via the first check valve and the second valve section, and the hydraulic oil in the working chamber through the first valve section. an orifice disposed between the inflow port and the third valve part of the passage that leads the working oil in the inflow port to the outlet port via the third valve part; A spool valve that forms a first variable orifice through which hydraulic oil flows from the inflow port to the outflow port, and a second variable orifice through which hydraulic oil flows from the orifice to the third valve portion, and the spool valve is connected to the first variable orifice. a spring biasing the second variable orifice toward one end where the second variable orifice becomes narrower as the valve becomes smaller; A flow dividing valve is provided, and an accumulator is connected between the first check valve and the second valve portion of the hydraulic oil introduction passage via a second check valve, and the second check valve is connected to the second check valve. The valve is located at one end of the spool valve, and is configured such that when the pump is stopped, the force of the spring is applied to the second check valve via the spool valve, opening the second check valve. Hydraulic brake booster.