JPH0215424B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides signal generating means for generating a plurality of wheel speed signals corresponding to circumferential speeds of a plurality of wheels selected in advance; A signal selection means for selecting a signal corresponding to the circumferential speed, and control for detecting a wheel slip state based on the wheel speed signal selected by the signal selection means and performing antilock control on the plurality of wheels. The present invention relates to an anti-lock braking function testing method for performing a functional test on an anti-lock braking system having a means while the vehicle is stopped.

For example, in an anti-lock braking system for a front-engine, front-wheel-drive four-wheel vehicle in which the load supported by the front wheels is greater than the load supported by the rear wheels, the driving stability of the vehicle is improved by avoiding locking of the rear wheels. In order to ensure this, anti-lock control is performed in response to the circumferential speed of the pair of left and right rear wheels that is more likely to become locked, that is, the circumferential speed of the wheel with the lower circumferential speed. is normal.
In this way, when performing a functional test of an anti-lock braking system on a vehicle equipped with an anti-lock braking system that performs anti-lock control in response to the lowest circumferential speed of a plurality of wheels selected in advance, conventionally The anti-lock braking system was functionally tested while running tests on each vehicle.

However, in order to test the functionality of anti-lock braking systems through driving tests, a test course is first required, and not only is it necessary to have a running surface with a low coefficient of friction, but it is also necessary to have a test course with a running surface with a low coefficient of friction. However, there were disadvantages such as requiring a large amount of driving time, high-speed driving tests being dangerous, and making pass/fail judgments difficult.

SUMMARY OF THE INVENTION Accordingly, the main objects of the present invention are to provide a signal generating means for generating a plurality of wheel speed signals corresponding to the circumferential speeds of a plurality of wheels selected in advance, and a signal generation means for generating a plurality of wheel speed signals corresponding to the circumferential speeds of a plurality of wheels selected in advance; A signal selection means for selecting a signal corresponding to the speed, and a control means for detecting a wheel slip state based on the wheel speed signal selected by the signal selection means and performing antilock control on the plurality of wheels. An object of the present invention is to provide an anti-lock braking function testing method capable of statically testing the functionality of an anti-lock braking system having a vehicle while the vehicle is stopped.

In order to achieve the above-mentioned object, the present invention provides that a plurality of wheel speed signals corresponding to circumferential speeds of a plurality of wheels selected in advance are inputted to all input sections of a signal selection means from the acceleration process of the wheels. The first step up to the normal deceleration process without wheel locking.
A first inspection step in which a pseudo wheel speed signal is input, and whether or not antilock control is performed in a normal deceleration state is confirmed by detecting brake oil pressure, and the case where the antilock control is not performed is considered normal; At the same time, inputting a second pseudo wheel speed signal from an acceleration process of the corresponding wheel to a constant speed to a deceleration process of deceleration while receiving anti-lock control to an arbitrarily selected one of the input units; The first pseudo wheel speed signal of the corresponding wheel is input to the remaining input section, and whether or not antilock control is performed based on the second pseudo wheel speed signal is checked by detecting the braking oil pressure. The present invention is characterized in that it includes a second test step in which all input sections are sequentially tested to determine that the anti-lock control is normal.

Hereinafter, with reference to the drawings, an embodiment will be described in which the present invention is applied to an anti-lock braking device for a front engine, front wheel drive type four-wheel vehicle in which the load supported on the front wheel side is greater than the load supported on the rear wheel side. do.

First, in FIG. 1, when a brake pedal 2 is depressed, a tandem type master cylinder 1 transfers brake oil supplied from an oil tank 3 to a pair of oil passages 4, which constitute an independent brake hydraulic system. 4′
The hydraulic pressure is sent to the primary brake hydraulic chambers 6, 6' of the front wheel brake hydraulic pressure adjusting device 5, respectively.

The front wheel brake hydraulic pressure adjustment device 5 includes a cylinder 7 whose both ends are closed by a pair of end wall members 8 and 8';
A pair of partition walls 9, 9' are provided within the cylinder 7 at positions spaced apart from the respective end wall members 8, 8'.
and a pair of pistons 11 and 12 at both ends, respectively.
and 11', 12', and a pair of rods 10, 10' that pass through the corresponding partition walls 9, 9' in the portion between each piston so as to be able to freely slide in the axial direction.
The cylinder chamber between the partition wall 9 and the piston 11 is connected to the master cylinder 1 via the oil passage 4 as the primary braking hydraulic chamber 6 of the first hydraulic system, and the cylinder chamber between the partition wall 9 and the piston 12 is The cylinder chamber between is connected to the wheel cylinder hydraulic chamber 20 of the right front wheel wheel cylinder 19 via the oil passage 18 as the secondary braking hydraulic chamber 14 of the first hydraulic system, and is connected to the end wall member 8.
The cylinder chamber between the piston 12 and the open oil chamber 1
5, the cylinder chamber between the partition wall 9' and the piston 11' is connected to the oil tank 3 via the oil passage 21, and the cylinder chamber between the partition wall 9' and the piston 11' is connected to the oil passage as the primary braking hydraulic chamber 6' of the second hydraulic system. Master cylinder 1 through 4'
The cylinder chamber between the partition wall 9' and the piston 12' is connected to the secondary braking hydraulic chamber 1 of the second hydraulic system.
4' communicates with the wheel cylinder hydraulic chamber 20' of the left front wheel wheel cylinder 19' via an oil passage 18', and the cylinder chamber between the end wall member 8' and the piston 12' is connected to the open oil chamber 15'. The cylinder chamber between the pair of pistons 11 and 11' serves as an anti-lock control hydraulic chamber 13, and is connected to the pressure control valve 41 and the exhaust pressure control valve 42. Depending on the operation, anti-lock brake fluid is supplied or discharged.

