GB2046355A

GB2046355A - Vehicle speed control system

Info

Publication number: GB2046355A
Application number: GB7911813A
Authority: GB
Original assignee: Associated Engineering Ltd
Current assignee: Associated Engineering Ltd
Priority date: 1979-04-04
Filing date: 1979-04-04
Publication date: 1980-11-12

Abstract

The control means of the system for setting a predetermined speed of a vehicle includes an actuator device 30 in combination with a resonator R, a reed device or a whistle for producing an audible warning in the event of a malfunction of the actuator device or of a part of an electrical system associated with the actuator device. Failure of the actuator valve B to close the air inlet 39 permits air flow due to suction through the resonator R when the sealing ring 37 is unseated in response to operation of a brake pedal 31. <IMAGE>

Description

SPECIFICATION Speed responsive systems The present invention relates to speed responsive systems for motor vehicles whereby the vehicle may be maintained at a predetermined speed. Such.

speed- responsive systems are disclosed in our British specifications Nos. 1386961 and 1486821.

More specifically, the invention relates to a warning system for use in conjunction with actuator devices for vehicle speed control systems. Such actuator devices are disclosed inter alia in our specification No.1486822 and in our copending cognate applications Nos. 18747/77 and 47992/77, as well as in copending application No. 24542/78.

According to the present invention, a vehicle speed control system includes an actuator device and means for producing an audible warning in the event of a malfunction of the autuator device or of a part of the system associated with the actuator device.

As applied to the actuator devices disclosed in our cognate copending applications Nos. 18747/77 and 47992/77, or as disclosed in copending application No. 24542/78, the audible warning device operates in the event of a malfunction of one of the electromagnetic control valves associated with the actuator device.

Conveniently, the audible warning device is in the form of a resonator, a reed device, or a whistle.

As applied to a speed control system having an actuator device and control arrangement therefor as disclosed in our copending application No.24542/78, the audible warning device is associated with the valve device and is operable by air flow through the valve device when the latter supplies air to the bellows of the actuator device in the event of malfunctioning of one of the electromagnetic control valves.

The invention will now be further described by way of example, with reference to the accompa naying drawings, in which Figure 1 is a diagrammatic view of one embodi ment of an arrangement according to the invention, and Figure 2 is a cross-section through one embodiment of resonator assembly.

Referring to Figure 1 of th drawings, the actuator device 30 is intended to be employed in conjunction with, and form part of, a speed-responsive system for motor vehicles, such as is described in our British Patent Specifications Nos: 1386961 and 1486821, whereby a vehicle may be maintained at a predetermined speed. Briefly and by way of example, when in use, the actuator device 30 is connected to the carburettor throttle valve, fuel injection pump rack, or other speed control device or mechanism associated with the inlet manifold of an internal combustion engine of a road or other vehicle (not shown).

The actuator device 30 controls the opening and closing of the throttle valve in dependence upon signals from an electronic control circuit (also not shown) of the speed-responsive system, which detects various operating parameters or conditions of the engine and/or vehicle. The actuator device basically includes a chamber containing two electromagnetic control valves B and C, the chamber being connected to a bellows device D whose movement is employed to control the throttle valve. Valve C controls orifices 16 and 17 and valve B controls orifice 10. A pipe 21 connects orifice 16 to a sub-atmospheric pressure source such as the inlet manifold of an internal combustion engine. Orifices 10 and 17 are connected to atmosphere.The bellows 23 have a relatively fixed wall 23a, and a relatively movable wall 23b which is connected through a wire 26, or similar linkage, to control the throttle valve.

The spring 27 within the bellows urges the walls 23a and 23b away from each other.

For convenience the parts of the actuator device shown have been given the same reference numerals as in the aforementioned copending applications which describe the actuator device in more detail.

The brake pedal of a vehicle fitted with a speed control arrangement incorporating such an actuator device is shown at 31 and an auxiliary control valve 32 is mounted adjacent to the brake pedal and has one end 33a of its operating rod 33 bearing on the arm 31a of the brake pedal. The operating rod passes through the housing 34 of the control valve and is surrounded by a spring 35 extending between one end of the housing and an abutment 35a on the operating rod, such that when the brake pedal is depressed in the direction of the arrow X to apply the vehicle brakes, the spring urges the operating rod to the left as viewed in Figure 1 in orderto maintain its end 33a in contact with the arm of the brake pedal.