A compression spring 16 is provided between the pair of pistons 11 and 11.
are interposed, and the partition wall 9 and the piston 1
1 and between the partition wall 9' and the piston 11', compression springs 17, 17' are respectively interposed, and the elastic restoring action of these compression springs 16, 17, 17' causes each piston to 11, 12 and 11', 12' move elastically and smoothly, and are always held at proper positions when not braking.

Incidentally, in order to prevent leakage of pressure oil between the cylinder chambers, annular so-called cup-shaped seal members 11a and 11b each having a check effect against the pressure oil are provided on each side of each of the pistons 11 and 11'.
and 11a', 11b' are installed,
Cup-shaped seal members 9a, 9a' are installed on the primary brake hydraulic chambers 6, 6' side of each partition 9, 9', respectively, and further, cup-shaped seal members 9a, 9a' are installed on the secondary brake hydraulic chambers 14, 14' side of each piston 12, 12'. A cup-shaped sealing member 12a, 12a' is attached to each. Among these, the pair of seal members 9a, 9a' in particular are such that the internal pressure oil of the primary brake hydraulic chambers 6, 6' is connected to the secondary brake hydraulic chamber 14,
14' by leaking into each piston 1
The pair of sealing members 12a, 12a' prevents the secondary brake hydraulic chambers 14, 12 from losing their ability to move toward each other.
When the pressure oil in 4' leaks into the oil passage 21,
To prevent generation of sufficient secondary braking hydraulic pressure from being hindered.

In addition, the piston rods 10, 10' are provided with several communication grooves 10a, 10a' extending in the axial direction on the outer periphery of their intermediate portions, so that when the piston rods 10, 10' move inward beyond a predetermined distance, The primary brake hydraulic chambers 6, 6' and the secondary brake hydraulic chambers 14, 14' formed on both sides of the partition walls 9, 9' are communicated with each other through communication grooves 10a, 10a', respectively. ing.

Each primary brake hydraulic chamber 6, 6' is further provided with a hydraulic control valve 22, 22' midway, respectively.
3' to the corresponding primary brake hydraulic chambers 25, 25' of the rear wheel brake hydraulic pressure adjusting device 24. The rear wheel brake hydraulic pressure adjustment device 24 basically has the same structure as the front wheel brake hydraulic pressure adjustment device 5, and includes a cylinder 26 whose both ends are closed by a pair of end wall members 27 and 27'. , this cylinder 2
a pair of partition walls 28, 28' arranged in a position spaced apart from each end wall member 27, 27' in 6;
A pair of rods 29, 29' are provided with a pair of pistons 30, 31 and 30', 31'' at both ends, respectively, and pass through the corresponding partition walls 28, 28' in the portion between the pistons so as to be able to freely slide in the axial direction.
The cylinder chamber between the partition wall 28 and the piston 30 serves as a primary brake hydraulic pressure chamber 25 of the first hydraulic system, and contains an oil passage 23, a hydraulic pressure control valve 22, and a primary brake hydraulic pressure of the front wheel side brake hydraulic pressure adjustment device 5. The chamber 6 communicates with the master cylinder 1 via the oil passage 4, and the cylinder chamber between the partition wall 28 and the piston 31 serves as the secondary braking hydraulic chamber 33 of the first hydraulic system, and is connected to the left rear via the oil passage 37. It communicates with the wheel cylinder hydraulic chamber 39 of the wheel wheel cylinder 38, and the end wall member 27 and the piston 3
The cylinder chamber between 1 and 1 is a release oil chamber 34, an oil passage 40, and a release oil chamber 1 of the front wheel side brake hydraulic pressure adjustment device 5.
5. The cylinder chamber between the partition wall 28' and the piston 30' is connected to the oil tank 3 via the oil passage 21, whereas the cylinder chamber between the partition wall 28' and the piston 30' is connected to the primary braking hydraulic chamber 25' of the second hydraulic system.
It communicates with the master cylinder 1 via the oil passage 23', the oil pressure control valve 22', the primary brake oil pressure chamber 6' of the front wheel brake oil pressure adjustment device 5, and the oil passage 4', and connects the partition wall 28' and the piston 31'. The cylinder chamber between is connected to the wheel cylinder hydraulic chamber 39' of the right rear wheel wheel cylinder 38' via an oil passage 37' as a secondary braking hydraulic chamber 33' of the second hydraulic system, and is connected to the wheel cylinder hydraulic chamber 39' of the right rear wheel wheel cylinder 38'. The cylinder chamber between 27' and the piston 31' is connected to the oil tank 3 as a release oil chamber 34' via an oil passage 40', a release oil chamber 15' of the front wheel brake hydraulic pressure adjustment device 5, and an oil passage 21. Furthermore, the cylinder chamber between the pair of pistons 30, 30' serves as an anti-lock control hydraulic chamber 32, and is controlled to supply or discharge anti-lock control oil through the related operations of a pressure control valve 43 and an exhaust pressure control valve 44. It's getting old.

A compression spring 3 is provided between the pair of pistons 30 and 30'.
5 is interposed, and compression springs 36 and 36' are interposed between the partition wall 28 and the piston 30 and between the partition wall 28' and the piston 30', respectively. 36,3
6', each piston 30, 3
1, 30', and 31' move elastically and smoothly, and are always held at proper positions when not braking.

As in the case of the front wheel brake hydraulic pressure adjustment device 5, in order to prevent leakage of pressure oil between the cylinder chambers, there are provided on both sides of the pair of pistons 30, 30'.
Cup-shaped seal members 30a, 30b and 30a', 30b' are installed respectively, and cup-shaped seal members 28a, 28a' are installed on the primary braking hydraulic chamber 25, 25' side of each partition wall 28, 28', respectively. Further, cup-shaped seal members 31a, 31a' are installed on the secondary braking hydraulic chambers 33, 33' side of the pistons 31, 31', respectively.

In addition, the piston rods 29, 29' are provided with several communication grooves 29a, 29a' extending in the axial direction on the outer periphery of their intermediate parts, so that when the piston rods 29, 29' move inward beyond a predetermined distance, , the primary brake hydraulic chambers 25, 25' and the secondary brake hydraulic chambers 33, 33' formed on both sides of the partition walls 28, 28', respectively, are connected to communication grooves 29a,
They are communicated separately via 29a'.

The pair of hydraulic control valves 22 and 22' are configured so that the braking force applied to the rear wheels with a smaller supported load is smaller than the braking force applied to the front wheels with a larger supported load, in accordance with the distribution of the supported load, especially immediately after the start of braking. This is a control valve for adjusting the primary brake hydraulic pressure, and by the hydraulic pressure lowering action of the pair of hydraulic pressure control valves 22, 22', the hydraulic pressure in the pair of primary brake hydraulic pressure chambers 6, 6' is reduced, especially immediately after the start of braking. The oil pressure in the pair of primary braking oil pressure chambers 25, 25' is kept lower than that in accordance with the distribution of the supporting load of each wheel. As a result, after the start of braking, the hydraulic pressure generated in the secondary brake hydraulic chambers 14, 14' behind the front wheels is larger than the hydraulic pressure generated in the secondary brake hydraulic chambers 33, 33' on the rear wheel side. If a failure occurs in the front wheel side secondary braking hydraulic system, each wheel cylinder 19, 1 on the front wheel side
If a situation occurs in which hydraulic pressure is not transmitted to the rear wheel, the loss of braking effect on the entire vehicle will be greater than in the case where a failure occurs in the secondary brake hydraulic system on the rear wheel side, resulting in an inconvenient situation. Become. Therefore,
As a means to prevent such a situation from occurring, the pair of oil passages 18, 18' are connected to each other via oil passages 56, 56', which are provided with check valves 55, 55', respectively. Due to the action of these pair of check valves 55, 55', the secondary brake hydraulic system on the front wheel side malfunctions, and the pair of secondary brake hydraulic chambers 1
4, 14', and the hydraulic pressure in the wheel cylinder hydraulic chambers 39, 39' on the rear wheel side is reduced to the hydraulic pressure in the wheel cylinder hydraulic chambers 20, 20' on the front wheel side. If the hydraulic pressure exceeds the set pressure, the hydraulic pressure in the secondary brake hydraulic chambers 33, 33' on the rear wheel side immediately changes to the corresponding wheel cylinder hydraulic chamber 20 or 2 on the front wheel side.
0'.

Next, the anti-lock control system will be explained. For example, control oil pressurized by a hydraulic source P such as a plunger pump is sent to the pressure control valve 41 via a check valve 45 and an oil path 47 that communicates with a pressure accumulator 46 midway, and is also It is also sent to the pressure control valve 43 via an oil path 48 branching from 47.
Further, the control oil discharged by the exhaust pressure control valve 42 is sent to the oil tank 51 via the oil passage 49, and the control oil discharged by the exhaust pressure control valve 44 is sent to the oil tank 51 through the oil passage 50.
The oil is sent to the oil tank 51 via 49. and oil tank 51
After passing through the filter 52, the control oil in the oil passage 5
3. It is pressurized again by the hydraulic source P via the check valve 54.

Next, as shown in FIG. 2, the pressure control valves 41 and 43 and the exhaust pressure control valve 4 in the antilock control system are
The opening/closing control device A of No. 2 and 44 will be explained.