The other end of the operating rod can slide in a tubular end 34a of the housing 34 and carries longitudinal grooves or flutes 36 which in cooperation with a sealing ring 37 forms a valve member.

This valve member is connected by means of a pipe 38 to an orifice 39 controlled by the electromagnetic first control valve B and located at its end opposite to that adjacent the orifice 10 to atmosphere. The housing 34 of the control valve is provided with apertures 40 to allow atmospheric air to enter the housing and as soon as the control rod 33 moves to the left upon operation of the brake pedal, the sealing ring 37 is moved off its seating so that atmospheric aircan flow via grooves 36 through the pipe 38.

The pipe 38 incorporates a resonator R which operates to produce an audible warning when air flows through the pipe 38 to the actuator device and thereby indicates a malfunctioning of the actuator device, as will hereinafter be described.

If the actuator device 30 is operating normally, when the electromagnetic control valve B is deenergised, the orifice 39 is blocked by the valve B and therefore no airflow takes place through the pipe 38 and resonator R and inflation of the bellows 23 is effected via the orifice 10 of the control valve B, which is then open, thus restoring the engine throttle or other speed control member to the closed or off position. However, if a fault occurs such that the electromagnetic control valve B does not operate to open the orifice 10 to atmosphere, then upon operation of the brake pedal 31, atmospheric air is fed via the valve member 35,36,37, through the pipe 38 and resonator R to the orifice 39, which is now open, thereby allowing the bellows 23 to be inflated by the flow of air through the pipe 38 and so closing the engine throttle or its equivalent.This airflow through the resonator produces an audible warning signal indicating that a fault condition exists.

The electromagnetic control valve B may, for example, fail to open to atmosphere through its normal orifice 10 either due to the valve sticking with the orifice 10 closed, or due to an electricai fault such that the energising coil of this control valve remains energised.

Figure 2 shows one form of the resonator R, which is made of a plastics material. As shown in Figure 2, the resonator comprises two component parts 41,42 which are secured togther. The part 41 includes a tubular end portion 41a which is connected to the auxiliary control valve 32 by one section of pipe 38.

The part 42 includes a tubular end portion 42a offset with respect to, and extending in the opposite direction to, end portion 41a. Another section of pipe 38 connects end portion 42a to the first control valve B of the actuator device.

In normal operation it may be arranged that the brake operated valve 32 is phased to open shortly before the valve B shuts orifice 39. In this case, the audible warning will occur for the short period during which the two valves are both open. Thus, the occurrence of a short audible signal when the brake is operated indicates to the driver that the system is operating correctly.

Alternatively, in normal operaton, it may be arranged that the valve 32 is phased to open after the valve B shuts orifice 39, and in this case there will be no audible signal.

It will be appreciated that in normal operation the valves 32 and B will both be open only for very short periods of time, or not at all, as described above.

Consequently, there will not be a continuous stream of air through pipe 38 into the actuator device and therefore the need to provide a filter to prevent entry of foreign matter into the actuator device is reduced or completely avoided.

Claims

1. A vehicle speed control system including an actuator device forming a part of the control means of said system and means for producing an audible warning in the event of a malfunction of the actuator device or of a part of a system associated with the actuator device.

2. A system as claimed in claim 1, wherein the actuator device is associated with an electromagnetic control valve and wherein said audible warning device operates in the event of a malfunction of said electromagnetic control valve.

3. A system as claimed in claim 1 or 2, in combination with a valve device which is operable under engine speed control closing or decelerating conditions of the engine so as to be able to supply atmospheric air to a chamber of said actuator device.

4. A system as claimed in claim 3, wherein the audible warning device is associated with said valve device and, in the event of malfunctioning of said electromagnetic control valve, is operable by airflow through said valve device when the latter supplies air to the chamber of said actuator device.

5. A system as claimed in any preceding claim, which is arranged such that a short audible signal is produced when the system is operating normally and a prolonged audible signal is produced if there is a malfunctioning of the system.

6. A system as claimed in any preceding claim, in which the audible warning device is in the form of a resonator.

7. A system as claimed in any of ciaims 1 to 5, in which the audible warning device is in the form of a reed device.

8. A system as claimed in any of claims 1 to 5, in which the audible warning device is in the form of a whistle.

9. A system as claimed in claim 6, in which the resonator is made of a plastics material and comprises a plurality of component parts which are secured together.

10. A vehicle speed control system substantially as hereinbefore described with reference to the accompanying drawings.

11. A vehicle including a speed control system as claimed in any of the preceding claims.