In FIG. 2, the pressure control valve 41 and the exhaust pressure control valve 42 are controlled to open and close by a late-acting anti-lock control hydraulic pressure supply device 65, while the pressure control valve 43 and the pressure control valve 44 are controlled by an early-acting anti-lock control system. Opening/closing is controlled by a hydraulic supply device 66. Wheel speed detector 57 for right front wheel
The generated signal is converted by a wheel speed calculator 59 into a wheel speed signal proportional to the circumferential speed of the right front wheel, and then sent to a high speed signal selector 61 such as a high select circuit via an OR circuit 67. The signal generated by the wheel speed detector 57' for the left front wheel is converted by the wheel speed detector 59' into a wheel speed signal proportional to the circumferential speed of the left front wheel, and then sent to the high speed signal selector 61 via the OR circuit 68. Sent. The high speed signal selector 61 selects the wheel speed signal of the wheel with the higher circumferential speed among the left and right front wheels, and sends the signal to the front wheel control circuit 63. The front wheel control circuit 63 is
After calculating the slip rate and increase/decrease speed of the wheel with higher circumferential speed among the left and right front wheels, the pressure control valve 41 is normally kept closed and the exhaust pressure control valve 42 is kept open. When the wheel with a higher circumferential speed, that is, the wheel that reaches the lock state later, reaches the lock state, the pressure control valve 41 is immediately opened and the exhaust pressure control valve 42 is opened.
is closed, and control oil sent from the hydraulic source P is introduced into the anti-lock control hydraulic chamber 13.

On the other hand, the signal generated by the wheel speed detector 58' for the right rear wheel is converted by the wheel speed calculator 60' into a wheel speed signal proportional to the circumferential speed of the right rear wheel, and then sent through an OR circuit 69. A signal sent to a low speed signal selector 62 such as a low select circuit and generated by a wheel speed detector 58 for the left rear wheel is converted by a wheel speed calculator 60 into a wheel speed signal proportional to the circumferential speed of the left rear wheel. After that, it is sent to the low-speed signal selector 62 via the OR circuit 70. The low speed signal selector 62 selects the wheel speed signal of the wheel with the lower circumferential speed among the left and right rear wheels, and sends the signal to the rear wheel control circuit 64. The rear wheel control circuit 64 calculates the slip rate and increase/decrease speed of the wheel with the lower circumferential speed among the left and right rear wheels, and normally controls the pressure control valve 4.
3 is kept closed and the pressure control valve 44 is kept open, but the wheel with the lower circumferential speed among the left and right rear wheels,
That is, when the wheel that reaches the lock state first reaches the lock state, the pressure control valve 43 is immediately opened, the exhaust pressure control valve 44 is closed, and the inside of the antilock control hydraulic chamber 32 is opened. The control oil sent from the hydraulic source P is introduced into the hydraulic pressure source P.

Each pressure control valve 41, 43 and exhaust pressure control valve 4
2 and 44 may be electromagnetic control valves operated by electromagnetic solenoids, respectively, and the pressure control valves 41,
43 can be configured to remain closed when not energized and open when energized, and exhaust pressure control valves 42 and 44 may be configured to remain closed when energized. It can be configured so that it remains open at times and becomes closed when energized.

With the above structure, when the brake pedal 2 is depressed during braking, the brake pressure generated in the master cylinder 1 is transferred to each primary brake hydraulic chamber on the front wheel side via the oil passages 4 and 4'. 6 and 6', and is further transmitted to the respective primary brake hydraulic chambers 25 and 25' on the rear wheel side via oil passages 23 and 23'. As a result, each pair of pistons 11, 11'
and 30, 30' are pressed by the primary brake hydraulic pressure in the primary brake hydraulic chambers 6, 6' and 25, 25', respectively, and the rods 10, 10' and 29,
29' are moved axially in each cylinder 7, 26 toward each other to generate secondary brake hydraulic pressure in each secondary brake hydraulic pressure chamber 14, 14' and 33, 33'. At this time, a pair of hydraulic control valves 2
2, 22', the primary brake hydraulic pressure in the primary brake hydraulic chambers 25, 25' on the rear wheel side is higher than the primary brake hydraulic pressure in the primary brake hydraulic chambers 6, 6' on the front wheel side.
The secondary brake hydraulic pressure generated in the rear wheel side secondary brake hydraulic pressure chambers 33, 33' is adjusted to be lower according to the distribution of the supporting load of the wheels. It is lower than the secondary brake hydraulic pressure generated in the secondary brake hydraulic pressure chambers 14, 14' depending on the distribution of the supporting load of the wheels.

The secondary braking hydraulic pressure in the secondary braking hydraulic chambers 14, 14' on the front wheel side is immediately transferred to the wheel cylinder hydraulic chamber 20 of the right front wheel wheel cylinder 19 and the left front wheel wheel cylinder 1 via oil passages 18, 18', respectively.
By being transmitted to the wheel cylinder hydraulic chamber 20' of 9', the left and right front wheels receive braking force, and the secondary braking hydraulic pressure in the secondary braking hydraulic chambers 33, 33' on the rear wheel side is transmitted through the oil passages. 37, 37' to the wheel cylinder hydraulic chamber 3 of the left rear wheel wheel cylinder 38.
9 and the wheel cylinder hydraulic chamber 39' of the right rear wheel wheel cylinder 38',
The left and right rear wheels receive braking force.

If the secondary brake hydraulic system on the front wheel side malfunctions for some reason, the hydraulic pressure in the wheel cylinder hydraulic chamber 39 or 39' on the rear wheel side will be reduced to the wheel cylinder hydraulic chamber 20 or 20 on the front wheel side during braking. 'If the internal pressure becomes higher than the set pressure of the corresponding check valve 55 or 55', the oil pressure in the corresponding rear wheel side secondary brake hydraulic chamber 33 or 33' immediately closes the oil path. 56 or 56' into the wheel cylinder hydraulic chamber 20 or 20' on the front wheel side to compensate for the loss of braking force on the front wheel side.

During braking, when the left and right front wheels reach a lock state later, the late-acting anti-lock control hydraulic pressure supply device 65 operates to close the lead which had been in the closed state until then. By opening the pressure control valve 41 and closing the exhaust pressure control valve 42, which had been open until then, the control oil sent from the hydraulic source P is immediately transferred to the anti-lock control hydraulic chamber. 13 and presses the pair of pistons 11, 11' in directions away from each other. As a result, the secondary brake hydraulic pressure in the secondary brake hydraulic pressure chambers 14, 14' decreases, and the braking force applied to each of the left and right front wheels by each wheel cylinder 19, 19' changes from the state in which at least one of the left and right front wheels is locked. It will be relieved until it comes off,
Or it will be canceled. During this time, each release oil chamber 15,
The oil in 15' is pressed by pistons 12 and 12', respectively, and flows back into oil tank 3 through oil passage 21.

Furthermore, when at least one of the left and right rear wheels reaches a lock state during braking, the early-acting anti-lock control hydraulic pressure supply device 66 is activated.
As the pressure control valve 43, which had been in the closed state until then, is placed in the open state, and the exhaust pressure control valve 44, which was in the open state until then, is placed in the closed state,
The control oil sent from the hydraulic source P is immediately introduced into the anti-lock control hydraulic chamber 32 and presses the pair of pistons 30, 30' in a direction away from each other.
As a result, the secondary brake hydraulic pressure in the secondary brake hydraulic pressure chambers 33, 33' decreases, and each wheel cylinder 38, 3
The braking force applied to the left and right rear wheels by 8' is relaxed or released until the left and right rear wheels are released from the locked state. During this time, the oil in each release oil chamber 34, 34' is removed from the piston 31, 34', respectively.
31', the oil flows back into the oil tank 3 via the oil passages 40, 40', the open oil chambers 15, 15', and the oil passage 21.

By the way, during braking, the wheel cylinders 19, 19',
38, 38', for example, when the front wheel wheel cylinder 19 of the first brake hydraulic system fails, the hydraulic pressure in the secondary brake hydraulic chamber 14 communicating with the wheel cylinder hydraulic chamber 20 decreases. Therefore, the rod 10 moves to the left by the hydraulic pressure in the primary brake hydraulic chamber 6 (Fig. 1), and the primary brake hydraulic chamber 6 moves into the communication groove 10a.
The pressure oil flows into the secondary brake hydraulic chamber 14 from the primary brake hydraulic chamber 6, and the pressure in the primary brake hydraulic chamber 6 is reduced. Therefore, the primary brake hydraulic chamber 25 for operation of the rear wheel wheel cylinder 38 of the first brake hydraulic system, which communicates with the primary brake hydraulic chamber 6, is also depressurized, and the rear wheel wheel cylinder 38 becomes inoperable. As a result, all the wheel cylinders 19 and 38 of the failed first brake hydraulic system become inoperable, and only the wheel cylinders 19' and 38 of the other second brake hydraulic system operate normally, so that the brake is applied to the wheels. The power is balanced as a whole and steering stability is not impaired. If the rear wheel wheel cylinder 38 breaks down, the primary brake hydraulic chamber 25 for its operation communicates with the secondary brake hydraulic chamber 33 via the communication groove 29a and is depressurized, and as a result, the primary brake hydraulic chamber 33 is depressurized. Since the primary brake hydraulic pressure chamber 6 for operating the front wheel wheel cylinder 19, which communicates with balance.

Next, an anti-lock braking function testing method for performing a functional test on the illustrated anti-lock braking system while the vehicle is stopped will be explained, focusing on the anti-lock braking function testing method of the present invention.

In FIG. 2, the input side of each OR circuit 67, 68, 69, 70 of the control valve opening/closing control device A is connected to connection terminals J, K, and
Connected to L and M. When the vehicle is stopped, each wheel is not rotating, so each wheel speed calculator 59, 59', 60', 60 does not generate an output signal. The anti-lock braking function testing device B is itself a single unit and can be separated from the vehicle and carried freely.When performing an anti-lock braking function test, the connecting wire is connected to the connecting part 73, for example, by a socket. It can be connected at any time using a connector.

The anti-lock braking function test device B includes a pseudo signal generator 71 having output parts C, D, and E, a pseudo signal selection switch 72, and each wheel cylinder 19, 19', 38, and 38' shown in FIG. A confirmation lamp 76 is connected to the hydraulic vibration detectors 74, 74', 75, 75' via the connection terminal N of the connection part 73.

The output section C of the pseudo signal generator 71 repeatedly generates a pseudo wheel speed signal c as shown in FIG.
The output section D repeatedly generates a pseudo wheel speed signal d as shown in FIG. 3D and sends it to the pseudo signal selection switch 72. A pseudo wheel speed signal e as shown in FIG. 1 is repeatedly generated and sent to the pseudo signal selection switch 72.

In FIG. 3, the pseudo wheel speed signal c is
Indicates the circumferential speed of the wheel, which is accelerated from a stopped state to the circumferential speed Vw between t ₀ and time t ₁ , then goes through the normal braking process without wheel locking, and comes to a stop at time t ₄ . The pseudo wheel speed signal d is a pseudo signal, and after the wheel is accelerated from a stopped state to the circumferential speed Vw between time t ₀ and time t ₁ in synchronization with the pseudo wheel speed signal c, the braking force is applied to the wheel. When the braking force is too large and the wheels are about to lock, anti-lock control is performed and the braking force is released.When the circumferential speed of the wheels recovers, the braking force is applied to the wheels again, increasing the braking force. This is a pseudo signal that indicates the circumferential speed of the wheel that stops at time _t3 while repeating the process of anti-lock control being performed again and the braking force being released when the wheel is about to lock. e indicates that the wheels are accelerated from a stopped state to the circumferential speed Vw from time t ₀ to time t ₁ in synchronization with the pseudo wheel speed signal c, then the wheels lock and rapidly decelerate, and then at time t ₂ This is a pseudo signal indicating the circumferential speed of a wheel that stops at .

The pseudo signal selection switch 72 selects the pseudo wheel speed signals c, d, and e generated by the pseudo signal generator 71 according to a predetermined selection mode, and selects each of the pseudo wheel speed signals c, d, and e. OR circuits 6 through connection terminals J, K, L, and M, respectively.
Send to 7, 68, 69, 70. At this time, the method of the present invention is applied to the early-acting anti-lock control hydraulic pressure supply system 66, but for reference, the selection mode for the late-acting anti-lock control hydraulic pressure supply system 65 will also be described below. This will also be explained.

In FIG. 4, the selection mode selects the pseudo wheel speed signal c for all left and right front wheels and rear wheels, and each OR circuit 67, 68, 69, 70
The selected modes are shown when the pseudo wheel speed signal c is sent to each of the following. In the selection mode, the pseudo wheel speed signal d is selected for the right front wheel, the pseudo wheel speed signal e is selected for the left front wheel, the pseudo wheel speed signal c is selected for the left and right rear wheels, and the OR circuit 67 is selected. shows a selection mode in which a pseudo wheel speed signal d is sent, a pseudo wheel speed signal e is sent to the OR circuit 68, and a pseudo wheel speed signal c is sent to the OR circuits 69 and 70, respectively. Similarly, in the selection mode, the OR circuit 67 receives the pseudo wheel speed signal e.
A selection mode is shown in which a pseudo wheel speed signal d is sent to the OR circuit 68, and a pseudo wheel speed signal c is sent to the OR circuits 69 and 70, respectively. A selection mode is shown in which a pseudo wheel speed signal d is sent to the OR circuit 69, and a pseudo wheel speed signal c is sent to the OR circuit 70. A selection mode is shown in which the wheel speed signal c is sent and the pseudo wheel speed signal d is sent to the OR circuit 70.

The anti-lock braking function is tested, for example, according to the following procedure. First, start the engine of the vehicle, and then connect the connection terminals J,
After connecting K, L, M, and N and turning on the power to the antilock braking function testing device B, select selection mode I with the pseudo signal selection switch 72,
Depress brake pedal 2. At this time, the pseudo wheel speed signal c is sent to each OR circuit 67, 68, 69, 70, so as long as the antilock braking function is normal, antilock control is not performed and each hydraulic vibration detector 74 ,74',7
5, 75' does not generate an output signal, and the confirmation lamp 7
6 does not light up, and no hydraulic vibration is sensed via the brake pedal 2. At this time, if the confirmation lamp 76 lights up or if hydraulic vibration is sensed via the brake pedal 2, it can be determined that a failure has occurred in the anti-lock control system.

Next, when the selection mode is selected by the pseudo signal selection switch 72 and the brake pedal 2 is depressed, a pseudo wheel speed signal d is sent to the OR circuit 67, a pseudo wheel speed signal e is sent to the OR circuit 68, and the OR circuit 67 receives the pseudo wheel speed signal d. The circuits 69 and 70 each have a pseudo wheel speed signal c.
is sent, so as long as the anti-lock braking function is normal, the hydraulic vibration detector 74 detects the hydraulic vibration generated based on the operation of the anti-lock control system and generates an output signal, thereby turning on the confirmation lamp 76.
At the same time, hydraulic vibration is transmitted to the brake pedal 2, and the operator can see that the anti-lock control system is continuously operating while the signal d is decreasing based on the pseudo wheel speed signal d. can be sensed. At this time, if the confirmation lamp 76 does not light up and no hydraulic vibration is sensed via the brake pedal 2, it can be determined that a failure has occurred in the antilock control system related to the right front wheel. In this selection mode, if a pseudo wheel speed signal e is sent to the OR circuit 67 instead of the pseudo wheel speed signal d, the anti-lock function is activated in the process of decreasing the signal e based on the pseudo wheel speed signal e. The control system is in an operating state that reduces the braking oil pressure (induction control valve 41 is opened and exhaust pressure control valve 42 is open).
Since the anti-lock control system is kept in a state in which the brakes are kept closed from beginning to end, it is difficult to accurately judge whether or not the anti-lock control system can perform the so-called anti-lock control that reduces the brake oil pressure intermittently without failure. There's a problem.

Next, when the selection mode is selected by the pseudo signal selection switch 72 and the brake pedal 2 is depressed, a pseudo wheel speed signal e is sent to the OR circuit 67, a pseudo wheel speed signal d is sent to the OR circuit 68, and the OR circuit 67 receives a pseudo wheel speed signal e. The circuits 69 and 70 each have a pseudo wheel speed signal c.
As long as the anti-lock braking function is normal, the hydraulic vibration detector 74' detects the hydraulic vibration that occurs based on the operation of the anti-lock control system and generates an output signal, causing the confirmation lamp 7 to be activated.
6 is illuminated and hydraulic vibrations are transmitted to the brake pedal 2, allowing the operator to sense that the anti-lock control system is operating. At this time, if the confirmation lamp 76 does not light up and no hydraulic vibration is detected via the brake pedal 2,
It can be determined that a failure has occurred in the anti-lock control system related to the left front wheel.

Next, when the selection mode is selected by the pseudo signal selection switch 72 and the brake pedal 2 is depressed, pseudo wheel speed signals c are sent to the OR circuits 67, 68, and 70, and pseudo wheel speed signals d are sent to the OR circuit 69. is sent, so as long as the anti-lock braking function is normal, the hydraulic vibration detector 75' detects the hydraulic vibration generated based on the operation of the anti-lock control system, generates an output signal, and lights up the confirmation lamp 76. At the same time, hydraulic vibrations are transmitted to the brake pedal 2, and the operator senses that the anti-lock control system is continuously operating while the signal d is decreasing based on the pseudo wheel speed signal d. Can be done. At this time, if confirmation lamp 7
6 does not light up and no hydraulic vibration is sensed via the brake pedal 2, it can be determined that a failure has occurred in the antilock control system related to the right rear wheel. In this selection mode, if a pseudo wheel speed signal e is sent to the OR circuit 69 instead of the pseudo wheel speed signal d, the anti-lock function is activated in the process of decreasing the signal e based on the pseudo wheel speed signal e. Since the control system is continuously placed in an operating state that reduces the braking oil pressure (induction control valve 41 is held open and exhaust pressure control valve 42 is held closed), the anti-lock control system is There is a problem in that it is not possible to accurately judge whether so-called anti-lock control, which intermittently reduces the braking oil pressure, can be performed without failure.

Finally, when the selection mode is selected by the pseudo signal selection switch 72 and the brake pedal 2 is depressed, the pseudo wheel speed signal c is sent to the OR circuits 67, 68, and 69, and the pseudo wheel speed signal c is sent to the OR circuit 70. d is sent, so as long as the anti-lock braking function is normal, the hydraulic vibration detector 75 detects the hydraulic vibration generated based on the operation of the anti-lock control system, generates an output signal, and lights up the confirmation lamp 76. At the same time, hydraulic vibrations are transmitted to the brake pedal 2, allowing the operator to sense that the anti-lock control system is operating.
At this time, if the confirmation lamp 76 does not light up and no hydraulic vibration is detected via the brake pedal 2, it can be determined that a failure has occurred in the anti-lock control system related to the left rear wheel. .

Therefore, the present invention is applied to the functional inspection of a so-called early-acting anti-lock braking device that performs anti-lock control based on the one corresponding to the lowest circumferential speed among a plurality of wheel speed signals. In the illustrated example, only the left and right rear wheels correspond to the "pre-selected plurality of wheels" of the present invention. Among the selected modes, . The portions corresponding to the left and right rear wheels in the inspection process, mode, correspond to the second inspection step of the present invention, and the portions corresponding to the left and right front wheels in other modes, modes, are applicable to the present invention. Not applicable.

In the above embodiment, the wheel speed detectors 58, 58' for the left and right rear wheels and the wheel speed calculator 60,
60' cooperates with each other to carry out the signal generation means of the present invention;
The high-speed signal selector 62 for rear wheels is the signal selection means of the present invention, and the OR circuits 69 and 70 are the input parts of the present invention.
Further, the rear wheel control circuit 64 and the control valves 43 and 44 cooperate with each other to constitute control means of the present invention.

As described above, according to the present invention, the signal generating means generates a plurality of wheel speed signals corresponding to the circumferential speeds of a plurality of wheels selected in advance, and the A signal selection means for selecting a signal corresponding to the speed, and a control means for detecting a wheel slip state based on the wheel speed signal selected by the signal selection means and performing antilock control on the plurality of wheels. An anti-lock braking function testing method for performing a functional test on an anti-lock braking system having a vehicle while the vehicle is stopped, the method comprising the steps of: , the first pseudo wheel speed signal from the wheel acceleration process to the normal deceleration process in which wheel lock does not occur is input, and whether or not anti-lock control is performed in the normal deceleration state is determined by detecting the braking oil pressure. Confirmed,
A first inspection step in which the case where the anti-lock control is not carried out is determined to be normal, and the anti-lock control is applied to one arbitrarily selected input section from the acceleration process of the corresponding wheel up to a constant speed. At the same time, the first pseudo wheel speed signal of the corresponding wheel is input to the remaining input section, and the second pseudo wheel speed signal is inputted to the remaining input section. The method includes a second inspection step in which all input sections are sequentially inspected to confirm whether or not anti-lock control is being performed based on the detection of braking oil pressure, and to determine that the anti-lock control is normal if the anti-lock control is being performed. Signal generation means for generating a plurality of wheel speed signals corresponding to the circumferential speeds of the plurality of wheels, signal selection means for selecting one of the plurality of wheel speed signals corresponding to the lowest circumferential speed; A so-called early activation type anti-lock control device has a control means for detecting a wheel slip state based on a wheel speed signal selected by a signal selection means and performing anti-lock control on a plurality of wheels. Therefore, the function test can be easily and statically performed while the vehicle is stopped, and in a short period of time, which can greatly contribute to improving the test efficiency.

In particular, the first inspection process checks whether the antilock control is performed inadvertently when the wheels are decelerated normally, and the first inspection process checks whether the antilock control is performed normally when the wheels are decelerated too much. Each of these can be accurately determined through the second inspection process. Moreover, in the second inspection step, one arbitrarily selected input section of the signal selection means is used to detect the second signal from the acceleration process of the corresponding wheel up to a constant speed to the deceleration process of decelerating the wheel while being subjected to anti-lock control. At the same time as inputting the pseudo wheel speed signal,
The remaining input section receives the first pseudo wheel speed signal from the acceleration process of the corresponding wheel up to the constant speed to the normal deceleration process in which the wheel does not lock, and outputs the second pseudo wheel speed signal. Since it is checked whether anti-lock control is performed based on the speed signal, anti-lock control can be performed from beginning to end during the decreasing process of the second pseudo wheel speed signal, and whether anti-lock control is continuously performed or not. It is possible to accurately judge whether or not.

[Brief explanation of drawings]

Fig. 1 is a hydraulic system diagram showing an example of an anti-lock braking system for a four-wheeled vehicle, and Fig. 2 is a combination of the electrical control circuit of the anti-lock braking system shown in Fig. 1 and a wiring diagram showing an example of an anti-lock braking function testing device. FIGS. 3C, D, and E are waveform diagrams of different pseudo wheel speed signals, respectively. FIG. 4 is a selection mode chart showing an example of the types of selection modes of the pseudo wheel speed signals. 58, 60; 58', 60'...Wheel speed detector for rear wheels constituting signal generation means; Wheel speed calculator, 62...High speed signal selector for front wheels as signal selection means, 43, 44; 64 ... Rear wheel control valve constituting the control means; control circuit, 69, 70 ... OR circuit as an input section, c... first pseudo wheel speed signal, d... second pseudo wheel speed signal.

Claims (1)

[Claims] 1 Signal generation means 58, 60; 58', 60' for generating a plurality of wheel speed signals corresponding to the circumferential speeds of a plurality of wheels selected in advance, respectively; A signal selection means 62 selects a signal corresponding to the speed, and a slip state of a wheel is detected based on the wheel speed signal selected by the signal selection means 62, and antilock control is performed on the plurality of wheels. Control means 4
3, 44, and 64, the anti-lock braking function testing method is for performing a functional test on an anti-lock braking device having a vehicle wheel speed while the vehicle is stopped, the signal selection means receiving the plurality of wheel speed signals. The first pseudo wheel speed signal c from the acceleration process of each wheel to the normal deceleration process in which wheel lock does not occur is inputted to all input units 69 and 70 of 62, and anti-lock control is performed in the normal deceleration state. a first inspection step in which it is determined whether or not the anti-lock control is performed by detecting the braking oil pressure, and the case where the anti-lock control is not performed is determined to be normal;
one input section 69 arbitrarily selected from 0;
At the same time, the second pseudo wheel speed signal d from the acceleration process of the corresponding wheel up to a constant speed to the deceleration process of deceleration under antilock control is input to the remaining input section 70; 69. The first pseudo wheel speed signal c is inputted, and whether or not antilock control is performed based on the second pseudo wheel speed signal d is checked by detecting the brake oil pressure, and if the antilock control is performed, it is determined that the antilock control is normal. An anti-lock braking function testing method comprising: a second testing step in which all input units 69 and 70 are sequentially tested.